Coplanar or Not Coplanar bandsaw wheels.......That is the question

[James Nugnes]

I was going to post this in the thread on Laguna 14 twelve wheel alignment issues. But I decided that would amount to hijacking the OP's thread and I did not want to do that. However there is enough differing opinion on coplanar wheel alignment just in that thread to suggest to me that there are some additional questions worth exploring and then some additional questions that might be specific to the Laguna 14 twelve. I do also own one as does the OP of the other thread.

This is a long post. But it is the product of having done a ton of reading the past few days here and elsehwere including reading manufacturers owner's manuals for a multitude of different bandsaws and watching countless videos on bandsaw tuning and whathaveyou. Most of the post uses Grizzly and Laguna bandsaws for purposes of discussion, mainly because I own a Laguna 14 twelve on the Laguna side, because there is a great deal of information available form Grizzly for other members to go explore and because as you will likely see shortly, both companies lie on opposite sides of the coplanar wheel discussion in my opinion.

I think there is enough evidence out there from experienced users to suggest that there is advantage to aligning crowned bandsaw wheels so that they are coplanar. That said there are other experienced users that simply do not think it matters and in one sense I think I can see their point as well.


Those that have managed to acheive coplanar alignment report these advantages:

1) Far less adjustment when changing from one blade size to another
2) Better, straighter cuts even though they are adjusting less
3) Blades falling right onto the center of both the top and bottom wheels

4) Smoother, quieter operation
5) According to Grizzly, less wear on saw components

So if all is true, there certainly does appear to be advantages to achieving coplanar alignment of the wheels.

What is fairly clear (as mud) is that there is a dizzying array of different bandsaw designs...even within those that are primarily marketed as woodcutters. Some of the manufacturers appear to be big proponents of coplanar wheel alignment (Grizzly for one) others at least from their websites and their product documentation appear to reside on the other side of the fence (Laguna for one). Then there are those that do not have crowned wheels....an entirely different story. I don't think I can categorize Laguna as a fence sitter. There is absolutely nothing in any Laguna bandsaw documentation or video that discusses coplanar alignment. The subject is completely ignored or avoided and neither the 14 twelve or any other Laguna bandsaw in their current product mix includes the kind of left/right allen screw adjustment for the upper wheel that is on the Grizzly for example. You can only adjust the upper wheel alignment as a byproduct of adjusting the blade tracking via the tracking knob on the back of the saw. The Grizzly has both left/right alignment of the upper wheel via those allen screws and the tracking knob that the Laguna has.

The "problem" for some of us with the 14 twelve if there is one is that Laguna is painfully silent on the topic of coplanar wheels. There is not even any help in the manual or in their vaunted videos for removal and re-installation of the wheels. Is there a torque spec for the nut on the shaft? Who knows! Granted I think you want to avoid over-tightening the nut on any bandsaw wheel shaft but even the slightest bit of help from the manufacturer in that regard would be helpful. Don't want to give us a torque spec...how about telling us that it should be a 1/4 turn past snug or a half turn or whatever you want...but say something!!!!

Do they have factory installed shims sitting on the shaft out of view and do they not want customers messing with the factory alignment on the 14 twelve? Hard to imagine that is the case as it is hard to imagine the saw maintaining alignment for its entire usable life without some adjustment eventually.

The Grizzly does not have the familiar four bolt lower wheel pattern for adjustment of the lower wheel. The Grizzly relies on wheel shimming and only wants customers moving the lower wheel out or in (forward or backward) reference the upper wheel via adding wheel shims to the shaft behind the wheel.



As is the case with any four bolt pattern lower wheel bandsaw, only the N/S bolts on the Laguna should be used for adjustment. The E/W bolts should not be adjusted. There is nothing in the Laguna documentation regarding adjustment of the four bolts on the lower wheel assembly although many of us are probably familiar with the four bolt pattern and it adjustments.

Also as the OP of the other thread has indicated, it is a bit difficult to even check alignment on the 14 twelve as the wheels sit in the upper and lower wheel housings such that the edges of the housings extend out past the edges of the wheels not the other way round with the edges of the wheels exposed when you have the doors open. All by way of saying that even with the table out of the way, you have to make a gauge that has two perfectly straight edges that are just the right size to meet the wheel edges top and bottom without interference from the wheel housing leading edges. The gauge edges must be exactly straight, parallel and in exactly the same plane in order to gauge the wheel alignment of the 14 twelve wheels. It could be done. Off the top of my head I guess I would try to take two strips of aluminum of exactly the right length but no longer to use as my straight edges and affix them to a piece of ply or something else long and rigid to span the distance from top wheel to bottom wheel making sure that the two aluminum strips are exactly parallel and exactly in alignment top to bottom as nothing less will accurately gauge the alignment of those wheels. By affixing two straight edges to a piece of something, you would hope to allow the straight edges to get past the wheel housing edges. Your gauge would end up in the shape of a C clamp with the forward edges of the aluminum strips at each end of the C hopefully getting past the edges of the upper and lower housing in order to get onto the wheel edges. The entire process even if there is adjustment available is made much more difficult by the leading edge of the wheel housings extending past the leading edges of the wheels themselves as that is what precludes simply running a single straight edge all the way from top to bottom of both wheels.

The complete lack of information from Laguna on the entire subject of coplanar alignment of wheels nor any of the fixturing that one would need to deal with plus the complexity of having to build a gauge just to get past those wheel housing edges suggests that they prefer to have the customer mess with blade adjustment each time a new blade is installed. In my opinion, they either don't believe in or don't care to give customers help in trying to gain the apparent advantages of coplanar alignment. Even if they are delivering their bandsaws with coplanar wheels, I seriously doubt they would stay that way without needing any adjustment for the life of the saw. Hence Laguna seems to be coming down firmly on the side of considerable blade adjustment each and every blade change or accepting some level of compromise as opposed to providing for field coplanar wheel alignment. I don’t think that is an unfair statement.

Grizzly goes as far as saying that coplanar wheel alignment will in fact extend the life of the saw and its components. They are firmly on the coplanar side of the fence.

So far, I have not attempted to build a gauge to test for the coplanar alignment of my 14 twelve wheels. I have only had one size blade on the saw so far and it is a very quite and smooth running bandsaw so far. As you guys might have seen from my other thread, I have had to adjust every other Tom, Dick and Larry thing on the saw. The dead quiet operation of the saw does lead me to believe that the saw wheels are not that far out of alignment although I can see with the naked eye that they are not quite exactly coplanar.


So from where I sit here are the general questions that might be worth additional exploration:
1) For those that support coplanar wheel alignment of crowned bandsaw wheels, are the purported advantages as I have described them? Have I missed some....have I overstated others? Here I am not asking about the differences of opinion between supporters of running coplanar wheels and those that do not think it matters. I am asking supporters if I understand the advantages as they understand them.
2) Should any woodworking bandsaw lets say 14 or greater have upper wheel left/right adjustment allen bolts or bolts of some kind thus providing for left/right field adjustment of the upper wheel or is blade tracking wheel adjustment sufficient for purposes of achieving coplanar alignment of the wheels, assuming you can gauge them? Myself I am thinking that left/right wheel alignment is not the same as upper wheel blade tracking. Hence, bandsaws that have both, give the user a better shot at coplanar alignment.
3) Should any woodworking bandsaw lets say 14 or greater have some sort of lower wheel adjustment capability and should the manufacturer offer information regarding the proper adjustment of the lower wheel?

As for question 1 above I do not want to limit the observations of members that do not believe there are advantages to acheiving coplanar alignment. Just do me a favor and tell us where you are coming from if you simply do not think it worthwhile vs somebody who believes in coplanar alignment telling me that I have either missed some of the advantages or have overstated others.



As for things along these lines that are specific to the Laguna 14 twelve:


Based on my description of the 14 twelve wheel housings does the coplanar wheel gauge design I suggested above make sense for this saw or any other with the wheel housings configured as they are on the 14 twelve or have I missed something critical that would suggest a different gauge design?

Thats' it folks. Have at it hopefully. I do apologize for the length of the post. I have no idea how guys like Erik keep track of all the stuff they see and have to compete with in the business they are in at least as it relates to bandsaw variables. Not that it appears all that difficult to deal with as a tool. It is just surprising how many different answers there are to the Market's desires for a woodcutting bandsaw.

[Dan Clark]

James,

Thanks for posting this. I'm the OP of that other thread and am very interested in the topic.

One of the challenges with measuring coplaner in the 14-12 is that the wheels are set back from the surrounding housing. And, while it's feasible to remove the table, that seems like a hassle if we need to remove and reinstall it several times.

One solution for this might be to cut a very straight piece of 1/4 or 3/8 plywood long to reach both wheels and wider than the distance from the table to the wheels. Then cut out a big slot in the center of the plywood so that the top and bottom of the plywood can reach the wheels - like a cookie byte in the center of the plywood.

Think this might work?

Dan.

[John Huds0n]

Didn't read your whole post - but have you watched this youtube video? (best one I have seen for tuning up a bandsaw)

Bandsaw clinic with Alex Snodgrass
https://www.youtube.com/watch?v=wGbZqWac0jU

[Phil Thien]

You need to remember that just because someone insists their saw runs perfectly fine and they never even bothered to check whether their wheels are coplaner, doesn't mean the wheels weren't already coplanar (from the factory).

Wheels are aligned at the factory, likely using setup blocks. They're likely pretty darn close right out of the box.

Also, there clearly comes a point where the wheels are "close enough," and efforts to get them any closer provides little to no return.

But for those that imagine alignment doesn't matter, I encourage you to measure how close your wheels already may be, and then shift them a bit. If they're within 1/16", shift them to 1/4", and try running a blade. How does that work? Now try 1/2".

Many manufacturers likely insist coplanar doesn't matter simply because they don't want owners fiddling with the saw. There are OC people out there that will try to align their wheels within the thickness of a business card, which certainly wouldn't be necessary. By making certain the saws are aligned close enough at the factory, and then telling users not to worry about coplanar, you probably save yourself a bunch of technical support and warranty calls.

[Phil Thien]

Didn't read your whole post - but have you watched this youtube video? (best one I have seen for tuning up a bandsaw)

Bandsaw clinic with Alex Snodgrass
https://www.youtube.com/watch?v=wGbZqWac0jU

I'm just going to reiterate that the guy apparently doesn't understand how tension gauges work. Hard to qualify him as an expert in anything mechanical if he doesn't understand spring scales.

[John TenEyck]

I've never heard anyone say coplaner wheels are a bad thing. It takes no more than 30 minutes to take a piece of plywood and cut it out into a C-shape to fit around wheel covers, etc. so you can check yours. If your saw runs great, no need, who cares. But if it doesn't, why wouldn't you spend those few minutes to find out if the wheels are out of alignment. What you do with that information is up to you. Me? I aligned the wheels on mine - and it instantly resolved my problems of not being able to cut straight.

John

[Curtis Myers]

I have a 14" Powermatic bandsaw and checked for coplaner several years back and they are not coplaner. I got wrapped around the axel somewhat until I called Powermatic and spoke with tech support. They agreed the saw was not coplaner and stated it was not a problem. He said the saw was designed this way and not to worry about it. He talked me through setting the saw up which is just like Alex Snodgrass (in post #3) describes. Very few of us here on Sawmillcreek are experts. I'm certainly not. I recommend calling the manufacture and ask them.
I personally think if you follow Alex Snodgrass direction on the above video you will be fine.

[Ethan Melad]

I've got an older (late '60s, i think) Powermatic 81, and the wheels are far from coplanar. Like Curtis, I called and spoke to a tech who said this should not be a problem. Phil, I would hope and assume that the tech did not presume I was incapable of working on my own machinery, and that he would have given me accurate information.

[Lee Reep]

I swear by the Alex Snodgrass procedures. My experience with my Powermatic 14" was problematic until I followed his advice. I had real issues with getting satisfactory resawing until I used his recommendations on blade location and bearing adjustment (placement). I highly recommend his video to anyone with a bandsaw.

[Chris Parks]

Instead of making a jig and all the problems surrounding its use get a cheap laser level and project a line vertically beside the saw. Using a rule or tape a measurement can then be made from the laser to any part of the wheel. The saw might have to be shimmed truly vertical if the floor is not level and the laser level can be used to check that.

[Chris Parks]

I wonder about this coplaner thing that everyone gets excited about. Getting the wheels aligned when the saw is not tensioned and then putting it in tension will just about guarantee that the wheels will misalign to some degree. The only way to do it properly is align the wheels unloaded, tension the saw, measure the misalignment, and align the wheels at no load to take into account the movement that took place under tension. is it worth it all the hassle? I don't know, I suppose if the loaded alignment is a long way out then it would be.

[Roger Pozzi]

I swear by the Alex Snodgrass procedures. My experience with my Powermatic 14" was problematic until I followed his advice. I had real issues with getting satisfactory resawing until I used his recommendations on blade location and bearing adjustment (placement). I highly recommend his video to anyone with a bandsaw.

I first found the video by Alex Snodgrass while I was shopping for a bandsaw. I followed his procedure exactly while setting my new saw up. and have never looked back. Perfect !!!
BTW, I've never checked my wheels for being co-planer but, the blade run centered, as Alex explained to center, on the upper and lower wheels right from the start.

[David Delo]

I first found the video by Alex Snodgrass while I was shopping for a bandsaw. I followed his procedure exactly while setting my new saw up. and have never looked back. Perfect !!!BTW, I've never checked my wheels for being co-planer but, the blade run centered, as Alex explained to center, on the upper and lower wheels right from the start.Another vote for Alex's procedure in setting up the bandsaw. Forget the word co-planer when it comes to wheels on a bandsaw.

[Keith Pleas]

Another vote for Alex's procedure in setting up the bandsaw. Forget the word co-planer when it comes to wheels on a bandsaw. +1. I may or may not buy a Carter add-on, but there can be no doubt Alex knows his way around many different bandsaws of the type we all have.

[Lee Schierer]

I have seen the Alex Snodgrass demonstration in person and his method does work really well. I have used it on my own 14" saw and have not had any problems with tracking.

[Phil Thien]

I wonder about this coplaner thing that everyone gets excited about. Getting the wheels aligned when the saw is not tensioned and then putting it in tension will just about guarantee that the wheels will misalign to some degree. The only way to do it properly is align the wheels unloaded, tension the saw, measure the misalignment, and align the wheels at no load to take into account the movement that took place under tension. is it worth it all the hassle? I don't know, I suppose if the loaded alignment is a long way out then it would be.

I once owned an Inca with 8"-ish FLAT wheels, and it vibrated quite a bit no matter what blade I used. When investigating the shaking I discovered the bottom wheel had been removed/reinstalled at some point (I could see the two divots on the key). I moved the wheel to the other location and voila, shaking grossly reduced. BTW, the difference was about 3/16".

It was only later that I checked whether the wheels were coplanar and sure enough, they were nearly spot-on, with a 1/4" blade installed and tracked.

My current saws are Skil, with 10" wheels. I know people scoff at my small saws but these are 15-20 years old, made in Taiwan, have 1/2-HP motors, and 7" resaw height. I'd put them up against any "standard" 14" saw in terms of smoothness and power. They vibrate less than any other saw I've ever used. You can literally put your hand on the saw while it is running and hardly tell the thing is under power.

And the wheels are nearly perfectly coplanar with a blade installed and tracked. They came like that from the factory.

[Erik Loza]

....The "problem" for some of us with the 14 twelve if there is one is that Laguna is painfully silent on the topic of coplanar wheels...

Does this particular saw have flat wheels? If so, then co-planarity doesn't matter.


...I have no idea how guys like Erik keep track of all the stuff they see and have to compete with in the business they are in at least as it relates to bandsaw variables...

Easy: I have no life. Just ask my wife...

Honestly, though, the real answer is because I don't compete with 14" machines. That's not to sound smug or derogatory, it's just a statement of fact. The customer who is shopping for that level of saw is not going to spend $3K+ for a bandsaw so I rarely have that type of discussion. It's usually and "italian vs. Italian" converation because the guy has already decided that's where he wants to be. Hope this makes sense.

Erik Loza
Minimax

[glenn bradley]

I've never heard anyone say coplaner wheels are a bad thing. It takes no more than 30 minutes to take a piece of plywood and cut it out into a C-shape to fit around wheel covers, etc. so you can check yours. If your saw runs great, no need, who cares. But if it doesn't, why wouldn't you spend those few minutes to find out if the wheels are out of alignment. What you do with that information is up to you. Me? I aligned the wheels on mine - and it instantly resolved my problems of not being able to cut straight.

John

This is a bit of a dead horse but, newcomers or folks who newly visit the topic may find the discussion useful. I can't imagine any manual that says the wheels being aligned "doesn't matter". As mentioned Grizzly is quite thorough on this. Laguna not so much as they simply state:

"We recommend that you balance all blades on the center of the wheels for optimum performance and a smoother cut."

I'm with John in that if you are not getting the results you want and suspect wheel alignment as a possibility, adjusting for coplaner is not a long tedious effort in order to eliminate that as a possibility. If you don't feel like doing that, rock on ;-)

P.s. I think we do Alex S a disservice by continually quoting his statement that coplaner doesn't matter. He is speaking during a demo of a product. I believe Michael Fortune also made this statement in a bandsaw "tune-up" article in FWW. This wouldn't be the first highly skilled woodworker who's craft I admire that I don't agree with on all things ;-)

[Phil Thien]

I've got an older (late '60s, i think) Powermatic 81, and the wheels are far from coplanar. Like Curtis, I called and spoke to a tech who said this should not be a problem. Phil, I would hope and assume that the tech did not presume I was incapable of working on my own machinery, and that he would have given me accurate information.

I'm never sure how to respond to posts like this, there is so little information. Like, how far-off were the wheels? How were they measured (no blade/blade/what size blade, etc.)? How does the saw run? What was the experience level of the tech?

So my question for those that think wheel alignment is unimportant: Do you think the manufacturers install the wheels arbitrarily? They just mount them wherever they may fall?

And why don't we see any bandsaws where the wheels are misaligned by inches? If alignment isn't important, they could be off by a foot, right? Wait, you couldn't get a blade mounted in that case. Well, you could probably get a blade mounted if they were misaligned by an inch, if the saw is large enough, right? But wait, off by an inch, that is extreme, that saw can't run smoothly if the wheels are off by an inch. How about a 1/4"?

See where I'm going with this? If you put your critical thinking cap on, you will see 12" is undoable, so is 6". 1" may be very rough. As we approach 0", things continue to improve. Certainly there is a point of diminishing returns (there always is). But certainly people are capable of reasoning through this, no?

[Phil Thien]

BTW...

We want our blades to be square to the table, front to back. This is important for operations like cutting the shoulders of tenons.

Coplanar wheels are about the best way to make sure your blade's teeth are square to the table. Falling short there, you are likely going to need to shim your table.

So for you guys that think your wheels aren't coplanar, is your blade square to the table? If it is, see any shims?

[John TenEyck]

This is exactly right. Manufacturers must design and hopefully build their saws so that the wheels align somehow, whether coplaner or not. It can't be that no thought is given to it. So if there's thought given to it there must be specs. whether or not they are willing to disclose those.

If I here another shout out for Mr. Snodgrass I'm going to get sick. I'm sure he knows his stuff, but he can't go around to everyone's shop and solve their problems. If his methods worked universally no one here would be posting about the problems they are having with their saw. Saws can and do go out of alignment, for a variety of reasons. My own was out when I got it. Why? I don't know, it was 30 or 40 years old. Things wear I suppose. It never really bothered me until I wanted to saw veneer with it. In trying to figure out why it wouldn't cut straight I found the wheels were out by more than 1/4" and cocked as well. Shimming the upper wheel and adjusting the frame to get the wheels in the same plane in both planes - it was like a new saw. Oh, maybe better, hard to say.

When all else fails, go back to first principles. Start with the machine itself and work out from there. If you are having problems it's 30 minutes to check the wheels. Why wouldn't you?

John

[Brad Adams]

My old 14" Delta bandsaw didn't cut worth a darn when I got it. I had to drill out the pin in the cast iron to align the upper and lower frames. The wheels were out about a 1/4" in front to back alignment. Guess what, after aligning the wheels to be "co planer" it cuts smooth as as can be. No more oscillating of the blades. To say it doesn't matter if the wheels are co planer is just silly. Anything running in perfect alignment is going to run smother with less wear on components. Why do you think we do four wheel alignments on our cars?

[Mel Fulks]

I've only scanned this,forgive me if this has already been said. Some of the bandsaws have adjustable lower wheels that
were properly set at factory and later "adjusted" out of bounds by a user. That can make normal simple adjustment of upper wheel impossible.

[Frank Pratt]

When I got my Rikon 14" 10-325 I had not experience with a bandsaw. I proceeded to check the wheel alignment & get the 2 wheels coplanar. So far, great! Started doing a test cut & a few minutes later it started making some horrible noises. Problem was, now the motor pulley was not coplanar with the bottom wheel & the ribbed belt partially came off & shredded itself to death. Then it took me a good 3 hours of futzing around to line up the motor, which has no provision for adjusting. What a FRUSTRATING experience!

Which brings me to a point that the OP brought up. Why, oh why do the manufacturers not address or explain these things in the manual. If it is not to be adjusted, then tell us. If it is to be adjusted, then tell us how. I think better documentation is the single biggest thing manufacturers could do to improve the initial user experience with their product.

The saw is now set up & cuts really well, but every time I look at it, I still get a little pissed of. And this is 2 years after the fact.

[Rod Sheridan]

Does this particular saw have flat wheels? If so, then co-planarity doesn't matter.

[FONT=&]



Erik Loza
Minimax

Erik, if you have flat wheels you're running the teeth only off the edge of the wheel correct?

If so, coplanar wheels are extremely important............Rod.

[Erik Loza]

Erik, if you have flat wheels you're running the teeth only off the edge of the wheel correct?

If so, coplanar wheels are extremely important............Rod.

In theory, perhaps, but not in reality.Or at least not in my experience. Reason being that in this era of huge-resaw-capacity bandsaws, if there is any "non-coplanarity" between the upper and lower wheels, there is such much distance between the upper and lower flywheels that it just doesn't manifest itself in the blade performance. Or at least not in my experience.

I can tell you, for example, that in 10+ years of setting up Italian bandsaws, I have never once checked "co-planarity" if the upper and lower wheels. It's just never been an issue.

Erik Loza
Minimax

[Dan Clark]

I've only scanned this,forgive me if this has already been said. Some of the bandsaws have adjustable lower wheels that
were properly set at factory and later "adjusted" out of bounds by a user. That can make normal simple adjustment of upper wheel impossible.
The 14-12 does have these adjustable lower wheels. I've had to adjust mine based on direction from Laguna support. Note that issue occurred BEFORE the lower wheel was adjusted.

I found that adjusting the lower wheel so that the 1/2" blade is centered on both wheels means that the 3/4" blade is shifted one way on the lower wheel and smaller blades are shifted the other way. I don't particularly like it that misalignment occurs, but the saw works well so it's an acceptable compromise for me.

Based on testing, the I found that cause is blade tension. Wider blades need higher tension. Narrower blades need lower tension. If the 3/4" blade is lightly tensioned like a 1/4" blade, most of the misalignment goes away. As the tension is increased misalignment increases.

The first assumption might be that the frame is twisting. Based on my own testing, this is not the case. Increased tension makes the upper wheel move slightly towards the front of the saw - up to about 70/1000 (measured). "Front" means the side with the fence bar. Movement is relative to the frame. Increasing tension does not cause the frame to twist.

Note that "C" plywood method and method I described above are the same - cutting a chunk out of a piece of play and placing the straight edges against the wheels. I'm going to do that this weekend. To ensure that the ply has a clean, straight edge, it will be cut using a rail saw. Then the "cookie-bite" will be cut from the center with a jigsaw.

Regards,

Dan.

[John Schweikert]

If a bandsaw runs smooth, the blade is vertical to the table and the blade tracks correctly and stays consistent on the wheels, why obsess over the wheels being coplanar? Only if your saw exhibits issues should you even bother delving deeper. Kind of like buying a new car and checking to make sure that the your alignment numbers are correct even when the car drives perfect.

I too used the Snodgrass youtube video years ago in setting up my 14" bandsaw and never looked back, it runs great, resaws very well, tracking of the blade is excellent and no drift when resawing with the fence set up stock (no adjustment). I can understand not all tools run flawlessly out of the crate but if they do, just use them and move on to making things.

[Phil Barrett]

I'm far from an expert so I'm just applying logic. Obviously, you can construct a thought experiment that has the wheels grossly out of alignment and clearly the saw will fail to cut properly, if at all. Clearly, co-planar wheels are desirable. However, there is some range of misalignment that will permit the saw to function reasonably well. What I have never seen is a statement as to what is an acceptable range and what isn't. Grizzly has several pages in the G0555 series manual that describes how to make the wheels co-planar but is silent on how much difference is acceptable. They imply zero but there has to be some minimum below which it's simply not necessary. (Clearly, 1/2 the width of the thinnest shimming washer is acceptable.) The manual notes that you must check alignment under tension as well. I think the vast majority of saws out there probably fall into the acceptable range, especially if last aligned at the factory, even for an old saw. This is, I believe, the wellspring of Alex Snodgrass' advice to not worry about it. It seems unlikely to me that the wheels would be significantly misaligned with no other obvious wear or damage or ham handed maintenance. Certainly, when rebuilding a bandsaw one should make the wheels co-planar but I'm not so sure people should run out to their shops and tear into a functioning saw.

I had a 14" delta clone with about 1/4" difference between the tracking locations on the two wheels. It cut just fine. The manual was completely silent on co-planar alignment. I got all wound up over the issue and in doing my research to try and align the wheels, I found the snodgrass video. End of angst and plenty of wood subsequently went through that saw with zero problems. My brother in law has it now and it continues to work well.

[Rod Sheridan]

In theory, perhaps, but not in reality.Or at least not in my experience. Reason being that in this era of huge-resaw-capacity bandsaws, if there is any "non-coplanarity" between the upper and lower wheels, there is such much distance between the upper and lower flywheels that it just doesn't manifest itself in the blade performance. Or at least not in my experience.

I can tell you, for example, that in 10+ years of setting up Italian bandsaws, I have never once checked "co-planarity" if the upper and lower wheels. It's just never been an issue.

Erik Loza
Minimax

I have to admit Erik, that with 35 years of industrial experience I've never seen a bandsaw checked for coplanarity or had the blade tension released except when changing blades, nor have I ever adjusted a fence for drift.

Regards, Rod.

[Jim Seyfried]

I can tell you, for example, that in 10+ years of setting up Italian bandsaws, I have never once checked "co-planarity" if the upper and lower wheels. It's just never been an issue.

Erik Loza
Minimax

I have a 20" MM and right now it has a 1/2" blade on. It is set up so that the teeth are off the top wheel and are close to even with the edge of the bottom wheel. It doesn't seem to be a problem or to be damaging the bottom wheel. I see in the manual it does tell about using a board to check "co-planarity". I haven't really thought about it until recently reading post like this one. The saw is the "Ferrari" tool in my shop and I want make sure I have it setup properly. There seems to be even less info on this for saws with flat wheels. Perhaps that is because it isn't that critical.

[James Nugnes]

Erik,

No the 14 twelve has crowned wheels if you were asking me. Glad there is some category of something that does not have to be on your plate. Although to be honest, even if I had restricted research to 16" and above bandsaws there still would have been a dizzying array of different design features and combinations of design elements for top wheel vs bottom wheel, table tilt, blade guides etc. It is probably the combinations that make for the most variety. I get your point though. Size alone probably takes some of the combinations off the table whereas just about everything is within the bounds of possibility for a 14".

I have probably watched the "Alex Bandsaw Video" enough times over the years to quote the thing. While much of what is there is useful info, there still seems to be enough either disparity of design elements and maybe even just disparity between saws of the same design that clearly the individual experience of users covers a pretty broad spectrum.

For example, Dan, the OP of the other thread who chimed in here was able to reach the latter of the two options Laguna seems to offer. He got to a compromise point. But if I read his thread carefully and I think accurately that compromise does not get him where the Laguna text suggests he should be....."the blade [regardless of size] always balanced in the middle of both wheels". He is close enough for his purposes but not where Laguna's own written instruction wants him to be.

I will add a bit of personal experience here. When I got a bandsaw to be truly coplanar for the first time, my blades also just fell right into the middle of the wheels top and bottom just as the experts on coplanar suggest. I could have installed blades blindfolded ( a stretch but for those who have done this, you get my meaning). So while i posed the question from as close to a new user as I possibly could on purpose, frankly that is one "advantage" that has been noted by experienced users that resonates for me. Blades just seem to fall right in the middle of the wheels so easily that you are reluctant to even try to mess with them further.

That is another interesting point by the way. Blades fall so easily and quickly into the place where the saw's designer probably intended them to be that the other most common bandsaw discussion sort of goes by the boards. "Should the gullet of the blade be centered on the wheels or should the blade itself be centered on the wheels or should the blade be somewhere else." In my experience, once you are as close to coplanar as you can get with a crowned wheel bandsaw, wherever the blades fall is the place where they should be. You really have a hard time continuing the "where should the blades fall optimally" discussion. The whole design of the saw seems to make so much sense to you at that point that a whole bunch of bandsaw "discussions" "arguments" call them what you will seem to go by the boards.

As for the comment from crowned wheel bandsaw manufacturers that their saws are designed for the wheels NOT to be coplanar. Let me offer a slight modification to that statement that I think you would hear from the designer if you were talking to him instead of somebody from Tech Support. "The saw I have designed will tolerate a certain number of degrees out of wheel coplanar alignment". Those two comments are not at all the same. However I believe that Tech Support groups have morphed what the designer actually did into a comment that gets them off the phone and onto the next issue ASAP. That is really not a criticism of Tech Support groups. They are trying to do a tough job as well as they can do it in a reasonable length of time per each issue they confront every day. It is the nature of the beast. To the extent that they are trying to help get you to where you want to be "cutting" on your bandsaw and not adjusting it to perpetuity they want what you want. That does not prevent them from morphing reality into something that helps them deal with their reality.

I like the idea of using a Laser leveler. That has occurred to me for this particular bandsaw because of the interference of the leading edges of the wheel housing. A laser leveler could be very helpful. You could only use the leveler to get you part way there. Set up properly it might tell you enough by itself to know how far out off you might be from coplanar. But it could also really help make the gauge you would need. I also understand Dan's comment about the table. The table is a beast for this size bandsaw. It really is far easier (as Laguna suggests) for two people to deal with the table. Given the need on occasion for tuning with the table off the saw, I am just going to have to build up a few fixtures that help make it more of a one man job. Might mean jockeying the table trunnion bolts down through their holes with some different sized support mechanisms helping you as you go. There is enough tolerance in those bolt holes to allow you to jockey those bolts. But you do want some support there if you are alone as it gets pretty heavy pretty quickly if you are trying to get the bolts properly positioned and hold up the table at the same time. You don't want to rush it either and damage the threads. That said it is only a common bolt going through the trunnion bracket. So I think I will opt to have a couple of replacements around as well in case I damage some threads someday.

Dan, I have given serious consideration to your idea of one large "C" shaped gauge as well. I think accuracy might be an issue doing it that way. Remember the real problem we have is with those wheel housings. The wheels are 14" in diameter. The length top to bottom of the two housings with there wheels is about 52" and the width out to the deepest part of your "C" if you want to leave the table on would be about 16". Heck lets face it, if you want to leave the table on you want to leave the fence rail and all that claptrap on as well. Plus I would prefer metal straight edges supported by wood to wooden straight edges any day. The more you do in wood, if you try to make the gauge accommodate the table, the bigger and more cumbersome your gauge will become. Since there are other good reasons for removing the table from the saw, I think I would prefer turning table removal into a reliably done, damage to body and saw limited, one man job anyway. So doing it with the table off turns the 16" wide "C" into something more like a straight support about 52" long with two 14" long strips of aluminum of some width at top and bottom. Maybe even 1" x 4" gets it done for the support with a few notches to clear some other claptrap that might get in the way even with the table off. Surely 1" x 6" would get it done. Now you have something of manageable size that you can also store pretty easily without worrying that you are going to knock your gauge out of whack and you have something not too cumbersome in use as well. I think you could make it the way you suggest. I just think it will be more difficult to make it dead straight, parallel and in the same plane for the lengths you need hitting the wheel edges. Then being able to store the thing conveniently might be an issue as well. But that is a good idea Dan and if you want to persue a gauge design that allows you to leave the table in place I would love to see it once completed. I think I will try some fixtures that allow me to get the table on and off reliably, quickly and alone without risking damage to body or saw. If I can get there, then I will just make a gauge like the one I envision.

[Phil Thien]

I'm far from an expert so I'm just applying logic. Obviously, you can construct a thought experiment that has the wheels grossly out of alignment and clearly the saw will fail to cut properly, if at all. Clearly, co-planar wheels are desirable. However, there is some range of misalignment that will permit the saw to function reasonably well. What I have never seen is a statement as to what is an acceptable range and what isn't. Grizzly has several pages in the G0555 series manual that describes how to make the wheels co-planar but is silent on how much difference is acceptable. They imply zero but I there has to be some minimum below which it's simply not necessary. (Clearly, 1/2 the width of the thinnest shimming washer is acceptable.) The manual notes that you must check alignment under tension as well. I think the vast majority of saws out there probably fall into the acceptable range, especially if last aligned at the factory, even for an old saw. This is, I believe, the wellspring of Alex Snodgrass' advice to not worry about it. It seems unlikely to me that the wheels would be significantly misaligned with no other obvious wear or damage or ham handed maintenance. Certainly, when rebuilding a bandsaw one should make the wheels co-planar but I'm not so sure people should run out to their shops and tear into a functioning saw.

I had a 14" delta clone with about 1/4" difference between the tracking locations on the two wheels. It cut just fine. The manual was completely silent on co-planar alignment. I got all wound up over the issue and in doing my research to try and align the wheels, I found the snodgrass video. End of angst and plenty of wood subsequently went through that saw with zero problems. My brother in law has it now and it continues to work well.


When the wheels are coplanar, the band will always track further forward on the bottom wheel.

Again, that is because the length of the band is less than the distance around the two wheels. That is the only way you can apply force to, and tension, the blade.

So if the distance around the two wheels is greater than the length of the blade, and if we use the camber adjustment to center the blade on the top wheel, then the blade MUST run forward of center on the bottom wheel.

So many times people have pointed to a blade riding forward on the bottom wheel as evidence that the wheels aren't coplanar. It isn't. It is only proof that the blade is shorter than the distance around the wheels.

[Larry Edgerton]

Erik,

No the 14 twelve has crowned wheels if you were asking me. Glad there is some category of something that does not have to be on your plate. Although to be honest, even if I had restricted research to 16" and above bandsaws there still would have been a dizzying array of different design features and combinations of design elements for top wheel vs bottom wheel, table tilt, blade guides etc. It is probably the combinations that make for the most variety. I get your point though. Size alone probably takes some of the combinations off the table whereas just about everything is within the bounds of possibility for a 14".

I have probably watched the "Alex Bandsaw Video" enough times over the years to quote the thing. While much of what is there is useful info, there still seems to be enough either disparity of design elements and maybe even just disparity between saws of the same design that clearly the individual experience of users covers a pretty broad spectrum.

For example, Dan, the OP of the other thread who chimed in here was able to reach the latter of the two options Laguna seems to offer. He got to a compromise point. But if I read his thread carefully and I think accurately that compromise does not get him where the Laguna text suggests he should be....."the blade [regardless of size] always balanced in the middle of both wheels". He is close enough for his purposes but not where Laguna's own written instruction wants him to be.

I will add a bit of personal experience here. When I got a bandsaw to be truly coplanar for the first time, my blades also just fell right into the middle of the wheels top and bottom just as the experts on coplanar suggest. I could have installed blades blindfolded ( a stretch but for those who have done this, you get my meaning). So while i posed the question from as close to a new user as I possibly could on purpose, frankly that is one "advantage" that has been noted by experienced users that resonates for me. Blades just seem to fall right in the middle of the wheels so easily that you are reluctant to even try to mess with them further.

That is another interesting point by the way. Blades fall so easily and quickly into the place where the saw's designer probably intended them to be that the other most common bandsaw discussion sort of goes by the boards. "Should the gullet of the blade be centered on the wheels or should the blade itself be centered on the wheels or should the blade be somewhere else." In my experience, once you are as close to coplanar as you can get with a crowned wheel bandsaw, wherever the blades fall is the place where they should be. You really have a hard time continuing the "where should the blades fall optimally" discussion. The whole design of the saw seems to make so much sense to you at that point that a whole bunch of bandsaw "discussions" "arguments" call them what you will seem to go by the boards.

As for the comment from crowned wheel bandsaw manufacturers that their saws are designed for the wheels NOT to be coplanar. Let me offer a slight modification to that statement that I think you would hear from the designer if you were talking to him instead of somebody from Tech Support. "The saw I have designed will tolerate a certain number of degrees out of wheel coplanar alignment". Those two comments are not at all the same. However I believe that Tech Support groups have morphed what the designer actually did into a comment that gets them off the phone and onto the next issue ASAP. That is really not a criticism of Tech Support groups. They are trying to do a tough job as well as they can do it in a reasonable length of time per each issue they confront every day. It is the nature of the beast. To the extent that they are trying to help get you to where you want to be "cutting" on your bandsaw and not adjusting it to perpetuity they want what you want. That does not prevent them from morphing reality into something that helps them deal with their reality.

I like the idea of using a Laser leveler. That has occurred to me for this particular bandsaw because of the interference of the leading edges of the wheel housing. A laser leveler could be very helpful. You could only use the leveler to get you part way there. Set up properly it might tell you enough by itself to know how far out off you might be from coplanar. But it could also really help make the gauge you would need. I also understand Dan's comment about the table. The table is a beast for this size bandsaw. It really is far easier (as Laguna suggests) for two people to deal with the table. Given the need on occasion for tuning with the table off the saw, I am just going to have to build up a few fixtures that help make it more of a one man job. Might mean jockeying the table trunnion bolts down through their holes with some different sized support mechanisms helping you as you go. There is enough tolerance in those bolt holes to allow you to jockey those bolts. But you do want some support there if you are alone as it gets pretty heavy pretty quickly if you are trying to get the bolts properly positioned and hold up the table at the same time. You don't want to rush it either and damage the threads. That said it is only a common bolt going through the trunnion bracket. So I think I will opt to have a couple of replacements around as well in case I damage some threads someday.

Dan, I have given serious consideration to your idea of one large "C" shaped gauge as well. I think accuracy might be an issue doing it that way. Remember the real problem we have is with those wheel housings. The wheels are 14" in diameter. The length top to bottom of the two housings with there wheels is about 52" and the width out to the deepest part of your "C" if you want to leave the table on would be about 16". Heck lets face it, if you want to leave the table on you want to leave the fence rail and all that claptrap on as well. Plus I would prefer metal straight edges supported by wood to wooden straight edges any day. The more you do in wood, if you try to make the gauge accommodate the table, the bigger and more cumbersome your gauge will become. Since there are other good reasons for removing the table from the saw, I think I would prefer turning table removal into a reliably done, damage to body and saw limited, one man job anyway. So doing it with the table off turns the 16" wide "C" into something more like a straight support about 52" long with two 14" long strips of aluminum of some width at top and bottom. Maybe even 1" x 4" gets it done for the support with a few notches to clear some other claptrap that might get in the way even with the table off. Surely 1" x 6" would get it done. Now you have something of manageable size that you can also store pretty easily without worrying that you are going to knock your gauge out of whack and you have something not too cumbersome in use as well. I think you could make it the way you suggest. I just think it will be more difficult to make it dead straight, parallel and in the same plane for the lengths you need hitting the wheel edges. Then being able to store the thing conveniently might be an issue as well. But that is a good idea Dan and if you want to persue a gauge design that allows you to leave the table in place I would love to see it once completed. I think I will try some fixtures that allow me to get the table on and off reliably, quickly and alone without risking damage to body or saw. If I can get there, then I will just make a gauge like the one I envision.

You are over thinking a problem that does not exist. I have had many bandsaws from a 36" Oliver down to a 14" Delta, and not one band ran the same on the bottom wheel as it did the top. All of them cut well. I did check the two saws I have now just for kicks, both cut very well indeed, and neither one of them have coplaner wheels. Looking at my 20" Delta it is pretty obvious that they never intended them to be on the same plane, and, wait for it......... The saw cuts perfect!

Coplaner is a cool buzz word, but just forget about it and go make some sawdust.

[Phil Thien]

You are over thinking a problem that does not exist. I have had many bandsaws from a 36" Oliver down to a 14" Delta, and not one band ran the same on the bottom wheel as it did the top.

That doesn't really mean anything other than the length of the band is shorter than the distance around the two wheels at their crowns.

Do you guys get that? I'm not sure you guys are understanding that. This is really a basic concept. If you have a 72.5" long band, and the distance around your two wheels is 72.6", the band can run only center of one wheel, and front of center on the other.

Why is the distance around the two wheels greater than the length of the band? Because that is how you apply tension to the band.

Is that clear?

[Erik Loza]

I have to admit Erik, that with 35 years of industrial experience I've never seen a bandsaw checked for coplanarity or had the blade tension released except when changing blades, nor have I ever adjusted a fence for drift.

Regards, Rod.

+1, though I do suggest relaxing the blade after use with carbides. For blade life, not machine life.

Erik Loza
Minimax

[Larry Edgerton]

That doesn't really mean anything other than the length of the band is shorter than the distance around the two wheels at their crowns.

Do you guys get that? I'm not sure you guys are understanding that. This is really a basic concept. If you have a 72.5" long band, and the distance around your two wheels is 72.6", the band can run only center of one wheel, and front of center on the other.

Why is the distance around the two wheels greater than the length of the band? Because that is how you apply tension to the band.

Is that clear?

Not sure what you are getting all fired up about Phil. Don't really care how far it is around the wheels or if my wheels are in the same whatever, all I care about is that may saws cut well.

That is the point I am trying to make.

[Rod Sheridan]

+1, though I do suggest relaxing the blade after use with carbides. For blade life, not machine life.

Erik Loza
Minimax

Oh, well, I've never used a bandsaw with carbide tipped blades........Rod.

[Bill Space]

That doesn't really mean anything other than the length of the band is shorter than the distance around the two wheels at their crowns.

Do you guys get that? I'm not sure you guys are understanding that. This is really a basic concept. If you have a 72.5" long band, and the distance around your two wheels is 72.6", the band can run only center of one wheel, and front of center on the other.

Why is the distance around the two wheels greater than the length of the band? Because that is how you apply tension to the band.

Is that clear?

Clear? No, not really...what you are trying to communicate that is.

Granted, there are variables that need to be considered, like angle of the blade between the wheels, if the wheels are positioned in a way that causes the blade to track in a plane slightly different that the wheels may find themselves.

In this case the blade may in fact end up being longer than it would be if the wheels were coplanar and the band was tracking in the center.

I take it by saying "the distance around the two wheels at their crowns." you mean the length of a band that goes around two wheels separated by a distance, which would be equal to the circumference of one wheel, plus twice the separation distance of the wheel axles.

Initially the two lengths are the same (or close) when the top wheel is adjusted to pull the blade tight between the wheels. In my eye the tension of the band is determined by increasing the distance between the wheels while the band is wrapped around them, in each specific case. In one case, if the wheels are coplanar, the length of the inside of the band will equal the circumference of one wheel plus whatever separation exists between the wheel axles. As wheel position is changed to increase blade tension two things happen: The blade length is a variable which changes with tension and the separation between the wheels also changes with tension adjustment.

If wheels are out of alignment, the blade length may end up being longer than the theoretical minimum length (for coplanar wheels) when one starts to tension it.

Granted other things are going on too. The wheels may deform a bit under tension, and the saw frame may flex, etc.

I am not sure of the point you are trying to make Phil...

[Phil Thien]

Not sure what you are getting all fired up about Phil. Don't really care how far it is around the wheels or if my wheels are in the same whatever, all I care about is that may saws cut well.

That is the point I am trying to make.

I'm not fired up, I'm just explaining that your assertion that the band running forward on the bottom wheel doesn't, in fact, mean your wheels aren't coplanar.

[John TenEyck]

With all due respect, in the time you have taken to discuss this you could have made a C-shaped jig and checked the wheels on your saw. You don't need metal edges to see if the wheels are in plane. Joint a straight edge and cut it out where it needs to be to clear the wheel housings, table, whatever. 1/4" Masonite, plywood, whatever you have lying around, keep it light, keep it simple.

John

[Phil Thien]

Clear? No, not really...what you are trying to communicate that is.

Granted, there are variables that need to be considered, like angle of the blade between the wheels, if the wheels are positioned in a way that causes the blade to track in a plane slightly different that the wheels may find themselves.

In this case the blade may in fact end up being longer than it would be if the wheels were coplanar and the band was tracking in the center.

I take it by saying "the distance around the two wheels at their crowns." you mean the length of a band that goes around two wheels separated by a distance, which would be equal to the circumference of one wheel, plus twice the separation distance of the wheel axles.

Initially the two lengths are the same (or close) when the top wheel is adjusted to pull the blade tight between the wheels. In my eye the tension of the band is determined by increasing the distance between the wheels while the band is wrapped around them, in each specific case. In one case, if the wheels are coplanar, the length of the inside of the band will equal the circumference of one wheel plus whatever separation exists between the wheel axles. As wheel position is changed to increase blade tension two things happen: The blade length is a variable which changes with tension and the separation between the wheels also changes with tension adjustment.

If wheels are out of alignment, the blade length may end up being longer than the theoretical minimum length (for coplanar wheels) when one starts to tension it.

Granted other things are going on too. The wheels may deform a bit under tension, and the saw frame may flex, etc.

I am not sure of the point you are trying to make Phil...

I've bolded some of your text: The blade length isn't a variable. The blade will stretch, steel stretches. But its elasticity is limited. The distance around the wheels is increasing (by virtue of the tension mechanism) more than the blade is capable of being stretched, so the blade rides forward on the bottom wheel.

*****

My point is, every time there is a thread similar to this one, people come out of the woodwork to insist their wheels aren't coplanar and yet their saw works fine. Their evidence that the wheels aren't coplanar is that the blade doesn't ride perfectly centered on both the top and bottom wheels. My point is, their premise is wrong.

This has occurred a number of times in this very thread.

So follow me here (below). Stop me if you get stuck and tell me which # you're on:

(1) To apply tension, the distance around the two wheels has to be greater (minutely, but it IS greater) than the length of the blade. You can't start to put any force (tension) on the blade until you've met that requirement.

(2) If the blade is shorter than the distance around the two wheels (at their crown), there is no way for the blade to ride perfectly centered on the crowns of both wheels.

(3) If it can't ride perfectly centered on both wheels, the best you can expect is for it to ride perfectly centered on one of the wheels, and front of center on the other.

(4) Seeing as the camber of the top wheel is typically used for adjustment, that will be the wheel where the band rides centered.

(5) And so now we see the band will always ride front of center on the bottom wheel whether your wheels are coplanar, or not.

[Ethan Melad]

I'm never sure how to respond to posts like this, there is so little information. Like, how far-off were the wheels? How were they measured (no blade/blade/what size blade, etc.)? How does the saw run? What was the experience level of the tech?

So my question for those that think wheel alignment is unimportant: Do you think the manufacturers install the wheels arbitrarily? They just mount them wherever they may fall?

And why don't we see any bandsaws where the wheels are misaligned by inches? If alignment isn't important, they could be off by a foot, right? Wait, you couldn't get a blade mounted in that case. Well, you could probably get a blade mounted if they were misaligned by an inch, if the saw is large enough, right? But wait, off by an inch, that is extreme, that saw can't run smoothly if the wheels are off by an inch. How about a 1/4"?

See where I'm going with this? If you put your critical thinking cap on, you will see 12" is undoable, so is 6". 1" may be very rough. As we approach 0", things continue to improve. Certainly there is a point of diminishing returns (there always is). But certainly people are capable of reasoning through this, no?

I'm not sure why more information was all that necessary here - my point is that in discussing the fact that my wheels were not coplanar (by about 1/4-3/8", i think), the tech believed that the saw was designed this way. And I had no reason to think the tech was uninformed, or that he thought I was uninformed. And it makes sense, since both wheels are clearly (based on paint and wear) in the same position they were at the time of manufacturing 50 years ago.

I don't think anyone would claim that a saw should (although maybe it could) run with the wheels 6" out - but thats pretty much a moot point since saws aren't built to allow that to happen anyway. Sure, saws are built with a specific wheel alignment, but I don't think that wheel alignment is necessarily coplanar, and tolerances are built in to allow the wheels to move.

[James Nugnes]

I suspect Dan is going to do that. I think the table has to come off the saw enough over its life that it is to my advantage to build a gauge designed to work without the table in place and make some sort of support apparatus that allows me to get the table back on again without assistance etc etc. Getting it off without assistance is a big nothing. Getting it back on again without assistance tends to be more of an issue. I suspect my gauge WITH METAL EDGES will be far less complicated to build than whatever I come up with to assist me with installing the table. But even that should not be too bad. That will probably turn out to be a neat project. Once I have both, they are done and will be good for the life of the saw.

You have no idea how many times the first thing out of a Laguna tech support rep's mouth is "well first you want to take the table off". "Thanks, are you going to fly over here and help me get it back on again?" Its not their fault. Just the way it is.

By the way I have always liked the 4 bolt pattern for lower bandsaw wheels, especially the way Laguna has implemented it for the 14 12. Maybe I am just used to it but I prefer it to just using shims on the shaft and at least IMO Laguna has chosen the better of the versions I have seen for the 4 bolt pattern. But again it might just be familiarity. When I see it, I pretty much know what to expect.

[Bill Space]

"I've bolded some of your text: The blade length isn't a variable. The blade will stretch, steel stretches."

Hummm.... So the blade length varies (stretches) but it isn't variable? Your words not mine :)

Many things are happening. I would not discount wheel deformation under tension, for example. Also the effective wheel diameter changes as the blade moves off the crown.

I don't have the answers, but I am not sure your conclusions cover all the variables.

Bill

[Phil Thien]

"I've bolded some of your text: The blade length isn't a variable. The blade will stretch, steel stretches."

Hummm.... So the blade length varies (stretches) but it isn't variable? Your words not mine :)

Many things are happening. I would not discount wheel deformation under tension, for example. Also the effective wheel diameter changes as the blade moves off the crown.

I don't have the answers, but I am not sure your conclusions cover all the variables.

Bill

The degree that the band stretches or the wheels deform is negligible, they're orders of magnitude smaller than the change we're making with the tension mechanism. So we don't need to account for stretch, so it isn't a variable as far as this exercise is concerned.

We increase the distance around the wheels by increasing the tension. The blade can't stretch enough to satisfy the increase, so it rides forward on the bottom wheel (where, as you say, the diameter is smaller).

I'm surprised this seems controversial.

[David L Morse]

The blade can't stretch enough to satisfy the increase, so it rides forward on the bottom wheel (where, as you say, the diameter is smaller).



Why doesn't it go to the back? Where's the asymmetry that sends it forward instead of backward?

[Phil Thien]

The blade can actually ride backwards if, when you first place it on the saw it is too far back on the bottom wheel, and if the camber of the upper wheel is adjusted so the wheel tilts down rather than up. And I've had that happen to me right after reassembling a saw on which I was working.

[Bill Space]

I do not see the reason why the blade should need to move to one side or the other when tension is increased or decreased if everything else is in equilibrium...

Granted this could be caused by flex in the saw frame. What do you see as the reason for this movement if it does occur only in one direction?

And as as pointed out above(ca not see the post right now) if a move did occur why not move back rather than to the front?

Edit: Phil, you posted while I was typing. If the cAmber of the top wheel is adjusted, would the wheels still be coplanar? Seems not...

Not sure at this point if we are talking about the same thing now...:confused:

Bill

[Phil Thien]

I do not see the reason why the blade should need to move to one side or the other when tension is increased or decreased if everything else is in equilibrium...

Granted this could be caused by flex in the saw frame. What do you see as the reason for this movement if it does occur only in one direction?

And as as pointed out above(ca not see the post right now) if a move did occur why not move back rather than to the front?

Edit: Phil, you posted while I was typing. If the cAmber of the top wheel is adjusted, would the wheels still be coplanar? Seems not...

Not sure at this point if we are talking about the same thing now...:confused:

Bill

The reason the band is moving is because we're pulling the wheels further apart, but keeping the blade trapped in the center of the top wheel via the tracking adjustment. So if the blade can't stretch, it just scoots further from the crown on the bottom wheel.

I think coplanar is a terrible term that gets misused/abused, because coplanar is an absolute. And we're certainly not going achieve anything like perfectly coplanar wheels.

On an Inca saw I owned, the bottom wheel could be adjusted +/- .5" in/out. It rode directly on the motor's shaft (it was direct-drive). And those 8" wheels, short bands (maybe 65"), and flat wheels/tires sure didn't accommodate much in the way of misalignment. The saw couldn't achieve higher levels of tension and any misalignment would result in fluttering of the blade. And like I said, it was only off 3/16" from the factory position.

On a friend's Delta clone with riser block (he purchased used), the saw vibrated so much that the previous owner gave up on it. On that saw, the wheels were off by a good 5/8". My friend did quite a bit of filing and fitting of the frame, and the riser block, and other parts, to get the wheels close to within maybe 1/8", at which point the saw was perfectly usable.

So my point isn't that the wheels need to be coplanar. Just that, closer is better than further. And you can hit a point where the saw just becomes garbage until the wheel alignment is addressed.

BTW, Mark Duginske's books on bandsaws indicates that when a saw is properly aligned, a band riding centered on the top wheel will ride front of center on the bottom wheel. I can find it and post it verbatim, if anyone needs.

[John TenEyck]

BTW, Mark Duginske's books on bandsaws indicates that when a saw is properly aligned, a band riding centered on the top wheel will ride front of center on the bottom wheel. I can find it and post it verbatim, if anyone needs.

This is exactly how a blade rides on my 14" Delta. After I adjusted the wheels to be, yes, coplaner (or darned close) under zero tension, a 1/2" blade that is centered on the top wheel, under tension, rides front of center on the bottom wheel.

John

[James Nugnes]

Just thought I would close out final activities related to the thread and my 14 12. I did end up making a gauge that I could use to reach into the wheel housings of the 14 12 in order to check wheel alignment. I made mine to work with the table off the saw. So I also went ahead and made the table alignment aid I said I was going to make in order to make it easier to install the table back on the saw. I have degenerative discs so while the table is not all that heavy, a twist in the wrong direction and I am laid up for two weeks. The alignment tool both supports the table while I am fudging around getting the trunnion bolts lined up and it lines up the whole table with the saw so that finding the bolt holes is easier and installing the table is now an easy one man job.

I did make my gauge with metal edges supported by a wood stand 52" long with a cutout for the big cast trunnion bracket that is usually somewhat hidden by the table. The wheels were very close to coplanar as I suspected and the only adjustment required in my case was to the top wheel. It was a very minor adjustment and the action of the blade as I tracked it on the wheels was consistent with what my gauge told me.

While the table was off, I made the final adjustments to stuff that had just been out of adjustment from the factory. The table was too far forward on the trunnions for one thing. They were so far forward that a blade would not get past the table insert. But everything is now flat, level, parallel and the wheels are coplanar.

One bit of good fortune for me is that I really don't have a need for a 3/4" blade. So the spectrum of blade widths I need to put on the saw only goes from 1/4" to 5/8".

Anyway now that I have them, the gauge and the alignment tools will last the life of the saw and work as I need them to work. Unless you have a bad back as well, you might not find much use for the table alignment tool. But I am sure you would want to be able to put an edge to the wheels and there is just no way to do it on this design with a single straight edge. Too much stuff that gets in the way.