Band Saw Modifications

[Rich Aldrich]

I have a ShopFox W1706 14" band saw with the riser for 12" cuts. I have a lot of trouble cutting bowl blanks out of green wood. Most of the blanks are cut reasonably flat, so I do not get into rocking issues. I have been using 3/8 AS - 4 TPI Timberwolf blades. The issue seems to be the blades bend easy and run off the guides. I went through the set up several times and everything seems to be in order. The only issue seems to be that I cant tension the blade enough.

I searched the forum for the post I saw a few months back about a company other than carter that had springs and guides. My first thought is to replace the spring so the blade can be tensioned enough. After that, the saw might be worth putting guide blocks or some other upgraded guides. I am not a fan of the original guide rollers.

[Steve Schlumpf]

Rich - do you have a wider blade? I use a 5/8" or sometimes a 1/2" and have found that the wider the blade - the less it wants to wander.

[Rick Markham]

Rich, are you trying to cut the blanks into circles? Or are just straight cuts? When does the blade "run off the guides"? My first impression is that your right and the spring needs to be replaced your not putting enough tension on the blade. I've never used the Timberwolf blades, but I believe they are made for resawing hence a thin kerf which would be one reason they are bending and kinking (other than tension.) I haven't cut green wood with my laguna yet, but my understanding of the physics involved, is since the wooden fibers are still swollen with moisture the blade needs a lot more time and space to clear the cut. 4 TPI might be clogging and forcing too much tension on the blade inside the cut, once again causing bending, and making it come out of the guides. If your making curved cuts it would compound this problem. Hopefully someone with your saw can chime in soon. How are you deciding your tension setting? Your setup as is should work, I'm suspecting the timberwolf isn't the blade choice you want for what you are doing.

I personally don't like roller guides, My laguna with it's ceramic laguna guides make a huge difference in how they support the blade and easy of setup. Their pricetag is a premium though. The Carter Stabilizer is hands down the best guide for cutting curves and scroll work with a 1/8" to 1/4" blade.

[Harvey Schneider]

In addition to Steve's comment, I would like to add the following thoughts. A three TPI skip tooth blade clears chip faster and generates less heat, therefore, stays sharp longer. Wandering is often caused by a dull blade. Another cause of wandering is too much feed pressure

[Jake Helmboldt]

Rich, if you are cutting round blanks then you may also be applying side pressure and forcing the blade out of the guides. In combination with the other issues previously mentioned you can easily do so.


I don't think it is a spring tension issue.

[Rich Aldrich]

I am trying to cut round blanks out of green half logs.

I have used a 1/2" blade, but also had issues. I don't have wider blades at this time, but maybe I should try the wider blades.

Smaller blanks (shorter, not necessarily diameter) are less trouble for the blade.

I have destroyed a blade on the first blank, but may be it was dull out of the box.

Side pressure could definitely be the issue.

Maybe I should try a different brand. I have also tried Olson which actually have worked better (lasted longer and cut better) than the TimberWolf. Myabe they aren't the best blade for cutting green wood.

Blade cost is why I normally use the chainsaw. I bought the band saw purposely for cutting bowl blanks and can't use it effectively. I could have bought another chainsaw for what I paid for the band saw.

[Steve Schlumpf]

Rich - are you using a jig or are you trying to freehand it?

[Rich Aldrich]

Steve,

I am doing it free hand. I could make a jig like Norm had shown at the one meeting. A jig would help reduce the side pressure. I like the idea. Things get really interesting on pieces that are 6" and thicker.

[Steve Schlumpf]

Rich - you pretty much have to have a jig or else the blank will try and self-feed and that will cause the blade to bow - no matter how much pressure you have on the blade. If you need any assist with the jig - let me know and I can take a few photos of mine if you think it could help.

[Rick Markham]

Rich, here's my take. It's your blade. building a jig is a good idea too, that will help, plus it should make the blank nice and even. 3/8" and 1/2" blades are pretty big for cutting smaller diameters. The back of the blade is probably binding in the cut compounding your problem. The timberwolf blades are very thin (thickness of the blade) since they are for resawing. I would get a blade with less TPI and a thicker kerf. It will help prevent the blade wanting to kink. I'd give suffolk machinery a call and tell them what you are doing and see what they suggest. At this point you have ruled out blade tension as a factor. Depending on what diameter your cutting is how you determine how wide your blade is (front to back, not thickness) My supposition is that your blades are binding and kinking or breaking because they are too wide for the radius your cutting. Beefing up the thickness and choosing a different set and tooth pattern more suited to green wood will make it cut like a hot knife through butter. Van Nuskey in the general woodworking forum is a great guy to send a PM too, he knows a TON about different blades for bandsaws, and is a heck of a nice guy who is always willing to talk bandsaws!

[Mark Levitski]

Hey Rich,

You guys getting dumped on w/ snow up there?

I agree with Rick: try a blade that gives a wider kerf for green wood, and stay with 3/8" or smaller if you can. At least that's what I've seen as recommendations, and it works well for me. I do not however use the bandsaw for my blanks too often. Chainsaw gets it round enough. We've got two bandsaws. The big one, a 24 X 24" Laguna, is more of a dedicated slabbing machine. The smaller 14" Grizzly has a 1/2" blade for generic cuts in dry wood. When I do a bunch of blanks on it, I switch to a smaller blade because the 1/2" does not go 'round the corner well enough due to its size and its tooth design.

Jigs help a lot, but I do not think they will help with your particular problems. If your blank is getting flat on the table and not rocking while you cut, then any free-hand stuff you do should not by nature give you binding trouble. I just got done reviewing a Mahoney DVD where I watched Mike free-hand cutting a blank. If you make a jig, try cutting out circles of various sizes from cardboard or plywood. Tack it on center on top of the blank and cut around it.

[Dennis Ford]

Timberwolf makes more than one style of blade, you need one with a wide kerf to cut wet wood. A resaw type blade has a narrow kerf and is good for cutting dry wood in a straight line but sucks at cutting bowl blanks.

[Jim Underwood]

I use that inexpensive woodturners blade from Highland Hardware that's a 3tpi blade x 3/8 wide and has quite a large set to the teeth. http://www.highlandwoodworking.com/woodturners-bandsawblade.aspx

I get a couple at a time, and if there's a problem with the blade they don't hesitate to replace it for you...

If anyone has a better idea, I'm all ears.

[Dick Strauss]

Guys and Gals,
He does have a blade made specifically for cutting green wood. The Timberwolf 3/8"-3TPI AS blades are a wide set (and kerf) blade made for cutting circles in green wood.

I don't know your experience level on the BS so I'm going to cover some things that you probably already know. All of my notes assume you have your saw set up properly as far as wheel alignment, etc is concerned.

Make sure that only the gullet and tooth are sticking out beyond the roller bearings. Also, make sure that the rollers are very close to the blade but not touching. The rollers guide assembly should be just above the maximum thickness of the piece you are trying to cut (if not, you give the blade too much room to flex and kink).

Springs in the 14" saws typically need to be tensioned more than the spring guides indicate for a given size blade. Try tensioning to 1/2" for a 3/8" blade and 3/4" indicator for a 1/2" blade.

When cutting, the blade will move easily across the grain (across the log) and slowly with the grain (along the length of the log). Don't force things! Try to feed the piece directly into the blade with one hand behind the blade and one off to the back and side (that way you won't get cut if something slips/happens).

FYI-I'm not a fan of using roller guides in green wood. The rollers tend to compress the sap/shavings onto the blade while the standard blocks tend to clean the blade as it passes. I've used both and see definite advantages to each one (rollers work better for resawing IMHO).

Take care,
Dick

[Josh Bowman]

Rich,
I've used different band saws for 28 years and think I've done about all to one that can be done, good and bad:o. I don't get real hung up with the type of blade unless I'm doing alot of the same type cutting. I use what's on the saw mostly. Right now I have a 3/8", with too fine a blade for green stuff, but can make it cut my green blanks, just fine. I do find the narrow blade will come out of the guides and drift some.......if......I don't let the blade do the work. I'm really not talking about forcing so much, as not going slow enough for the blade/tension to maintain track. IAW, if you cut into a piece and stop, the blade will find it's center, but if you move too fast it may drift. So there's a small skill set, based on moving the blank at a speed that will not let the blade drift, if it does, stop and allow the blade to cut back to its center. I do this by just watching the cutting action of the blade and moving accordingly.
Also, I don't use any fancy jigs to cut my blanks. I have a few round disks of plywood/cardboard and screw one of them to the bark side of the blank (half log) and try to follow that circle. When done, I unscrew the template and rescrew and then unscrew it on the flat sid of the blank, therefore have both centers marked for the lathe..

[Kyle Iwamoto]

I was going to mention keeping the guide as low as you can also. I've very seldomly had my band jump off the guides on my PM with riser. It happens when I pull the wood back. If all else fails, you can try cutting the corners off and getting an octagon. I'm assuming that you can cut a straight line with no porblems. If you can't cut straight either, your saw needs some form of adjustment. I don't think it's your blade.

[Jake Helmboldt]

Rich, I never assume anything, so don't take offense if I state what seems to be the obvious.

Cutting blanks requires moving the blank into the blade to the point where it is tangent to the circle and then rotating while keeping the blank in essentially the same place. In effect you are pushing and turning at the same time since you want the wood to move front to back past the blade, not technically turning.

It is hard to articulate the concept in words, but turning the blank without moving it into the blade simultaneously will result in the binding and pulling on the blade.

[allen thunem]

rich
if you want the definitive on what will make your bandsaw purr like a kitten contact
luois iturra in jacksonville fl
this guy KNOWS everything about a bandsaw and can get you pointed in the direction you need to be
he has no website but type in iturra design and you can get his phone number
he loves to talk bandsaws

[Rich Aldrich]

Thanks for all the help. I think I need to look at the guide adjustment again. I plan to move the guides out of the way and get the blade running true. Then I will try the flutter method to make sure the spring is not the issue - that the blade can be properly tensioned. Then I will reset the guides. I think I should also make the jig, then try cutting a blank.

The thing about the spring is that I destroyed blades at all tension settings starting with the proper tension all the way to max tension. The blades just seem too easy to twist. That is why I havent walked away from the spring tension being the issue. I definitely will try some other manufacturer's blades.

If I am satisfied, I will try a set of blocks. Otherwiise, I think I will talk to Van Husky and see what he suggests.

All I have done today is deal with snow. Now I am going to change oil and then I finally get some shop time. Winter sucks.

[Alan Tolchinsky]

Josh says it all here: " I don't use any fancy jigs to cut my blanks. I have a few round disks of plywood/cardboard and screw one of them to the bark side of the blank (half log) and try to follow that circle. When done, I unscrew the template and rescrew and then unscrew it on the flat sid of the blank, therefore have both centers marked for the lathe.. "

If you are trying to cut free style with the bark down on the table, this is not the way to go. A flat area has to be on the table or you will ruin blades or worse get hurt. If you put the bark side up then use Josh's idea to cut the circle. I don't know what other set up problems you may have but please do this safely. If your log is rolling on the table that should be a big red flag for you.

[Prashun Patel]

Rich-
I think the opposite of everyone on this thread: go thinner on the blade.

What size blanks are you trying to cut? 3/8" won't navigate tight circles - for me, less than say 6" - very well. When I try to adjust the blank while cutting, it can pull the blade out of the guides.

Are you sure the bottoms are dead flat? It's hard to get a flat enough surface for bandsawing tight radiuses with just a chainsaw. I have had better luck hitting it with a power planer or even a handplane.

Last, if u are married to the 3/8" then try rounding the back of your blade with a honing stone. This is supposed to enable thicker blades to navigate curves.

[Kelvin Burton]

Timberwolf makes more than one style of blade, you need one with a wide kerf to cut wet wood. A resaw type blade has a narrow kerf and is good for cutting dry wood in a straight line but sucks at cutting bowl blanks.

Yes, they make a blade described as "3/8 x 3AS" which is specifically for green wood. That's what I bought for my 14" Delta and it works fine cutting bowl blanks in both green and dry wood. I don't have a riser on my bandsaw though so I'm limited to 6.5".

[Nathan Hawkes]

Guys and Gals,
He does have a blade made specifically for cutting green wood. The Timberwolf 3/8"-3TPI AS blades are a wide set (and kerf) blade made for cutting circles in green wood.

Springs in the 14" saws typically need to be tensioned more than the spring guides indicate for a given size blade. Try tensioning to 1/2" for a 3/8" blade and 3/4" indicator for a 1/2" blade.


I have a Ridgid 14" saw, with the riser block, and a bunch of other modifications. A 2HP Baldor motor was the biggest (most expensive) modification, but the most important thing I did was replace the POS factory spring with a yellow iturra spring. That $17 spring did more than replacing tires, guides, and the motor, for that matter. When the blade doesn't drift, there's not as much drag on the blade. I strongly suggest that you ditch the factory spring, pronto. The iturra tension spring puts WAY more tension on the blade at the 1/2" or 5/8" setting than the factory one could fully compressed. I mostly use 2 tpi blades, which I believe are only available in 1/2 or 5/8", but are great for green wood. Right now I have a 3/8" blade on my saw, with a 3tpi configuration.

[Jeff Nicol]

I use Olson blades from 1/4-5/8 in the 3-4tpi range and I cut everything freehand. The BS is a fickle machine if you don't keep the blade cutting as you make the curved cut. If you cut to slow and turn the wood to fast you will twist the blade or push to fast into the wood and not turn to follow the curve you will bind and pack the teeth with wood. The saw and the blade will only cut as fast as it can cut and by maintaining a even feed into the blade and letting it cut and clear the sawdust you will get a better result. There are some woods like Aspen, Pine, Hickory, Birch, Elm and others that are either hard or stringy or both. With the very wet wood that is very fiberous like aspen when you make the cut the fibers swell behind the cut and if the kerf tends to close and tighten around the blade, this creates some problems. I will keep a can of WD40 close by to give the blade a little squirt to help it around the cut usually from endgrain going against the long grain as the fibers of the wood are not laid down but picked out. I only do this on wet wood as the oil may discolor the dry wood, but will mostly be turned away if used on dry timber.

The lat and best thing is not to try and cut the complete circle in one pass, cut off the corners in a straight cut and then remove the remaining wood around the circle, this relieves the tension in the corners and the waste will flex more and not bind.

Wordy reply, but hope it helps,

Jeff