A Question for Flat Tired Bandsaw Owners

[Bill Space]

Bill

This bandsaw bug has bitten you hard my friend. No worries though, I understand completely.
I'm not quite the bandsaw aficionado Van Huskey is..

HA HA HA! You got me!

After buying the Davis & Wells bandsaw and realizing that I did not know much about bandsaws (other than they cut wood well), I decided to learn something, or try to. I think I have been progressing. But you sure called me out for when I am!

[Bill Space]

Are you suggesting we all believe in fairies? Teeth off the front of the tire is just how most flat tired saws are designed to run. Otherwise, the teeth will chew up the tire, at some width thinner blades have to be run near the center of the tire usually that is about the 1/4" band area.

BTW what saw do you have?

Just to add to Van’s comment, I believe it is pretty much accepted that when a blade overhangs the front of the tire, the effect of that overhang is similar to what a blade sees when running on a crowned tire.

So the short of the story is that on flat tire bandsaws they get blade stability from the point of overhang, in a fashion similar to how a crowned tire bandsaw gets blade stability from the effect the crown has on the blade.

But this difference was not the the purpose of this thread.

I was really just curious as to how blades generally tracked on flat wheels. I regret at the time I did not realize the difference between flat and crowned tires and crowned my tires without experimenting.

[Bill Space]

Why do flat tired saws have their wheels chewed off if the blade rides back into the rubber, but the crowned tire saws do not?
IF the flat tire saws run better with teeth off the front, it is only because the set of the teeth change the blade dimension, and therefor the running dynamics over the flat wheel.
No blades should chew a tire, unless you are using the saw wrong.

Peter,

Van addressed you post with specifics and I will defer to him as I am a learner.

BUT I would guess that if a flat tire bandsaw has its tires chewed off, that it is because it has not been set up to run as designed.

By design, a flat tired bandsaw should run with the blade overhanging the front of the tire. In most cases, except for possibly the highest TPI blade, this should put the teeth off the rubber. So no chewing of the rubber should occur.

I think most would would agree with you: “No blades should chew a tire, unless you are using the saw wrong.”

[David Kumm]

I would only add that I would not equate flat tires to high end saws. Vertical bandsaws of the size used in wood shops ( 20-36" ) using blades in the 1" range run flat tires for ease of changing, not because they are better than crowned. Crowned tires are a pain to swap and crowning them is usually beyond the ability of a hobby or even a commercial shop guy. I have to pull mine off and take them to a shop. I equate it to machines using sealed bearings. It is not about making machines better ( sealed bearings in many applications are an inferior option ) but making them easier to maintain. Both sealed bearings and flat tires may need to be replaced more often, but they require less skill and cost when it is needed. Dave

[Edwin Santos]

Edwin,

That is interesting. It seems to concur with others inasmuch that when running narrower blades on flat tire wheels they seem to move the tracking fully onto the tires...

My take on it anyway.

Bill

Bill,
Well after reading Van Huskey's post above, I don't want to chew my rubber tires up, so maybe I should be tracking my 1/2" and 3/8" bands with the teeth off the upper wheel. I don't often run narrower blades on the MM20/s500P but when I have a moment, I'll try tracking a narrower blade both ways and see what happens.

Or if I keep living dangerously and tracking the narrower blades in the center, I can keep an eye on the tires for signs of "chewing".
Not that I would step out on a high wire and disagree with Van on the subject of bandsaws, but in my simpleton mind, the tire is rubber because rubber has the property of give and spring back. I can more easily visualize the die cutting action Van mentions on an older tire that has become dried out or brittle. Or maybe in a situation where way excessive tension is being applied. Or maybe the saw left under excessive tension for months unused where the tooth pattern is left to emboss itself into the tire.
But in the absence of those conditions, I would have to see the phenomenon to believe that teeth can laterally cut the bandsaw tire.
Edwin

[Van Huskey]

Edwin, don't think anything of disagreeing with me, I am on a learning arc like everyone else. Dave corrects me often and he knows a lot more about old iron saws than I do.

Rubber is indeed resilient and the durometer impacts how quickly this happens. While I can't show you I can give an idea about what to consider. First, keep in mind the teeth are rolling into the wheel hundreds of times a minute. Also, think about the action of the tooth edge as the tire rolls into it so that the leading edge of the tooth is pressing into the rubber under pretty high pressure. The grind of the teeth will also affect how quickly damage occurs. A blade like a Resaw King with high shear faces is likely to cause quicker damage than the triple chip grind of a Trimaster. Think about pressing the side of a blade into the rubber with a couple of hundred pounds of pressure 5 or so times a second. Now understand I have not created this damage myself. It has been mentioned by Erik and Sam in the past and I have seen the results which the only logical explanation was damage caused by teeth. I run 1/4" blades back on the tires but I have seen no damage from them, but they are set teeth not ground, run at lower tension and they are rarely on my flat tired saws.

[peter gagliardi]

Van, what you suggest, may well be true. However, it does not compare with my experiences, over the last 32 years in my own small pro shop.
I have had many bandsaws, and never experienced those effects. Just sold my 36” Tanny last year, after owning it for 20 years with moderate use. I put new tires on it when I got it. Always ran every kind of bandsaw blade on it in the center of the crown. Steel and carbide.
Lots of hours and miles of sawing.
Tires nearly perfect when it left.
I now have a Y-30, and a Y-36. The 30 I put new tires on about 8-10 years ago, and the 36, needs them as the final on my restoration.

In my opinion, Proper care and use, setup and tension, along with PROPER dust collection, and most if not everyone on this forum would never wear out a new set of tires.

Poor maintenance, combined with poor operation will do much more harm to tires than the actual position they sit at in my opinion that is backed by some experience. I certainly don’t know it all myself, but I do understand what works on my machines.
Perhaps the rubber compounds used on some of these machines is not optimal.

[Van Huskey]

Always ran every kind of bandsaw blade on it in the center of the crown.

The discussion is primarily about flat tires. Rereading your post I may have misunderstood your point. Running the teeth on a flat tire is using it incorrectly (save narrow blades which you have no choice but to track them back on the tire). If that was your point then I agree. Obviously crowned tires like you have on your saws left the teeth up to either clear or at least significantly reduce the touching of the teeth to the tire.

"Why do flat tired saws have their wheels chewed off if the blade rides back into the rubber, but the crowned tire saws do not? "

I am kinda confused about the exact meaning of this question from your first post and read it like I I figured you meant it. I replaced wheels chewed off with tires chewed off and blade rides back with teeth ride back. Honestly, this seems self-explanatory to me, the teeth are lifted by the crown but flat tires have nothing to lift them clear of the tire.

All the saws you listed are designed for crowned tires, though they are generally relatively low crowns compared to smaller saws. Unless you ran them without crowning the tires they aren't germane to the discussion.

[Randall J Cox]

I have an 18" S45 MiniMax running a lennox die master II 1/2" blade and teeth hang off the rubber of the top tire but run in the middle of the bottom tire. Been running it that way for a couple of years, bottom tire looks fine. Seems to track fine also. Randy

[peter gagliardi]

I understand what you are saying, but just because the saws I reference run a crown, doesn’t necessarily take them out of the discussion.
The first time I checked the “crown” I thought they were flat.
What I came to understand is that “crown” is sometimes measured in thousanths of an inch across a tire.
My Tanny had effectively only about .030” across the 2” wide tire. Add the proper tension, and the tire is almost effectively flat at the top and bottoms of the wheels, as it compresses slightly- certainly not enough to keep the set of teeth from contacting the rubber.

Crown comes into play, and does it’s job almost completely at a point level to the axles- biggest part of the tire “grabs” the blade and keeps it tracking.

Not being argumentative, just offering more info to the discussion.

I have run smaller saws that did have flat wheels, but the setup,and tracking in my case was always the same. Center of wheel as much as possible.

Essentially, unless the compound on flat tired saws is vastly different than crowned, It should make no difference whether teeth are on or off the tire in regards to WEAR.
If however, you run heavy set on the teeth- effectively creating the same idea of crown, but with the bandsaw blade being the dimensionally changing dynamic vs the crowned tire.

The exception I have seen are the industrial powerfed resaws that run flat steel wheels. They run teeth hanging off the front- set teeth contacting steel wheels is not a good combo.

[Van Huskey]

I understand what you are saying, but just because the saws I reference run a crown, doesn’t necessarily take them out of the discussion.
The first time I checked the “crown” I thought they were flat.
What I came to understand is that “crown” is sometimes measured in thousanths of an inch across a tire.
My Tanny had effectively only about .030” across the 2” wide tire. Add the proper tension, and the tire is almost effectively flat at the top and bottoms of the wheels, as it compresses slightly- certainly not enough to keep the set of teeth from contacting the rubber.

Crown comes into play, and does it’s job almost completely at a point level to the axles- biggest part of the tire “grabs” the blade and keeps it tracking.

Not being argumentative, just offering more info to the discussion.

I have run smaller saws that did have flat wheels, but the setup,and tracking in my case was always the same. Center of wheel as much as possible.

Essentially, unless the compound on flat tired saws is vastly different than crowned, It should make no difference whether teeth are on or off the tire in regards to WEAR.
If however, you run heavy set on the teeth- effectively creating the same idea of crown, but with the bandsaw blade being the dimensionally changing dynamic vs the crowned tire.

The exception I have seen are the industrial powerfed resaws that run flat steel wheels. They run teeth hanging off the front- set teeth contacting steel wheels is not a good combo.

I'm with you now and understand what you are saying. As for the compound and characteristics of the various tires, all I can say is they vary quite a bit. The Agazzani with the grooved tires were vulcanized and normally outlast other tires by a good margin which is a good thing since they had to be sent back for replacement. This process may have made them more susceptible to tooth damage despite being more durable otherwise. Erik and Sam (former and current sales people) have both mentioned the issue and have been hands-on with hundreds of flat tired saws, Sam doesn't visit anymore and Erik is out of the biz and visits rarely. I have to talk to Sam fairly soon to get some quotes on saws for my new shop and will ask him about the issue. It is somewhat of a non-issue since running blades centered on the wheel is incorrect on these saws.

[Edwin Santos]

Edwin, don't think anything of disagreeing with me, I am on a learning arc like everyone else. Dave corrects me often and he knows a lot more about old iron saws than I do.

Rubber is indeed resilient and the durometer impacts how quickly this happens. While I can't show you I can give an idea about what to consider. First, keep in mind the teeth are rolling into the wheel hundreds of times a minute. Also, think about the action of the tooth edge as the tire rolls into it so that the leading edge of the tooth is pressing into the rubber under pretty high pressure. The grind of the teeth will also affect how quickly damage occurs. A blade like a Resaw King with high shear faces is likely to cause quicker damage than the triple chip grind of a Trimaster. Think about pressing the side of a blade into the rubber with a couple of hundred pounds of pressure 5 or so times a second. Now understand I have not created this damage myself. It has been mentioned by Erik and Sam in the past and I have seen the results which the only logical explanation was damage caused by teeth. I run 1/4" blades back on the tires but I have seen no damage from them, but they are set teeth not ground, run at lower tension and they are rarely on my flat tired saws.

Van, just because I cannot easily visualize something doesn't mean it isn't correct. When I'm back from traveling, I'll have to experiment a little with this.

I do recall Sam telling me that the saw is set up at the factory so that if you track a 1" blade with the teeth just overhanging the wheel, it should be in the same position on the lower wheel, but as you go to smaller bands, they will track forward on the lower wheel when compared to the position on the upper wheel. I just assumed that this might be part of the reason to track a narrower band in the center on the top wheel, the assumption being that overhanging the top tire would run the band right off the lower one. But as I say, I haven't tried it. I'll report back when I do.

Thanks for the additional explanation,

[Joe Calhoon]

I have never run blades hanging over the edge of the wheel. But reading through this not sure now if I have crowned tires or flat. My 36 Agazzani and 20” Hema have what appear to be flat wheels but putting a ruler on them they taper off just slightly. My 14” Delta a little more. And I recall that a 20” Delta I had was very crowned.

My rubber is are all in good shape, the Agazzani I bought new and have done a lot of resawing with it using mostly bimetal 1” and 1 1/4 blades. The Hema was used but the rubber is in good condition. The Hema actually has a sign inside saying to run blades to the center of wheel.

[Erik Loza]

Merry late Christmas, gang. On the Italian bandsaws, here is how they break out...

-True-flat tires: Centauro (aka Minimax MM16/20/24/S400/500/600/et al), ACM, and (I assume) Felder.

-“Slightly crowned” tires: Agazzani, Minimax S45 and S45N (which are actually made by Minimax rather than Centauro), Meber, and all the ancient ones like Sagittario.

I cannot remember what Stomana of Bulgaria’s tires looked like. That was Laguna’s budget LT series for a while. Regarding tire design, this is one of the last things the various engineers spend any time on. We like to analyze this or that about the Euro bandsaws and from the sales side of things and it’s used for marketing here but a bandsaw is one of the least engineered machines from a European perspective. In fact, I would be willing to bet that if you asked one of they why they used a truly flat tire versus a slightly crowned tire, the answer would be some combination of, “Because that’s why we’ve always done it” and “It’s the most economical way”. Just like if you were to ask any of the mass-producers of Asian budget bandsaws why all their tires are crowned, they would probably say, “Aren’t they all that way?”.

Erik

[Edwin Santos]

Merry late Christmas, gang. On the Italian bandsaws, here is how they break out...

-True-flat tires: Centauro (aka Minimax MM16/20/24/S400/500/600/et al), ACM, and (I assume) Felder.

-“Slightly crowned” tires: Agazzani, Minimax S45 and S45N (which are actually made by Minimax rather than Centauro), Meber, and all the ancient ones like Sagittario.

I cannot remember what Stomana of Bulgaria’s tires looked like. That was Laguna’s budget LT series for a while. Regarding tire design, this is one of the last things the various engineers spend any time on. We like to analyze this or that about the Euro bandsaws and from the sales side of things and it’s used for marketing here but a bandsaw is one of the least engineered machines from a European perspective. In fact, I would be willing to bet that if you asked one of they why they used a truly flat tire versus a slightly crowned tire, the answer would be some combination of, “Because that’s why we’ve always done it” and “It’s the most economical way”. Just like if you were to ask any of the mass-producers of Asian budget bandsaws why all their tires are crowned, they would probably say, “Aren’t they all that way?”.

Erik

Erik - Would you comment on the question of running bands narrower than 1" in the center of the tire versus teeth overhanging the edge? One of the sub-questions in this thread is the risk of chewing up the tire when running a band in the center where where the teeth in the field of the tire.

Changing subjects, from your comment, it sounds like we might be over thinking and over discussing these machines in the eyes of the Italian manufacturers, and maybe we would give them a good laugh.
Thanks,
Edwin