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Bill Space
12-09-2018, 6:42 PM
First I should apologize for posting so many bandsaw related threads recently!


But there is a specific reason for this question. In the spring I bought a used 20 inch Davis & Wells bandsaw. The blade tracking was terrible because the tires were flat and I did not know that with flat tires you need to track the blade off the front edge of the wheel. So I crowned the tires, as the tires were originally crowned by D&W to begin with. Tracking became excellent immediately afterwards.


Now I am wondering...can any bandsaw run flat tires without issues, if the owner understands that the blade needs to hang over the front edge of the tire for proper operation?


I would like to think the answer is yes, but really don’t know. My gut is telling me the answer is yes, but I really don’t have anything but intuition to support this conclusion.


Does anyone have experience or knowledge leading to a conclusion one way or the other?


Appreciate your thoughts!


Bill

Darcy Warner
12-09-2018, 6:45 PM
Robison, stenner, etc. Big resaws rund the blade on flat steel wheels with no tires.

Van Huskey
12-09-2018, 7:26 PM
Yes, most of my saws have flat wheels. Check the Myth 2 thread, I'll explain it.

Edwin Santos
12-09-2018, 7:29 PM
First off, OP, methinks you need to change your signature tag line!

On the subject of flat non-crowned tires, I have a bandsaw with flat tires (S500P/MM20). When running a larger blade i.e. 1", I indeed track with the teeth slightly overhanging the edge. Tracks fine.
When running a narrower blade i.e. 1/2", 3/8", 1/4", I position the band in the center. Tracks just fine. Admittedly, I run narrow blades on this machine infrequently.

I also have a smaller 16" Italian bandsaw where the tires are slightly crowned, owing to a stub in the bottom tire that rides in a recess machined into the wheel. The stub pushes an ever-so-slight crown into the tire. I tend to run smaller blades on that machine and track them mostly in the center, sometimes forward or back of center if I feel like it. I let the blade land wherever it lands on the lower wheel. Tracks fine, and I've never given it any more thought.

So in my shop apparently the blade does not *need* to overhang the front edge of the tire for proper operation unless I'm just doing it all wrong.

If a bandsaw will do what you want it to do, I see no point in fooling around with it, just get to work.

If you have a specific performance problem, that's different, let's tackle it.

Mike Cutler
12-09-2018, 7:56 PM
My Rikon 10-340 is flat, well it may have a slight crown, possibly a 32nd or so, but the profile is basically flat.
Saw is setup for the blade teeth to run just behind the front of the rim, on the tire, on the top wheel. On the lower wheel the blade is maybe a 1/4" back the front of the rim. I would guess that is not "co-planar by current definition. I've never even checked, or made any attempt to make them coplanar The blade is a 1", Lennox 2/3 varipitch, TriMaster.
The saw has been setup this way since 2005. I leave the blade relaxed when not in use, so it has to be checked and adjusted slightly for tracking, and thrust bearing clearance, when re-tensioned. It might go months between use. Crank the quick release tension arm, check the guides, and off I go.
Fence is set dead on 90 degrees to the front of the table. There is no accommodation whatsoever for drift.
It resaws extremely well. That's all it does. I have a Jet 14", with crowned tires for the curvy work.

Van Huskey
12-09-2018, 9:06 PM
I just now realized you were asking a different question than I had thought. I read it as how does a BS run with flat tires but I think you are asking if you could get most any BS to run correctly if you removed the crowns. I think the answer is yes as long as the upper wheel has enough adjustability on the correct side. I think you would find that the smaller the blade is the more tricky tracking it would be, but this is a characteristic of narrow blades on flat tires. The large blades are generally run off the front of the tire which causes them to track forward and produce a very stable track, smaller blades need to be run back on the tire so they don't have this advantage.

I think of the overhanging portion of the blade like a front tire of a car with low pressure. The car will tend to drift toward the tire with low pressure.

Bill Space
12-10-2018, 9:27 AM
At the time I bought the D&W saw I gave little thought to bandsaws, and believed the blade should track in the center of both wheels. The previous owner had it set up this way, although he had flat tires in it, and the blade did not track as I thought it should.

At the time I had no clue that flat tires were different than crowned tires as far as bandsaws go. Trying to get the blade to track well and be stable was very frustrating. A little reading indicated I should crown the tires. Crowning the tires made great positive improvement.

My intuition now is that had I set blade tracking so the blade teeth were off the front of the tires, I may have had better results, even to the point where crowning the tires may not have been necessary.

Carrying that thought a step further, I started to think perhaps any bandsaw could probably be set to run with flat tires. I asked the question here in case I was missing something obvious.

At this point it seems that flat tires are more common on larger saws (16” and upward?) that run wider blades.

I think I have my answer. I probably could have run the D&W saw by tracking the blade to the front of the tires like one would with any flat tires bandsaw of similar size. (Even though D&W does call for crowned tires)

Tracking narrow blades on flat tires may be more difficult, and this may be why the smaller bandsaws are likely to have crowned tires.

Thanks for the input!

Bill

David Kumm
12-10-2018, 9:39 AM
Isn't there someone in the area that you can take the wheels to and have them crowned? It is worth the effort. Dave

Bill Space
12-10-2018, 11:23 AM
Isn't there someone in the area that you can take the wheels to and have them crowned? It is worth the effort. Dave

Dave, as I mentioned above, I crowned the wheels myself (using methods I found at the OWWM site). Yes, it does make a world of difference, as compared to trying to run your blades on the center of a flat wheel...

Bill

David Kumm
12-10-2018, 11:40 AM
Sorry, Brain f*rt. Dave

Steve Rozmiarek
12-10-2018, 7:33 PM
Not apples to apples, but I've never been around a metal cutting bandsaw that had crowned wheels.