Horizontal Bandsaw Speed

[macrnr]

If one wants to run a a bandsaw dry, should the speed be high or low? The saw has a 101", 14tpi blade and will be cutting tubing.
Thanks

 

[Tony Wells]

Type of material? Wall thickness? General answer will be that the blade will last longer due to the cooling and lubrication cutting wet. it's messier, with tubing allowing the coolant to run to the low end so that you need a bucket under it.

 

[macrnr]

I am selling my saw and the gentleman buying has indicated he wants to run it dry. It has been my experience with this saw that if enough coolant is not used it will throw the blade. I was going to try some test cuts in the morning and try to keep from throwing the blade. For the sake of argument, 2" sched. 40 steel pipe is what I will be using. The saw has 4 speeds and it is set mid high range now. Also, how much tension should I apply to the blade? I have been tightening the blade tensioner fairly lightly.
Thanks

 

[Tony Wells]

Well, you should be looking for something in the range of 250 fpm on a mild steel like that. As far as tension, without a tension gage, it's a bit subjective, but I generally run my blades pretty tight. I have a small saw with a 1/2" blade, as well as a larger aw with a 1" blade. Each has an appropriate size handwheel for the size of the saw. On both, the tension handwheel tends to limit just how tight the blade can be set anyway. No wrenches allowed, but almost as tight as you can get it reasonably with one hand should be pretty close.


edit to add: If your blade is not tight enough, if your feed is heavy, that would contribute to the blade throwing problem. Tightening the blade, and/or easing up on the feed pressure could help or eliminate the problem.

 

[bjmh46]

If you're running a carbon blade, shoot for 100-150 fpm, without coolant. 250 fpm is OK for bi-metal on free machining material, however I'd err to the low side if cutting a steady diet of pipe, as it is not made from the highest quality steel.

Regards
Bob

 

[Rbeckett]

Also try to instill the three tooth rule into your buyer. If you have a minimum of three teeth in contact with the cut at all times blade life will be dramaticaly improved. Otherwise he is going to strip teeth and really have an issue with cutting speed and quality in addition to durability. The common complaint is "you sold me junk, it only cut 6 pipies and I had to replace the blade!!!!" Been there and got burned by that.
Bob

 

[Pacer]

Your description of blade tightening really sounds like its not enough - which would certainly give the problem of the blade jumping off. As Tony said, the tightening wheel is designed for hand and with most guys that means all you can get on it by hand will be almost close enough to being tight.

I think most of us HSM'ers run their saws dry - I do - and have never thought it would be worth the effort (and mess) to hook it up. If I mess up a blade its usually gonna be from cutting some thinner material (another blade killer is torch burned edges)

So - I think its safe to say in general terms that when cutting thinner material, the thinner the stuff the more problematic the loss of teeth becomes.

 

[jumps4]

the blade jumping off may well be because it is cutting too thin of a material for the number of teeth and it doesnt jump wet because it is not grabbing the material. i was using 14tpi for shock absorber, strut tubes ( im a scavenger ) and gave it up. it was costing too many blades. i now just cut the shafts off at the end ( i didnt give up scavenging )
steve

 

[Metalmann]

If one wants to run a a bandsaw dry, should the speed be high or low? The saw has a 101", 14tpi blade and will be cutting tubing.
Thanks

Run it slow with zero coolant. How slow, will depend on the type and speed changing capabilities. Just experiment, before you start running production.

14 TPI, should be fine for cutting most tubing. May even want to use less teeth.

 

[Hawkeye]

Does the saw have a hydraulic support? The blade I got for my 9 x 12 is really course, but I can still cut thin material if I have it coming down really slowly. I would prefer a finer pitch, but 10 foot by 1" blades can get pricey.