Bandsaw setup for metal (ss issues)

[Paul_VR6]

I am the proud owner of a lightly refreshed 14" Rockwell (Delta) 14" bandsaw. Model 28-303 w the adjustable speeds. Set on the outer pulleys.

I thought I had it set up decent with a 10/14 bimetal blade w tension in the range. Blasts through thin plate just fine.

I am cutting some 304ss tubing bends and i cannot keep the blade from getting stuck and popping off. Trying to figure out what my issue is. Waffled the blade yesterday when a part stuck bad. Internet tips have not helped so far. The only off one I found is that someone mentioned on these saws is the rubber on the wheels should only be used on wood not metal but no ref to this in the manual.

I have about 30 more cuts to do and popping the blade back on every two cuts is getting old. Help!

 

[cvairwerks]

Probably need to switch to an 18 or 24TPI blade, use lube and slow down your feed rate.

 

[MOS3522]

OP hasn't given us the thickness on the tube but I think a 14 TPI sounds best for stainless, not a higher TPI.

 

[Paul_VR6]

Tubing is 16g 1-7/8" od

Guide w the saw shows 14tpi for a 1/2" blade for ss w a 40 speed.

I am on the outer pulleys but now thinking they may be swapped around giving me 115 instead of 40. No good way to tach it but I'll measure the pulleys later. Figuring too fast wouldnt be helping.

 

[Paul_VR6]

Pulley setup looks right.

 

[GeoBruin]

Tubing is 16g 1-7/8" od

Guide w the saw shows 14tpi for a 1/2" blade for ss w a 40 speed.

I am on the outer pulleys but now thinking they may be swapped around giving me 115 instead of 40. No good way to tach it but I'll measure the pulleys later. Figuring too fast wouldnt be helping.

You know the blade length. Just put a white dot on the outside of the blade, start it up, and count the number of times the white dot comes around in a minute (or 30 seconds x 2, etc.). The numbers you're seeing in the table are SFM, not RPM, so even if you were to measure the pulleys, you would have to convert to CFM anyway. By just measuring the blade, you get there directly.

Edit: for 16 gauge tube, I would probably go with a higher tooth count myself. Stainless is hard and with walls that thin, I would be affraid of breaking teeth.

 

[Paul_VR6]

Got some 24tpi and another 10/14tpi to try out and will report the speed testing once I get a blade dialed again.

 

[ez-duzit]

That machine is not really up to the task; too fast. Are you using the correct stick lube on the blade?

 

[whateg01]

That machine is not really up to the task; too fast. Are you using the correct stick lube on the blade?

Why isn't it? If he has it on the slowest speed, that 115 fpm. Should be fine.

Does the 3 tooth rule not apply here? 16 ga, or ~0.060" should have no more than 0.030" tooth spacing, or 33 tpi. I wouldn't try that with less than 24 tpi.

 

[ez-duzit]

Why isn't it? If he has it on the slowest speed, that 115 fpm. Should be fine...

I've owned that exact rubber-tired machine. It is a huge compromise, especially on stainless, which you really want to run slow. Also I'll bet he is not using any lube. I cut stainless at around 50 FPM on this:

 

[Firebrick43]

I am the proud owner of a lightly refreshed 14" Rockwell (Delta) 14" bandsaw. Model 28-303 w the adjustable speeds. Set on the outer pulleys.

I thought I had it set up decent with a 10/14 bimetal blade w tension in the range. Blasts through thin plate just fine.

I am cutting some 304ss tubing bends and i cannot keep the blade from getting stuck and popping off. Trying to figure out what my issue is. Waffled the blade yesterday when a part stuck bad. Internet tips have not helped so far. The only off one I found is that someone mentioned on these saws is the rubber on the wheels should only be used on wood not metal but no ref to this in the manual.

I have about 30 more cuts to do and popping the blade back on every two cuts is getting old. Help!

Do you have a riser on the saw?

 

[whateg01]

I've owned that exact rubber-tired machine. It is a huge compromise, especially on stainless, which you really want to run slow. Also I'll bet he is not using any lube. I cut stainless at around 50 FPM on this:

Definitely not the ideal saw for it, but it should do it, especially thin wall stainless tubing. I cut stainless dry, as I do most things except when aluminum wants to weld itself to the blade. But blade choice makes a huge difference.

 

[Firebrick43]

Definitely not the ideal saw for it, but it should do it, especially thin was stainless tubing. I cut stainless dry, as I do most things except when aluminum wants to weld itself to the blade. But blade choice makes a huge difference.

The wax blade lube sticks make a world of difference in blade life and later life cut speed for those not wanting the mess of a most lube or flood lily be set up.

We used the Walter cool cut but a friend has good luck with the Lennox brand stick as well

 

[slowtwitch73]

Yeah you should be able to that with some futzing.

A big part of blade popping is flex in the system. Frame, blade, tires, wheel hubs/bearings/spindles etc etc. Which to a degree, you are stuck with pending machine mass. So a tooth grabs, and instead of cutting or getting sheared off, something 'gives' and the blade pops.

But you can get gains here and there to get the most out of what you have.

Most guys run their blades too loose. I have a Doall blade tensionometer and I'm always amazed at how tight the correct tension is. I don't even go all the way to spec b/c I'm chicken... but it gets me way tighter than if I was doing it by the seat of my pants. That's two common flex sources addressed.. the blade and the tires (which are now more compressed).

Make sure your belt is tight, get the right tooth count (maybe a tad coarser if no cooling), if its real thin run something sacrificial under it like some aluminum (heat sink) or even wood.

Mind your feed... pushing hard will often toast a blade, esp a fine one. Use bare hands if your feel it getting too hot to handle, back off.

 

[Rusted Nut]

Tighten blade. If you have a manual, it should state blade deflection; it’s usually not much. Back the tension off, try just weight of blade/arm, no additional pull.

 

[Paul_VR6]

There is a tension gauge on the back for different blade widths. I have had it set past 1/2" closer to 3/4" I did get some of the tube lube as well. Gotta get back on this been a few days thrashing on the car getting in the way.

 

[isb cornbinder]

Probably need to switch to an 18 or 24TPI blade, use lube and slow down your feed rate.

I agree, and, I think the tube is pinching the blade. A pinched blade is very likely to jump off the wheels.
I like to put a thin wedge in the tube as I finish the cut. This prevents the tube from closing and destroying a $47 bi-metal blade.
This is a table I made for my horizontal bandsaw. I have a Walker Turner blade welder. It has never been used except for 2 tests. I would like it to go to a new home.

 

[GeoBruin]

There is a tension gauge on the back for different blade widths. I have had it set past 1/2" closer to 3/4" I did get some of the tube lube as well. Gotta get back on this been a few days thrashing on the car getting in the way.

That tension guide was made long before modern blade alloys were around. I promise you can not tension your saw enough to get the recommended tension for a 1/2" x .030" bimetal blade. You will bottom out the spring (which you don't want to do) before you get there.