Bandsaw speed for metal?

O

oldwolf

Joined
Dec 29, 2002
Messages
617
Got my bandsaw running but I think too fast. Tried a test on some of Aldo's 1084 and it cut fine for about 3/4" and then just stopped cutting. I put a 1/2 HP 1725 motor on it and the pulley on the motor is 3"OD and the small pulley of the 3 step is 2 1/4' OD. What pulley should I have on the motor to get a good speed for metal? Also what TPI? I'm using a Rigid Metal blade.
 
14-18 TPI in a good bi-metal blade...rule of thumb is 2 to 3 teeth sitting on the steel at a time. You want the blade running at about 75 RPM for steel, 150 max. Any faster and you will work harden as you cut (due to heat build up) and fry your blade. The slower the better...
 
Need more info. The motor is turning 1725 and the smaller driven pulley being smaller means that shaft is turning even faster. :eek: The question comes with respect to what drives the blade wheel. If that 2.4" shaft directly drives the blade wheel, then the blade wheel would be moving - I dunno, maybe 2000 RPM. If its a 14: wheel, that would be about 7000 SFM.

You want about 120 SFM for mid-range. Somewher4e in there you need some big reduction. We need more numbers.

  • Motor speed
  • Motor Pulley Size
  • Driven Pulley Size
  • What does the driven pulley turn?
  • Any reduction between driven pulley shaft other end and blade drive wheel (size of both)
Rigid metal blades are (I think) a home depot brand or something like that. They will not last long. Follow the bandsawbladesdirect link above and get a good m42 bimetal blade - maybe a lennox classic or Diemaster II. It is well worth the extra. Some sort of cutting lube will make big difference in blade life. If you can't do liquid cooling of the cut, consider Lennox Lube - applied manually.

24 tooth if you cut 3/32 or less
18 tooth for 1/8 or more
14 tooth (or 10/14 var) if you only use
5/32 or greater.

Feel free to follow with more questions or information.

Rob!
 
Yeah the Rigid is all Home Depot carries. I'll get a better one online. It's got some sort of gear reduction. When the motor pulley turns one revolution the edge of the 7 1/4" drive wheel only moves a couple inches. The pulley that drives the gears is 3". I'll try putting the belt on the largest of the three step pulleys when I get a larger belt. That should help, I think:confused:
 
ridgid.jpg


Is this the saw? I think it says 2700 RPM :eek:

I have had great luck cutting with a 10/14 vari-tooth blade Lenox Diemaster 2 blade for 1/8" and up. Definitely end up breaking some teeth off if you cut 1/16" with it or less than 1/8" stuff. I'm cutting A2, maybe 1084 is easier to cut?
 
Leu Custom said:
ridgid.jpg


Is this the saw? I think it says 2700 RPM :eek:

I have had great luck cutting with a 10/14 vari-tooth blade Lenox Diemaster 2 blade for 1/8" and up. Definitely end up breaking some teeth off if you cut 1/16" with it or less than 1/8" stuff. I'm cutting A2, maybe 1084 is easier to cut?
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Nope, the blade is Ridgid. Mine is an old vertical/horizontal. bandsaw i was given. I was cutting 1/8".
 
Just a follow up. I got a proper size belt and put it on the largest pulley on the 3 step and a new blade and it's cutting fine now Just need a new bearing for the upper wheel as it's loose and the blade won't track well.
 
Erik, I hope you meant 75-150 feet per minuite, not RPM. A normal band saw running at 100RPM would be doing about 500-600 FPM, way too fast.
Stacy
 
bladsmth said:
Erik, I hope you meant 75-150 feet per minuite, not RPM. A normal band saw running at 100RPM would be doing about 500-600 FPM, way too fast.
Stacy
Click to expand...
LOL...yes, I guess that would be a little quick and yes, I meant FEET not revolutions. Ooops :D
 
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