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Metal Bandsaw questions

lightn95

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Sep 2, 2012
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89
I've got a vertical band saw that I'm going to pulley down for.cutting.metal... the motor currently is 1750 rpm how much slower should I make it??

What's a good Teeth Per Inch for a metal cutting only blade??

Thanks
 
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kevinstj

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Feb 9, 2010
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The speed will depend on the SFPM (surface feet per minute) of the blade (steel is about 230 SFPM) . You can find charts online for speeds. Number of teeth depends on the thickness of material . You want to always have a minimum of 2 to 3 teeth in the material at all times. But once the material gets thicker you need a heavier gullet in the tooth to carry the chip out of the material so it doesn't plug up. You should always break in you blade or " hone" it before you use it. This can be done by running it through a soft material like aluminum and goin slower than normal. This will hone the edge and prolong blade life.
Hope this helps
 

cooljoe57

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Your best bet would be to find a gear box you can add in between the motor and main pulley. It will be very handy to be able to change the speed, plus your going to have to slow that motor way down for steel.
 

Doug Arthurs

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Make sure the saw is heavy duty enough for steel or you will be disappointed. Kevinsti was right on the money until he said to hone the blade with aluminum. It will take a month of sundays to break in a blade on alum. Just cut you steel but use very light feed pressure for the first couple times. I doubt on a manually fed vertical saw breaking in the blade will have much effect overall. Jut my 2 cents after ten years in the Metal cutting bandsaw industry.
 
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lightn95

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Bull, I get the SFPM calculations... but what does that number mean?
I'm only cutting 3/8" thick MAX. Mostly sheet metal and exhaust pipe type metals...
 
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Doug Arthurs

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Different materials need different sfpm. Alum you can cut at 300+ sfpm carbon steel 290 and lower. If you get into tool steels or stainless steel you could need to be as low as 70-100. Surface feet per minute is how many feet of blade are going through the cut in a minute.
 
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lightn95

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I understand that. But my question is, in the example that Bull linked, I know he used random pulley sizes, the calculation came out to 4,178 SFPM. And your saying those type of materials need 300ish SFPM (roughly). So do I need to pulley it down so my SFPM are 300? (As an example?)
 

yaidunno

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You wont be pulley-ing this down, unless you really like to buy pulleys, pillow blocks, and jack shafts. A gear box is the proper way to go about this. Pulley size and reduction ratio can be determined after you tell us what diameter wheels your saw has.

What is the model and size of your saw?

This topic seems to come up almost weekly, and some great advise has already been given in said topics. A simple search would answer all your questions.
 

bullnerd

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L95, I didn't put those numbers in the calculator. You have to do that. Fill in what you know and reverse engineer your way back to an output RPM of either a pulley system or gearbox.

Like mentioned, a gearbox is probably way easier to start with, but pulleys has been done.
Be creative! Look around, maybe you have something already with a gear reduction on it.

Didn't like the Delta? I have that same saw for at least 20 yrs, wouldnt do with out it now.
 

zkling

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Jan 23, 2007
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Another vertical bandsaw conversion thread? :shocking:

You wont be pulley-ing this down, unless you really like to buy pulleys, pillow blocks, and jack shafts. A gear box is the proper way to go about this. Pulley size and reduction ratio can be determined after you tell us what diameter wheels your saw has.

What is the model and size of your saw?

This topic seems to come up almost weekly, and some great advise has already been given in said topics. A simple search would answer all your questions.

WTF is this "search" you so speak of sir?
 

zmotorsports

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Oct 20, 2009
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I had a Wilton 14" vertical bandsaw that had a gearbox and I kept it in the 250 sfpm range for the majority of what I was cutting, occassionally slowing it dow more for stainless. The saw worked well but was a little on the light duty for my liking. Even running a 10/14 variable blade and keeping enough teeth engaged if it caught I could literally see the frame of the saw flex which was usually enough to spit the blade off. Frustrating to say the least.

I recently sold it (as well as my Jet 7x12 horizontal) and purchased a larger 18" industrial vertical bandsaw that should work much better. I have seen quite a few vertical bandsaw conversions and for hobby type work they are fine but if you plan to start throwing more work at it you would be better off using the money to step up to a heavier machine.

Mike.
 

zkling

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To answer your questions directly.

~20-30x on top of the built in reduction for wood cutting.

As mentioned depends on the sections you are cutting, but a ~10-14 vari pitch is a pretty good compromise.

As zmotorsports brought up, watch the table and trunnions. Most wood only saws and even the smaller metal saws don't have beefy enough trunnions to support a heavy work piece.
 
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