VFD for bandsaw?

I did a bandsaw conversion a couple of years ago, yeah you cannot get there with by VFD alone, gear/pulley reduction will be necessary.
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Bandsaw speed reducer build.

Hi All, I recently picked up a nice mid 50's vintage, Boice Crane, 14" vertical bandsaw. It has a three phase motor so I figured I'd simply throw a VFD on it and be able to get down to metal cutting speeds, wrong!... The motor is rated at 1150 rpm and running it at 15hz only gets the blade down...
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Eddyde said:
I did a bandsaw conversion a couple of years ago, yeah you cannot get there with by VFD alone, gear/pulley reduction will be necessary.
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OK, then the VFD + 3-phase would be entirely unnecessary (other than variable-speed being a nice-ta-have).

I guess I'll look at the slowest motor I can find (likely 6-pole) and a gear reduction, as mentioned above by MachPete I think) and a suitably large pulley on the bandsaw shaft, then simply take the belts off the gearbox when I need to do higher speeds. Basically, a 2-speed, steel-or-aluminum bandsaw.
 
Not necessary but I did use a VFD and 3 phase motor, it does give a quick n'easy speed range adjustment. The gear/pulley ratio I leave the saw in gives me a VFD adjustable range between roughly 100-300 SFM which is great for steel and okay for aluminum. I only have to change pulleys or the gear range if I need to cut wood or aluminum at a faster speed.
 
Poking around ebay, found some 3-phase Brother gear motors in the 10:1 to 20:1 range for sub-$100 prices. Only 1/2 HP though.

Any thoughts on a VFD + gearmotor? Would 1/2 HP be too underpowered for cutting, say, 1" thick steel?

Getting this in for under two hundred bucks would be ideal.
 
OK so here goes. I bought a bandsaw with a 1.5 HP motor and VFD on it. This is a direct drive unit, driving an 18" wheel with no belts or reductions on it. It handles down to 120 SFPM just fine - it begins to get wimpy at about 70 SFPM blade speed.

My recommendation? if you are talking a small bandsaw, and you aren't the impatient kind, a 3/4 HP unit with VFD and 2:1 belt reduction will do all you need. At 100 HZ you will have not so bad wood speeds, and at 15 Hz, you will be in a great metal cutting range with as much or more torque than I have.

Just my 2 cents worth.
 
Dabbler said:
I bought a bandsaw with a 1.5 HP motor and VFD on it. This is a direct drive unit, driving an 18" wheel with no belts or reductions on it. It handles down to 120 SFPM just fine
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That is good to know. Yes, this would be a small saw, with wheels half that diameter.

Grainger has a 2-HP single-phase motor for about a hundred bucks in their clearance section. Might pick one up just to get a start on this, then look into a VFD for it later. It's cheaper than any of the 3/4 HP ones, though the RPM is 3500 (so would need 2:1 pulley reduction right off the bat). With it being single-phase, I could also just do a gear-reduction + step pulleys and forego the VFD. Saw a motor mount in one of the Fine Woodworking books that I could fab up pretty easily.
 
For metal your target should be between 100 and 250 SFPM.
 
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