Speed control for 1.5 hp bandsaw

[Matt Benton]

Can anyone tell me if there is a speed control available for a 1.5 HP (115V) bandsaw, and if so, will it get me slow enough to cut metal? I'd like to avoid going the pulley route if possible...

Thanks!

[CPeter James]

The short answer is NO.

CPeter

[david brum]

You should be able to do it easily with a used 3 phase motor and TECO VDF. This is common practice on lathes and will allow you to operate your bandsaw on single phase power. http://www.automationstock.com/teco_westinghouse_drives.htm?gclid=CPyB--ag9KYCFRxqgwod5BsdGg

Note that pullies probably would no doubt be cheaper, but you can get 3 phase motors pretty cheap. A VDF should also serve as a brake.

[Van Huskey]

You should be able to do it easily with a used 3 phase motor and TECO VDF. This is common practice on lathes and will allow you to operate your bandsaw on single phase power. http://www.automationstock.com/teco_westinghouse_drives.htm?gclid=CPyB--ag9KYCFRxqgwod5BsdGg



Note that pullies probably would no doubt be cheaper, but you can get 3 phase motors pretty cheap. A VDF should also serve as a brake.

Ignore my response below, Rod pointed out later I am incorrect and I am! For some reason I read it as non-ferrous metal which would be fine at 1,500 fpm which you could do with a VFD but ferrous metal will take a more in the range of a 40-1 reduction which will take a gear box.


That is the answer, replace the single phase motor with a 3 phase one and use a VFD. Buying new and being frugal you should be able to do it right at $250 with a Teco FM50 (up to 2hp) and an inexpensive 3 phase motor, Grizzly has a 1.5hp on sale for $90 http://www.grizzly.com/outlet/Motor-1-1-2-HP-3-Phase-3600-RPM-TEFC-230V-460V/G6241 I think the Teco FM50 for 2 hp is $145 so both shipped will be right over $250. With some luck with a used motor you might be able to get close to $200.

[Stephen Cherry]

Although the pulleys are not very high tech, a 4-1 reduction is cheap, and also gives a 4-1 torque rise.

[Rod Sheridan]

If you use the VFD/3 phase motor approach you'll have almost no power available at the speed you need for metal.

Lets assume that you need 100 feet per minute for cutting mild steel.

My wood working bandsaw has two speeds 1560 FPM and 3100FPM.

So to obtain maximum power for metal I would select the lower speed by changing the belt position on the saw to the low speed setting.

Now I need to reduce from 1560 FPM to 100 FPM, which means that my saw motor would now have to rotate at 0.064 X rated speed.

So if I now used a 3 phase motor and a VFD my motor would run at 0.064 X rated speed, however it would also be running at 0.064 X rated HP.

Since I have a 2 HP saw it would now be a 0.128 HP saw.

If I started out with a single speed band saw of 3100 FPM it's worse, I would only have a 100/3100 X 2 HP saw or 0.065 HP.

That's why a wood/metal cutting bandsaw uses mechanical speed reduction via pulleys or a gearbox, you lose almost no motor power.

Regards, Rod.

[Matt Benton]

Thanks everyone. Looks like pulleys it is...

[Carroll Courtney]

I guess that's why you can put a 3hp VFD on a 5hp sander as long as you don't run the hz up to where your over amping the 3hp VFD.Unless your cutting real thick metal vs just plate steel I would not think you would not need alot of hp for that.Thanks Rod,I have always wonder about that,VFD's have been around for yrs----Carroll

[John Coloccia]

The horsepower is less because the motor is turning slower, but the motor will develop constant, maximum torque with a VFD up to 60hz. At that point, HP is constant and torque drops off. It will develop less torque at the bandsaw wheel than an equivalent bandsaw motor running full speed with a smaller pulley, but that's only because of the additional mechanical advantage from the pulley.

[Van Huskey]

As I refer to above if you indeed want to cut ferrous material you are going to need a reduction larger than you will be able to get with a single step pulley arrangement, you need at least two shafts (prior to final drive) and you are probably better off searching for a metal saw designed for ferrous material. Many of the wood metal saws that just use two pulleys aren't near slow enough, you will in two sets of drive pulleys to get the huge reduction you need to have the full proper range for ferrous material. If you only want to cut non-ferrous materials it is possible with a motor change and VFD or a single set of step pulleys.

[Curt Harms]

Unless space were an issue, would it make better sense to just get a metal cutting bandsaw like this? (http://www.grizzly.com/products/4-x-6-Metal-Cutting-Bandsaw/G0622) This wouldn't cost any more than a 3 phase motor & VFD and can be used vertically much like a woodworking bandsaw. [Warning: stealth gloat] I got the Shop Fox version at a Griz tent sale for $110 a couple years ago.