Bandsaw speed control

[Speedy Builder5Participant @speedybuilder5]

[Speedy Builder5Participant @speedybuilder5]

I have a Dewalt wood bandsaw which saws at 330 meters/min, and would like to slow it down to about 30m/min for use with a metal cutting blade.

 

The motor runs at 2830 rpm (230v 3.4amp or 0.56kw)  Commercial speed reducers are very expensive.  Has anyone got plans for a home made electronic speed controller?

 

There isn’t much room to put additional pulley stages onto the saw, or alter the existing pulley arrangements.

[Jeff DaymanParticipant @jeffdayman43397]

If you do make an electronic controller and get the speed down far enough, you will not likely have enough power to saw. You would be better to rig up a jackshaft and pulley transmission with a stock motor.

 

Is the bandsaw a three wheel type with aluminum frame and plastic wheels? If so, it will not last long sawing metal.

 

You would be farther ahead making a saw with a simple angle iron frame and two plywood wheels. Yes plywood wheels. A friend and I built one that way almost twenty years ago for exclusively metal cutting and it is still going strong. We made two 24″ (as I recall) wheels of 3/4″ thick plywood faced with neoprene rubber strips glued on with contact cement. The rubber provides plenty of grip for the saw band over half the wheel, a huge contact area, and the large radius gives a 12″ throat for the cut. Each wheel has a steel hub and shaft inset into it and large 3/16″ thick washers each side 6″ diameter bolted thru the wood to support the plywood and drive the saw. We drove it with a 1/3 HP washing machine motor and two stage pulley drive, a 2″ to 10″ first stage and a 3″ to 12″ second stage. Bronze bearing plummer block were used on all shafts. This drive gave 150 sfm with the motor we used, a little fast but with a GOOD QUALITY industrial bimetal blade works great in any metals including stainless and A or D tool steels. We made some blade and wheel guards of galvanised sheet steel to keep fingers away from the blade. Also 3 ball roller brgs were used a blade guides just over the table and adjustable up and down. I’ll see if I can get him to make some photos to post here.

Edited By Jeff Dayman on 07/03/2010 19:40:39

[Les Jones 1Participant @lesjones1]

Hi Robert,

                    I agree with Jeff’s comments. The motor will be an induction motor so you can not use a simple phase control speed controller like you would use on an electric drill. The only way to vary the speed would be to use a variable frequency supply. The motor would probably not even start with the supply frequency reduced to about 5 HZ. The supply voltage would also have to be reduced so I do not think you will be able to find any speed controller that will meet your requirements. (At any price.)

Les.

[Ian S CParticipant @iansc]

If you do decide to use the existing machine, you would do well if you could find a similar sized 1450rpm motor, this would go a long way to simplifying the speed reduction, you would be able to use 2:1 reduction +/-. Ian S C

[Speedy Builder5Participant @speedybuilder5]

Thanks for the comments – seems like extra shafts and pulleys would be the way forward.  I don’t have space for another machine in the shed,  and I don’t think my wife would appreciate a bandsaw in the lounge, so Thanks Jeff, but no-thanks.

[Peter TuckerParticipant @petertucker86088]

Hi Robert,

 

My father in law used a worm gear on his band saw, much more compact than belts and pulleys.

 

Peter.

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