Bandsaw For Metal And woodworking

[velocette]

Bandsaw Re Power

My vertical band saw Was a converted woodworking machine with an 18 to 1 worm drive for cutting metal driven by a 1/2 hp motor

Three speed poly vee belt drive with 39 52 66 Metres Per Minute

A 1 hp motor and 3 speed poly vee belt direct drive gave 650 900 1100 metres per minute.

Becoming fed up having to swap belts for speed changes so time for improvement.

Having bought a 1.5 hp Baldor DC motor from a factory closure sale for peanuts it was a brand new spare.

It gathered dust in my workshop for a while until a project to use it came to being.

Unsure if it would be possible to use it on the bandsaw some research over a period of time found that it was a possible conversion with some sacrifice

of top end speed for better torque at low speed.

Being a DC addict for a number of years gained experience setting up drive controllers to match the motor so it was eventualy game on.

Removed the motors and the gearbox and create enough room for the rather larger Baldor motor.

After trying different size poly vee 6 rib motor pulleys settled on 50 mm for the motor and 162 for the band wheel shaft.

This gave me from 39 metres per minute to 620 metres per minute.

Using a bi-metal blade for cutting mild steel, cast iron, and aluminium it will cope with light woodworking at slower feed rate at full speed

With a 6 teeth per inch woodworking blade it copes with resawing planks 200 mm wide.

While on the bandsaw mods can I pass on some more tips.

Some years ago I built a bandsaw from scratch using "A" section pulleys for the band wheels and "B" section belts for the tyres.

Top pulley tyre was cut with a scarfed join and glued in place.

Bottom pulley is the drive for the band with the blade running on the back and the driver pulley on a counter shaft located inside the saw blade Photos explain better.

Stepped "A" section pulleys give three speeds 453 254 136 metres per minute cutting speed.

Kicking this drive setup around for a while my thoughts are that instead of a "B" section belt that a "Poly Vee Belt" could be used for the drive.

This then means that the band speed is calculated on the circumference of the small driver pulley.

Eric

 

[Wizard69]

Nice work!

Variable speed is very handy, but honestly I think you will eventually want a speed reduction. It won't need to be a gearbox with a high ratio though.

 

[velocette]

Nice work!

Variable speed is very handy, but honestly I think you will eventually want a speed reduction. It won't need to be a gearbox with a high ratio though.

Thanks Wizard69

Extensive testing with various ratios has been done and this is what seems to work best for me.

Minimum speed used is with the motor running at 112 RPM gives a cutting speed of 40 Metres per minute band speed and is adequate and able to cut 2 inch thick cast iron or 1 inch mild steel.

This is 1/15 of full motor speed Minarik and KB Controllers are capable of 1/50 of full motor speed.

The control was set up to match the motor and uses the back EMF from the armature to maintain a constant speed.

Information on the motor and controller at

http://www.baldor.com/catalog/CDP3575

http://www.surpluscenter.com/Electr...rs/90-180-VDC-SPEED-CONTROL-W-POT-11-2269.axd

Eric