More power for my 6 X 48 belt sander.

John Conroy

Retired old guy
Premium Member
#1
My belt sander is a very solid cast iron piece made by Crafstman in the 60's. The only complaint I have is the lack of power. The 1/2 HP motor can be stalled quite easily. Since I had the 1.5HP single phase motor left over from my drill press conversion I decided to install it on the belt sander.



Pretty simple really as the motor just bolts under the stand on a mounting plate with horizontal slots to allow for lots of motor possibilities. I need to add the ability to adjust vertically so I sliced a 8" long piece of 1.5" square tubing in half lengthwise and milled some slotted holes.













I bought a 4" OD aluminum pulley at PA. It had a 3/4" bore so I had to bore it slightly to match the 20mm shaft and widen the keyway slightly to fit the 5mm key. After I got it all installed and wired up I hit the switch and tried to sand a piece of steel and got a surprise. The motor turns the wrong direction! It turns CW and I need CCW rotation. I was pretty choked at myself for not thinking of that before I started. The motor has no provision for reversing the direction. I found a very good video on youtube and followed the instructions from it. Basically you need to reverse the polarity of the start windings only. I took the motor apart and found the start winding leads buried under a bunch of insulating sleeves and held in place by string. It was pretty easy to cut the 2 leads at their original solder joints and reverse and re-solder them. I used sail makers thread to replace the string ties holding it all together. I was quite surprised when it actually worked. I figured for sure I would be back to the old motor. Link to the video.






Any way the motor swap was a success and the sander has tons of power now.
 

DPittman

Ultra Member
#2
Nice improvement. I'm trying to figure out what I could use my single phase motors on from the drill press and milling machine...it would be easier to justify the vfd change for me.
 

John Conroy

Retired old guy
Premium Member
#3
Yeah I was thinking of selling the motor but I realized it could be of use. The perfect belt sander would have a three phase motor/vfd but this will be a huge improvement.
 

CalgaryPT

Ultra Member
Vendor
Premium Member
#4
My belt sander is a very solid cast iron piece made by Crafstman in the 60's. The only complaint I have is the lack of power. The 1/2 HP motor can be stalled quite easily. Since I had the 1.5HP single phase motor left over from my drill press conversion I decided to install it on the belt sander.



Pretty simple really as the motor just bolts under the stand on a mounting plate with horizontal slots to allow for lots of motor possibilities. I need to add the ability to adjust vertically so I sliced a 8" long piece of 1.5" square tubing in half lengthwise and milled some slotted holes.













I bought a 4" OD aluminum pulley at PA. It had a 3/4" bore so I had to bore it slightly to match the 20mm shaft and widen the keyway slightly to fit the 5mm key. After I got it all installed and wired up I hit the switch and tried to sand a piece of steel and got a surprise. The motor turns the wrong direction! It turns CW and I need CCW rotation. I was pretty choked at myself for not thinking of that before I started. The motor has no provision for reversing the direction. I found a very good video on youtube and followed the instructions from it. Basically you need to reverse the polarity of the start windings only. I took the motor apart and found the start winding leads buried under a bunch of insulating sleeves and held in place by string. It was pretty easy to cut the 2 leads at their original solder joints and reverse and re-solder them. I used sail makers thread to replace the string ties holding it all together. I was quite surprised when it actually worked. I figured for sure I would be back to the old motor. Link to the video.






Any way the motor swap was a success and the sander has tons of power now.
That's some higher end electrical work and a killer save on your part. Great work John. Thanks for posting the vid too.
 

Tom Kitta

Ultra Member
#5
My belt sander is powered by 2hp motor but I found out that single pulley is not enough and I need two belts. Also I recently burned out the switch with too much load. These things eat a lot of power.
 

Dabbler

Ultra Member
#6
Nice work John!

My sanders have 3/4 HP and 1 HP, but both are a bit lame for hogging metal. I have a 3PH 3HP motor waiting in the wings for a 3X79 belt sander build - probably 100 years from now...

Until then I'll cope.

Really nice idea to get the most out of your sander!
 

Brent H

Ultra Member
#7
I have the CAD plans for a 72x2 belt sander built up out of 1/2” plate I’d anyone is interested I can post in the plans section
 

Brent H

Ultra Member
#11
I will dig them out and put them on the plan section. You will - or should use a CNC to cut out the patterns - I will put as much detail I can on the plan section
 

John Conroy

Retired old guy
Premium Member
#12
There's quite a bit of info on this link/forum for additional ideas/plans
https://www.homemadetools.net/homemade-belt-sander

There are also Ebay & kit sellers who offer some of the pita components if you are so inclined. Depends on what you want to make yourself.

One of my fav's from a features & functionality standpoint
I like his method of holding the flat plate on the rotary table with the 3 jaw chuck. Never thought of doing it that way.