# My Grizzly 12x36 belt drive VFD conversion



## seanb (Jan 18, 2017)

The motor on my grizzly went bad a while ago so I decided to do a 3 phase motor with a VFD

I had to make some mods to the lathe which I will detail. The old motor is pictured. You cant see the broken capacitor on the other side. the motor would also not go in reverse anymore. The screws on the motor plate came loose which allowed the motor to fall off the lathe. It was never the same after that.




Next pic is the replacement motor 2hp 3phase got it on ebay for less than $200


When buying a replacement motor its best to buy new so you get this info also all the wires will be clearly marked so you know which ones to short
The neat thing  about the vfd is that if you confuse L1,L2,L3 It just wont run or it will run backwards. 


Here is the plate the Motor sits on, there's a screw for tensioning the motor. I had to remove the plate and drill new holes for the motor mount. Its important here to measure the original motor so you can size the replacement accordingly. I didn't but I got lucky.

Make sure you mount the motor so the pulley can be placed in the same spot if possible. Pulley should be parallel and the motor not tilted left or right to avoid throwing the belt.


This is a piece of 1x1" square tubing I added to move the splash shield down to make room for the motor 
Which is longer than the original

When buying a replacement motor its best to buy new so you get this info also all the wires will be clearly marked so you know which ones to short
The neat thing  about the vfd is that if you confuse L1,L2,L3 It just wont run or it will run backwards. 


The top of this pic shows the motor mount and one of the sensors I removed. Some of which you could reuse if you bought a VFD with enough inputs. The square box on the left is all the electronics that you wont need anymore. I kept these for now but they're not connected


Drum switch, I used 16 gauge wire here because I had it. You could use network cable if you wanted.  I used electrical conduit and bolted it to splash guard.


I migged this together and painted its mostly to keep chips off. The flex conduit is probably overkill but its shields the cable and I have no issues with the VFD disrupting things, got the conduit dumpster diving at work.
I have to get a new pulley from grainger, the old one didnt fit on the motor. The old pulley had 2 sheaves ?
the new one only 1 but with the VFD I can compensate for the speed. I cut the old belt off and use a link belt.

Im very happy with the results and it was pretty easy. 

I had issues with the lathe bogging down but I traced that to a slipping belt.


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## Reddinr (Jan 18, 2017)

Hey Seanb.   I was just in your part of the country about a month ago for work.    Nice work on the VFD conversion.  I was wondering, what does your drum switch do?  Is it your forward/reverse/off control?


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## seanb (Jan 18, 2017)

Yeah thats it,  its easier to use than the controls on the VFD


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