# Clausing drill press question



## jmhoying (Sep 4, 2014)

Since my Clausing 16VC-1 drill press has a single speed motor (not factory), I can  only get it down to 800 rpm.  My plan is to swap out the motor with a 3-phase  version controlled with a VFD (only using the VFD to cut the motor speed by 1/3  or so for a slow range) and still use the variable speed belt system on the  drill press in order to maintain sufficient torque.

   When taking apart the variable speed pulley that is mounted on the motor,  I found that the keyway on the drive shaft (on the pulley) is worn very badly. (photo below)    Overall shaft size is pretty good.  I was wondering what others would do in this  situation.  This is going in my home shop and will not be used on a daily  basis.   My first thought is to make a new keyway at 180 degrees to the worn  keyway.  I know that isn’t ideal, but since the shaft diameter is decent, I  don’t think it will cause any extra wear on the matting pulley.    
  Another  thought would be to make a new hub, which is an option, but I haven’t gotten  the pulley off of the motor yet to inspect it, so I don’t know if the hub and  flange are welded together or just press fit.

 Thanks for any help,
 Jack


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## Andre (Sep 4, 2014)

Make a new key that runs the full length of the keyway, applying more even force over a larger area. Make sure when you install the pulley to load or force the pulley against the side of the key it will be against when drilling to keep from hammering.


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## chips&more (Sep 4, 2014)

A 3ph motor and vfd is a great choice. And the vari drive is also good to have. You may find yourself looking for that “sweet spot” in the drive mechanizim by dialing in the vari drive and VFD. So, if it was me, I would try and save the vari drive feature. Your idea of a newly located keyway should work…Good Luck.


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## JimDawson (Sep 4, 2014)

I think you are on the right track.  My first thought would be to weld up the existing keyway, but cutting a new keyway should work also.  I assume the keyway in the pulley half is OK.  Is there a plastic sleeve that goes around the hub in this one?


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## Andre (Sep 4, 2014)

JimDawson said:


> I think you are on the right track.  My first thought would be to weld up the existing keyway, but cutting a new keyway should work also.  I assume the keyway in the pulley half is OK.  Is there a plastic sleeve that goes around the hub in this one?



I don't think welding the keyway is a good option. If he welded the keyway and cut a new one the shaft would bent towards the old keyway since the weld puddle "pulls" and the new keyway would let the shaft pull even more. 

Since this is a variable speed pulley, any bend in that shaft will lead to belt vibration which is not pleasant to hear.

If you want to fill the old keyway, I think the best way to do it would be to silver solder it with pipe sweating solder. It would pull less.


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## jmhoying (Sep 4, 2014)

JimDawson said:


> I think you are on the right track.  My first thought would be to weld up the existing keyway, but cutting a new keyway should work also.  I assume the keyway in the pulley half is OK.  Is there a plastic sleeve that goes around the hub in this one?



   In the opposite pulley, there is a small internal key pressed into a 1/4" hole through the hub, maybe only 1/4" total length.  It looks to be worn done in width and will need to be replaced also. In the Clausing parts diagram (part 5999-29), it looks like the key should be 1" long or so.  There isn't a sleeve used on these.
  The part with the worn keyway is the lower motor pulley assembly.
Jack


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