# Getting Ready To Bore My Pulley



## Dman1114 (Jul 27, 2016)

Ok Im sure this is an easy project but I'm just an  amateur  at best...  and I'm looking for some set up pointers

I have a G1008 and The previous owner put a 1 HP 56 frome motor on it.   He shimmed the pulley to fit the smaller crank shaft.

Long story short the Factory bolt pattern is for a  90 Metric motor.   But the pulley is 19 mm

So i have a 2HP metric motor coming 3 phase with a VFD and its got a 24mm shaft.

so i have G4003G lathe that i will be boring out the Pulley in.   Just not sure how to go about indicating it in .

Should i Go off the Factory Bore?   What would be the Best way to set this up?

Thanks in Advance


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## T Bredehoft (Jul 27, 2016)

If you trust  your three jaw chuck use it.   I'd use a four jaw, indicate the bore to under .001, then make sure there is no run out in the V groove, as near .0000 as you can get, then go back to the bore and get it to .000 at least.


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## Bob Korves (Jul 27, 2016)

Do not try to chuck on the pulley belt flanges.  You will damage them and it won't hold well.  Instead, use some appropriately sized dowel pins that fit down in the V grooves to chuck on.


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## Randall Marx (Jul 28, 2016)

I'll likely be needing to do something similar soon, so I appreciate the advice here also. The suggestion from Bob about chucking on dowel pins in the groove sounds great!
Good luck Dman. Please keep us posted.


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## Ulma Doctor (Jul 29, 2016)

this was my set up to do the very same job.



https://lh4.googleusercontent.com/-...d8vl5b1a0kVF4ivjwCL0B/w640-h480-no/VFD+15.jpg


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## Dman1114 (Aug 12, 2016)

Just an update...

This pulley had a long shoulder on on the back so I gripped it in the 4 jaw. ..  and indicated it off of the center of the top and bottom grooves..

Took me a while had to keep tweeking it to run paralel but I got it within .0003.. 

I turned the pulley around and put it in my 3 jaw aND I had to take .800 off the shoulder...


The pulley stuck out of the shaft almost  1.5"    so I lowered the pulley height and raised the motor to make up for it.


Broached the 8mm key and now she's up and running.

Very smooth and no vibration. .


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## bfd (Nov 9, 2016)

what I do is to duplicate the shaft that the pulley will run on an take a skim cut on all the pulley surfaces. keeps the vibration down and everything runs true to the bore as mounted. set screws throw off the true running. bill


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## Christian Poulsen (Nov 9, 2016)

Dman1114 said:


> Ok Im sure this is an easy project but I'm just an  amateur  at best...  and I'm looking for some set up pointers
> 
> I have a G1008 and The previous owner put a 1 HP 56 frome motor on it.   He shimmed the pulley to fit the smaller crank shaft.
> 
> ...


If I am following you right you have to bore out the pulleys anyway to fit your shaft so just indicate the faces and  belt minor OD on them (in a 4 jaw or bucking 3 jaw) and your new bore will run perfect with where the belts run...so then Ifn' the existing bore is in or out of concentricity with the ODs, it doesn't mater unless the exsisting bore is "in" and it's just easier to indicate with your indicator) ....plus yes, if you don't have "bosses) sticking out and you have to chuck on the major OD's of the pulley's but I suggest 4 soft (brass if possible or ? (not plastic) rounds in the V grooves or thick soft (brass) shims between the jaws and major ODs to prevent damage to the ODs of your pulleys (that are probably cast?)...(Hard dowel pins, tightening in the V groves can damage them (more "vibration"/noise) ifn' the pulleys aren't pretty hard.


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