# Spindle Question



## Rick H (Nov 10, 2014)

I recently received my new Grizzly G0729 and have been just trying to get it setup and working properly.  I am still trying to amass the other items I need to really get going, put I have noticed something I would like some further help with.  When I run the quill down from the upper stop and I put an indicator on it, I notice that by pushing the quill side to side or front to back I get roughly .004" to .006" of movement.  The more I push the quill the more movement I get but it seems to stop at around .006".   Knowing that this is a relatively inexpensive import mill, is this play or movement anything to be concerned with?  Is there a way to eliminate or reduce this movement?  Would installing higher quality bearings in the spindle help to eliminate this movement?  Is this a difficult process?

Thanks for any help or advise........Rick H.


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## Ulma Doctor (Nov 10, 2014)

i don't own one, but 4-6 thousandths sounds like a lot of deflection IMHO.
maybe another owner can chime in with their findings and fix


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## Kernbigo (Nov 10, 2014)

is the lock locked when you are checking the quill ?


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## Rick H (Nov 14, 2014)

With the quill lock not engaged I get the .004" to .006" movement.  With the quill locked I get between .001" and .002" movement.   With the quill completely retracted I maybe get .001".

Rick


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## JimDawson (Nov 14, 2014)

I don't think you have a spindle bearing problem.  It sounds like the quill is loose in the bore.  0.001 could be just flex in the whole system.  You might check if there is a difference in play between the spindle and the quill, anything there would indicate spindle bearings.

I think the only real fix would be to hard chrome the quill, hone the bore, and grind the quill to a precision fit.  This is probably not practical given the type of machine.


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## spaceman_spiff (Nov 14, 2014)

Rick H said:


> I recently received my new Grizzly G0729 and have been just trying to get it setup and working properly.  I am still trying to amass the other items I need to really get going, put I have noticed something I would like some further help with.  When I run the quill down from the upper stop and I put an indicator on it, I notice that by pushing the quill side to side or front to back I get roughly .004" to .006" of movement.  The more I push the quill the more movement I get but it seems to stop at around .006".   Knowing that this is a relatively inexpensive import mill, is this play or movement anything to be concerned with?  Is there a way to eliminate or reduce this movement?  Would installing higher quality bearings in the spindle help to eliminate this movement?  Is this a difficult process?
> 
> Thanks for any help or advise........Rick H.



In regards to improved bearings, the way I understand it, higher grade (ABEC 5, 7, 9, etc..) would not improve this parameter at all, because even the worst bearing you have should be preloaded and have zero play. The better grade bearings would improve runout while spinning not static deflection. 

If I am wrong about this please correct.

Have you made any test cuts yet? Try doing the gnarliest cut you think you'd might make and see how it turns out.

All machines deflect. And even if the machines dont deflect much, the work, workholding, or tool does. Thats why they invented finishing cuts! 

Before you get to bothered by it, try doing some gnarly roughing cuts, then a light finishing pass, and see how you did as far as accuracy, and with the quill fully extended. If you get within 1 thou accuracy you are doing pretty great!

NOTE: if your machine is flexing so much that its significantly limiting your ability to make roughing cuts with realistic amounts because of chatter/vibration, then that is an issue that should be addressed..but only within the realistic limits of your machines weight/structure


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## Rick H (Nov 15, 2014)

Thanks for the replies gentlemen.  I am away from home for a while, but I will try your suggestions and see where they go.

Rick


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