# G0762 Benchtop Mill — Z-crank 0.118" Per Revolution?



## Rex Walters (Jun 11, 2015)

I'm a recent owner of a Grizzly G0762 benchtop mill. Overall I'm quite happy with it, but a question came up in another thread regarding the Z-axis head crank: was it 0.100" per revolution or 0.125"?

I never use the head crank for anything other than gross positioning. I use the dial on the quill (with the feed knob engaged) for precise positioning in Z.

So I pulled out an indicator to answer the question, but now I'm more puzzled than ever. I've measured umpteen times, and the answer keeps coming out to 0.118" per revolution (or 3 mm).

Is it really possible that despite inch dials in X and Y as well as Z (on the quill) that the gearing is metric for the head crank? Not only is it annoying, it makes creating a dial for the crank difficult. I'm starting to regret only buying a two axis DRO....

Nothing special about the setup, just a 0 to 1" dial indicator:
	

		
			
		

		
	




Any comments or suggestions for creating an inch dial for the crank will be appreciated.
-- 
Rex


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## Holescreek (Jun 11, 2015)

Standard 3mm thread pitch.


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## tmarks11 (Jun 11, 2015)

That is not abnormal in machinery coming from Taiwan and China.

Maybe you can Ebay your 2 axis DRO and get a 3 axis one.  The convenience and precision is worth the extra $$$.


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## epj (Jun 15, 2015)

I have a 2 axis DRO. I fitted a digital scale on the quill to serve as the Z axis. Not quite as good as a real DRO, but it is a million times better than the scale on the hand wheel. Only cost about $35 from eBay.


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## tmarks11 (Jun 15, 2015)

In the absence of a DRO for the mill head, just use a dial indicator on a magnetic base.  Attach the magnetic base to the head, with the dial indicator probe on the part, and use the dial indicator to read-out how much the head moves. 

Even when you can trust the dials on a mill, this is more convenient (since you don't have to count rotations) and accurate (since it accounts for backlash).  I do this on my lathe all the time when I need to move the cross slide or carriage by a precise amount.

Personally, I would shop for a 3 axis DRO.  Life with it is so much better.


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## kennyv (Jun 16, 2015)

epj said:


> I have a 2 axis DRO. I fitted a digital scale on the quill to serve as the Z axis. Not quite as good as a real DRO, but it is a million times better than the scale on the hand wheel. Only cost about $35 from eBay.


did You use this for full z  axis travel ? Can you post a pic  and link you spoke of thanks
I  have a PM25MV that has a fine digital   z axes feed (quill only)  but not for full column Z travel. I am  thinking about using a 12 dig caliper to and modiphy for this use looking for ideas.


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## epj (Jun 16, 2015)

I have a picture on my iPhone if I could figure out how to post it. Mine is a 6"'and covers the 5" quill travel.


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## epj (Jun 16, 2015)




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## wrmiller (Jun 16, 2015)

Nice. I have the same one in black on my quill.


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## kennyv (Jun 16, 2015)

Sorry   I chimed in  perhaps posted in wrong place. Forgive me brothers ....  However  like to give a quick shout throw one thing out there if someone catches post thanks .
I have   A PM25 MV  little dif set up  than the Griz . My model came with quill travel down feed  DRO (fine adjustment )  but not Full Z travel on  column   . I was thinking of adding in addition to fine feed DRO. . Like to see a pic of someone who may have put  Z depth  on  the side of column .  Or a mod like wise thanks


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## bpratl (Jun 17, 2015)

Just my 2 cents. Go with a 3 axis DRO and you will never look back. The best thing , other than the accuracy, is the fact that you can switch  between metric and inch's on the fly.
I seem to be using metric layouts more and more due to its simplicity.  Bob


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## kennyv (Jun 17, 2015)

alltho  I like Dro's  and  may i add they are convenient   but been doin manual  stuff for years. Learned allota tricks  from an ole timer when I  machined  large diam 4 start acme threading on the lathe . ( Internal and external threading) .. Used 2 indicators  besides compound and  bed stops.

I prefer  dialing once checking measuring and working to a Indicator and or work stop. I do run  CNC and than of Couse  its DRO fashion. Just my feel and flavor . Now with that said I will say 2 more cents worth. I always like  the feel and read of a dial over a dig  readout. Never liked watches  when they went digital nor do I like to use a dig caliper ...  I don't mind a mic that has a counter style readout as long as it has a thimble reading too. So I guess that's the first cent worth AND  where the real money is.....lol..

Don't get me wrong I am going  add some sort of  dig caliper style DRO on my machine  but im not gona invest allot  for the size of the machine and capabilities I think it may be over kill.  Just my 2 cents .

*So id still Like ideas  for  from guys who added  modded them  with  made shop made caliper style  z axis Dro  travel ideas . Even folks who made  and inexpensive way out by buying the scale and making the rest* .
Hope that makes sense    ohh as far as metric  scale  my machine is in inch  so same same like anything else  divide or multiply by 25.4   Kinda 2nd nature now  

thanks again


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## Falcon67 (Jun 22, 2015)

My G0519 has a "skip" on the Z and loses about .005 every .3 of travel.  Grizzly sent me new parts - same deal.  As above, I put a digital scale on the Z and fergotaboutit.


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## epj (Jun 22, 2015)

I like that one. Mine is also attached to the metal plate on the front, but it in turn is attached to a plastic piece on the front of the  head. Probably not quite as rigid as yours. Had to work with the cards dealt though. I may look to see if I can come up with a better method of attachment.


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## kennyv (Jun 22, 2015)

thanks looks good
 now  im really thinkin not sure if that's my answer right now till I start using machine  (PM25MV mill with fine down feed)
 cuz mine does have  a DRO for the quill  fine feed ... id like to add another DRO  to column that way i have  a  measure range  for  full Z axis travel .

Need to think this out Bc i am limited with Quill travel and the machine is NOT a knee mill. It s a babby  and  im used to doing things different. what i also missing is a quill stop. I used to use gauge blocks with a quill stop .. thought this through i can still use gauge blocks but my method to touch off gauge  will be different . 

Here is what i have come up with  so far... fig if i bottom out my quill as a stop and ADD another  DRO to Z Couum  i can than get full range measurement in Z hope that makes sense 
Still up for other ideas and perhaps someone who did Mount DRO for Z on column can chime in too
 thanks in advance


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## Falcon67 (Jun 22, 2015)

I suppose it depends on what you're doing.  The 4 3/4" spindle travel on mine has been plenty.  I raise and lower the head as needed but have not felt the need -yet I suppose- to know where it is in relation to anything.  Only that the thing in the spindle clears the workpiece.


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