G0752 Lathe- What Is The Largest Tool U Can Use?

JoJo1

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I can not center a 1/2 inch cutter on my g0752 lathe as the compound is too high by at least a 1/16 of an inch. Is this common with this lathe?
Thanks
Jojo
 
Why not use a 3/8" bit? For a 10" lathe, 3/8" would be about right, I think. A quick change tool post is a good idea, too.
 
JoJo1, All the responses you've received, although somewhat sarcastic (c'mon guys) had very good solutions to the problem. HOWEVER, I completely agree with you and the few others that said "Grizzly should make this right". Sure, China machines need to be tweeked a little, But Grizzly advertised this lathe as capable of using up to 1/2" tool bits. If it doesn't, they need to replace something. Good Luck, JR49
 
Maybe Grizzly will cut you a deal on their QCTP. Or at least, explain the discrepancy between catalog and real world.

In all seriousness, though, you will lose nothing by going to a 3/8" tool, at least for now.
 
First of all, thanks for all the responses. I especially appreciate the individual that sent me the measurements from his machine. That is usable data.

To clarify couple of things, the four tool holder that came with the lathe is the correct size. The 1/2 inch tool being a 1/16 of an inch high is with the 4 tool holder and the QCTP (AXA) Phase II tha I have.
The issue is not with the tool holders, but the fact the compound is just too high. Manufacturing defect....

The cutting tool I am using is just a 1/2" high speed blank that I ground down. (And it is exactly 1/2" by 1/2")

And by the way, the individuals that suggested solving the problem with a QCTP really do not understand the purpose and/or function of the QCTP, especially when using the largest size cutter that it is made for. If the compound is above the normal spec. the QCTH will do nothing to resolve the problem with a 1/2" tool. That one is a thought statement. think about it. Hint- it does not lower tools, just raises them....

So the solutions provided were: - Suck it up and accept a defective tool... not acceptable to me
- rebuild the entire compound--- not acceptable to me
- buy and install a QCTP - -- Again, that will not fix the problem using a 1/2" tool
- Solution-- call Grizzly and request a new lathe (I was told new parts would not fix the issue by
Grizzly) This is the solution to my issue and I will call them tomorrow.

Have a great day and if you have a G0752 or equivalent from Grizzly, I recommend you check the height of the compound. If it is low, not an issue.

Regards,
JoJo1

GrizzlyIMG_0599.JPG
 
First of all, thanks for all the responses. I especially appreciate the individual that sent me the measurements from his machine. That is usable data.

To clarify couple of things, the four tool holder that came with the lathe is the correct size. The 1/2 inch tool being a 1/16 of an inch high is with the 4 tool holder and the QCTP (AXA) Phase II tha I have.
The issue is not with the tool holders, but the fact the compound is just too high. Manufacturing defect....

The cutting tool I am using is just a 1/2" high speed blank that I ground down. (And it is exactly 1/2" by 1/2")

And by the way, the individuals that suggested solving the problem with a QCTP really do not understand the purpose and/or function of the QCTP, especially when using the largest size cutter that it is made for. If the compound is above the normal spec. the QCTH will do nothing to resolve the problem with a 1/2" tool. That one is a thought statement. think about it. Hint- it does not lower tools, just raises them....

So the solutions provided were: - Suck it up and accept a defective tool... not acceptable to me
- rebuild the entire compound--- not acceptable to me
- buy and install a QCTP - -- Again, that will not fix the problem using a 1/2" tool
- Solution-- call Grizzly and request a new lathe (I was told new parts would not fix the issue by
Grizzly) This is the solution to my issue and I will call them tomorrow.

Have a great day and if you have a G0752 or equivalent from Grizzly, I recommend you check the height of the compound. If it is low, not an issue.

Regards,
JoJo1

View attachment 116092

The compound is .927" below the centerline on my G0602. The AXA type tool holders are usually (Aloris, Phase II, Shars) specified at 15/16" or .9375" which would be .0105 over center for a 1/2" tool bit. Dorian shows theirs at .875" or .052" under the centerline.

I measured two 250-101 tool holders with 1/2" bits from Grizzly at .944" and .947" , .023" and .020" over the centerline. Shars sells a 250-101XL which is specified for 5/8" tools and measure out at .912" and .917" or .015" and .010" under the centerline with a half inch tool bit. I also measure the 4 way tool, post sent with the lathe and it measures .891" to .897" or .025" and .020" under the centerline with a 1/2" tool bit. Measurements were made with a digital height gage.

The Shars catalog states a 15/16" upper level height which implies that the minimum tool height for a 5/8" tool bit is equal or less than .9375 and for a 1/2" tool bit, the minimum tool height would be equal to or less than 13/16" or .8125". Clearly, their product specification does not match actual measurement.

The bottom line? The OEM 4 way tool post that I received with the lathe will properly seat a 1/2" tool bit on my lathe. Standard type 1 tool holders from most suppliers will not work with 1/2" tool bits on my Grizzly G0602. The Shars 250-101XL and possibly the tool holders will work (barely) on my lathe

There is no requirement that an AXA QCTP fit a Grizzly lathe. When people buy a QCTP, they make the height measurement on their lathe to determine suitability and order accordingly. Grizzly does have an obligation to ensure that their OEM tool holder works as specified. I would measure the distance from the base of your tool holder to the floor of the tool slot (mine is .394") and the distance from the top of the compound to the centerline of the spindle (mine is .927"). I would also measure the distance to the top of the cross feed (mine is 3.100) and the distance to the flat of the ways (mine is 5.005). In creating your problem, the tool holder, the compound, the dial, the cross feed , carriage, and the headstock itself could all be suspect. You should be able to narrow the field with a few measurements.

Bob
 
The problem is not with the lathe or the compound when using the supplied 4 way holder as you say. Therefore you must focus on the fact that The problem is with the quick change tool post and holders. They are generic in the fact that they will fit some and not others. ( fits 9-12 lathes ) :cautious:
There is no standard size lathe.
The only way to solve this problem is to do what I have done in the past for friends is to mill the bottom of the individual tool holders.
In your case that 1/16 will require that you remove around .080 3/32 + - to get the needed adjustment range.
And not having a mill you have to find a machine shop or a school to get it done.

Tomh
 
Bob
That is the smart way to go. Also easier on the tooling.:encourage:
Then frugal folks :rolleyes: will go medieval on what they have:confused:

Tomh
 
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