New G0759 Owner - New Guy Questions

bluepythons

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Hi Everyone,

First I want to say hello and thank you for all of the awesome content I have been reading. I have read tons and tons of awesome info. I just took delivery of a G0759, this is my second bench top machine as I just sold by Grizzly mini mill. A friend and I were able to lift it on the bench, it is heavy but manageable. That being said it was awkward and I felt like we almost dropped it at one point so my advice would be to have a third set of hands.

Being this is my first machine with the R8 collet I have a couple of questions.

1. How tight should the draw bar retainer cup be on the holding the draw bar. I understand it holds it in place but is there a too loose or too tight issue?
2. The draw bar sucks, the one on my mini mill was better as it had a larger hex head. I know some have used a 9" bolt. I searched every store and online hardware dealer and no one has that 9" bolt, fasten can't even order me one. So that brings...
3. Does anyone have any plans or ideas to make a better drawbar with a hex head and some sort of bushing. I don't have a lathe but a friend does and I could talk him in to help if we had a plan. I'm new so simple would be awesome!
4. Anything else I should do before I start using it? I know I have to clean all packing grease off and tram the column and head but any other advise would be very welcome.

A different topic but new question, I bought a small collet rack from LMS and am wondering if I can mount that to the motor cover or if that would be a bad idea? Ergonomically I would be nice for me but would it add weight to the add, cause vibration etc?


I mainly got the 0759 because I wanted a mill with DRO. The 0704 has been a popular model it seams and the built in glass DROs looked nice. I am sure I could have gotten a 0704 and added something for less but this was a doable solution that was ready to go. Hopefully you guys won't convince me I made a mistake :).

Thanks again for all of the awesome info in the forum. I look forward to learning more!

Dave
 
It looks like the G0759 is substantially similar to the PM-25MV with DRO. I agree with your assessment on the draw bar. There have been a few threads on a better solution. Check under grizzly forum. I have been OK with it, but sometimes mutter under my breath. As to how tight, most of the folks here will say not ridiculously tight. From a mechanical standpoint you have a thread and the taper on the collet. That will exert considerable pressure. I haven't had anything slip just applying what is about a few ft-lbs. Usually using the wrench on the top and holding the spindle by hand. For larger tools, say 5/8 up and when using the chuck, I apply a little more, usually using the spindle wrench, probably up to about 20 ft-lbs. Nothing like torquing a head bolt or barrel nut. If something slips in a collet, you have another problem. Good luck
 
I made a new draw bar with some 4140 allthread and a coupler. Have your friend make you a new bushing for the top of the drawbar.
 
I made a new draw bar with some 4140 allthread and a coupler. Have your friend make you a new bushing for the top of the drawbar.
Would you happen to have a photo? I'm new and have an idea but I'm a visual guy. Does your new bushing thread on the spindle or is it just a spacer?

Thanks!
 
It looks like the G0759 is substantially similar to the PM-25MV with DRO. I agree with your assessment on the draw bar. There have been a few threads on a better solution. Check under grizzly forum. I have been OK with it, but sometimes mutter under my breath. As to how tight, most of the folks here will say not ridiculously tight. From a mechanical standpoint you have a thread and the taper on the collet. That will exert considerable pressure. I haven't had anything slip just applying what is about a few ft-lbs. Usually using the wrench on the top and holding the spindle by hand. For larger tools, say 5/8 up and when using the chuck, I apply a little more, usually using the spindle wrench, probably up to about 20 ft-lbs. Nothing like torquing a head bolt or barrel nut. If something slips in a collet, you have another problem. Good luck
Thank you for the info, how tight do you tighten the retainer bushing that holds the drawbar?
 
Would you happen to have a photo? I'm new and have an idea but I'm a visual guy. Does your new bushing thread on the spindle or is it just a spacer?
Thanks!

I will try to remember to take a pic tonight when I get home. As for the spacer, it's just a shouldered spacer with a few thou clearance on it's OD and ID to center the drawbar in the spindle and not allow it to flop around.
 
Here's a pic of the drawbar I made.

IMG_0669.jpg
 
Another question if you guys can help. Just got done tramming it as I wanted to start making some test cuts. Out of the box it appeared the column and head are pretty good. I then mounted the vise and trammed that, it was probably the most accurate I've ever gotten a vise. I used the fixed jaw and ran the dial indicator running the x axis and it's really spot on.

However when I made a test cut using the y axis it appeared to not cut straight. I don't have that big of scrap pieces to test but when I made a cut in a 1" piece it was .005 off. Just for fun I ran the indicator along the right edge of the vise behind the movable jaw and ran it along the y axis and the indicator showed movement. I have some squares on order to help me but thought I would ask first. Again I'm new and watching as many videos and reading as much as I can. Thanks for all the help!
 
Did you have your piece of scrap at one end or the other in your vise? Reason I ask is because many machine vises, my Kurt included, don't like to clamp anything at the edges of the vise jaws without having a similar sized piece on the other side of the vise. Without the extra piece, the movable jaw will tilt slightly and this can cause problems like the part you're machining not being grabbed accurately or moving during the cut.

Just offering a suggestion. :)
 
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