Headstock alignment

epanzella,

At the time I bought my G4003G, Grizzly didn't make a collet closer for it. I ordered one for the same spindle size but for a lathe with a shorter spindle. I had to make some modifications to the closer, I didn't use the entire quick opening mechanism that it came with. I made some tubes and an adapter for the outboard end of the spindle and used one of the adjustment nuts as the basis for a hand wheel closer. Slower and somewhat more clumsy than a closer designed for the G. I've since used the method you describe with a rod out of a 4 foot wide Printer, That's the principal reason I think I must be very close, I had less than 0.001 average run out over 24 inches at the time.

All the best.

Olin
The Grizzly drawbar and the 5MT-5C collet adaptor came today. What a dunce I am, I should have ordered the spanner nuts at the same time, they're under ten bucks. I figured I's just make them but forgot they were metric. I'm not gonna get involved with change gears and burning up time I don't have to save such short money. I'll order them first thing in the morning. I indicated my spindle with and without the collet adaptor today. The grads on the indicator are .0005 and it was moving about half of one graduation. Unfortunately the cheap 1 inch collet I bought won't pass my 1 inch drill rod so I'm probably gonna buy a Hardinge collet for the test bar for $32. I would really appreciate it if you could post a picture of your drawbar handwheel setup. Thanks,
Ed P
 
All

I don't know if I should blush or crow, some of both I expect. Well, I did "map" one of the ends of my 1 Inch IPS "test bar". I used a Chinese granite surface plate and a matched set of v blocks. Should have been a clue when the high spot and low spot were only about a quarter of the OD apart and varied 0.012 inch. Stuck the pipe, "test bar" is just too pretentious for this gadget, in the spindle bore. Second clue that this was a doomed idea; could not obtain better than 0.001 - 0.002 inches at either the Chuck or spider, and that was only because I decided that I would settle for the opposing jaws to agree.

After that, I got my runout at the far end of the pipe, noting runout in relation to the "mapped" out of round. I plotted these on a spreadsheet and found, drum roll please for the surprise!: I was more confused than ever, a huge investment of time to learn that lesson.

I looked the situation over and decided that if I turned a narrow area round at the end of the pipe I wouldn't have to worry about the out of round. So I chucked the pipe with about an inch sticking out of the chuck and centered that up as good as I could and took the lightest cut that cleaned up.

I reset everything, centering as good as the pipe would allow at the chuck and spider. 0.037 total run out. With visions of moving the lathe and tearing it down for adjustment dancing in my head, it came to me: take light cuts and see if the runout will clean up.

It was long and tedious and with 11 inches of tube that started at about 1.3 inches OD hanging out, perhaps a bit risky. I took 0.005 cuts and did succeed without a crash.

The best news: at the end, although the finish was rough, I ended up with a maximum variation in OD of 0.0005 and I truly think that's just a result of using such poor metal. My average variation in OD is more on the order of 0.0003.

I can't say that my headstock is in the best possible alignment with my ways, but I don't think I can be very far off and produce an 11 inch long turning, one that didn't have the outboard end supported, and produce an OD that consistent.

So, I guess I will go to the scrap yard and see if I can pick up something suitable, DOM tubing if I can find it, AL if I can find a chunk of that, and do the ring test, but I am fairly confident that better metal will not produce a significantly different result.

All the best.

Olin
 
epanzella,

Well I've attached some photos, guess we will see in just a bit if I can follow directions.

All the best

Olin

A note: you can't really see it in the pictures, I used one of the adjustments nuts provided and then cut a ring out of some flat stock, bored a hole to suit, drilled and tapped six holes right at the place where the adjustment nut and ring met. The six screws also hold the piece of sheet metal to which I epoxied the sixteen wooden segments that make up the hand wheel.

Olin


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All

A further attempt to clarify my alignment issues based on a true ring test resulted in 0.004 IN difference in ring sizes. So its off to see what can be done.
I did find my manual. but the manual is for a G4002, I have the letter from Grizzly saying that is the case, apparently, I got my G4003G very soon after it entered Grizzly's line up.

All the best.

Olin
 
What is s totally frustrating for me is I repair these types of issues all the time and trying to help via the internet is so difficult when I know it is an easy fix and can't help I wish I could just come and show you, but that's not possible. Last week I aligned a 24 x 84" Nardini Lathe that was cutting a .003" / 8" taper after the operator crashed the compound into the chuck. after about an hour of work of adjusting the head straight to the bed with it's adjusting screw under the head-stock, it is cutting .0001" / 8". I used the methods I described before, not these newly invented by hobbyist methods. Your head might be be out of alignment with the bed-ways too as we have seen that happen on here a few times. Too bad you can't find a local pro or a professional machinist to come over and help you. Rich
 
All

As of this writing my head stock aligns with the ways. Using the ring test method, I was able to reduce the difference in ring diameter to 0.0001 Inches with the rings 10 inches apart, the out board end of the test shaft was unsupported. (DOM tubing, 1.625 IN diameter with 0.315 IN thick walls.) I unplugged my Lathe and took the rear gear train and quick change gear box off to get at the adjustment screws and the screws that hold down the head stock. I had forgotten in the six or so years that I've had this lathe that the adjustment are all in the back. That is correct, a cast lug along the rear edge of the bottom of the head stock, nothing what so ever to use as anchor point along the front edge of the head stock for adjustment. The Manual I have makes no mention of this, guess you just have to learn it your self. Taking the quick change gear box off was just a waste of time, especially since I had to put it back on almost immediately so as to take cuts.

I loosened three of the bolts that hold down the head stock and using a 0.0001 IN DI at the far end of the ring test piece I moved the the head stock just enough to give me a 0.002 IN movement at the end of the ring test piece. After tightening everything up and re installing the rear gear train and guards. I took some cuts and ended up with about 0.0004 IN difference in ring diameters. I was getting ready to loosen every thing up when it occurred to me to just put a little more pressure on the adjustment screw. I did so and got my 0.0001 IN result. After making sure everything was tight I said "good enough"

I then used part of the left over DOM tubing to make a spud after the manner suggested by Mr. King for head stock - tail stock alignment. Alas, I made it a little too small, tomorrow, I will turn it around and try that again.

Thanks to all who have endured this tale of learning.

All the Best

Olin
 
Thanks, you made my night....I am glad I could have helped. Good night, Richard :thumbsup:

PS: Please call me Richard, Only the Doctors or Bill collectors call me Mr. King....lol
 
Richard

Your apparent level of experience and sophistication in metal working and your status as a Moderator, elicited the Mr. King title.

As things worked out, I haven't done any work in the shop since that post, the piece that I intend to use is sitting on the Head stock when I go back.

Thanks very much for your encouragement.

All the best.

Olin
 
FWIW, this thread should be in the Grizzly subforum.

Olin and all, I'm necroposting this in hopes it'll help others with their G4003G. A friend just got a G4003G and asked me for help in aligning it. I didn't have to adjust my headstock but on his it appears it might have to happen. We've ran my machinist level up and down the ways with the level sitting on the crosslide perpendicular to the ways. After shimming between lathe and stands the bubble doesn't even move traversing up and down the ways. He let it sit for almost two weeks and we just did the 2 collars test last night. On a 2"Dx12"L 6061 aluminum rod in a 3-jaw chuck he's getting 0.00325" over 10" with the larger diameter at the tailstock end. I'm wondering if this it too much stick out though. I just called my buddy and advised to take the bar down to 7" and do the 2 collars test again. I just received a roughly 12" sched 40 pipe that I'm going to take over to his house and try the test with. Maybe the 2" 6061 rod is too heavy for that much stickout. Any help or thoughts on this whole shebang would be appreciated.

Olin, did you have to really loosen the 2 bolts on the outboard and inboard side right under the spindle or just crack them? Also, did you have to mess with the 4 bolts on the rear of the headstock (above the motor)? Thank you.
 
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