Getting my new G9729 Grizzly up running! Help

[LX Kid]

WHEN IT RAINS IT POURS!! Removed the cross-feed gear box and sure enough it was gunned up with casting sand and other dirt, etc. The problem was in fact the hand crank drive gear as it was filthy and rusty. After cleaning everything with solvent, lubeing and re-assembly "I've got metal grit showing up on the lead screw!" There are only three things that could leave a deposit on the lead screw being the two pinion gears and half nut. The metal left on the lead screw is not brass so that leaves the two pinion gears, which the lead screw passes thru the center of. I did not remove them but they were cleaned, lubed and were functioning properly. There is no adjustment and is yet another mystery to me. Don't have time, or desire, to disassemble today due to the frustration factor and it's 90 degrees out in my shop. Here's some pics.

[LX Kid]

Starting to realize why a lot of people don't like the Grizzly 3-In-One's. However, I've had great success with my Grizzly mill. Thinking of drilling and tapping another table lock between the two existing ones. Seems "sloppy table" problem starts when the back table lock leaves the end of the gib. Gotta be a better way with dealing with the table movement. I saw Torch's modification but a little beyond my expertise to do.

[Torch]

Here is my gib assembly:

The two large head bolts "1061" serve to position the gib. Actually, it's not shown but the front one actually engages a notch in the gib and can pull or push the gib. Both the gib and the dovetail are tapered but in opposite directions so it's like sliding two wedges against each other, expanding and contracting their total width.

Here is the relevant parts from the on-line manual for your machine:

It looks very, very similar. Oddly, there's only one 726 shown, but you said you do have two, correct?

Ok, now here are the two screws on the side of yours that correspond to the locking screws on mine (since replaced as per the thread above):

Now, one last look at your manual. In the parts listings, 707 is listed as "Locking Screw" and 726 as "Adjusting Screw".

I realize that this differs from the text of the manual:

Cross-slide Gib: The gib on the cross-slide is adjusted by tightening or loosening the 2 wing bolts located on the right hand side of the slide (see Figure 74). These will also serve as table locks."

I think that is wrong. I think that it was written by an English-speaking technical writer who misinterpreted the original Chinese directions. There are other errors and omissions in the manual, which support that view. For example, no mention is made of the extra set screw (732/733 combination) when adjusting the table gib.

I could be wrong. It is possible that the manual I am looking at represents some specification changes from your earlier machine. But I think it's worth close investigation. Loosen the rear 726 off, loosen the two 707 screws off and adjust the front 726 in and out to see what effect it has on your cross-slide. Or take the gib out and measure the thickness of each end.

That's just my 2¢. Worth every penny.

[LX Kid]

Thanks Torch for a very thorough examination/evaluation of my problem. Maybe tonight I'll tear it back down for the metal on the lead screw. My parts diagram is identical to yours. I know it hasn't been mentioned yet but the heads of the two #726 screws are elliptical. Parts 734 and 735 are one piece on mine. Set screws #732 and 733 are on the right side and is only one set screw.

I'm going to strain the solvent thru a coffee filter and post a pic of all the casting sand and grit that was in the apron gear box. I dread to thing what might be in the headstock gear box!

If it weren't for the short 20" center-to-center and the CNC portion of my old Shop Task 17-20, I'd be missing her really bad right now. Even though it was made in 1993 it was/is a better machine.

[LX Kid]

I WAS WRONG! At least twice. The gib is tapered and the metal was my half nut being eaten up. Can you explain what happened to the half nut? "Seems" like it was just a straight forward sliding the lead screw thru while aligning the the keyway into the lead screw slot. Guess not!

[LX Kid]

Looking at my parts breakdown #748 is the half nut. Is it also called the "pivot?" Also #754, shaft with gear, is it called the "shaft pinion?" There naming for part nomenclature seems a little funny to me! When I order I just want to make sure I'm ordering the correct parts. My luck will be they are not in stock and have to come from China in a container ship.

[Torch]

Set screws #732 and 733 are on the right side and is only one set screw.

Not right AND left? I wonder if that could be part of the problem then. Mine has two pairs. Pressure is equal on both ends of the gib. Much like the problem you noted with the cross-slide when one lock screw passed the end of the gib, having an adjustment screw on only one end of the table gib seems like a Bad Idea.

I see you posted while I wrote the above.

Looking at the close up, I think there might be two things. First, I would suspect the asymmetry could be caused by sharp edges on the lead screw where the groove is milled. Since the feed is most often towards the chuck, then released and wound back by hand (or in the case of threading, run back but without any cutting pressure) it would wear most on one side of the half-nut thread.

Second, it looks like there might be a false thread. Possibly just an artifact of the above asymmetrical wear, or possibly someone has tried to engage the lever at the wrong moment (eg: trying to time the action to a threading dial position). I personally avoid engaging the half-nut with any force. I "feel" it into place gently while rotating the carriage wheel, then start the lathe when I know it's properly engaged.

If Grizzly can't supply you with a new one, BusyBee had them in stock when I needed one two or three years ago. I can check to see if they still do. I bet they are the same.

[Torch]

You did it again, damn you.

Yes, 748 should be the half-nut. I have no idea why they are calling it a "pivot". Wrong name? Wrong index number? I think I'd want to clarify that with Grizzly before plunking down any cash.

754 sounds ok, it's a pinion gear on a shaft. Makes sense to me.

I might have bought 2 half-nuts. I'd have to check.

[LX Kid]

Thanks Torch and maybe I should get two half nuts. Seems like I'm the first to run this machine. I was not eating the half nut before "I" worked on it. All I did today was clean the shipping grease off the lead screw and put some N0. 1 oil on when I put the apron gear box back together.

Anyway it's been a terrible day in the shop and I'm going to bed. Good nite!

[Torch]

I've got another 8-1/2 hours before my shift is over and I can go home to bed. Enjoy!

[LX Kid]

Wow! I just can't believe how much a half nut and shaft gear cost! Grizzly charged me $71 for the half nut and $17.50 for the shaft gear. REALLY! $71 FOR BRASS HALF NUT!
Anyway, they will be here probably Monday or Tuesday.

What could I have done differently, when assembling, to keep from ruining my half nut? I wonder if I wire wheeled the lead screw, along it's key way, would keep such sharp edges from cutting up the half nut. (Those sharp edges already cut a couple of my finger tips.)

[Torch]

I lightly dressed each and every edge along the lead screw slot with a file.

It took a while.

Now I'm off to bed -- it was a long night. Perhaps not quite as long as dressing the dang lead screw, but long enough nonetheless.