# Grizzly G4003 lathe cross slide



## Mutt (Jan 5, 2023)

I bought this lathe new in 1999. The tolerences werent too good when it was new, but they are really bad now.  The bushing in the gear on the left  change gear handle went south first. I ordered a new bushing, which didnt fit, but I made it work. Years later, that handle broke at the hole that the gear shaft rides in.  Had to replace the 3 screws that hold the tail stock together  3 or 4 times. The nut that  keeps the tail stock locked, constantly comes loose. Tail stock comes out of adjustment constantly. I think the block that does the locking isn't  machined  close enough to the sides of the ways.  Replaced the cross slide gib once. Replaced the cross slide table once. Replaced the motor with a Marathon 2 hp US made motor. On / off switch went out. They had already "upgraded" that switch 2 more times and the current switch they offered did not interchange. I replaced it with a Square D  reversing switch. Replaced the standard 3 jaw chuck with a new chuck with reversible jaws. That was  a major improvement.  Cross slide  lead screw and half nut have so much slop in it, it's pathetic. Overall, if I ever buy another new lathe, I will have to do some serious research into quality of the lathe before buying it

That said, I was wondering if anyone has converted the old acme thread lead screw and half nut to a modern ball screw? If so, do you have the particulars on the conversion? What diameter ball screw? What length?  Where did ya source the ball screw and ball nut from?


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## Nutfarmer (Jan 5, 2023)

How would one engage and disengage a ball screw to thread on a manual lathe? It might work on a full cnc,but I don't understand how it would work other wise. Maybe just my lack of understanding


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## Mutt (Jan 6, 2023)

No, not the carriage lead screw, the  cross slide


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## Ken226 (Jan 6, 2023)

Mutt said:


> No, not the carriage lead screw, the  cross slide



A ballscrew cross slide would be a very cool upgrade.

If you do it, take some pics and post back.

If yours goes well, I'll copy you..


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## Mutt (Jan 6, 2023)

If I can find a source for the ball screw and nut, I sure will


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## mksj (Jan 6, 2023)

I would not be advised to use a ball screw in that application unless you plan to go CNC and/or always lock the cross slide. Ball screws do not lock in position so if you where to release the feed dial the cross slide would move away from the cutting surface unless you locked it. Same issues with using them in mills in a manual mode.


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## Huub Buis (Jan 6, 2023)

Most ball screws are right handed thread. The cross slide needs a left handed thread. A low cost, low quality, Chinese left handed, 12 mm balscrew, 450 mm long, 2 mm pitch for my lathe will cost about € 250. If the costs wheren't so high, I had tried one (lathe is CNC but still manual capable).

As already stated, when a ball screw is fitted, the cross slide will move when some load is applied.

I know that Paulimot Germany sells manual mills equipped with ball screws (X and Y) and the reviews are good. So maybe maybe, it is a want to have feature!


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## keeena (Jan 7, 2023)

@Mutt - sorry to hear about the issues; I have the same one (kinda; G4003G; I'm guessing its ~2014 model) but not the same issues as you.

One thing that might help if you're talking about the bolt/assembly which locks the TS to the ways: I added a spring between the cast clamping plate and TS to help avoid racking when sliding the TS along the ways. It may help in your case by keeping some tension on the threads. A lick of blue loctite on the bolt would probably do it too.



mksj said:


> Same issues with using them in mills in a manual mode.


I had never heard this before, so thanks! I've never been bit by it on my mill as far as I know; never noticed the DRO show movement during any side milling ops. I do sometimes lock the axis on certain ops. Either way: glad I know to pay closer attention to it.


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