# Grizzly G4003g Compound/cross Slide Locks



## kplyler (Feb 26, 2016)

Recently acquired a G4003g , used but in great condition.  The cross slide lock set screw was missing, so I replaced it.  But in noticed turning the cross slide and compound lock set screws all the way in only adds a little resistance to the gibs?  There was a recent related thread on this: http://www.hobby-machinist.com/threads/g4003g-lock-on-the-compound.25680/ what I am wondering is there a pin or something that goes beind the set screw that actually does the tightening?  I have to thread them in a long way before the bind.

Thanks


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## Bob Korves (Feb 26, 2016)

I just looked at the manual:
http://cdn0.grizzly.com/manuals/g4003g_m.pdf 
On pages 95 and 96 of the manual the cross slide and compound parts are shown.  It only shows gib adjustments for the cross slide, no set screw.  The compound shows a set screw along with the gib, no other parts.  I am surprised that the cross slide does not show a locking set screw.  Perhaps that was a mistake in the manual.  Gib lock set screws will not tighten the gibs to where they cannot be moved with the lead screw handle, but they should get pretty tight when you lock them down with the set screws.  On page 71 it explains how to adjust the gibs.  Making that adjustment first might give you better locking of the slides.


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## rgray (Feb 26, 2016)

Some ideas here. 
http://www.hobby-machinist.com/threads/can-i-lock-the-cross-slide-or-compound.25989/#post-229615

Mine got covered by a DRO scale and I built the front lock and really like it.
Never thought it very good to just push in the center of the gib like they do with the set screw.

Your set screw hole may not be tapped all the way through. There is nothing behind them on my lathe (same as yours)


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## tmarks11 (Feb 26, 2016)

rgray said:


> Never thought it very good to just push in the center of the gib like they do with the set screw.



Better than poking at the edge of the dovetail on the cross slide and indenting it or placing a burr on it that will wear a groove in the gib strip. Pretty much every manual way that has a tapered gib locks the cross slide by pushing on the gib strip.

To me, easy access to cross slide, compound, and carriage locks are important.  You can buy some very decent handles from McMaster to install instead of the set screw to make it convenient to operate.


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## kplyler (Feb 27, 2016)

Bob Korves said:


> I just looked at the manual:
> http://cdn0.grizzly.com/manuals/g4003g_m.pdf
> On pages 95 and 96 of the manual the cross slide and compound parts are shown.  It only shows gib adjustments for the cross slide, no set screw.  The compound shows a set screw along with the gib, no other parts.  I am surprised that the cross slide does not show a locking set screw.  Perhaps that was a mistake in the manual.  Gib lock set screws will not tighten the gibs to where they cannot be moved with the lead screw handle, but they should get pretty tight when you lock them down with the set screws.  On page 71 it explains how to adjust the gibs.  Making that adjustment first might give you better locking of the slides.



Ya, the set screws I was talking about are on page #96, 645 and 648. Its also interesting there is the 646 locking nut.


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## Bob Korves (Feb 27, 2016)

648 is the compound gib locking screw.  I do not think 645 is for locking the gib, rather for retaining the lead screw nut, 607, unless I am missing something there.  That lock nut confuses me a bit.  I still do not see any provision in the parts drawings for locking the cross slide, other than adjusting the gibs up tight.  Usually there is a screw on the right side of the cross slide that presses on the gib, like the compound has, and if you do not have one it could fairly easily be added...


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## planeflyer21 (Feb 27, 2016)

This is a footnote in the Grizzly manual for the 4002/4003:

"When adjusting gibs, keep in mind that the goal of gib adjustment is to remove unnecessary sloppiness from the slide’s movement without causing them to bind. Loose gibs may cause poor finishes on the workpiece. Over tightening may cause pre- mature wear."

I'm thinking Grizzly feels they don't need a cross slide lock.


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## tmarks11 (Feb 28, 2016)

planeflyer21 said:


> I'm thinking Grizzly feels they don't need a cross slide lock.


It is hit and miss.  Maybe they did a design change, but the earlier ones had a threaded hole on the tailstock side of the cross slide that was meant to be a cross-slide lock.


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## planeflyer21 (Feb 28, 2016)

tmarks11 said:


> It is hit and miss.  Maybe they did a design change, but the earlier ones had a threaded hole on the tailstock side of the cross slide that was meant to be a cross-slide lock.



On the horizontal or vertical surface of the cross slide?


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## tmarks11 (Feb 28, 2016)

On the vertical surface on the tailstock side of the cross-slide, should be a threaded hole, maybe with a allen set screw in it.   If it is anything like mine, the set screw had a long pointed tip on it.  The hole must not be drilled all the way through with the outer diameter.

Since the manual still identifies the cross slide lock (pg 43), I suspect that if it is now missing, that this was done as an oversight rather than on purpose. It is crazy not to put a cross-slide lock on a lathe.  If yours is missing it, I would call Grizzly CS and complain.  Maybe they will ship you a new cross slide.  Maybe they will give you a couple free crappy carbide bit tools.  Maybe they will tell you to pack sand! But there is a chance they will feed that tidbit back to their QC folks and correct the oversight on future orders.


On my lathe, I replaced all the allen set screws in those locks with handles from McMaster, as you could see in my previous post.

The SHCS in the middle of the horizontal surface of the cross-slide is what attaches to the leadscrew nut.  The manual discusses this on page 70:



If I didn't have a cross slide lock, I would pull off the cross slide and drill it out and tap it.  Not much of a job.  Just measure twice and drill once.


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## ch2co (Feb 29, 2016)

I've noticed the on my cross slide, the locking screw and the gib adjustment screws
all have a small free floating pin placed in the hole before the allen screw in threaded 
in. This allows tightening without a screw scarring the the mating surface.
The pins (small diameter steel rods) also have an angle cut on the end that engages
the gib so as to evenly rest against the angled side of the gib. Maybe this is
common knowledge? If so, then, nevermind.

CHuck the grumpy old guy


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## tmarks11 (Mar 1, 2016)

nope, not common knowledge (at least to me).  My allen set screws were turned down on the end to a narrow round tip, so I am guessing no intermediate pin.  But that would be a good idea, especially making it out of bronze.


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## tomh (Mar 1, 2016)

This shcs screw is in a adjustable bushing that moves up or down to properly align the feed screw and brass nut, the set screw on the headstock side is what locks the bushing in place.  If this has been said already than please over look this.


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