# Shimming a gib



## taiwanluthiers (Jul 12, 2022)

So the cross slide gib on my lathe is really worn, so much so that when I take it out and cleaned all the grits off, I needed a 0.5mm thick copper shim on the nonmoving side to get the gib properly shimmed up.

I have no idea how to scrape and I certainly don't have any idea where to buy new gibs or fit new gibs.

Anyone shimmed a gib rather than try to make a new gib when it's badly undersize?


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## markba633csi (Jul 12, 2022)

I think it's often done as a temporary measure
All you need is a milling machine and you can make a new one 
-M


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## Cadillac (Jul 12, 2022)

Instead of copper I’d try using some shim stock. Harder material and flat. Glue to the non sliding side.


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## taiwanluthiers (Jul 12, 2022)

markba633csi said:


> I think it's often done as a temporary measure
> All you need is a milling machine and you can make a new one
> -M



How? What material would you use? Do you use specially made gib strips, or just any old 1018 steel bars? I think you also have to scrape them in too.


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## taiwanluthiers (Jul 12, 2022)

Cadillac said:


> Instead of copper I’d try using some shim stock. Harder material and flat. Glue to the non sliding side.



I looked all over, copper is about the best thing I can find.

I was hoping to use steel straps they use to hold crates together, but they are sold in 50kg rolls and I don't need that much. 

I do not really have purpose made shim stocks.


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## projectnut (Jul 12, 2022)

I did a similar job on my 1916 Seneca Falls lathe as a "temporary fix" about 10 years ago.  The intention was to fabricate a new gib within a few weeks, but 10 years later it's still working fine.  In my case I bought some 12" ready to use steel feeler gauges from McMaster.  The smaller sizes are around $3.00 a unit.  I just cut the gauge to size and slipped it in under the existing gib.  Making a new gib is still on the back burner.









						McMaster-Carr
					

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.




					www.mcmaster.com


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## Richard King 2 (Jul 12, 2022)

0.5mm thick - .020 Inches. Here in the USA we can buy Plastic feeler gage and we can slide it behind the back side.  Make sure to cut the oil holes through it.  Or use Rulon / turcite.  I have friends in Taiwan as I taught machine building for several new machine builders. I have friends who teach machine repair . rebuilding / buildings at PMC https://www.pmc.org.tw/    Email me Richard@handscraping.com  and I will forward your info to write my friends in Taichung and you can ask them in Chinese.


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## sdelivery (Jul 12, 2022)

Plastic shim stock...available at mcmaster and most tooling companies...
Cuts with scissors!
Buy the assortment


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## Richard King 2 (Jul 12, 2022)

He is in Taiwan


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## sdelivery (Jul 12, 2022)

Delivery might be a little more .....lol


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## taiwanluthiers (Jul 12, 2022)

sdelivery said:


> Plastic shim stock...available at mcmaster and most tooling companies...
> Cuts with scissors!
> Buy the assortment


How is plastic shims better than copper?


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## matthewsx (Jul 12, 2022)

I just used a random piece of plastic, worked great until the guy I bought the lathe from found the original.

John


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## sdelivery (Jul 13, 2022)

I have used brass,copper,steel and plastic.
The plastic is the easiest and most forgiving to work with.
Less burs on the cut edge and less likely to cut you while handling it.
Less expensive than copper.


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## Technical Ted (Jul 13, 2022)

I shimmed the back side of the gib for my Y travel on my Bridgeport J mill... works fine. I used steel shim stock, but any material that will hold up should work OK. It doesn't need to be glued unless you find it is moving around on you. If you cut a notch in it where the shoulder of the adjustment screw goes that should keep it in place.

Making or obtaining a replacement gib would require scraping the gib in to do the job correctly. IMO, if you were to go that far you should really scrap in the ways as well since they are worn in the middle (if you need the shim in the first place). 

Just make sure the shim is behind the gib and not installed on the sliding side of the way. It should be fine running it that way although the slide will most likely get tight on both extreme ends of travel, which you can probably live with.

Ted


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