gib material

I interested in learning more about gibs and the materials that can be used.

The application is for a hardinge taper attachment shoe . I plan on using oil hardened tool steel although I think gibs are usually cast iron????


thanks
Markus

Larger gibs are usually cast iron, smaller ones brass or bronze.
You want the gib to wear out, not the sliding member or the slideway.

Hardened too steel wouldnt be good. Get a piece of cast and make it from that. It has one of the lowest coefficients of friction for a metal. Brass will work too but not as slick.

Hardinge gibs are made of grey iron.

Other makers have used other materials. O-1 tool steel is certainly the easiest material to use for flat gibs, since it can be bought in most any size you would likely need, leaving very little stock to remove.

I have been thinking of adapting a ball slide assembly to the taper attachment for my TFB-H lathe (same as the HLV-H attachment). That solves my missing follower and gib problem, and will probably work better anyway.

Larry

Well while on this subject where do you find suitable CI material to make gibs.I just finished a compound and swivel for a 12X30 Hendey and ended up using brass as the gib material because I couldn't find casr iron anywhere near the size I needed.

Look up Dura-bar or continuous cast grey iron bar. It is sold in many sizes of round and rectangular shapes.

Or, as I have done, find a junk yard (metal recycling facility) that will let you walk around and pick up odd bits of metal for use in your shop. Look for chunks of iron that were machined, proving that they are capable of being machined. They can be bandsawed to near your required size and then milled, surface ground and hand scraped to make whatever machine part you need. But old window sash weights, for instance, were not meant to be machined and might be really bad stuff.

Larry

Hello Markusfu,

Call me. I may have a piece of DuraBar cast iron you can make your gib from.

Brian

I used SAE 954 Aluminum-Bronze. Very enjoyable to work with, but required noticeable tool pressure to cut. It even scrapes nicely.

I have a piano string frame I'm looking for an excuse to cut up. It's heavy and I keep having to move it. WWQ

VersaMil manufactures machine tool slides, and I am going to start running GIBS from patterns I have. I have gib patterns for gibs up to SIXTY INCHES LONG! I currently stock smaller lengths of tapered gib castings that are 9 inches long and already tapered. I'm having 20 inch gib strips poured now. I've always heard people talking about just getting Dura Bar but then when you cut to the chase and call up the distributor, they don't stock much, and DURA BAR doesn't seem to make the stuff for the steel supply yards. They want you to order LOTS of it. Certainly not a piece for a gib. I was considering making machine tool slides out of Dura Bar rather than using my patterns because of lead time at the foundry. I CAN WAIT! Besides the three times the money, I'd be machining off a ton of iron to get what I needed.

It's kind of a pain to deal with little orders for me, but if someone needs small amounts of Class 30 iron, in short lengths, give me a call. Also because I stock so many machine tool castings now, I have a rather large variety of cast iron round bearing retainers. These are castings that range in size from 2 inches in diameter up to eight inches, some with cored holes, some solid. It's kind of nice to design something and just go out to my shelf and grab some almost net size casting and make something different out of it. The bearing retainer castings are all Class 30 grey iron. My slide patterns for the bases are 8 feet long, and sometimes I get an order for a six foot slide. Well I end up with cut off piece too short to make anything out of, but a great source of cast iron to use for other items. www.versamil.com

Greetings All

I got the idea that much of the work adjusting and restoring machine tools related to removing the wear in VEE slides and probably the taking up of wear with a new larger gib.

There is no shortage of machine tool restorers browsing these here parts and consequently, I suspect, a wealth of knowledge in this area.

I would think that the most essential machining process for a gib would be surface grinding. I imagine there would be lots of gibs needing to be tapered also. Agreeing with the proposition that it is preferable to have the gib wear before the Vee then a softer material is indicated.

But to use bronze or a copper alloy would present troubles in holding the gib/key for surface planing/grinding.

Obviously cast iron being ferrous will be held to a magnetic chuck, and yes it would be somewhat slippery but is it a compromise?

No need to grind. Mill it, file it, scrape it. Hard part for me on the compound gib for the SB10L at the museum was figuring how to hold it on the bench for scraping. Ended up with little finish nails around the edges. Still no fun.

Holding even non magnetic pieces in a surface grinder is easy. You just make a nest for the part out of pieces that are. BUT even cast iron gibs I grind without sucking them down. I want them straight in their natural state. The magnet sucks down warped gibs and when you're done grinding you have a thinner warped gib. I grind tapered gibs by just setting one end down on an accurately sized spacer for the taper and providing blocking around the gib so it can't move. Fortunately I make a lot of two sizes of gibs, so I have a method to make them quickly.

Taper Gibs for Machine Tool Slides

I started using Antyfriction Coating about 30 years ago and it made my professional life very much easier .I take a pice of Brite Bar that suits my dimension and prepare the Ends for the adjusting screw to work against the Steel not to damage the Antyfriction material .I Coat the Slides with release agend.I Cast the back first on my Surface Plate coated with release agend approximately 4mm thick.Grind by hand all Antyfriction coating to required size. Mix appropriate amount,a bit more then necessary,lay the gib against the moving part and slide together entill end of gib matches adjusting Screw.A blow with a soft hammer will release the components,Grind the flashings with a smal angul grinder with a sanding disc drill the oil hole and grind oil grooves being careful ,use a piece of wood underneath not to break the coating on the back.
I found this method fantastic,also after a long time of wear all you have to do is coating that face again,no more scraping, the Antyfriction Coating Material dose not shrink,dose not absorb any moisture,dose not stick slip,and can run a long time without lubrication.
The Brand I am using is called SKC Gleitbelag Technic ,made in Germany

Brian@VersaMil said:

Holding even non magnetic pieces in a surface grinder is easy. You just make a nest for the part out of pieces that are. BUT even cast iron gibs I grind without sucking them down. I want them straight in their natural state. The magnet sucks down warped gibs and when you're done grinding you have a thinner warped gib. I grind tapered gibs by just setting one end down on an accurately sized spacer for the taper and providing blocking around the gib so it can't move. Fortunately I make a lot of two sizes of gibs, so I have a method to make them quickly.

Click to expand...

and another way is to dress the needed angle on the wheel. double back tape or blockk in .. both ways are good.
good to wet grind even if with a hand spray bottle

I made a pair for a A42Traub that was purchased in pcs. The originals were lost. I used 416 heat treated 28 to 32RC material, milled them from round stock. I think I did surface grind them before they were finished. My trick is to grind long stuff on parallels to eliminate the bowing. Too many years ago to remember all the details, but the gibs are still in the machine and never gave a lick of trouble. 416 with the sulfur inclusions is easy on the mating wear surfaces so it was not a bad choice. I never adjusted the gibs after installing in 30 years of occasional use.