Getting started with tapered gib conversion on mini-lathe.

I seen this thread and would like to make a comment about brass...

brass is not a bearing material it will gall...bronze, cast iron, Are bearing materials

not trying to hurt feelings here but IMO this will not work very well for very long..


Lawrence
 
In my opinion the brass will work as it is harder then Turcite I have seen several machines built using brass gibs. I hope the gibs were fit by scraping and new oil groves were machined in them. I recommend a diagonal line versus a straight line groove. I would also think you need to think about installing way wipers on all your ways and gibs. If any of you care to learn about scraping check out my forum. If the factory had installed the wearstrips that you removed, it looks like a very poor job, who ever did it. We are discussing Rulon and tapered gibs in our forum now.

Many times you get scoured ways because the machine did not get proper lubrication and the way wipers failed and let the dirt and chips under the ways. Rich
 
In my opinion the brass will work as it is harder then Turcite I have seen several machines built using brass gibs. I hope the gibs were fit by scraping and new oil groves were machined in them. I recommend a diagonal line versus a straight line groove. I would also think you need to think about installing way wipers on all your ways and gibs. If any of you care to learn about scraping check out my forum. If the factory had installed the wearstrips that you removed, it looks like a very poor job, who ever did it. We are discussing Rulon and tapered gibs in our forum now.

Many times you get scoured ways because the machine did not get proper lubrication and the way wipers failed and let the dirt and chips under the ways. Rich

Hello Richard for someone who seems to be intelligent ...your not thinking clearly here......I repeat brass is not a bearing/sliding material it will gall against metal/cast iron etc.....this is a fact!!!.....dont believe me!!! look it up in your metallurgy book

why would anyone use something that is not as good or even as good as cast iron .....

cast iron has been used for bearing material for over 100 years!

Hell lignum vitae is a wood that would be suited for this job!
 
I just want to apologize to the OP...Like i said in my first post not meant to hurt feelings but facts are facts



Lawrence
 
David,

I just emailed Dave Kruger to come and comment on this issue with the gib. I see Dave wrote his Instructions in 2001 on how to convert to taper gibs and he recommend using brass. I also see Rick is an expert on the Mini-Mill Forum. I think his opinion here would be of value and how the brass gibs he made back in 2001 are doing. Here is a link to the info you also provided to the group. I think you did a bang up job on the gib and love the knurled gib screws. There are several materials manufacturers use to make gibs and one is brass.
Rich

http://warhammer.mcc.virginia.edu/ty/7x10/vault/Lathes/7x10-7x12-Projects/TaperedSaddleGibs/
 
Hi Sk8ter,

As the material for making a bearing, you are perfectly correct. As a "bearing surface" for a slow moving saddle working against a lathe bed it is fine. It is softer than the cast iron. The gib is a sacrificial surface. It wears, you readjust it. They have been using brass in this application for a few hundred years that I know of.
 
Hi Sk8ter,

As the material for making a bearing, you are perfectly correct. As a "bearing surface" for a slow moving saddle working against a lathe bed it is fine. It is softer than the cast iron. The gib is a sacrificial surface. It wears, you readjust it. They have been using brass in this application for a few hundred years that I know of.

Thanks for your reply....everyone has opinions

I call :whiteflag:

just so everyone knows I am not here to start crap just wanted to inform and IMO this is what the forum is about

I would like your honest experience in using brass in this situation at a gib....so please carry on


Lawrence
 
That's fine. I have a very thick skin and don't take it personally. Things always sound more harsh in text than they do in person.

Initial impressions:

Once past the initial break in, I have not had to adjust them again yet. It rides very smooth and without any noticeable play. I started with just a belt sanded finish on the brass and they have lapped in. Lots of metal in the oil at the beginning. I give it a quick squirt from the oil can each time I start using it and every once in a while as I am working on it. When it is not cutting, the gibs don't bear against the ways at all since they come up from the bottom and just keep it from lifting under load.

It has been a wonderful upgrade but in all honesty, just about anything would be an improvement over the original system. I probably would have been just as well off with some made from delrin. The little lathe just doesn't have that much power and it doesn't take much to hold it. The little Sherlines do just fine with plastic gibs. As to the tapered gib concept itself, I can't say that it really is much better than if I had just put flat gibs and put set screws on the underside of the bracket. It was a bit fiddly to make them and they don't need frequent adjusting. Only the back one gets a lot of pressure on it normally and it is easy enough to reach for adjustment. The front gib only gets a load on the occasional time I am cutting with the spindle in reverse.

I made a few mistakes in the process. When I made the rear gib, I cut the adjuster slot too close and the gib rides beyond it's range. Next time I tear it down, I will make a new gib to fit. It will only take a few minutes. As it is, I am in no hurry. It works fine.

The next upgrade will be the gibs on the cross slide and the compound. The ones on the compound are more of a problem than the ones on the cross slide. LMS sells a brass set already cut with the right geometry as an upgrade and I might order them if I am ordering something else or I will make some myself. I just don't have any suitable stock right now.

Thanks for your reply....everyone has opinions

I call :whiteflag:

just so everyone knows I am not here to start crap just wanted to inform and IMO this is what the forum is about

I would like your honest experience in using brass in this situation at a gib....so please carry on


Lawrence
 
Guys,
Not to be heavy handed or be "The Big Brother"......BUT....... This thread is an excelent showcase of a mans skill and handy work. His selection of materials is his decision and is based on whatever research he did or did not do. Getting into the semantic argument of the best bearing material for this particular application is POINTLESS. He has made a fine demonstration of Gib strips that I would gladly use in my machine any time, the quality of workmanship is outstanding, the presentation is also excelent. Will brass wear? Yes, but so will a diamond so lets applaud the effort and boost the fellow up for doing good work. If he needs to replace them in 2 years or 20, who cares.....He has demonstrated his ability to make more when he needs them if that issue ever arises. Lets get back to the original discussion and leave the material as ......imaterial. Nuff Said?????

Bob
 
It's good that this thread has cooled off a bit. One of the founding principles of this place is that it is different in the way disagreements are handled, when and if they occur. In the long run, no one generally win an online argument, and at times even enemies are made when the opposite could just as easily be true. We want this place to be a place where people are comfortable asking questions, giving answers, no matter if the question is simple or complex. We have quite the variety of experience here, and that means an equally varied set of answers on some subjects. We expect (and the User Agreement states) that we all treat each other with respect. Anything short of that is a disappointment, especially if it comes from the professionals among us. But any member should treat others as they would like to be treated, and has the right to expect the same from everyone else.

I'm glad that the parties involved have simply agreed to proceed with the project, and let everyone learn how this particular example works out. None of us knows it all, and it will stay that way. We simply don't live long enough. But we can make the best use of time while we're around. Have fun everybody!
 
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