Gib tightness ?

[JimM]

Hi guys

How tight should the gibs be on the milling machine. I've got an old Elliott Juniormil which has a 28" table and if I grab the ends of the table and rock it back and forth I can feel the table moving, if I put the gib lock on the table feels solid. I've tried tightening up the tapered gib but although I've screwed the adjuster in quite a lot the table still rocks. Do I keep going until the table feels solid or will I never get it to that state because the leverage I apply at the table ends is more than the slideways can resist ?

Cheers

Jim

[ieezitin]

Jim.

Here is a link on the subject. Just scroll down to gib tightening on the page. He explains it better than I.

http://www.thewarfields.com/cnccookbook/MTCNCDictGangtoKnee.htm

He pretty much has covered the basics for you in the article. The way with the test indicator is the normal way to get a view but remember its only giving a little inside information on what’s going on inside the table.

Setting gib screws and applying pressure is really more of a feel and understanding of your machine, playing around and taking notes while playing with settings will be the only way of finding out what the machine likes or not. Assuming your slides and keys are not wrecked.

This is one subject that’s hard for a lot of people. I will share this with you, while setting gib keys I work from center out and run the saddle / table and feel with my hand by actuating it, I apply a push pull method like you and try to eliminate as much backlash or unwanted travel. I own a Logan lathe and I get a nice tight yet smooth action by tweaking the gib-set screws on the other hand my Atlas lathe will not cooperated and either has a little slack or will bind up, with the atlas I just know it and build it in my machining maneuvers.

Hope this helps     all the best.                 Anthony.

[NickG]

Thanks for that Anthony, sure this will be useful to a lot of people.

Nick