Lathe problems

Charl · Post by **Charl** » Mon Jun 01, 2009 12:22 pm

My lathe is about 0.5mm out. How do you shimmy a lathe, first of all, and how do you measure exactly by how much it is out?
Any help would be appreciated!

Frank · Post by **Frank** » Mon Jun 01, 2009 2:08 pm

What is out and where? In relation to what - The bed, the tailstock, the centre line - The X-axis or Y-axis? Where on the lathe do you want to shim it? What make of lathe? Need more specific info.

Charl wrote:...and how do you measure exactly by how much it is out?

You probably need something like this: http://www.use-enco.com/CGI/INPDFF?PMPAGE=355

ckr · Post by **ckr** » Mon Jun 01, 2009 2:28 pm

Different lathes may require a different remedy. This doc touches on quite a few problems and possible repairs.

http://jlrodgers.com/pdf/lathe_alignment.pdf

Hope it helps somewhat.

Charl · Post by **Charl** » Mon Jun 01, 2009 3:35 pm

Sorry for being vague

, had a very rough Monday.
It is a very old Eglish model (still have one leather V belt) and the tailstock is a bit low in relation to the headstock. I don't know much about metal lathes, but I would suppose that you need to somehow raise the tailstock by inserting something between it and the bed?
Will try and get a photo tomorrow when I'm not half asleep

Frank · Post by **Frank** » Mon Jun 01, 2009 8:43 pm

Get an assortment of Shim Stock like this and cut to size with scissors: http://www.use-enco.com/CGI/INSRIT?PMAK ... PG=INLMK32

The other alternative is to have the foot/base of the tailstock built up (with weld?) then ground down to the correct height. This would probably require a professional machine shop, because the foot/base of the tailstock has to be perfectly parallel to the centre line of the tailstock.

The easiest way to check spindle/tailstock alignment is to put a dead centre in both the spindle and tailstock. Place a stiffish piece of paper between them and run the tailstock centre almost up to the spindle centre so that both points are just supporting the paper. When the paper remains perfectly perpendicular to the centre axis, the spindle and tailstock are aligned.

Frank · Post by **Frank** » Tue Jun 02, 2009 3:16 am

ckr wrote:This doc touches on quite a few problems and possible repairs. http://jlrodgers.com/pdf/lathe_alignment.pdf

His solution of shimming just one corner of the head or tailstock could result in introducing more runout. You need to shim one entire side of either the head or tailstock to keep the centre line running dead straight through the spindle to the end of the tailstock quill.

Charl · Post by **Charl** » Tue Jun 02, 2009 11:29 am

Thanks for all the advice, guys. Appreciate it! Now all that remains is to find a place where I can get shim stock in SA!