PDA

View Full Version : headstock bearing shimes



tanii51
12th Mar 2009, 06:58 PM
i have a model c hercus thats got 5 thou vertical play in the shaft at the opening of the 3 jaw chuck.(piece of 25mmshaft inserted in jaws) can i remove some of the shims to reduce it

aljunk
13th Mar 2009, 02:52 AM
I think you just have to make the adjustment on the back end of the headstock if it is a roller brg headstock. There are 2 tapered roller brgs so tighten the adjuster to set the proper preload (basically zero clearance i believe), remember to loosen the collar locking setscrew first.

tanii51
13th Mar 2009, 07:52 AM
thanks this one is the plain bearing type not the roller bearing

pipeclay
13th Mar 2009, 10:40 AM
I suppose you could try but if the clearance is due to wear you will possiblly by putting your spindle out of true.
If the bearing area is worn and you remove the shims you might end up jamming the spindle as well,is there anyway to tell if your wear is on the top or bottom of your bearing.
May take a little bit of effort but might be worth removing the spindle and checking the bearing areas for wear if removing shims has no effect.

You could at the moment set up a parallel bar in your chuck running true and place a dial indicator on top of it and check to see if it reads the same along its length,would only need to be 200/300mm long.
If there is no great variation along its length would probablly indicate the top of the bearing surface is worn and not the bottom.

blackfrancis
13th Mar 2009, 11:40 AM
I would say you should be able to. Any idea why it's worn? Has it been run too fast? Or has it been run without oil? You don't want to tighten it up and have it wear more.

The bearings have a ton of meat around them, If you're able to get the spindle reground, or fixed up some other way, you can bore the headstock bearings out and put bushes in them. I did that once, it worked a treat.

If the lathe is rough it's probably best not to bother fixing it up unless you want to do a complete reco. If you're going to reco it's better to start with something that's reasonably good anyway.

tanii51
14th Mar 2009, 08:17 AM
think ill leave evry thing as is till i learn how to use it
first things first learn how to sharpen tool bits so they cut properly ( google is my friend:U