Problems machining brass - Bad finish !

Chris

I'm not sure why you would want to use the internal jaws to grip a smaller diameter but regardless the last post does sound as if you are making some progress.

Do you have a grinder that you can use to make youur own cutters (or at least modify existing ones?

If you put some details on your 'profile' so that people here have an idea whereabouts you are located it may be that someone local will offer some practical help.

As others have mentioned you need a tool with no top rake for brass. with a oilstone or a diamond file you could quickly take the rake off just the very the tip of even a steeply raked tool.

Ian P

Chris

Have you tried adjusting the headstock bearings? if they are not properly adjusted it will not help your problem. Regarding a H.S.S. tool for brass If you get a suitable sized piece of H.S.S. for your lathe and the grind it with front rake and side rake of about 10 deg and angle the front of the tool to about 20deg stone a small rad on the tool at the junction of side and front rakes, then stone the top of the tool which should be dead flat (negative rake) and set it to cut on dead centre that should do the trick, and at the cost of less than a quarter of a ready ground tool.

I second Dusty. For brass I use HSS just ground on the end and one side, left as is on top. I would use more like 600 rpm for 1 1/2" bar and expect a shower of chips but a decent finish.

Neil

Hi Chris

Long time ago I watched a pillar drill have one after the other of the drill bits be sharpened..

Problem was the beastie was running in rev...

I had a problem similar to this 2 weeks ago but i was machining some 36mm round bar for a T&C grinder .

It ended up being a belt problem as some of the lube i used on the back gears had flung off and contaminated the belt .

The belt on this machine at the moment is one of those horrible and expensive little vee belts that are only 4 or 5 mm across so it took only a small amount of contamination to cause some slippage .

After a clean all was well again but i think i will peg this system and go for a toothed belt and a decent variable speed set up so no more belt changes .

Ian

Chris,

Read your "my messages". I have sent you a message.

Ketan at ARC.

Edited By wheeltapper on 17/02/2012 13:11:41

Hi , Just a message to say thanks to everyone who contributed on here and especially to Ketan from Arc Euro Trade who called me personally. I have now solved the problem with all the help.

After trying all the different cutting tools i decided to strip the headstock and found some play in the front ball race bearing , the rear one seemed ok. I purchased a set of new taper bearings from Arc and fitted these.

As has been already mentioned the difference is amazing , the lathe runs far quieter , no vibration and the finish using the tipped tools is now superb on the brass or steel.

Would definitley reccomend the upgrade.

Thanks again everyone

Glad to read you got it sorted.

Ketan