Best way to machine ball screws?

[gavztheouch]

Thanks,

I think they are Chinese, they are branded Gten. Definitely not top quality whatever they are?

What sort of carbide holder and tips would you recommend? I am looking to try a carbide holder for my Myford so a nice general shaped holder would be ideal, but I am new to lathes and don't know what that would be?

Thanks for the ball screw offer, but I ordered some extra length on each ball screw to try it out.

The only problem would be I have a HSS threading tool and the 12 dia might still be too hard to thread with that.

[Jonathan]

Thanks,

I think they are Chinese, they are branded Gten. Definitely not top quality whatever they are?

I recently machined some Gten 15mm ballscrews ... they were a nightmare compared to the standard Chinese (RM1610, RM1204 etc) ones I've done. The metal was still very hard at 12mm, so no chance of getting anything like a good enough tolerance/finish to fit a bearing unless you have a cylindrical grinder as John S suggested. Instead I just annealed the ends of the screws using the wet rag technique to limit how much is annealed, then it was easy. I didn't want to go down the putting bar into the ends of the screws since these ballcsrews were going to be put in tension - not sure if they'd hold up to that?

This is what it turned out like:

[JAZZCNC]

What sort of carbide holder and tips would you recommend? I am looking to try a carbide holder for my Myford so a nice general shaped holder would be ideal, but I am new to lathes and don't know what that would be?

Will need the smaller holders which often have CCMT tips. The holder I use is SCLC with CCGT or CCMT tips and this the company I use. http://www.cutweltools.co.uk/home/la...g-tool-holders
They arn't the cheapist but they are quality, Can't remember the number of the tips I just told them what I wanted to do and they sent me the tips. They've worked a treat on hardened screws I've done thou I dont get more than 2 screws per tip (1 screw per tip turn) and it's slow away stuff. ( I use them on softer materials like ALu or delrin when the edge goes off on hardened stuff).

BUT . . . If your new to turning then I strongly urge you to practice on some scrap before you try machining ballscrews for real.!! . . . You don't often get a second chance.!!

Same goes with threading, if you haven't done much threading then get plenty of practice before attempting on ballscrews because like John S mentions the hardening hisn't always consistant so can easily have soft and hard spots which can make threading a real bitch, esp on a small machine that flexs.!! Again I use indexed tipped threading tool, to be honest I can't be arsed with HSS and grinding for standard stuff like threads or run the mill turning and only grind for special or awkward jobs.!! . . . Yes it's more expensive but not too much when you consider the time saving and repeatabilty of tipped tooling.!
Annealing works but again got to be done carefully and correct other wise can spread up the screw further than desired.!!

Practice and practice a bit more is my advice then go for it if you feel confident.!!