Thread: Scrap steel - machining a drive shaft

That looks like a Paramount lathe, I had a look at them some time ago, how do you find it?

Originally Posted by nearnexus

Thought you may find this interesting.

Got back onto making up the motor mount for the Schaublin and went through the scrap pile looking for round stock to make a long spacer tube.

Dug out a drive shaft from a Mitsubishi Colt and decided that would do nicely.

So set about to machine off the splines etc, and wow was that shaft hard. The case hardening was really thick and I've put up a few photos of the shaft end after facing, where you can clearly see the hardening.

This is after I've machined off the thickness of the splines AND half as much again of the hardening as is left in the photo.

The centre section is hard but able to be drilled. To strip off the hardening I used pointed carbide at coarse feed with a heavy cut at about 700 RPM.

The little 10" Chinese lathe did it easily (although there was a bit of flex in the compound ) and the spirals were coming off RED hot. Blue is normal, but glowing red is something I don't normally get.

Anyway here's a few shots of the shaft metal.

Cheers

Rob

Love recycling stuff love my ''junk pile'' Harold Steptoe.

Originally Posted by th62

That looks like a Paramount lathe, I had a look at them some time ago, how do you find it?

I give this lathe hell and it always comes back for more.

Extremely accurate. Best $1100 I ever spent.

I see Paramounts no longer list or have this model lathe, so I don't know what's happening there.

I've had this one about ten years (it was one of the first they brought in to Oz) and it's been excellent.

Rob

I had a look at the small one $1100 and the next size up ($1645) but I was a bit concerned about the auto feed running on the half nuts. Obviously with the 10 years you have gotten from it, it's not an issue. Both good value considering they both come with just about everything.

Originally Posted by th62

I had a look at the small one $1100 and the next size up ($1645) but I was a bit concerned about the auto feed running on the half nuts. Obviously with the 10 years you have gotten from it, it's not an issue. Both good value considering they both come with just about everything.

The half nuts on this model are massive for the size of it. See video below.

What's inside a cheap Chinese lathe - a quick look under the carriage of a CQ9325 - YouTube

Also, having leadscrew covers the cuttings and grit doesn't get to stuff them up like on other lathes.

After ten years of fairly heavy use (using Loctite lithium based lube on the leadscrew) they are as good as new.

I see that Paramounts only have the Seig C6 in this size now. Not what I would buy. I would go the next step up to the $1600 job.

But I really like the one I have at the moment as it has 10" swing, 1" spindle, reverse tumbler, simple QC gearbox and a compact length.

And was dirt cheap.


Rob

It was the large spindle bore and reverse tumbler gear that attracted me to this one originally. Titan still sell it as the TL-250. This site is dedicated to the CQ9325. CQ9325 10x18" (250x450mm) Chinese bench lathe. I've also noticed all the paramount lathe stands are very low, I have to stoop and I'm only 5'7". I think the designer must be very short indeed.

Originally Posted by th62

I had a look at the small one $1100 and the next size up ($1645) but I was a bit concerned about the auto feed running on the half nuts. Obviously with the 10 years you have gotten from it, it's not an issue. Both good value considering they both come with just about everything.

Does it actually drive the auto-feed off the lead-screw thread or does it have a keyway in the lead screw for the auto-feed like the AL-320G and other similar lathes do?

The half nuts clamp onto the leadscrew for auto drive and screw cutting, most lathes available now, at least the ones I've seen: Paramount, Impala, Workman, etc, work on this principle. Hafco appear to be the odd man out here, I think the autofeed on all Hafco lathes work off the keyed leadscrew and worm wheel principle. Some lathes only have one half nut, the AL-250G is a good example. Being a Hafco though, at least the auto feed is a keyed leadscrew wormwheel system