Starting turning on an old lathe

[lo-fi]

Not one of mine, but this shows it:

 

[Gazzar]

Yes. You are right. I couldn't get the clamp to clamp that way, I think the tool was too short or something.

This way worked for the job, but I've some cheap tooling on the way, that might work better the right way around.

It feels like a somewhat crude way of holding the tool, though.

Thanks.

[landroversforever]

52 minutes ago, lo-fi said:

Not one of mine, but this shows it:

 

Normally I'd say that the whole tool post needs rotating 90Deg anti-clockwise, and use a RH tool instead for most stuff normally.

[lo-fi]

I mean with regard to the foot > tool orientation. 

Agreed, that's not the usual setup for turning, but it does give a great surface finish 

[steve200TDi]

I think also that that way is more for boring internal diameters, but if it works, then great!

I must have a go on my lathe as I've built, but haven't done any turning let along seeing if its flat/true........haha, so many jobs and projects on the go!

Steve

[landroversforever]

45 minutes ago, steve200TDi said:

I think also that that way is more for boring internal diameters, but if it works, then great!

I must have a go on my lathe as I've built, but haven't done any turning let along seeing if its flat/true........haha, so many jobs and projects on the go!

Steve

It is Steve. However you’d struggle on anything less than a massive internal diameter with a tool like that.

[steve200TDi]

1 hour ago, landroversforever said:

It is Steve. However you’d struggle on anything less than a massive internal diameter with a tool like that.

Oh yes, I was going more on the position rather than the tool type, but yes, you would need a proper boring bar for boring!

 

Steve

[Gazzar]

I was trimming the inside of the shim washer for the railco Bush, so that makes me feel better.

[Gazzar]

A bit more success today. By exploration I changed gear on the lathe and, to my surprise, the speed increased, without tripping the electric.

I can get to 800 rpm. Rather than 46 rpm. That's judging by the gearbox plate.

This makes a massive difference to the quality of the work.

I've also bought some tooling. It's too small, I think but it confirms that I need to learn what tool holders I need for the inserts I've inherited.

 

[Gazzar]

Is this a parting tool?

Would it shorten a CV stub axle?

[Stellaghost]

Looks like one but just cut steady away too greedy and you will wreck the tip

Regards Stephen

[lo-fi]

Yep. Great to have, but probably one of the most challenging turning tools to use. You need the work held really rigidly, plenty of cutting oil, low rpm and feed that's firm, but not too heavy. If you try to feed to gently you'll end up with lots of chatter and getting nowhere. Too heavy and it'll dig in and break something or at very least stall the machine. Best practiced on some mild steel first, and it may not like hardened stuff much at all. 

[Gazzar]

Thanks to Ross I've a couple of CVs to practice on.

I'm cutting the splined party of the CV off. I suspect the splines will cause grief and I'll end up using a grinder with a plasma disk.

 

Actually, can I mount a grinder to a lathe?

 

[lo-fi]

Yep, toolpost grinding can be set up on most machines 

Not sure I follow which bit you're trying to machine? 

[Gazzar]

I'm trying to shorten the shaft bit of a CV. The bit the drive flange slides onto.

The lightweight has narrower flanges and a simple flat cap, rather than the threaded end of standard series half shafts that take castle nuts

I'm converting the axle to CVs, but preserving the lightweight look.

So I need to take about 20 mm (+) off the CV shaft.

I'd rather avoid holding the grinder and just cutting the shaft, it's a bit agricultural as a technique ( last resort), so if i could part the shaft with s bit of precision, that would be good.

 

 

[Gazzar]

To get the tool central, all I've been doing is using shims to get the tool in the right place.

Is there a better way?

Seems a bit heath Robinson.

[lo-fi]

Ah, I see. I'd just use a standard carbide turning tool and take facing cuts. HSS won't touch hardened splines, but carbide should power through. 

Yep, shims are the way to do it. Ideal if you can find something that's the right height in one piece. I use a piece of brass under the 10mm insert tools I have and it brings them right on center. Harder with HSS as it changes a little  every time you grind it, and every tool will be different, but that's where a quick change is really handy. 

[landroversforever]

I’m not sure how well the parting would go on the CV shaft. It wouldn’t worry about the intermittent cut, but they’re likely to have been heat treated I’d have thought. 

As for the technique with parting, I’d have to disagree with the above and say don’t slow it down. Keep it at the same speed you would do any other processes on that material/size. Number 1 thing people cock up when parting off is the tool height, it needs to be spot on. Too high and you’ll rub, too low and it has the tendency to dig the tool under the job and is the easiest and most common way of snapping the tool. You also want to keep the tool as short as possible for the job in hand, particularly on the harder materials like steel or stainless, that keeps to rigid and will give you a better surface finish. With parting you’ve also got to get a little brave and get the tool cutting and keep it cutting. Have you got a coolant pump on your lathe? If so parting is one of the jobs that loves to be drowned and kept cool. 

[Gazzar]

When you say "facing cuts", do you mean start clearing a space in the side of the shaft, and working in, or just take the face all the way down to the final dimension?

Thanks.

 

[landroversforever]

Facing is taking material off the end. So in your case the end of the shaft with the tapped hole in. 

[Gazzar]

That's what I thought, I'll try it for the CV, but the angle grinder might come into play if it's tough going.

Thanks.

Once I get the electrics sorted I'll try figure out a suds pump. Spraying with WD 40 isn't a long term plan.

[lo-fi]

I'd probably take the end off with the grinder and a slitting disc leaving a few mm, then pop on the lathe for a clean up. 

[Gazzar]

I think I'll do that.

I've a question. I've a selection of inserts, carbide, I think. But no holders. Where would I look on-line to get holders? What dimensions would I need to know? The labels on the packets are faded, so I don't know the names of the inserts.

And the opposite, I've a holder with a worn out insert, but don't know what to order.

I don't need amazing quality, it would be wasted on me, so cheap, crude but serviceable is what I need now, I think.

[landroversforever]

RDG tools on eBay aren’t too bad. We used to use them in my old department, not the likes of sandvic but reasonable. 

Sometimes the tips themselves will have the part number written on them. Or written on the tool body. 

[Cynic-al]

I wouldn't try to part those off, I think you'll get pretty disheartened. Expecially if you have to go through the splines. I would just keep taking small cuts off the ends. Even that might be hard if they're hardened in any way?

If you buy a quick change tool post (or make them) you can adjust the tool height with a screw, otherwise it's shimming. I used to keep the shim with the tool once it was right and I've used stuff like broken hacksaw blades in the past.

For tool holders etc in the past i've used , cutwell, rdg tools, JB cutting tools, drill services and Tracy tools and have been reliable.