parting off copper pipe in the lathe

I was turning a small file handle on my wood lathe which went to plan. However the problems started when I tried to part of a copper ferule on the (speed 10) to stop the file tang from splitting the wooden handle.

I must admit that the pratt bernard 3 jaw chuck has some tapering issues on the external jaws which could have caused my lack of grip. The first cut went ok parting off the 15mm reducer end of a 22mm-15mm fitting. However I had approximatly 10mm to grip in the chuck and the pipe must have slipped or snagged as the parting off tip went through the pipe. The result was one shattered blade and broken quick change tool holder!

Thankfully no injuries sustained apart from my pride.

What I wanted to no is how could I grip the pipe better, eg make an internal collet, turn down a wooden mandrel or other options?

Jon

I use a cheaper version of one of THESE when I have made handles for my home made woodturning tools and then just deburr the inside

I've found copper hard to part off, its really soft and kinda gummy so a dig in seems to end badly. When I did the shell for my Cringle boiler I resorted to making a delrin mandrel for it and going through.

Thanks Derek, I did consider a pipe cutter. Due to the shortness of the fitting I was trying to cut I would have found this difficult.

Nick Do you have any pics of the mandrel you made?

I also tried using a wooden mandrel pressfit on but the copper pipe had a tendancy to slip. The mandrel was 0.2mm oversize, perhaps I could glue it....

If the piece you're cutting is too short for a pipe slice, square off the end, cut a piece off with a hacksaw slightly longer than needed, fit it on the wooden handle squared-off end first, then make the protruding excess of copper flush with the wood using a belt sander and/or file.

I prefer brass tube to copper for ferrules. It ages more pleasingly besides being a slightly tougher metal.

Cut it off with a mini hacksaw then mount it on a steel stub mandrel turned down in situ to a tight fit inside the copper with a half to one thou taper over its length. Tap the copper ring into position on the taper and clean up the end with a sharp HSS turning tool. Finished ring can be tapped off the taper. Or heated and it will fall off.

Use brass!

I use end-feed Yorkshire straight pipe fittings cut in two with a hacksaw and then retrued once supported on the wooden handle. Another advantage is that the internal diameter is standard.

As, I think, implied above, the outer end of the tube can be trued whilst the handle is in the wood lathe.

Pipe cutters seem to swage the tube inwards making it more difficult to achieve a tight fit on the handle.

Plumber's stainless steel pipe is an alternative material.

CAREFULLY wrap a piece of insulating tape round the pipe so the start and finish line up as a line all the way round, this is your guide, then cut with a junior hacksaw ! For larger diameters use the edge of a sheet of paper ! Noel.

"However I had approximatly 10mm to grip in the chuck and the pipe must have slipped or snagged as the parting off tip went through the pipe. The result was one shattered blade and broken quick change tool holder! "

You broke the tool holder? That shouldn't happen. Must be a defective holder. Maybe your failed tool holder caused the dig-in, not vice versa?

Bear in mind that copper tube will crush in a 3 jaw chuck so it is near impossible to grip it tight without a mandrel to support it. For a one off ferrule I think I would avoid the breakthrough and finish cutting off with a junior hacksaw and tidy up with a file. If I was going to make a bag full for stock I would make an expanding mandrel. A six jaw chuck can be useful for thin walled tube but is quite an investment unless you do a lot of tube work, of course it is useful for ordinary work and is often seen on Stefan Gotteswinter’s lathe as his regular chuck.

Mike

use collets and WD40 as a lube

Hi Hopper

I just posted on another thread about getting my leg cut off.

Then when I logged back on this thread came straight up with your post.

I wondered what you were on about, cutting it off on a hack saw and mount it on a stub mandrel.

I thought it was a joke particularly with reference to stub mandrel. .

I really thought I was losing the plot.

Ouch. I just read your post ln the other thread re the leg about one minute ago. Sounds like you were not far from hacksaws and stub mandrels as it was. Good to see you have retained your sense of humour at least. Never let them amputate that!

Hi Hoper, they will never remove my sense of humour no matter how hard they try.

Good on you mate. That's the stuff. Laughter really is the best medicine.