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3 cav 84a
20th July 2008, 01:36 PM
G'day, I just started playing around with a chuck today and was doing some practice on some timber I intend to make a salt mill out of. It was the first time I have used the parting off tool. It got very hot really quickly and even burnt the tip of the tool. The lathe was going at about half maximum speed. I haven't used this particular too before, it is a generic HSS type not one of the expensive brands and the timber is either old dry peach or apricot, any suggestions, regards Neil

orraloon
20th July 2008, 02:21 PM
Neil,
Hard to say as I don't know how you are using the tool. The trick is to make the cut a bit wider than the tool and this prevents the wood gripping the sides of the tool. You will only then get friction on the cutting edge. They can still get hot so do the parting off with a series of short cuts rather than one mighty thrust for the center. Allow the tip to cool a bit.
There is also a tendency to present the edge lake a scraper and this will generate more heat as well as dull the edge sooner. The parting tool is a chisel so rub the bevel same as with the gouge and skew.
Regards
John

NeilS
20th July 2008, 02:33 PM
Hi Neil

On deep cuts most of us run a second 'trench' next to the initial cut, about half the width of the first cut, and alternate between the two to give the parting tool some side clearance to avoid friction and heat build up. Diamond profile parting tools reduce the need for this.

Dense seasoned fruit woods will generate more heat than loose grain softwoods. Perhaps practice on some scrap pine to get a feel for the tool. The finish on pine will not be as clean as on the fruit woods but will preserve your valuable wood and your tool until you are up to speed on your parting technique.

And, as with all turning tools, the cutting edge needs to be kept sharp.

Hope that helps

Neil

3 cav 84a
20th July 2008, 02:42 PM
Thanks for the info fellas, I will go out into the shed and give it a go, thanks Neil

oldiephred
21st July 2008, 10:02 AM
There are times when I need to part pieces that do not allow enough room for conventional parting tools so I made a handle that looks like an oversized slingshot and stretched a fine wire across it. The wire cuts through most woods quite well. The similar handle I have has a heavier wire that I use for burning accent lines.
The wires that work well are the size of a small wire fishing leader (we call them 10lb leaders),or the lower E string from a guitar. It does get hot but cuts well with sufficient pressure.
Regular parting tools do require some getting used to (ie. swearing).:B

Cliff Rogers
21st July 2008, 10:13 AM
Another trick with a narrow cut from a parting tool to stop it burning is to wobble or rock it ever so slightly as you make the cut, this will make a slightly over sized cut & give the tool a bit of clearance.

It always helps to set up some scrap as a practice piece & play with all your tools on it too see how they do & don't work the best.

3 cav 84a
21st July 2008, 02:29 PM
Thanks for these ideas, really appreciated regards Neil

joe greiner
21st July 2008, 09:39 PM
Rocking the tool in accordance with Cliff's suggestion can be wobbled even more to function as a mini skew chisel, for a good tool finish on a tenon, for example.

Braided wire, e.g. picture hanger, by oldiephred's method should cut more aggressively, but would also be subject to side pressure. So try to make the slot wider there too. Ditto with unbraided wire.

Joe

AndyCJ
24th July 2008, 10:45 AM
As a real beginner, I have found some of the YouTube video's quite usefull.

...and others quite useless. :D

Parting Tool technique
YouTube - Parting Tool Technique

I'd be interested to hear what the pros think of this demo also.
Cheers,
Andy

Cliff Rogers
24th July 2008, 11:19 AM
Yup, I reckon it is pretty good. :2tsup:

AndyCJ
24th July 2008, 02:45 PM
Thanks Cliff - becasue this is what I've been practising! So I'm glad to hear it's the right thing to do!! :roll::U