wood turning

Can someone give me a few tips on woodturning? I'm not making furniture just cylinder hones, mandrels etc. . Sometimes the finish is not to bad, sometimes terrible. I'm using a metal lathe with carbon steel cutting tool similar to a metal cutting tool but with high clearance angles. The wood is a selection of chair legs etc. ,the last lot might be poplar or sycamore, very rough finish at all speeds, even though I can take a fine shaving cut

Gordon,

The main difference is that [properly used] wood-turning tools slice the wood, and the bevel rubs the work. Shavings should come off as a continuous ribbon, not as chips or dust.

MichaelG.

P.S.   I just found this site, which might help you.

Edited By Michael Gilligan on 03/08/2012 10:17:06

The other thing to appreciate is that when woodturning, the tool is offered up to the job and the angle of approach is that which cuts as intended. I used to make my own tools from old files, ground flat then with around 10 degrees front clearance angle. A slight change in vertical angle can make all the difference in obtaining a thin ribbon of "swarf" as opposed to chips, powder or a dig in!!

also the wood varies like metal does... some "billets " of the same stuff machine entirely differently.

..but the bit about tool advance at same angle as cutting "angle" intrigues me.

hmm tangential toolholders for wood?

Jason,

Have a look at Chap. 11 of the link I posted earlier

MichaelG.

Put a lot of top rake onto the tool say 20deg and you will get more of a shear cut.

Although the scraper type tool Kwil mentions is also good it the wire edge that is left on the tool that creates the top rake and gives a good cut.

The other thing with hand turning is that the tool should always cut down the grain, with using an engineering lathe there is a tendancy to cut up the grain which tears the unsupported fibres off. Again as Kwil says with teh eng lathe you can't feel what the tool is doing but with hand tools you just move the handle about until the tool is cutting.

Here are a few of my woodturnings

J

Nice work JasonB

... and you obviously know a thing or two about tricky grain !

MichaelG.

Gordon,

You can get a hand-turning rest for a Myford 7 series lathe, and no doubt one could easily be contrived for most other models. This kit:

**LINK**

is an example, but I'm sure you will find some ready made ones if you search.

David

Edited By David Littlewood on 03/08/2012 14:15:15

Thanks for all the advice. I was hoping to be able to just cut as metal but with different clearances, I'm using a tool made from 1/2" file with about 20deg angle on all sidesand a good radius on tip. Could easily make a hand rest, but will have learn a new skill. I can tell pine from oak but thats about it. What about RPM ? my friend says go as fast as you can, but is a bit hairy at times.

A simple alternative to a hand rest for me is a piece of bar held in the toolpost but it must be close to the work for safety. Yes, use high speed and make sure your tool is really, really sharp.

Russell

Edited By Russell Eberhardt on 03/08/2012 15:54:25

Oh No Jason - that's ANOTHER thing that you're good at!!! - I'm feeling quite inferior.

Nice woodwork and superb build journal for Firefly - with your lead I might even have a go myself sometime.

Keep up the good work

Regards

Norman

For cylinder laps you are best using the lathe as you would with metal that way your lap will be parallel.

I suspect your file based tool has little if any top rake, either regrind it top face down and leave the burr on the top edge or get a hss tool and put plenty of top rake on it, side angle will not make a lot of difference.

You should be able to get a finish like this with a lathe tool, though the ebony is a bit tighter grained.

Assuming your laps are quite small then spin it up fast.

J

Edited By JasonB on 03/08/2012 16:23:43

Very,nice chess table Jason

Did you inlay just the ebony top or both squares ?

Gordon

to make laps I would use a softer hardwood then ebony such as beech. The grits will get embedded and cut wellwhen you keep the lap mooving. High speed gives better finish as Jason says so lots of angle and high speed.

Regards Ian

The whole top is veneer, so individual squares of maple and ebony.

Yes the ebony would be overkill for laps, I just used it as an example of turning on the engineering lathe. Beech, maple and sycamore would all do the job.

J

GordonW, look in "Workshop Techniques", Favourite Finishing Tools, down near the bottom you'll find joegib, go to the site he has high lighted, and see the shaving tool, that is good for finishing wood. When I retired, did 5 or 6 yrs wood turning, The tool to use for a good finish is the skew-chisel, both this and theshaving tool will take the wood off in long ribbons. Ian S C

Thanks again, have now got a few ideas. Was talking to a carpenter yesterday about this problem, he pointed out the high speed that woodworking tools run, up to 20,000 rpm , 10,000 for a 25mm router, so logically my lathe would have to run the same for 25mmdia ? My max is 2000 rpm, I have large toprake on tool , will resharpen, try to find some better wood and try again. Also got some old wood bowling balls, heavy and dense, will try one of those.

Wood lathes don't go 'hell for leather' so 2000 rpm is easily enough. Routers are a different beast - just as ginding metal is different.

A tool with top rake may tear the grain out simply because it can dig in and wood flexes enough to let it . Mentioned earlier was rubbing the bevel on the work - this acts as a depth stop when hand turning . Beginners, when not trying to show off that they are 'wood turners' , are often recommented to use a scraper to get going. Flat top so no rake or tendence to dig in, gently curved end so no corners to catch on grain, almost no front rake so the blunt front rubs and prevents dig in, but that 85 degree cutting edge is kept regularly trued so it does actually cut. What comes off is dust but it works.

Gordon,

If the bowls (woods) are made of Lignum Vitae as many old one's were, it would be (in my eyes) sacrilegious to chop off little bits.

The classic conversion for these woods is for woodcarving mallets, these old woods are like gold dust at the moment.

Spindle speeds for normal wood turning lathes are nowhere near the speeds of conventional routers of which as you are now aware. My routers go up to about 30,000 rpm.

My large wood turning lathe is variable speed up to a maximum of about 2800 rpm and my small wood turning lathe for miniature work is variable up to 3200 rpm.

Your maximum lathe spindle speed is fine but your really should use a hand rest and proper HSS woodturning tools for best results. Ideally you try and get an hour or so tuition from a local friendly woodturner or come to that there must be many Youtube videos that show you the basics.

Finally people will try and put the frighteners on you about using what is known as a skew chisel, this will give you the best finish on cylinders but be prepared for some digins and always wear your safety glasses.

One of the best books on woodturning for beginners I read when I first started many years ago was called "Turning Wood" by Richard Raffan, he has written many books and you may well get some from your local library.

Best of luck.

Len. P.

Well I,ve been playing about again with some good results. Using the same wood and tool with a large toprake as before, but with the front of tool set parrallel with the work, much better, speed at max 2000 rpm even better. Tried my steel finisher, a 10mm dia HSS with a flat across, similar to one shown in the steel finishing thread, set at 45 deg. to the axis, very good, almost like the ebony. Tried a better wood, beech?. almost like cast iron, thanks to all. BTW I don't like cutting the bowls but they are cracked in places so don't think they will be much good. Any one lives near and wants them can have them. They are heavy, about 1.3 kg each x 3. Also have 6 old carpet bowls

Gordon,

Lignum vitae is an excellent wood for bearings, so if you have any old bowling balls which are not fit for purpose, don't be too quick to give them away, save them against the day when you want to use them in this way. But if you do insist on getting rid of them, where do you live?

David