Convert Wood Lathe from hand held tooling

Hi Folks,

I am a hobby woodturner with a problem. Due to circumstances beyond my control I am no longer able to hold the tools with any control. I am looking at the possibility of mechanising the process. The more I think about it then CNC would be an interesting way forward. If anyone has any experience of carrying out such a modification or has an idea for such a build, I would love to hear about it. The Lathe is an HDB 200XL see www.hegner.co.uk for details. Hegner make a duplicator, but at £700 +VAT, I am hoping that I can find, build or have built, something better, even if the cost is higher.

Thanks in advance,

Further to my post I would like to put a few thoughts forward for comment please.

Having spoken to Gary (Zapp) All my original ideas have been binned. So I have had a rethink ...

If I want to use 'fixed' tooling, and use the lathe as normal I would need to power the spindle with a servo motor, enabling me to slow the spindle speed right down to cut Barley Twists etc. also stop it at precise points for drilling and decoration. The Lathe has the capacity to spin blanks up to 900mm long and 450mm diameter. To machine the outside of a bowl/platter anywhere near 450mm dia. would mean a massive cross slide, however the Headstock can be swivelled 90deg each side of the centre line.

I am wondering about putting the headstock on a rotary base powered by a stepper, using a Kress or similar as a milling head (mounted horizontally) and then I would only need to turn the blank with a large stepper, turning the blank slowly and also around the axis of the C/L. The 'cross slide' would be stepper driven and would also have to rotate to allow the 'bowl' to be hollowed out.

I know I would have to build a 'saddle' from scratch and a whole lot more besides, but my reasons, to me at any rate are sound. I have a market for my bits and pieces that will disappear if I cannot fill it. I am sitting at home with a buggered lower spine, a knackered wrist, sod all income and am going stir crazy. I need a project!!

Feel free to shoot as many holes in the idea as you wish ... the other way could of course be a large milling machine with a 4th axis (which is beyond my financial means).

Hi,
Bit confused,how are you going to cut blanks up to 900mm long if you mount the headstock on a rotary base?,a little sketch may help me get my head round it.
Steve.

The 900mm length was just showing the capacity of the lathe , sorry I did not make that clearer. I want to retain the ability to machine that sort of length between centres, Newel posts, Spindles etc. right down to pens (a good seller). I would like to turn bowls, goblets and other chuck held items as well. Basically do all the things I used to be able to do ...

Quote:

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Originally Posted by Wobblybootie

The 900mm length was just showing the capacity of the lathe , sorry I did not make that clearer. I want to retain the ability to machine that sort of length between centres, Newel posts, Spindles etc. right down to pens (a good seller). I would like to turn bowls, goblets and other chuck held items as well. Basically do all the things I used to be able to do ...

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Hi,
Why not just set up a two guide rail cnc system running 900-1000 mm to the front or back of the lathe, with a two rail cross slide joined too it,with a router bolted to the cross slide, cutter facing wood ,which could then take care of your spindle work plus outside of bowls.then mount the router again on the cross slide but at a slight angle facing towards the chuck for your inside bowl work providing the radius of the bowl it big enough to clear the router body or you could play with the angles you mount it at.

I get what you mean ...and that is a possibility. I was looking at the bowl problem from the the direction of mounting the blank and machining in one go, if I mounted the blank then proceeded to mill the outside first then rechucked it as I would under normal circumstances, then milled the inside to finish, problem solved. I still may be better off mounting the router on a rotary table on the cross slide ... I am assuming that I would continue to keep the blank turning in the standard direction to get the cutter into a 'reversed' or concave bowl lip. I had fallen into my normal trap of overcomplicating things...

Quote:

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Originally Posted by Wobblybootie

I get what you mean ...and that is a possibility. I was looking at the bowl problem from the the direction of mounting the blank and machining in one go, if I mounted the blank then proceeded to mill the outside first then rechucked it as I would under normal circumstances, then milled the inside to finish, problem solved. I still may be better off mounting the router on a rotary table on the cross slide ... I am assuming that I would continue to keep the blank turning in the standard direction to get the cutter into a 'reversed' or concave bowl lip. I had fallen into my normal trap of overcomplicating things...

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Hi,
Yes think you might need the rotary table if using a normal router,something like this may work without because of the small body http://www.mycncuk.com/forums/showth...ight=brushless ,but it does mean your in for a lot of work with the total conversion,the good thing about using a router/spindle is the speed will do all the work,so you could drive your lathe chuck very slow,maybe with a stepper motor,the motor would run continually for turning work and then index round for your fluting,barley twists or any holes you need round the circumference.

Steve.

Sorry to piss on your chips but from the looks of that machine, nice as it is, it's not a real candidate for a CNC conversion.

You would probably be a lot better off selling it or using it as a second op machine and starting with a clean sheet of paper.
What you want to do has been done before in various stages, simple linear rails for the bed and cross slide and a double drive system for the head as Steve says, motor to spin at speed for turning and stepped geared drive for barley twists etc.

.

Well hope you get it sorted mate,so you can get back to making a living.

Steve.