View Full Version : cnc wood lathe??


dlh422
09-16-2005, 09:45 AM
Well, I've searched the forums and have found little or no information on converting a wood lathe to CNC.. Mostly, if not all refer to metal machines, mostly mills and/or routers. I've been turning duck calls manually off and on for almost 20 yrs and have my process down pretty good. I really want to upgrade to cnc but the only one I've found by searching the internet is $4K. Surely there is a more economical complete machine, kit or plans to upgrade out there. Any info would be appreciated.
Thanks,
D

JFettig
09-16-2005, 10:01 AM
I havent seen much for specifically cnc wood lathes, have you considered using a cnc metal lathe for turning wood? I personally dont see a problem with it but I dont know a whole lot about turning wood, I have only done a about 4 or 5 table legs(must have been a screwup in one).

Jon

Chris D
09-16-2005, 10:56 AM
D,

Before you even attempt to go down that road, you may want to cut a Duck call with the tool bits that can be used on a CNC lathe. I have only seen a couple of them (CNC Wood lathes), and the only tool bits I have seen used on them are scrapers. Usually 1/4" x 1/4" HSS and ground to a point which would look like a threading tool used on a manual lathe. Roughly speaking, it is a 60 point on the tool bit.

As such, you can imagine what the part will look like after turning. So, unless that is how you have been turning them, you may want to give it a try with that shape tool bit.

It has been a long time since I have messed with a CNC wood lathe, but unless magic has occured, they still use the same type of tool bits. You don't use anything like a gouge or skew chisel.

Chris

ger21
09-16-2005, 12:05 PM
Just mount a laminate trimmer that moves in 2 axis - along the spindle and perpendicular to it. Like this: http://www.alignritetool.com/cnc_router_poolcue.htm

ViperTX
09-16-2005, 12:17 PM
Great link ger21....that could also get people into ornamental turning, which is something I've been wanting to do.

acondit
09-16-2005, 12:22 PM
D,

I have frequently turned wood in my metal lathe. I ground a 1/2" M2 blank to approximate the profile of a gouge. I don't know why you couldn't use something like a 7x12 minilathe converted to CNC and grind your own tool bits to do what you need.

Look at Jon Fettig's or Ron Steel's conversion kits. Buying a minilathe, conversion kits and assembling them yourself should come in well below $2K.

Alan

ViperTX
09-16-2005, 12:23 PM
Well...it kinda depends on how long a piece you wish to turn...

dlh422
09-16-2005, 12:28 PM
I was told by a cnc kit maker that the metal lathe works fine on wood.. Oh, Hello JFetting, haha... It's a small world, I believe we corresponded y'day... I'm the guy that emailed you thru your website about turning wood with metal lathe.. thanks for the reply.. I'm checking all resources and looking for various opinions or suggestions. Especially anyone with a similar process. Pen makers are the only ones that I can think of and maybe I can check out one of their sites. I'm sure they have one...

I'm must confess Chris I'm ignorant about metal cutting tools, cnc terminology and cnc capabilities in general , I'm learning though.. As you mention The cutting tool would be critical part and just from looking at the angle on the 60 pt it doesn't look like it would be able to make a 90 degree parting tool type cut. That kind of information is helpful and I must do more research to find out about that.. curves, tapers, as well as the 90 degree cuts I mentioned would be needed capabilities..

Although it was taken with a low meg camera and if I've done it correctly I've attached an example of one the duck calls I make. Maybe one of you can tell me if it's cnc-able. I appreciate both of your replies. All suggestions are appreciated. thanks,
D

dlh422
09-16-2005, 12:30 PM
well while writing and sending my last post I've noticed more replies...thanks, I haven't read thru all yet.

dlh422
09-16-2005, 12:49 PM
Just mount a laminate trimmer that moves in 2 axis - along the spindle and perpendicular to it. Like this: http://www.alignritetool.com/cnc_router_poolcue.htm

interesting setup ger21.. Unless there's a size constraint for a mini lathe it looks workable as far as the designed cuts go, . As you can see from the pic we're talking about small pieces especially relative to a pool cue.. but a possible option..
D

dlh422
09-16-2005, 01:59 PM
I found this in one of my searches but didn't get a response from the company. I can't really tell but can anyone identify that as a router attached?
D

ger21
09-16-2005, 02:05 PM
Forgot about that one. It's the same laminate trimmer as the one in the link I posted. The Liberty lathe is basically the same thing, just a smaller package.

dlh422
09-16-2005, 04:25 PM
Forgot about that one. It's the same laminate trimmer as the one in the link I posted. The Liberty lathe is basically the same thing, just a smaller package.

sounds like you're familiar with the machine. Do you have any information on it other than the website that I found, http://www.leonardmusicalinstruments.com/liberty01.htm ? I like the looks of it and want to find out more but never got a reply from their advertised email address.
D

Mcgyver
09-16-2005, 04:27 PM
yeah ger that was good link - that's how i'd want a cnc wood lathe.

you can turn wood on a metal lathe. its worked for me with a lot of top rake and rounded nose, and if you were serious about it I'm sure there a ways to bring the right tooling to bear.

however, cutting wood in a metal lathe its not really a good idea - woodworking and metal working machines are not compatible because of dust. The machine is full of metal to metal bearing surfaces that require a film a oil. the dust dries out the oil which is a bad thing. Maybe if the lathe was a real beater that you could view as sacrificial, but I'd be concerned that longer term steady use would wreck the machine

ger21
09-16-2005, 08:36 PM
sounds like you're familiar with the machine. Do you have any information on it other than the website that I found

I'd seen it before, that's all. You might want to contact LibertyCNC http://www.libertycnc.com

OCNC
09-17-2005, 02:11 AM
I don't know much about lathe work but couldn't the shapes in question be cut using a profile knife attached to a cross slide which is then moved in against the work in very small increments (possibly even with a pecking motion) via the stepper motor? It might help prevent cross grain tearing if you put a fine serration on the cutting edge. I'm assuming that final smoothness of the piece is achieved with abrasives so if the serrations are small enough they will sand out easily. Another idea would be to use two knives, one with coarse serrations for a rough cut and another with the smooth profile for the finish cut. They could both be mounted on a cutter head attached to the cross slide and rotated into and out of position via a stepper controlled by the cnc software. Companies that make knives for shapers and moulders can make very precise profiles from drawings or samples. I think I paid about $40. per inch the last time I had some moulder knives made up. Since the knives aren't actually spinning it shouldn't be too difficult to fabricate a cutter head that only has to rotate through a few degrees. Using profile knives you would only need a cross feed mechanism which would be pretty easy to adapt to a stock wood lathe. Not having to precisely move a tool up and down the lathe bed seems like a significant simplification. Just a thought. :)

whiteriver
09-17-2005, 12:50 PM
Here are some sites on cc lathes for wood:

http://www.hapfo.co.uk/tech/vidpage.htm
http://www.jjsmith.co.uk/stock/website.nsf/0/D04CE148D7B0494380256FF1003C94F3

THe hapfo one is a sweet lathe and fast. Wish I had the money to buy it or copy it.

Donny

www.whiterivermfg.com

dlh422
09-17-2005, 04:13 PM
Ger, thanks for the Liberty site and thanks to everyone else who posted sites and suggestions. Also got a reply from the guitar maker who had the Liberty lathe pictured on his site. Said he wasn't a dealer but also gave me a TN number. No surprise the same guy you gave me Ger, different town and # though. Turned out to be the guys home number. I just got off the phone with his wife, very nice lady. Coincidently, he's less than 100 miles from me, I'm in north Alabama. Probably take a little trip after talking to him and check it out up close and personal. Maybe it's the right machine at the right price, maybe not, we'll see. Get some ideas anyway.. I appreciate everyones inputs.. very helpful, all of you.... I'll keep you posted..
thanks,

DH

wisp
09-18-2005, 01:41 PM
Are those duck call made from cocobola?

Switcher
09-18-2005, 07:09 PM
whiteriver, That video on http://www.hapfo.co.uk/tech/vidpage.htm (Cutting the ball,on the lathe) is cool!

dlh422
09-19-2005, 09:23 AM
Are those duck call made from cocobola?

yes

dlh422
09-19-2005, 09:36 AM
whiteriver, That video on http://www.hapfo.co.uk/tech/vidpage.htm (Cutting the ball,on the lathe) is cool!

very cool indeed..!

dlh422
10-03-2005, 02:21 PM
http://www.crankorgan.com/woodturtle.htm