[1bordeaux]

Hi all,
I've been involved in building and repairing instruments for 20 years. I have a business hand cutting shell inlays for other luthiers and individual owners,(mostly guitar and mandolin).
I have limited experience,(set zero point, push button), with cnc, but did quite a bit of vertical mill work and lathe work while working at Carruthers guitars in Venice,CA.
I would like some advice regarding purchasing a machine,(no time to construct), and software.
The only other info I can provide is my needs: Table must travel at least 22"
My overall depth of cut would be approx. .060 from the surface.

Thanks in advance for any help.
You can see my hand cut work at www.bordeauxinlay.com

[cncadmin]

How about a already built? http://www.cnczone.com/reviews/showp...php/product/10

[1bordeaux]

As I stated in my first post, I'm new at this and am looking for a complete unit, not just a table. I'm open to constructing one, within limits; my current backlog is typically 6-12 weeks which does not allow much time for "tinkering" in building a cnc unit.

Maybe I should post this in more of a generalized forum? Any other advice?
References?

Thanks in advance!

[corrie]

Hello 1B,check out www.durhamrobotics.com,this guy has got a pretty good setup at a reasonable price,you shouldn,t be disapointed.

[corrie]

Here is something all you guitar builders might be interested in www.forloversofwood.com.,In case you are having a hard time finding the proper tone woods for your build.

[1bordeaux]

Corrie,
Thanks! Now could you tell me the advantage of a" worm screw and pillow block " versus a carraige set up. A friend also mentioned backlash when changing direction.

Bottom line: What's the BEST transport assembly made of?

[corrie]

Hello 1b,does your friend mean ball-screw where there are several ballbearings that recerculate within a block in which gets screwed over the the ball-screw itself.I believe these type of lead-screws have little or next to none in back-lash.Back-lash from what I gather is the slop in the drive direction ,it,s like a chain on a bike sprocket as soon as you put pressure to pedal you see the chain tighten up just prior to motion,it,s the same principle with a lead-screw drive mechanism.Hope that can paint the picture for you.About a carriage setup,not sure what you mean,do you mean moving gantry where the router moves over the work or where the spindle is stationary and the work moves in it,s Axes direction.Cheers and hope I,ve been some help.

[1bordeaux]

Hey corrie, He has a shop bot and i believe he referred to the carraige being on wheels riding on a v track. He said he occasionally gets a bump in a pattern when a chip and / or sawdust gets on the track, or if someone bumps the frame itself.
What you described is what I'm looking for; No slop! I've turned down a few orders for multiples over 500 pcs. because I don't cnc. The time is here!

[1bordeaux]

Here's a photo of a handcut inlay I did for Sheldon Schwartz.
Can you say programming time?

[ger21]

my current backlog is typically 6-12 weeks which does not allow much time for "tinkering" in building a cnc unit.

Your going to need a bit of time for the learning curve, and possible figuring out the best wat to hold those small parts you'll be cutting.

[RandMan]

Paul - very beautiful work !!! I really like your taz !

custom inlay uses big techno routers with very high-speed spindles and mastercam cad/cam s/w. If you know Brian England you might want to talk to him about what he'd do if he were starting over...he's got a lot of capital invested being a volume shop. You should be able to do well with a much more modest approach both on the router and cadcam (ie Rhinocam). Ger21 makes excellent points. They glue their blanks to hardboard which are positioned on the router table and held down with vaccum. After cutting throw the hardboard in soapy water for a couple hours to soften the titebond and then peel them off. Doublestick tape works fine instead of the expensive vaccum option but takes more time to fuss with.

[dcd121]

Check out this site. He is doing what you do with cnc methods. He seems to be an artist such as youself. As far as holding down the shell he uses hide glue on a phonalic backer and soaks it off after cutting.

www.frets.com


If you want to come anywhere close to the quality you produce by hand you can forget building you own machine or worse yet a shopbot. A small techno-isel with a highspeed spindle would be something to look into.

[dcd121]

Sorry , here is the link of interest .

http://www.frets.com/FRETSPages/Fiel...lis/ellis.html

[1bordeaux]

Hi Guys,

Thanks for the response. I actually spoke with Tom Ellis a few years ago when CNC was just a pipe dream; perhaps it's time for a follow up!

Dc- I take it you have an opinion on the shopbot.
Care to share it, publicly or privately?
I'd be interested since I know nothing of the specifics on the tooling.

I also acquired a copy of Autocad 2004. Will this be useful, or should I begin my software "enlightening" with a program included with the machine of choice?

[1bordeaux]

Randman- Thanks for the compliment and the advice!

[RandMan]

I also would avoid the shopbot (w/screen door rollers and angle iron for rails) for the kind of precision work you do. You don't need to fight repeatability issues getting interlocking parts to fit into pockets. I go pretty slow (20ipm) when I cut abalam/MOP and acrylics for my simple inlays. Point is you don't need a real zippy machine, just a reasonably precise one. A low-end techno-isel, maybe even with steppers might be a good place to start looking. They have a lot of doco on their site to learn from even if you buy elsewhere.

Autocad will be OK for your cad if you already own it. You'll need to learn to play with SPLINETYPE and related settings to coax it to make lots of different types of curves. If you hadn't bought it I would have recommended Rhino since it has more artistic features. You'll need some kind of cam package to transform the drawing to the g-code to drive your router. You should be able to get by with low-end CAM with what's called 2.5d features for profile cutting, pocketing and engraving lines. Basically that means you get to specify a curve to cut around and a depth. I use Onecnc and they have a low-end package and I also have Visual Mill Basic which is part of Rhinocam. You'll want to check out engraving features for lettering etc. You can get lots of good suggestions from people here on s/w. The s/w is as important as the router. You're a great artist and you don't want to waste a bunch of time fighting with buggy cadcam s/w. Lots of systems combine cad with cam for a reasonable price.

[dcd121]

The above response by RandMan is dead on correct.

[1bordeaux]

As I run from computer to shop,(where I'm hand cutting shell), I'm amazed at the quick response from you guys!
You could teach the tech support guys a lot! No waiting!!!

[ger21]

You can download my macro from here http://www.cnczone.com/forums/showthread.php?t=8226 that will write your g-code from within AutoCAD. I like to think that it works pretty well, and it's free. You might want to look at SheetCAM http://www.sheetcam.com , which can do pocketing and a few other things.

[1bordeaux]

:idea: Ger21,

thanks! I hope a year from now, I too can contribute in this way!