Official Luthiers Forum!
http://mowrystrings.luthiersforum.com/forum/

Poor man's CNC
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10106&t=36565
Page 1 of 1

Author:  Bevan Frost [ Tue May 22, 2012 1:31 pm ]
Post subject:  Poor man's CNC

Hello Forum Members!

thought I would throw this one out there...

I redesigned a commercially available pantograph router to be stable and accurate. I also developed a cutting/registration sequence that allows me to duplicate 3d objects to within 0.001", a tolerance I choose to leave in place. I am establishing all of the relevant geometry for my necks using this machine and a series of 3 jigs to produce uniform blanks. Sum total time per unit from board stock to seal coat including hand finish sanding (a requirement in CNC as well) is about 5 hours, which includes 4 miters of the trim around the headstock. It will be less once I develop my solid headstock/no trim pattern. This is similar to the man hours required by the team at Breedlove (where I worked) to produce necks using their CNC machines. They invested hundreds of thousands of dollars, I invested $2000.

I also use this machine to duplicate gun stocks, and to make multiple identical guitar bridges. I just wanted to let folks know that production without measurement is possible for less $ than you would expect.

Author:  Sheldon Dingwall [ Thu May 24, 2012 2:44 pm ]
Post subject:  Re: Poor man's CNC

Any photos?

Author:  joe white [ Thu May 24, 2012 4:02 pm ]
Post subject:  Re: Poor man's CNC

Sheldon Dingwall wrote:
Any photos?


Hear hear!

Author:  Andy Birko [ Sat May 26, 2012 8:03 am ]
Post subject:  Re: Poor man's CNC

I believe that I've heard this sort of thing called a "carbon based" CNC before :D referring to the carbon based computer that runs the thing.

While this is cool and all, I think people are really missing the strengths of CNC when they refer to a duplicator as a "poor man's CNC". While CNC machines are indeed great at making the same thing over and over, their true strength lies in being able to make extremely complex one offs with a very short turn around between design and manufacture. Duplicators depend on a hand made (or whatever kind of made) physical template and the speed of the turn around depends on how quickly you can modify the template. In CNC, the template is the CAD model and those can usually be changed or created pretty darn quick.

As an example, I have a parametric CAD model for fretboards. There's about 8 or 9 parameters (e.g. width at the nut, radius at the nut, scale length etc.) that I input into a table and one mouse click later, I have a new updated model based on those custom parameters. Couple more mouse clicks and I've got G-code to cut a customized fretboard. Literally, less than 5 minutes of work if my computer's already booted up.

While duplicators are very cool and all and in probably a lot of cases are a more cost effective choice than CNC for a lot of applications, they're certainly not a poor man's CNC. Again, don't take this as a knock, just sharing my opinion.

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/