Re: [CAD_CAM_EDM_DRO] Basic questions

Gordon,
 
Your desire is what I am doing.  Cutting flat parts from sheet for my model railroad kits.  I also cut 3D parts.   I use Rhinoceros 4/5 to design in and it allows me to set up a jpeg of a drawing as a bitmap background so I can trace over parts. I then use Rhionocam basic to generate tool paths.   I am familiar with RC planes as I fly a bit and build kits.    You will probably end up tracing and to a certain extent be redesigning the parts so that they fit.    It isn't rocket science but there is a bit of work involved.    Model airplane drawings I have used from reputable sources aren't exactly precision so it is worth the design work.   In reality you could cut better/nicer parts than are typical with a laser.
 
Although I havent' cut balsa on my router I have cut thin basswood.  My simple solution to holding sheets as thin as 1/16" has been to bolt a sacrificial wood table to the router table.   I face it off so it is smooth and flat in relationship to the router bit.   I true up one edge of the sacrificial table which established a Y zero.    I then use a staple gun to staple the wood to the sacrificial table.      The alternative is to use a vaccuum table which is what I want to make but it is a matter of taking the time to build one.
 
I program my tool paths to include "bridges" which hold the part to the fret which  keeps parts from flying and in some cases becoming damaged.
 
The router you mentioned isn't familiar to me so maybe you could reply with a link?    I built my router and I built it with 6" of Z travel AND the gantry is high enough so that when the tool is as  low as it can go there are still 2-3 inches before it hits the table.   I am very thankful for this feature since it allows me to have various shop built work holding fixtures on my table.    If I had to do it again I would include a big hole for working on the end of a piece of wood.
 
Jack
 


________________________________
From: Gordon Anderson <GAA@...>
To: CAD_CAM_EDM_DRO@yahoogroups.com
Sent: Monday, January 2, 2012 2:23 PM
Subject: [CAD_CAM_EDM_DRO] Basic questions



 

Hello, I have been lurking on this list for sometime and I have a couple of dumb questions that I hope someone can answer for me or point me in the right direction. I am very close to buying a DIY CNC router kit like the blueChick. I have read a lot about the machines and control software but my questions are pretty basic and most likely dumb, here goes:
1.) How do I hold material on the table? I will be cutting thin wood, liteply and balsa wood. I will be cutting through the wood to cut out parts. My question is how do people hold the material in place and what do you put under the part you are cutting to make sure you do not cut into the bed of the machine.
2.) I have old drawings with patterns for formers (mostly from model airplanes) that I would like to convert to gcode files to enable cutting the parts. Is this possible? If so where can I learn more about the process. I hope I can scan them in and then convert them to gcodes.

I hope these questions are appropriate for this list and appreciate any input.

Thanks!

--Gordon

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