Machsupport Forum

General CNC Chat => Share Your GCode => Topic started by: ChandlerW on December 26, 2012, 11:54:02 PM

Title: Need G Code for a small brass cannon
Post by: ChandlerW on December 26, 2012, 11:54:02 PM

Hi all,
 I have a dxf file that I would like have the g code for.
I have not been able to find a CAM program that will produce the right code. I tried several for many hours and wasn't able to get anything decent from them.
The dxf is a small cannon for a model ship. Its about 2.5" long and .15" inches in diameter.
I'll be cutting it out of brass on a little sherline cnc if I can get the g code.
If someone can help me out I would appreciate it.

Title: Re: Need G Code for a small brass cannon
Post by: RICH on December 27, 2012, 05:30:47 AM

ChandlerW,
Why not do it youself using LazyTurn. The program is free and you only need to use one tool.
A manual for the program can be found in Member's Docs.
We can help you along the way if needed.

RICH

Title: Re: Need G Code for a small brass cannon
Post by: ChandlerW on December 27, 2012, 10:52:36 AM

Getting there.
When I open the g code in machturn it looks ugly and crashes.

Title: Re: Need G Code for a small brass cannon
Post by: RICH on December 27, 2012, 05:13:41 PM

Shouldn't do that, works fine here.

1. Fix your dxf drawing that you posted. Not all the elements were connected,ie. after the first breech circle.
    See Appendix "B" in the manual for common drawing mistakes. Aslo move the profile as show in the manual
2. Now think about how your going to machine that profile.
    How are you going to hold it,ie; in a lathe chuck and also use the tail stock?
    Test question: What kind of tool will machine around the balls and not gouge the work and can get into the corners?

RICH
   

Title: Re: Need G Code for a small brass cannon
Post by: ChandlerW on December 28, 2012, 12:02:28 AM

Here is a screenshot. I'm getting worse results.

Title: Re: Need G Code for a small brass cannon
Post by: Overloaded on December 28, 2012, 06:42:13 AM

Like RIch said.......

Quote from: RICH on December 27, 2012, 05:13:41 PM

1. Fix your dxf drawing ........ 

One of your biggest problems is that your drawn elements are in the wrong quadrant.
Rich explains this in detail in the manual. It is crucial.

Title: Re: Need G Code for a small brass cannon
Post by: RICH on December 28, 2012, 06:48:44 AM

See Appendix "B" figure 3.5.1 as you need to have the profile drawn in the correct quadrant..
RICH

Title: Re: Need G Code for a small brass cannon
Post by: ChandlerW on December 28, 2012, 06:00:38 PM

Yes that seems to be a problem I'm having. I've never drawn a dxf for a lathe. I can do mills no problem.
And someone told me lathes are easier than mills because there are only 2 axis.
How is the drawing setup in autocad? My defaults axis are x and y.
Do I need to setup the drawing along the x and z axis?

I'll fix that wrong quadrant thing.

Title: Re: Need G Code for a small brass cannon
Post by: ChandlerW on December 28, 2012, 06:26:29 PM

Ok, found appendix B. I'm all over it. It says to orient the drawing along the x and y.

Title: Re: Need G Code for a small brass cannon
Post by: RICH on December 29, 2012, 07:50:29 AM

Just draw the profile anywhere and when it's complete select the complete profile and move it such that
it is placed as shown in reply #6. Y will become X and x will become z on import to Lazyturn.
All covered in the manual.

RICH