Messages

7191

General Mach Discussion / Re: not circle that is a polygon

« on: August 26, 2010, 01:30:51 PM »

There have recently been a number of ebay listed pirated copies which I have reported and they have eventually been withdrawn but I suspect there are lots of copies in circulation which are "Licensed To: PAPA FABIO".

Tweakie.

7192

Show"N"Tell ( Your Machines) / Re: 6 axis CNC tube bender

« on: August 25, 2010, 11:27:29 AM »

Excellent. I could watch that working all day long. 

(I think we would need to have a lot of guards around a machine like that under our health and safety legislation).

Tweakie.

7193

General Mach Discussion / Re: not circle that is a polygon

« on: August 25, 2010, 08:47:20 AM »

I think that by using circular interpolation you will only cut a circle with 40 sides but the edge finish will be good. If you are getting a poor edge finish then it is something else which is machine related and probably, as Rich has said, mechanical.

These two discs have been shown before but the one on the left has been cut with straight but wobbly lines (bad finish) whereas the one on the right has been cut with 40 straight lines, using circular interpolation (good finish).

Tweakie.

7194

General Mach Discussion / Re: This motherboard is suitable for working with mach3?

« on: August 25, 2010, 06:52:41 AM »

Renato,

I can't remember if it was Rich or Gerry who had the brilliant idea.

Take a copy of Mach on CD when you go to buy the computer and explain you concerns to the seller. If the computer will run the 'Mach Driver Test' you buy it if it doesn't then you don't.

Tweakie.

7195

General Mach Discussion / Re: not circle that is a polygon

« on: August 25, 2010, 06:41:12 AM »

It is not possible to cut a true circle with a flatbed X-Y-Z CNC machine. Because the machine can only move in straight lines the circle must be comprised of straight lines and so is really just an approximation of a circle. (A CNC lathe would, of course be entirely different).
Mach outputs step and direction signals which are also a series of straight line moves - that is the way it works.
The circle quality starts to improve as you get more (shorter) lines up to the point where the GCode gets too long to be practical.

From tests using acrylic and relating to the optical quality of the edge I have found that a 50mm disc comprising 400 straight lines is about the minimum I would like to use. If the diameter of the disc is increased then so does the number of lines used and so on...

One trick with CAD is to draw many times full size then scale the GCode at run time.

Hope this helps.

Tweakie.

7196

Show"N"Tell ( What you have made with your CNC machine.) / Re: Gertrude Gets Some!

« on: August 25, 2010, 04:11:23 AM »

thanks guys, things been slow actually, may need to jump into another industry at some point in the future.. any tips? hints, what can i do other than jewelry that I can apply my skilset too guys?

I think we have been here before Chris.

Nobody ever got rich working for the man and nobody ever got rich working with their hands.

Sorry buddy but you just have to use your head.

Tweakie.

7197

General Mach Discussion / Re: Mach3 and Boxford Duet

« on: August 24, 2010, 03:37:05 AM »

Boxford are unwilling to provide any information which would help with the use of their machines once they have left the education loop and come into the 'second user' domain.

The only really practical solution is to replace the internal electronics driver card etc. with a new driver card which is Mach compatible (I used a cheap Chinese board bought on ebay). Some of the details here may be of help. http://www.cooperman.talktalk.net/files/14.htm

This approach may seem a little extreme but it is not too difficult to do and at the end of the day you finish up with a good machine.

Tweakie.

7198

General Mach Discussion / Re: Spindle delay

« on: August 23, 2010, 08:40:24 AM »

Hi Jim,

Here is a link to the thread and video.  http://www.machsupport.com/forum/index.php/topic,15465.0.html

This has no movement delay whilst the spindle is running up because the spindle only starts / stops when the Z axis has changed direction. This can be achieved by using the Z axis direction pin to switch the spindle rather than the pin associated with the M03 / M05 command.

Tweakie.

7199

FAQs / Re: I do not understand

« on: August 22, 2010, 02:25:01 PM »

Mijn Genoegen.

Tweakie.

7200

FAQs / Re: I do not understand

« on: August 22, 2010, 11:17:09 AM »

Hi Thomss,

The X,Y,Z,4 DRO's are in Units.
If you have selected native units as mm then the DRO's are in mm. (If you have selected native units as Inch then the DRO's are in Inches)
The units for the 4 DRO is usually always Degrees.

Hope this helps,

Tweakie.