Mach 3 Scaling Problem

[Ukie]

I am relatively new to CNC and am in the process of learning and running sample g-code programs on a 3 axis mill routing machine that I recently built. I have encountered a problem with the size of the parts that I am cutting as they are considerably smaller than what the original design calls for.  I have also used the roadrunner program to test my machine and although my machine cuts it out, it end up being quite small. I initially thought that I  had set up Mach 3 incorrectly but when I checked the "Units" setting it was set for inches and the various g-code programs that I have used were also in inches and yet this problem persists. I am at a complete loss as to what is causing this peoblem and would certainly appreciate getitng some advice as to how to fix it.  Much appreciated.

[Tweakie.CNC]

Hi Ukie,

Your Steps Per unit are probably set wrongly in Motor Tuning (perhaps you are using a reduction gearing on your motors or perhaps you are using Microsteps and  have not allowed for this ?)

As far as scale is concerned;
You can see the size of a loaded GCode program in the Toolpath page under Program Limits.
On the main page you can adjust the Scale DRO's (currently set to +1.000) and for example +2.000 (press return key after entry) for X Axis and Y Axis will produce double size and you can check this in the Toolpath page under Program Limits (you need to click the Regen.Toolpath button).

Hope this helps.

Tweakie.

[Ukie]

Thanks. I will give this a try.

[Ukie]

I have tried restting the x and y scales in toolpath but my changes are not being accepted by Mach 3. Settings keep on reverting back to what they were previously. What do I need to do to overcome this?

[Overloaded]

If you are sure you are hitting the RETURN key as Tweak mentioned, then there might be a G50 in the beginning of your code. If so, remopve it as it resets all scale factors to 1.0
RC

[Ukie]

I managed to get the scaling setting figured out. Thanks for your help.