[coby_johnson]

Hello all, I'm a CNC newbie who needs some help.

I have a small hobby router kit I put together w/ the trial of Mach3 and educational Fusion 360 for CAD/CAM, I found a piece of scrap wood 4x4x1 or so stock and wanted to use it to practice generating my own toolpaths (got the sample .nc toolpaths that came w/ my router to work). Generated a simple part with channel through the center in Fusion. When I ran it, it was moving in a small area, I believe the gcode is running correctly as the coordinates matched it on the Mach UI. The problem is the scaling of my coordinates... when I jogged the tool to center of my piece where I am trying to cut a channel through it the coordinates were 15 or 30 (which isn't conversion to mm) and larger than my stock dimensions.

Any clue what could be causing the coordinate scaling problem and if the solution would be in Fusion, Mach3, or either?

[machinehop5]

...welcome to the zone.

Work Offsets ? read thru this thread may help ya.
https://www.cnczone.com/forums/machi...retention.html

[coby_johnson]

Thanks for jumping in machinehop5, I read your thread and watched a video on work offsets.

Setting work offsets is zeroing the machine to the stock using probe or jogging (manually clicking zero axis on Mach) correct, or is it more involved to define the scale of the coordinates? If it is just zeroing I don't think its the problem, I was careful about setting my Work Coordinate System and origin in Fusion and zeroing the machine on the stock before operation. Instead it is the scaling of that coordinate system not translating from inches (fusion / gcode) to Mach coordinates. For example my stock is 4 x 4" from top view, so the channel should start cutting at X4 Y2, but for Mach that is just the area around the zero corner. The place I want my channel is ridiculously high like 30-40 Mach units.

Don't know if that explains the problem better, sorry if my wording is unclear
Thanks for help

[machinehop5]

...G51 is Scaling. G50 to reset Scaling of all axis to 1.0 for Mach3 code. G20(Inches) G21(MM) sets the Units for Mach3
https://machmotion.com/downloads/GCo...-Reference.pdf
maybe post your Program would help...use the Go Advanced button in reply to upload

[coby_johnson]

Here is GCode, I took out all the positional lines, notice it does the G20 you mentioned to make it inches which surprised me but doesn't do a G54 command until after 2d Adaptive operation starts.

(1001)
(0.125 L END MILL SIMPLE SMALL CHANNEL IN SCRAP WOOD)
(MACHINE)
( VENDOR AUTODESK)
( DESCRIPTION GENERIC 3-AXIS)
(T1 D=0.125 CR=0. - ZMIN=-0.23 - FLAT END MILL)
G90 G94 G91.1 G40 G49 G17
G20
G28 G91 Z0.
G90

(2D ADAPTIVE1)
M5
T1 M6
S5000 M3
G54
G0 X3.9592 Y1.9446
G43 Z0.6 H1
Z0.2
Z-0.1
G1 Z-0.1125 F40.
X3.9589 Y1.9447 Z-0.1153
X3.958 Y1.9449 Z-0.1179

...

X0.0558 Y1.9448 Z-0.2203
X0.0555 Y1.945 Z-0.2175
G0 Z0.6

G28 G91 Z0.
G90
G28 G91 X0. Y0.
G90
M30

[machinehop5]

...program looks ok. Should produce something about 3.500" long in X .2175" deep. Mach3 Parameters maybe your problem

[coby_johnson]

Okay, glad the program looks good thats a start

What do you mean by Mach3 parameters, I don't understand what you're referring to here

Thanks for the help

[ZASto]

Have you calibrated your axes?
What are your Mach settings?

[machinehop5]

Have you calibrated your axes?
What are your Mach settings?

...agreed. Next, would be checking command distance vs axis movement.
https://www.google.com/search?q=mach...client=gws-wiz

[coby_johnson]

I think this is my problem, I haven't done this. Will do some googling (your link) and try this.

Thanks guys!