Topics

1

General Mach Discussion / Mach3 Simple Test Program Skips Lines of Gcode

« on: July 09, 2016, 04:05:51 PM »

I am still trying to set my CNC mini-lathe up with the trial version of Mach3. I got the axes to work correctly, but now when I try to test the lathe with a simple turning job, Mach3 blows by lines of Gcode. I would really like to get this thing running and buy a license so I can run long programs. Any idea what could cause this?

I tried a simple turning program, using the Mach3 turning wizard. I was trying to turn the last half-inch of a piece of 0.75" Delrin down to 0.670". The z-axis refused to back up (positive direction). The stepper on that end only recognized commands to go in the negative direction.

I used simple test programs to tune the axes. One program moves the z axis back and forth half an inch without moving the x axis, and the other moves the x axis without moving the z axis.

2

General Mach Discussion / Why Does my Lathe Tool Think it's Inside the Work?

« on: July 01, 2016, 08:24:56 PM »

I gave up on my CNC mini-lathe a long while back, and today I am trying to resurrect it. Sorry to say, I have forgotten a lot.

I was trying to do a simple OD arc (like the round end of a broomstick). The code works fine, except for one thing. It thinks it's starting in the center of the broomstick. Not at the end...inside. It tries to back out before it starts cutting, even though it's already at the outside diameter of the work. Obviously, I can't start it in the center of the work.

Why does my tool think it's in the center of the sphere when I start the program?

I will post the code. It's supposed to make a round end 1" in diameter.

G18 G64 G80 G90 G40 G49
M3
G00 X0.51
G00 Z0.51
F2
G00 Z0.4929
G01 X0.5
G01 X0.5
G03 X0.4929 Z0.5 I-0.5 K-0.4929
G01 Z0.51
G00 X0.51
G00 Z0.4858
G01 X0.5
G01 X0.5
G03 X0.4858 Z0.5 I-0.5 K-0.4858
G01 Z0.51
G00 X0.51
G00 Z0.4786
G01 X0.5
G01 X0.5
G03 X0.4786 Z0.5 I-0.5 K-0.4786
G01 Z0.51
G00 X0.51
G00 Z0.4713
G01 X0.5
G01 X0.5
G03 X0.4713 Z0.5 I-0.5 K-0.4713
G01 Z0.51
G00 X0.51
G00 Z0.464
G01 X0.5
G01 X0.5
G03 X0.464 Z0.5 I-0.5 K-0.464
G01 Z0.51
G00 X0.51
G00 Z0.4566
G01 X0.5
G01 X0.5
G03 X0.4566 Z0.5 I-0.5 K-0.4566
G01 Z0.51
G00 X0.51
G00 Z0.4491
G01 X0.5
G01 X0.5
G03 X0.4491 Z0.5 I-0.5 K-0.4491
G01 Z0.51
G00 X0.51
G00 Z0.4416
G01 X0.5
G01 X0.5
G03 X0.4416 Z0.5 I-0.5 K-0.4416
G01 Z0.51
G00 X0.51
G00 Z0.434
G01 X0.5
G01 X0.5
G03 X0.434 Z0.5 I-0.5 K-0.434
G01 Z0.51
G00 X0.51
G00 Z0.4264
G01 X0.5
G01 X0.5
G03 X0.4264 Z0.5 I-0.5 K-0.4264
G01 Z0.51
G00 X0.51
G00 Z0.4186
G01 X0.5
G01 X0.5
G03 X0.4186 Z0.5 I-0.5 K-0.4186
G01 Z0.51
G00 X0.51
G00 Z0.4108
G01 X0.5
G01 X0.5
G03 X0.4108 Z0.5 I-0.5 K-0.4108
G01 Z0.51
G00 X0.51
G00 Z0.4029
G01 X0.5
G01 X0.5
G03 X0.4029 Z0.5 I-0.5 K-0.4029
G01 Z0.51
G00 X0.51
G00 Z0.3948
G01 X0.5
G01 X0.5
G03 X0.3948 Z0.5 I-0.5 K-0.3948
G01 Z0.51
G00 X0.51
G00 Z0.3867
G01 X0.5
G01 X0.5
G03 X0.3867 Z0.5 I-0.5 K-0.3867
G01 Z0.51
G00 X0.51
G00 Z0.3785
G01 X0.5
G01 X0.5
G03 X0.3785 Z0.5 I-0.5 K-0.3785
G01 Z0.51
G00 X0.51
G00 Z0.3702
G01 X0.5
G01 X0.5
G03 X0.3702 Z0.5 I-0.5 K-0.3702
G01 Z0.51
G00 X0.51
G00 Z0.3617
G01 X0.5
G01 X0.5
G03 X0.3617 Z0.5 I-0.5 K-0.3617
G01 Z0.51
G00 X0.51
G00 Z0.3531
G01 X0.5
G01 X0.5
G03 X0.3531 Z0.5 I-0.5 K-0.3531
G01 Z0.51
G00 X0.51
G00 Z0.3444
G01 X0.5
G01 X0.5
G03 X0.3444 Z0.5 I-0.5 K-0.3444
G01 Z0.51
G00 X0.51
G00 Z0.3355
G01 X0.5
G01 X0.5
G03 X0.3355 Z0.5 I-0.5 K-0.3355
G01 Z0.51
G00 X0.51
G00 Z0.3264
G01 X0.5
G01 X0.5
G03 X0.3264 Z0.5 I-0.5 K-0.3264
G01 Z0.51
G00 X0.51
G00 Z0.3172
G01 X0.5
G01 X0.5
G03 X0.3172 Z0.5 I-0.5 K-0.3172
G01 Z0.51
G00 X0.51
G00 Z0.3077
G01 X0.5
G01 X0.5
G03 X0.3077 Z0.5 I-0.5 K-0.3077
G01 Z0.51
G00 X0.51
G00 Z0.2981
G01 X0.5
G01 X0.5
G03 X0.2981 Z0.5 I-0.5 K-0.2981
G01 Z0.51
G00 X0.51
G00 Z0.2882
G01 X0.5
G01 X0.5
G03 X0.2882 Z0.5 I-0.5 K-0.2882
G01 Z0.51
G00 X0.51
G00 Z0.278
G01 X0.5
G01 X0.5
G03 X0.278 Z0.5 I-0.5 K-0.278
G01 Z0.51
G00 X0.51
G00 Z0.2676
G01 X0.5
G01 X0.5
G03 X0.2676 Z0.5 I-0.5 K-0.2676
G01 Z0.51
G00 X0.51
G00 Z0.2568
G01 X0.5
G01 X0.5
G03 X0.2568 Z0.5 I-0.5 K-0.2568
G01 Z0.51
G00 X0.51
G00 Z0.2457
G01 X0.5
G01 X0.5
G03 X0.2457 Z0.5 I-0.5 K-0.2457
G01 Z0.51
G00 X0.51
G00 Z0.2341
G01 X0.5
G01 X0.5
G03 X0.2341 Z0.5 I-0.5 K-0.2341
G01 Z0.51
G00 X0.51
G00 Z0.2221
G01 X0.5
G01 X0.5
G03 X0.2221 Z0.5 I-0.5 K-0.2221
G01 Z0.51
G00 X0.51
G00 Z0.2095
G01 X0.5
G01 X0.5
G03 X0.2095 Z0.5 I-0.5 K-0.2095
G01 Z0.51
G00 X0.51
G00 Z0.1962
G01 X0.5
G01 X0.5
G03 X0.1962 Z0.5 I-0.5 K-0.1962
G01 Z0.51
G00 X0.51
G00 Z0.182
G01 X0.5
G01 X0.5
G03 X0.182 Z0.5 I-0.5 K-0.182
G01 Z0.51
G00 X0.51
G00 Z0.1669
G01 X0.5
G01 X0.5
G03 X0.1669 Z0.5 I-0.5 K-0.1669
G01 Z0.51
G00 X0.51
G00 Z0.1503
G01 X0.5
G01 X0.5
G03 X0.1503 Z0.5 I-0.5 K-0.1503
G01 Z0.51
G00 X0.51
G00 Z0.1319
G01 X0.5
G01 X0.5
G03 X0.1319 Z0.5 I-0.5 K-0.1319
G01 Z0.51
G00 X0.51
G00 Z0.1107
G01 X0.5
G01 X0.5
G03 X0.1107 Z0.5 I-0.5 K-0.1107
G01 Z0.51
G00 X0.51
G00 Z0.0846
G01 X0.5
G01 X0.5
G03 X0.0846 Z0.5 I-0.5 K-0.0846
G01 Z0.51
G00 X0.51
G00 Z0.0459
G01 X0.5
G01 X0.5
G03 X0.0459 Z0.5 I-0.5 K-0.0459
G01 Z0.51
G00 X0.51
G00 Z0.0448
G01 X0.5
G01 X0.5
G03 X0.0448 Z0.5 I-0.5 K-0.0448
G01 Z0.51
G00 X0.51
F0.5
G00 Z0
G01 X0.5
G01 X0.5
G03 X0 Z0.5 I-0.5 K-0
G01 Z0.51
G00 X0.51
M5
M30

3

General Mach Discussion / Steps/Inch on Lathe = 75,000; Seems a Tad High

« on: August 30, 2014, 02:05:34 PM »

My last post got me no responses, but maybe I'll get lucky this time.

I am trying to adjust my mini-lathe steppers so the distances on the Mach3 screen have some relationship to reality. My z screw is 8 TPI, so 8 turns per inch. At 200 steps/turn, you would think I would be fine with 1600 steps/inch, but I am very close to correct with 6667 steps/inch. Obviously, something is messed up. I don't see any obvious relationship between 6667 and 1600. Maybe the correct figure is 6400, meaning I'm off by a factor of four for some reason, but I still have no idea what that reason is.

My x screw is 25 TPI, so presumably 5000 steps/inch. The figure I'm actually using is 75000!

Mach3 is set up for inches, but it says not to use this setting to change the way it reacts to G code. I can't find any other setting.

I am using a Kflop and Kstep. KMotion is set up in Step/Dir mode.

4

General Mach Discussion / X Axis Goes Backward in Mach3 Turn

« on: August 28, 2014, 01:46:46 PM »

I have a new mini-lathe running, but the x axis insists on moving backward. I am using Mach3 turn in Radius Mode. My controller is a Kflop with a Kstep.

I was told that in Mach3, +x means toward the user (away from the axis), because x is actually the radial direction. When I use the Turn Wizard or test code I wrote for myself, the x axis insists on moving the wrong way. The toolpath on the screen shows one thing, and the actual movement does another.

I changed the sign of the output gain in KMotion, and nothing happened. I also used the Reverse setting in Mach3. No change. I am reluctant to fool with the motor wiring.

Is there something I've overlooked?

This is my first CNC tool, and I have no background in engineering, so I really don't understand all the variables. I also have a problem with the steps per inch. Right now, my z is at 6667 with an 8-TPI screw, and the x is at 75000 with 25 TPI instead of the expected 5000. The movement magnitudes are nearly correct but I haven't calibrated them exactly.

5

FAQs / New Guy; Questions About Controllers, Threading

« on: July 14, 2014, 01:10:53 PM »

I thought this was a typical FAQ area, but it looks like it's devoted to noob questions, so here I am. I hope this is the right subforum.

I am just about done making the parts to convert a mini-lathe to CNC. Now I have to think about software and electronics. I am hoping to get some solid advice. I know virtually nothing. I plan to use Mach 3 because virtually everyone recommends it.

First, people have suggested I go with ethernet because it allows for longer cables. I have seen folks recommending Smoothstepper controllers, but I have also seen people claiming there are issues with them. Are they a good choice?

Second, I definitely want to thread, but I have read about people having problems with threading. Can I expect to be able to do this with Mach 3?

Thanks for any help you can provide.