Topics

1

General Mach Discussion / Radius of arc differs - but a different sort of problem

« on: December 28, 2020, 06:53:07 PM »

I'm getting the dreaded "radius of arc differs" error, but with a twist.
My code begins like this:

Code: [Select]

( Made using CamBam - http://www.cambam.co.uk )
( Bottom3 12/28/2020 12:39:25 PM )
( Post processor: Mach3 )
( T4 : 0.236 )
G20 G90 G64 G40
G91.1

The program errors out in the simulator on the marked line:

Code: [Select]

(many lines of previous pocketing operation omitted)
S19600
G0 Z0.75
G0 X8.2874 Y0.8916
G1 F25.0 Z0.375
G1 F75.0 X8.2708 Y0.8244
G2 X8.2707 Y0.8242 I-0.1213 J0.03
G1 X8.2018 Y0.5483
G2 X8.2016 Y0.5475 I-0.1213 J0.0303
G1 X8.1167 Y0.2176
G2 X7.9737 Y0.1257 I-0.1211 J0.0312
G1 X7.3166 Y0.2429
G2 X7.3149 Y0.2432 I0.022 J0.1231
G1 X6.6596 Y0.3695
G2 X6.6579 Y0.3699 I0.0237 J0.1227
G1 X6.0043 Y0.5053
G2 X6.0026 Y0.5057 I0.0254 J0.1224  <<------------error here
G1 X5.351 Y0.6501
G2 X5.3493 Y0.6505 I0.0271 J0.122
G1 X4.6998 Y0.804
(more code follows ...)

So, it's incremental mode and the website says to use absolute.
OK, so let's change the G91.1 to G90.1
Now things get weird. I still get the radius differs error message. But I also get incorrect tool paths in the preview. Instead of drawing/cutting 10-15° of arc, it draws the compliment - 350° or so.

Since debugging this on the laptop in my office is more comfortable than standing over the machine in the shop, I copy the g-code file and the Mach3 XML configuration file and bring them to my office.

I launch Mach3 using the config file from the shop computer and run the g-code. No error with either G90.1 or G91.1. Same funky toolpath with the G90.1 setting.

One more oddity:
If I launch Mach3 on the shop computer and don't hit reset, then load the g-code and run simulate, I don't get the error. But Mach3 launches in metric units and my initialization string - G80 G20 F1905 S1000 - isn't being executed so the DROs continue to appear in metric units in spite of the G20 at the start of the program. Even if I return to the Program Run tab, reset does not set the DROs to inch.

Both computers are running 3.043.066, and have been for several years with no problems like this.
I've been running CamBam for a while, as well, and have successfully run quite a few programs of comparable complexity (or worse).
The main difference is that one computer is actually connected to a controller.

I'm at a loss where to look next. Suggestions (preferably other than reinstall)?

2

General Mach Discussion / issue with homing macro

« on: October 27, 2020, 07:32:04 PM »

I have a fairly simple macro that touches off against a reference block to zero the X and Y axes. The machine moves 1" in +X, then moves in +Y till it makes contact, and sets the DRO. Next it  moves back to the starting position, moves 1" in +Y, then moves in +X until it makes contact and sets the DRO.

The macro has worked for quite a while (months). In the past day or two the behavior is bizarre. It will run the first time or two I invoke it (from a button on my pendant). But the next time, it will start up and run through the Y contact, but then instead of returning to the starting position, it moves towards the starting position but also moves in the +Z direction. Since there are no Z moves in the macro, this is extra baffling. If I restart Mach3 (but not the machine or interface board), all is good again for one or two runs of the macro.

Other than this, Mach3 and the machine seem to run normally.

Any ideas on what to look at?

3

General Mach Discussion / Using G54-G59 in macro?

« on: September 13, 2020, 06:06:56 PM »

I have a very simple macro to position my router above the touchplate  that relies on offsets saved in fixture 6 (G59):

Code: [Select]

code ("G59")
code (G0 x0 y0 z0)
code ("G54")
If I type this code manually it works fine. But in the macro the change of fixture offset doesn't seem to get recognized and the machine moves to the origin of the current fixture offset (usually G54). How do I make this work?

Bonus credit - how to a read the save and restore fixture current when the macro starts instead of relying on it's being G54?

Thanks

4

General Mach Discussion / Program has error in simulator, not in actual run

« on: October 24, 2016, 06:23:49 PM »

I tried to time a program in simulation mode (Tool path screen) and it fails with an error that the radius at the start and end of an arc don't match. The odd thing is that I can run the program in actual execution mode with no error. I would have thought the simulator and execution mode would have behave the same.

5

General Mach Discussion / Z-Probe macro for inches and millimeters

« on: April 09, 2016, 05:56:11 PM »

This Z-probe macro that works fine for me, as long as Mach3 is in inches:

Code: [Select]

Message( "Auto Zeroing..." )
If IsSuchSignal (22) Then
code "G31 Z-1 F10"
While IsMoving()
Wend
Call SetDRO( 2, .996 )
code "G1 Z1.5"
End If
 
But if the previous program is in millimeters, the distances and speeds are all wrong. I've tried adding a G20 ahead of the G31 in the code statement, but it appears to have no effect.
Any idea how to make this work?
Thanks

6

G-Code, CAD, and CAM discussions / Radius to end of arc differs from radius to start - again

« on: September 04, 2015, 03:27:08 PM »

I've read the previous posts on this, but they don't seem to apply.
I've got some g-code generated by CamBam that generates the error in the title.

The first line of the g-code is this:
G20 G90 G91.1 G64 G40

So it is indeed setting to incremental mode.

From there we do some cuts:

Code: [Select]

G17
M3 S18000
G0 X9.6381 Y7.9253
G1 F25.0 Z-0.0625
G3 F75.0 X9.5305 Y8.0994 I-5.7097 J-3.4091
G3 X9.7452 Y8.1213 I-0.5667 J6.6258
G3 X9.6381 Y7.9253 I5.7815 J-3.2859
G1 F25.0 X9.8152 Y7.8324
G3 F75.0 X9.65 Y7.4938 I5.7114 J-2.997
G3 X9.1676 Y8.2784 I-5.7216 J-2.9776
G3 X10.1402 Y8.3834 I-0.2037 J6.4468
G3 X9.8152 Y7.8324 I5.3865 J-3.548
G1 F25.0 X9.9923 Y7.7394
G3 F75.0 X9.6637 Y7.0005 I5.5343 J-2.9041
G2 X9.6589 Y7.0111 I0.3796 J0.1779
G3 X8.762 Y8.4785 I-5.7305 J-2.4948
G3 X10.5185 Y8.6716 I0.2018 J6.2467
G2 X10.5008 Y8.5655 I-0.2609 J-0.0112
G1 Y8.5654
G2 X10.4689 Y8.507 I-0.2433 J0.095
G3 X9.9923 Y7.7394 I5.0578 J-3.6717
G1 F25.0 X10.1694 Y7.6465

so far, so good. Numerous straight line cuts and arcs as well.

Then we come to this:

Code: [Select]

G3 F75.0 X9.7499 Y6.6331 I5.3572 J-2.8111

and I get the error. This is in the Tool Path screen, running Simulate Program Run. And for what it's worth, the graphics window shows exactly what I expect the path looks like.

To make it even more confusing -
This error occurs on the PC in the shop controlling the machine.
If I run this on the machine in my office to which I copied the machine's XML file, the error does not occur.

I'm lost here.

7

General Mach Discussion / Save/restore machine position

« on: July 24, 2015, 11:47:48 PM »

Is there any way to save the machine's position when shutting down Mach3 and restore the values on startup? It doesn't appear that there are a macros reserved to run at startup or shutdown, which would allow development of a macro for this purpose. I realize that for stepper-motor based machines this might not be the most accurate way to go if the machines moves a couple of steps when powered up (as far as I can tell, mine doesn't suffer this malady). Even if not fully accurate, it would allow writing a macro that moves the machine very close to home, the ref all axes.

8

Mach SDK plugin questions and answers. / MPG over USB?

« on: June 12, 2015, 09:48:54 AM »

Sorry for cross-posting, but it seems this might be a better forum to post this question:

I have Mach3 connected via USB to a Xulifeng (aka Leafboy) controller card. I just bought an XHC HB04 pendant with an MPG. All the functions work except for the MPG. The wheel itself works in continuous and step mode. In MPG mode it operates as if it's in step mode. After much head-scratching is occurs to me that the MPG might be incompatible with this setup. Unlike parallel cards where Mach3 is sending steps, the USB interface is sending some higher level commands. It occurs to me that the USB interface might not support MPG, either because Mach3 doesn't offer low enough level commands, or because the vendor didn't implement the MPG level commands. Anyone know which of these many possibilities is correct?

Thanks

9

General Mach Discussion / USB controller card and MPG

« on: June 10, 2015, 09:32:11 PM »

I have Mach3 connected via USB to a Xulifeng (aka Leafboy) controller card. I just bought an XHC HB04 pendant with an MPG. All the functions work except for the MPG. The wheel itself works in continuous and step mode. In MPG mode it operates as if it's in step mode. After much head-scratching is occurs to me that the MPG might be incompatible with this setup. Unlike parallel cards where Mach3 is sending steps, the USB interface is sending some higher level commands. It occurs to me that the USB interface might not support MPG, either because Mach3 doesn't offer low enough level commands, or because the vendor didn't implement the MPG level commands. Anyone know which of these many possibilities is correct?

Thanks

10

General Mach Discussion / what is Mach3 sending to the controller over the USB connection?

« on: March 30, 2015, 11:15:43 PM »

Is Mach3 sending step pulses, some higher level trajectory information, or perhaps even g-codes? Perhaps different USB controllers accept different level inputs. Is there an easier way than snooping on the USB port to tell what's going back and forth?
For what it's worth, I'm using a Xulifeng Mach3 USB Board, sometimes labeled as the AKZ250. The USB interface is handled by an ATMEL mcu, it looks like the stepper pulse formation in going on in an Altera CPLD.