CAMBAM/MACH3 - no rapids...

[wildwhl]

Hello -

working with the 0.9.8 demo. Pretty new here - been using G-simple for about 9 months on my converted X2.

So far liking what I see - but in first test file I've made I have a problem. When I run the simulation in Mach 3, the feedrate never goes above 1.

I have cut feedrate set to 10, and plunge set to 1.

Stepover feedrate is set to: cut feedrate.

Even from the start, when moving into position, feedrate remains 1. Mach 3 shows the correct speedrate in the set value...yet it runs at 1/10th. Finally, using cncsimulator the feedrates appear to be fine. I am using the Mach3 post-processor output setting in CAMBAM.

Suggestions?

Bill

[10bulls]

Hello Bill,

I've not come across that problem before.

Could you upload a CamBam drawing (.cb file) and I will look to see if I can spot anything?

If Mach is reporting the correct speed but not moving at that speed then is sounds like it might be a Mach3 configuration problem. The only other thought is that your drawing units may be set to millimetres rather than inches (set from the units drop down on the toolbar). The the gcode would be read as 10mm/min rather than 10in/min .... but the size would be wrong too.

[wildwhl]

Thank you 10Bulls -

here is the file. In fairness - I haven't actually tried to run the file in Mach 3 on my mill - only on the demo version of Mach 3 that is currently loaded on this (new to me) laptop.

Your input is greatly appreciated.

Bill

[wildwhl]

Bump....

Just sent the file to the mill for real, and same issue - cutspeed is always either 1 IPM or .6IPM (Plunge). Verified the drawing is correct dimensions (inches) and size (let it run for a LONG time to make an initial pass of the first element and measured).

Confused...and anxious to move forward from this CAM brain-lock I currently have

Bill

[Paulo Nobre]

Dear Friends,
I am having big problems, I use Mastercam for drawing and machining program of the work piece, everything is fine in the Mastercam simulator.
When I transfer the data to Mach3 a lot of errors accour and can not do the job properly, most of the times the program gets blocked and can´t
get anywhere which quite frustrating.
Does anyone know how can I solve this problem? Is Mastercam compatible with Mach3? Is any way we can make it possible to work?
Best regards.
Paulo Nobre

[10bulls]

Originally Posted by wildwhl Bump.... Just sent the file to the mill for real, and same issue - cutspeed is always either 1 IPM or .6IPM (Plunge). Verified the drawing is correct dimensions (inches) and size (let it run for a LONG time to make an initial pass of the first element and measured).

This does indeed sound a bit odd.

My gut feel is this is down to a Mach3 configuration problem somehow.

What do you have for your motor tuning velocity and acceleration settings?
Also make sure your Mach3 default units are set as you would expect (Config - Set Native Units).

The CamBam file looks OK here and runs OK in Mach, but I would suggest setting the fast plunge height value to a non zero height to speed things up.
I've just added a FAQ entry on the main site regarding that here:
CamBam CNC Software - FAQ

Good luck and I hope this helps.

[wildwhl]

Originally Posted by 10bulls This does indeed sound a bit odd. My gut feel is this is down to a Mach3 configuration problem somehow. What do you have for your motor tuning velocity and acceleration settings? Also make sure your Mach3 default units are set as you would expect (Config - Set Native Units).

I've been cutting with the mill via G-simple files for about 7-8 months (good fun it is!). Off the top of my head the accel is around 1-2 and the rapids are in the 50-75 ipm range (depends on the axis).

Originally Posted by 10bulls CamBam file looks OK here and runs OK in Mach, but I would suggest setting the fast plunge height value to a non zero height to speed things up. I've just added a FAQ entry on the main site regarding that here: CamBam CNC Software - FAQ Good luck and I hope this helps.

Thank you very much for looking at the file - it is greatly appreciated. I'll keep mussing around here - and I had actually already discovered a post somewhere on the web indicating the fast plunge change. All good information.

Once I figure out what the ailment was - I'll post the medicine here for others to administer should they come down with the same sickness

Bill

[wildwhl]

Welll what do you know. I decided to start a new project (tic tac toe board) and it seems to run just fine. I'm guessing it has something to do with the method with which I imported my previous project (just a dxf from G-simple).

Thanks for the help 10bulls.

I have another question regarding chamfer and finish passes - but started a thread elsewhere.

Gracias.

Bill

[10bulls]

Originally Posted by wildwhl Off the top of my head the accel is around 1-2 and the rapids are in the 50-75 ipm range (depends on the axis).

1-2 is rather slow for acceleration. I would expect you could put this up to at least 10.

I suspect what may be happening is this...

Was your original dxf composed of many small segments?
If so, each of those segments would require an acceleration up then back down again. As the acceleration is low, it sounds like there was not enough time for it to get up to the target feedrate on each segment.

For a tic-tac toe board, if you have long segments then it is more likely to have time to accelerate up to speed.

Another thing that can change this behaviour is constant velocity mode. In CamBam the machining operations have a property Gcode Options - Velocity Mode. Here you can set this to ConstantVelocity.
This should issue a G64 code to Mach3.
In this mode, Mach tries to maintain the feedrate without so much stopping and starting. It can be much faster and smoother using this mode.
However it can tend to overcut corners. The slower your acceleration setting the more pronounced these overcut errors become.