GRBL Multi-Axis Post Processor

[tsmarks]

I am piecing together a post processor script for multi-axis GRBL machines.  (i.e. Arduino Mega with a 6 Axis)  I have successfully tested the 4th axis function.  With my limited experience, I think it works flawlessly.  

I would like to give back to the community by sharing the script. (attached below) And, I would like some feedback/testing.  If you have a multi-axis GRBL machine, give it a try and let me know what works or doesn't.

[stnly_cry]

I'm using an open builds 3 axis machine with the Y converted to a rotary. Using this post how would I change the script to achieve this. I have not edited a post before. Everything looks fine on the CAM, but I'm getting a fail to post with the error "direction not supported for machine configuration "

 

[ethier.jeanpierre]

To my knowledge this version of GRBL is for 4,5 axis controllers with
the mega5x firmware using the arduino mega 2560 controller and the 5
axis ramps 1.5-1.6 board using separate drivers, i believe using the Y
axis as the 4 th axis, will generate an error, also, you need to edit
your machine configuration for 5 axis in the machine config in fusion
360.
Hope this info Helps !

Jean-pierre

[stnly_cry]

I used one of the above mentioned post edits grbl6axis (2) from engine guy. It sent the code, but the machine had an error 20 code, unrecognized gcode. I attemped to edit the post and remove the A and C axis since im only using B, but the post failed to process. Im sure i did something wrong in the edit. Again im using a 3 axis open builds with the Y as the rotary. I tried to link the post but i cant seem to get it to paste in here. Is anyone able to help with editing the post processor to suit this machine?

[engineguy]

@stnly_cry 

Try the attached PP, I have set it to just output the X/Y/Z and B axis, hopefully it will work for you.

[stnly_cry]

I'm still having the same issue, but I think it may be within fusion. I aligned the setup with X along the centerline or length of the part, since my gantry is fixed and the X moves along it, but when I choose the rotary plug in for for the tool path it wants to make X the rotary axis. It will fail to send code this way. If I set it as Y as the centerline it will send the gcode, but the code shows Y and B as having movement. I think that may be why it's sending the error 20 code on the machine with the contradicting movements to the same motor.

@engineguy 

[ratan98manish]

i am having issue in it while i am using 4th and 5th axis its getting zero again and again

like i firstly doing face from z then turn it 90 degree for doing facing both 4 sides of 

its turns well

but when it has to be rotate about 90 , 180 , 270 ,360 degree

but after doing first opertion at (0 or 360) after turning  it goes again in top postion again to  0 but it has to go in 90 . 

its exporting coordinates is not correct

if i going to correct it manually editing in gcode for A and B axises then it works very good but when i sent it through by post processor it goes wrong 

i need help in making postprocesor  for axis 4 and 5 for fusion 360 please help 

[ethier.jeanpierre]

Hi guy's, its me again with a weird one,   I get a failed to generate  tool path using the grbl post processor  when i setup mY  tool setting, in the section  where you define  either  flood or mist  this is where it gets weird  ,  If I choose either   flood or mist  no issues there, but if I  choose flood and mist  the post processor  comes up with an error !   thanks.

JeanPierre

[ezinser]

Thanks for posting this, I am building a cnc using GRBL5x , so your post will surely be very helpful. If I have any problems I will let you know.

Best

[nickPB4HT]

I´ll gave the PP a try but fusion reported that the machine simulation is not working with this PP. 

Is there any chance to get it working as the simulation is essential for the multi-axis work?

[tsmarks]

Unfortunately, my account no longer has access to simulations. I
can't test or work on this.

Tim

[godeye]

hi 

i want to creat 5 axis cnc wich is going to be (BC) head_table architecture the axis B attched on the head and the axis C attechedto the table , is it possible to use this post processor to generate gcode or there is pre programmed post processors in fusion .

thanks,

[godeye]

 i want to creat 5 axis cnc machine with BC head_table architecture , the B axis attached to the head and the C axis attached to the table with 360 degrees  , is it possible to use this post processor to generate gcode or there is preprogrammed post processor in fusion 360. 

thanks,

[sales]

These post processors are working nicely! I have my rotational axis aligned with my Y axis on the router table and "B" seems the appropriate output for these moves, but is what would be the procedure for altering this PP to output rotational moves to A instead of B? I'm asking because depending on the grblHAL controller used, B may not work. Any input would be welcome. I can open the cps and look, but it seems quite daunting. Perhaps a quick and dirty guide, "alter these lines to change angle output to A," would be very helpful.

Thanks for this!

[9056620232]

I don't know what the problem is, but it's showing completely random feed rates even though I set the working feed rate to 1500 mm per minute. I've checked all the machine settings, and the maximum feed rate is set to 1500 everywhere.

[9056620232]

G93 X-17.944 Z12.222 A-47.694 F1341.45
X-17.696 Z11.792 A-48.819 F1356.83
X-17.712 Z11.823 A-49.001 F13811.66
X-17.727 Z11.846 A-49.168 F15997.86
X-17.738 Z11.869 A-49.336 F16571.08
X-17.75 Z11.886 A-49.504 F17902.22
X-17.758 Z11.904 A-49.672 F18548.4
X-17.767 Z11.915 A-49.84 F20318.47
X-17.772 Z11.927 A-50.008 F21082.22
X-17.777 Z11.932 A-50.175 F23473.16
X-17.778 Z11.938 A-50.343 F24417.16
X-17.776 Z11.933 A-61.209 F440.68
X-17.772 Z11.929 A-61.363 F26042.4
X-17.768 Z11.919 A-61.516 F23556.48
X-17.761 Z11.909 A-61.67 F22764.83
X-17.744 Z11.88 A-61.977 F10273.61
X-17.722 Z11.841 A-62.284 F9230.69
X-17.704 Z11.808 A-62.495 F12317.04
X-17.948 Z12.231 A-63.599 F1383.1
X-18.191 Z12.653 A-64.703 F1367.71
X-17.948 Z12.231 A-63.599 F1367.71
X-17.704 Z11.808 A-62.495 F1383.1
X-17.67 Z11.832 A-62.55 F19043.55
X-17.603 Z11.87 A-62.649 F10214.99
X-17.535 Z11.898 A-62.723 F11277.11
X-17.501 Z11.907 A-62.754 F24082.66
X-17.467 Z11.917 A-62.772 F25687.42
X-17.434 Z11.922 A-62.791 F26328.13
X-17.4 Z11.926 A-62.797 F28239.75
X-17.014 Z11.927 A-62.8 F2587.47

Why does grbl6axis post processor give random feed values ​​even though I set the maximum to 1500 mm per minute?

[rosie_lucas1]

Hi @9056620232, 
I wanted to check in and see if you still needed assistance, or if you found a solution to your question already? Let us know if you need further assistance by providing an update or if you have found a solution, please share it with the community so other members who may have the same question could learn from your experience.

All the best,

Rosie | Community Manager

[programming2C78B]

Inverse time is a feedrate used for simultaneous multi axis machining. Linear axis feed in inches (or MM) per minute. Rotary axis feed in degrees per minute. To get all axis feeding correctly together they use inverse time.

[rosie_lucas1]

Hello @9056620232 ,

Did the information provided by @programming2C78B help you and answer your question?

If yes, please click on the "Accept Solution" button on the post(s) that solved your problem. This will assist other community users in finding and benefiting from this information.

If not, please do not hesitate to give an update in this thread so all community members receive an update on the progression of your question, and can suggest next steps that may be helpful for you to achieve what you're looking for.

All the best,

Rosie | Community Manager