Maintaining constant velocity while switching on an output
18 Oct 2019 18:37 #148213
by Arthur1
We are currently working on a project in which we apply are applying a patch of spray to a metal surface. This requires getting our CNC machine up to speed then turning on the spray (using the coolant flood command) at a precise position and then turning it off again at a precise position after it has traversed the desired patch. The problem we are having is that the machine slows down in between moves where we turn the spray on. This leads to the edges of the patch receiving a heavier treatment than the rest. I've made sure that G64 is turned on. We are running at relatively high speeds (300 ipm - 600 ipm). We are using a modified Shopbot system with a Mesa 5i25 -7i76 card setup. Is there any way we could do this while maintaining constant velocity? Or is there a way to signal the spray to turn on during the middle of a move? I feel like I'm missing something obvious.
A sample of the G-Code I'm using:
%
G17 G20
G80 G94
G64
G90
G1 Z 0.1 F50
G91
G1 F300
G1 X 3
M8
G1 X 3
M9
G1 X 3
G1 X -3
M8
G1 X -3
M9
G1 X -3
%
Thanks
A sample of the G-Code I'm using:
%
G17 G20
G80 G94
G64
G90
G1 Z 0.1 F50
G91
G1 F300
G1 X 3
M8
G1 X 3
M9
G1 X 3
G1 X -3
M8
G1 X -3
M9
G1 X -3
%
Thanks
Please Log in or Create an account to join the conversation.
- tommylight
- Away
- Moderator
Less
More
- Posts: 19112
- Thank you received: 6403
18 Oct 2019 18:52 #148214
by tommylight
Replied by tommylight on topic Maintaining constant velocity while switching on an output
linuxcnc.org/docs/html/gcode/m-code.html#mcode:m62-m65
Have a look at those, using flood or mist is not viable for that, as you've noticed.
Have a look at those, using flood or mist is not viable for that, as you've noticed.
Please Log in or Create an account to join the conversation.
- Todd Zuercher
- Offline
- Platinum Member
Less
More
- Posts: 5007
- Thank you received: 1440
18 Oct 2019 19:20 - 18 Oct 2019 19:24 #148219
by Todd Zuercher
Replied by Todd Zuercher on topic Maintaining constant velocity while switching on an output
You will want m62,m63 since m64 and m65 will be queue busters just like m8 and m9.
Last edit: 18 Oct 2019 19:24 by Todd Zuercher.
Please Log in or Create an account to join the conversation.
18 Oct 2019 19:49 #148222
by Arthur1
Replied by Arthur1 on topic Maintaining constant velocity while switching on an output
Thanks for the response. I tried setting up and using the M62 and M63 commands but still have the same issue. The motion slows down significantly between the linear moves.
Please Log in or Create an account to join the conversation.
- tommylight
- Away
- Moderator
Less
More
- Posts: 19112
- Thank you received: 6403
18 Oct 2019 19:51 #148223
by tommylight
Replied by tommylight on topic Maintaining constant velocity while switching on an output
Might have to increase acceleration quite a bit.
Please Log in or Create an account to join the conversation.
- Mike_Eitel
- Offline
- Platinum Member
Less
More
- Posts: 1150
- Thank you received: 184
19 Oct 2019 09:32 #148313
by Mike_Eitel
Replied by Mike_Eitel on topic Maintaining constant velocity while switching on an output
Look for G64. Probably you demand that stopping.
Please Log in or Create an account to join the conversation.
21 Oct 2019 13:00 #148467
by Arthur1
Replied by Arthur1 on topic Maintaining constant velocity while switching on an output
I increased the acceleration significantly and it seems to have helped but there is still a very clear slow down stutter between moves.
Please Log in or Create an account to join the conversation.
- Todd Zuercher
- Offline
- Platinum Member
Less
More
- Posts: 5007
- Thank you received: 1440
21 Oct 2019 14:25 - 21 Oct 2019 14:29 #148469
by Todd Zuercher
Replied by Todd Zuercher on topic Maintaining constant velocity while switching on an output
Are you sure you tried it with M62 and M63?
It doesn't seem to slow in my simulation, (It does slow with M64/M65 and M8/M9)
It doesn't seem to slow in my simulation, (It does slow with M64/M65 and M8/M9)
%
G17 G20
G80 G94
G64
G90
G1 Z 0.1 F50
G91
G1 F300
G1 X 3
M62p0
G1 X 3
M63p0
G1 X 3
G1 X -3
M62p0
G1 X -3
M63p0
G1 X -3
%
Last edit: 21 Oct 2019 14:29 by Todd Zuercher.
Please Log in or Create an account to join the conversation.
21 Oct 2019 14:43 #148470
by Arthur1
Replied by Arthur1 on topic Maintaining constant velocity while switching on an output
I had been using both M62/M63 and M64/M65 for testing it out. It looks like another reset of the system seems to have helped fix that last little bit of slowdown. Don't know how and it doesn't make me confident that it will stay that way but I'll take it for now. Thank you all for your help.
Please Log in or Create an account to join the conversation.
- Todd Zuercher
- Offline
- Platinum Member
Less
More
- Posts: 5007
- Thank you received: 1440
21 Oct 2019 15:11 #148474
by Todd Zuercher
Replied by Todd Zuercher on topic Maintaining constant velocity while switching on an output
There is one little thing you must remember about M62/M63. They require that a move be commanded after they are issued for their changes to take effect.
Please Log in or Create an account to join the conversation.
Time to create page: 0.104 seconds