Question re G76 threading code
- Clive S
- Offline
- Platinum Member
Less
More
- Posts: 2241
- Thank you received: 476
20 Jul 2016 13:25 #77710
by Clive S
Thanks again.
Replied by Clive S on topic Question re G76 threading code
Thank you for being so patient Andy You have just lit the light bulb for me. with the "Q is a virtual compound slide angle" I could not get my head around whether to physically set the compound on the slide to 29.5 or linuxcnc does it with the Q setting thus keep the physical compound at 0.I don't actually understand what you don't understand.
Q is a virtual compound slide angle. The thread forming tool necessarily has to be perpendicular to the work, or it won't form a thread.
Thanks again.
Please Log in or Create an account to join the conversation.
- andypugh
- Offline
- Moderator
Less
More
- Posts: 23536
- Thank you received: 4852
20 Jul 2016 13:38 #77714
by andypugh
Replied by andypugh on topic Question re G76 threading code
I was getting confused because I have not seen a CNC lathe with a compound slide.
(I have converted two manual lathes and removed the compound in both cases to increase stiffness)
(I have converted two manual lathes and removed the compound in both cases to increase stiffness)
Please Log in or Create an account to join the conversation.
- Clive S
- Offline
- Platinum Member
Less
More
- Posts: 2241
- Thank you received: 476
20 Jul 2016 13:46 #77717
by Clive S
Ah I see my bad. I am in the process of removing the compound as you say it is not necessary.
Replied by Clive S on topic Question re G76 threading code
I was getting confused because I have not seen a CNC lathe with a compound slide.
(I have converted two manual lathes and removed the compound in both cases to increase stiffness)
Ah I see my bad. I am in the process of removing the compound as you say it is not necessary.
Please Log in or Create an account to join the conversation.
- Clive S
- Offline
- Platinum Member
Less
More
- Posts: 2241
- Thank you received: 476
19 Aug 2021 11:06 - 20 Aug 2021 21:14 #218131
by Clive S
Replied by Clive S on topic Question re G76 threading code
I am sorry to open an old thread "but"
I would like some help with the G76 I,J and R commands
My small lathe cuts threads ok but on bigger threads and coarser pitches I would like to makes more passes.
This is the code I use for m10 thread
G0 X10 Z10
G76 P1.5 Z-12 I-0.1 J0.1 R1 K1.5 Q29.5 L0 H1
what controls the number of passes?
From the manual linuxcnc.org/docs/2.8/html/gcode/g-code.html#gcode:g76
I- - The thread peak offset from the drive line. Negative I values are external threads, and positive I values are internal threads. Generally the material has been turned to this size before the G76 cycle.
I would like some help with the G76 I,J and R commands
My small lathe cuts threads ok but on bigger threads and coarser pitches I would like to makes more passes.
This is the code I use for m10 thread
G0 X10 Z10
G76 P1.5 Z-12 I-0.1 J0.1 R1 K1.5 Q29.5 L0 H1
what controls the number of passes?
From the manual linuxcnc.org/docs/2.8/html/gcode/g-code.html#gcode:g76
I- - The thread peak offset from the drive line. Negative I values are external threads, and positive I values are internal threads. Generally the material has been turned to this size before the G76 cycle.
Attachments:
Last edit: 20 Aug 2021 21:14 by Clive S. Reason: Deleted some content that was incorrect
Please Log in or Create an account to join the conversation.
- andypugh
- Offline
- Moderator
Less
More
- Posts: 23536
- Thank you received: 4852
20 Aug 2021 20:29 - 20 Aug 2021 21:28 #218274
by andypugh
Replied by andypugh on topic Question re G76 threading code
R and J together control the number of passes, and then H spring-passes are added on top.
Fot coarser threads you can probably use the same J as you do already but set R to 2 so that the increments get progressively smaller.
Fot coarser threads you can probably use the same J as you do already but set R to 2 so that the increments get progressively smaller.
Last edit: 20 Aug 2021 21:28 by andypugh. Reason: Make it make sense
Please Log in or Create an account to join the conversation.
- Clive S
- Offline
- Platinum Member
Less
More
- Posts: 2241
- Thank you received: 476
20 Aug 2021 21:11 #218276
by Clive S
Thanks. But did you mean J to 2 or R to 2
I did read some ware (but can't find it again) that is was something like J/R that would make more passes !!
Replied by Clive S on topic Question re G76 threading code
R and J together control the number of passes, and then H spring-passes are added on top.
Fot coarser threads you can probably use the same J as you do already but set J to 2 so that the increments get progressively smaller.
Thanks. But did you mean J to 2 or R to 2
I did read some ware (but can't find it again) that is was something like J/R that would make more passes !!
Please Log in or Create an account to join the conversation.
- andypugh
- Offline
- Moderator
Less
More
- Posts: 23536
- Thank you received: 4852
20 Aug 2021 21:28 #218277
by andypugh
Replied by andypugh on topic Question re G76 threading code
Edited. I did mean R.
Why not try threading some air and counting the passes?
Why not try threading some air and counting the passes?
Please Log in or Create an account to join the conversation.
- Clive S
- Offline
- Platinum Member
Less
More
- Posts: 2241
- Thank you received: 476
20 Aug 2021 21:33 - 21 Aug 2021 13:42 #218279
by Clive S
I = 0.1 R = 1 gives 10 passes
I = 0.1 R = 1.2 gives 16 passes
I = 0.1 R = 2 gives too many to count
Replied by Clive S on topic Question re G76 threading code
Edited. I did mean R.
Why not try threading some air and counting the passes?
Yes of course I will.
Thanks for the input.
I = 0.1 R = 1 gives 10 passes
I = 0.1 R = 1.2 gives 16 passes
I = 0.1 R = 2 gives too many to count
Last edit: 21 Aug 2021 13:42 by Clive S. Reason: corrected formatting + added data
Please Log in or Create an account to join the conversation.
Time to create page: 0.160 seconds