Arc endpoint tolerance | Synthetos Forum

Started by jland on Dec 23, 2013 in TinyG Support. 3 replies, last activity Dec 23, 2013.

jland Dec 23, 2013 #

I came across a problem where tinyg would not execute an arc due to the start/end point being slightly off due to number rounding. The code (a snip from a larger program) is:

N1(ARC END POINT TOLERANCE PROBLEM)
N2G90
N3G17
N4G20
N5G40
N6G80
N7G0X.6953Y.6708
N8G1Z-.05F40.
N9G3X.7445Y.5382I.0909J-.0417
N10G2I-.0752J-.1642F80.
N11G3X.8771Y.5875I.0417J.0909
N12G0Z.5
N13X0Y0
N14M30

This is a finishing pass on a round boss, with arc lead-in and -out. After the lead-in arc, the arc on line 10 would not process and the next actual move was the lead-out arc. When I changed the J value to -0.1643, the line 10 arc worked. Is there any parameter I can set to make tinyg more tolerant of this kind of situation, especially when the "error" is on the order of .0001"?

Thanks,

Jim

jland Dec 23, 2013 #

BTW, this is on a TinyG v8 with fw 380.08

aldenStaff Dec 23, 2013 #

I had not seen this one before. Thanks for providing the code snippet. Wjat kind of machine are you on - screws, belts, other? I'll try to reproduce on a machine that's physically similar to yours.

jland Dec 23, 2013 #

The machine is a Shapeoko, although at the moment it exists as 4 motors sitting on a table. :-P

I ran it through tgfx and coolterm with the same results...