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UC100 Spindle Speed and Threading w/ Encoder

PostPosted: Sat Sep 26, 2020 5:58 pm
by eabrust
Hi Balzas/CNCDrive

It appears that UCCNC and/or UC100 reports incorrect spindle speed based upon encoder feedback. UC100 w/ firmware: 3.019, hardware v 2.0, API version 2.18 ; UCCNC v. 1.2112


I'm testing running a lathe via UCCNC. I am converting existing known machine setup from Mach3 (w/ single index spindle) to an encoder (and using the same single index for sync trigger in UCCNC).

Here is the issue I have:

Encoder just installed is a 360 ppr turning 1:1 with spindle, so I should be putting 1440 into UCCNC (4x quadrature) as the spindle ppr in UCCNC. When I put 1440 in, UCCNC reports actual spindle speed as 2x what is real (verified by a separate laser tachometer). If I disable the encoder, the speed reported back (based on single index) is correct again. So since the encoder is new, I figured vendor accidentally sent me wrong PPR as most likely problem. If I enter 2880 as ppr into UCCNC, it reports the right actual speed.

HOWEVER, If I run a G76 threading routine, I get the wrong actual pitch cut when the speed reads correctly using 2880 ppr.... but the right pitch when ppr=1440. So this seems to indicate the encoder really is a 360 pulse, UCCNC should bet set w/ 1440ppr, and there is a speed display issue w/ UCCNC or the UC100 firmware.

I work in inches, my GCode trying to get 20 TPI (.05" pitch):

G76 P.05 Z1.365 I-.1 J.010 K.077 E0 L0 Q29 H1 <- This gives me a correct .05" actual pitch if I have a 2x speed reading w/ 1440ppr, but gives me a .025" pitch if I have a 1x speed reading w/ 2880 ppr setup.

G76 P.1 Z1.365 I-.1 J.010 K.077 E0 L0 Q29 H1 <- This gives me a correct .05" actual pitch if I have a 1x speed reading w/ 2880ppr, but gives me a .1" pitch if I have a 2x speed reading w/ 1440ppr setup.

Now that I have verified I can cut correct thread pitch w/ the correct encoder value, I can live with the spindle speed display issue being 2x. Just thought I would see if you can verity if there is a firmware issue on UC100.


Profile is attached for reference.


regards,
Eric

Re: UC100 Spindle Speed and Threading w/ Encoder

PostPosted: Mon Sep 28, 2020 11:28 am
by eabrust
Hi Balzas,

Please disregard the above, at some point restarting UCCNC or unplugging/re-plugging in UC100 resolved the above issue with the speed reading, all works as expected with expected encoder count. Sorry for false alarm. :oops:


regards
Eric

Re: UC100 Spindle Speed and Threading w/ Encoder

PostPosted: Mon Sep 28, 2020 5:10 pm
by cncdrive
Hi Eric,

No worries. I was just about to send a bug report to my collegue. ;)