New Youtube chanel for CNC .... anything ! toma cnc

More
11 Apr 2020 21:26 #163660 by tommylight
Sorry it is BTS7960, my bad.
Today i used the Mesa 6i25 to do some more testing, the difference in stability of a servo loop closed in Linuxcnc between parallel port and a Mesa card is astonishing. With parallel there was always a bit of a whine from the motor and the rotation was a bit noisy, with Mesa it is silent.
Well one direction is silent for now, need some more tuning and some checking with PCW as i have requested from him a firmware for mode 1 PWM, but these drives need the mode 2 PWM, or UP and DOWN PWM. I did set it in hal as mode 2 and it does work with that issue that one direction is not stable as the other, might be due to using the DIR pin to output PWM ????
Leme go ask PCW while you watch the short video:

Please Log in or Create an account to join the conversation.

More
11 Apr 2020 22:00 #163667 by tommylight
Got the scopes out, it is due to dir pin remaining a dir pin as it is programmed in firmware.
Cr@p, i have to bother PCW again. Not good from my side, should have done some test before asking for custom firmware. I owe him a lot of beers.
The main thing is, those drives are nice for up to 200W motors, and i have some collecting dust.

Please Log in or Create an account to join the conversation.

More
11 Apr 2020 22:56 #163672 by tommylight
Found the problem, me again, had the pwmgen set at mode 2 and then again to mode 1 later in hal.
Fixed, works silently and perfectly in both directions ! :)
Thank you, all.

Please Log in or Create an account to join the conversation.

More
11 Apr 2020 23:04 #163673 by OT-CNC
tommylight, what is that fancy looking halscope you are using? What version linuxcnc?
The following user(s) said Thank You: tommylight

Please Log in or Create an account to join the conversation.

More
12 Apr 2020 01:45 #163697 by tommylight

tommylight, what is that fancy looking halscope you are using? What version linuxcnc?

All versions have it i think, at least since version 2.5.
It is in the "machine" menu, top left of the Axis screen, then choose "hal scope". There is a nice how to use in the docs somewhere.

Please Log in or Create an account to join the conversation.

More
12 Apr 2020 02:05 #163703 by OT-CNC
I have been using halscope. Did you change the background color? It looks different. Same functionality?

Please Log in or Create an account to join the conversation.

More
12 Apr 2020 02:36 #163714 by tommylight
Oh, i use Mint-y-dark theme on all computers, my face got sunburns from staring at white monitors. :)

Please Log in or Create an account to join the conversation.

More
12 Apr 2020 17:10 - 13 Dec 2020 00:27 #163791 by tommylight
Edit: attached the configs for parallel port and Mesa board.

Here is the updated video with the issue sorted out, had to do a lot of editing of hal and ini, so i had missed an error there that was causing one direction to not work properly.
Now it works perfectly smooth on both directions.

The motor has two protrusions that is why the DVM shows double the frequency, Linuxcnc shows correctly 2000mm/m and that is 2000RPM on the motor as it is scaled to 1mm per revolution.
With some tuning the Ferror is very small, so all in all, very nice results so far.
Added the arduino nano as it has 8 analogue inputs, will connect the IS pins (current sense on the drives, two on each) to those analogue inputs, and the enables to arduino outputs. Also will connect one output from Mesa 6i25 to arduino digital input, it is set as charge pump so arduino should enable the drives only when the charge pump signal is present and disable them in case any of the IS output goes over the threshold set, that will have to be adjusted after the motors are mounted and tested to find the current limits. This also makes possible wiring of the other outputs from the arduino to the other Mesa 6i25 port since there are another 4 encoders there and use that to show the actual load of each axis in each direction.
All this seems unnecessary as the drives will not work if both PWM inputs are set high, so that is a nice security feature, some other drives i have will run the motor at full speed in such a case. This is just more functionality and better overall security.
3 days on this, not very smart, but since i had the stuff thought I'd give it a go.
Attachments:
Last edit: 13 Dec 2020 00:27 by tommylight. Reason: attachment

Please Log in or Create an account to join the conversation.

Time to create page: 0.073 seconds
Powered by Kunena Forum