Prototrak Plus Retrofit with Mesa 7i77 & 5i25 cards

Todd, many thanks for your continued support!
As per (page 5 of 9 Hardware Settings) I plan to try DIP setting to 1=on & 2,3,4=off ie. voltage mode. I will start fresh, when tuning PID , heavy axes 1st.

many thanks!

Many thanks for all the help!

I have reached out to AMC, a knowledgeable engineer suggested the following based on the screenshot.

forum.linuxcnc.org/media/kunena/attachme...12/01yScreenshot.png

Blue line is encoder speed. "The linear line indicate constant speed and it is lagging behind your command. Based on this graph, the motor is giving you everything it has." ""You either need to slow down the acceleration and/or you need to increase the bus voltage.""

The bus voltage appears to be steady at 75vdc. Measured between (P2) lead 4 and 5. To "slow down acceleration" edit the .ini file? I just need to be clear in an approach.

many thanks!!

Yes simply change the MAX_ACCELERATION = N, under each [AXIS_N] heading in your ini file to a smaller number. From the looks of your Halscope plot I would guess it should be about 2/3-1/2 as large as it is now. I thought I had suggested this earlier but first I thought you should confirm that there wasn't a setting in the drive that was limiting your acceleration before resorting to dialing back the acceleration.

Todd, thanks for your help!!

Only if the bus voltage could be increased, I believe, and 75 is max.

many thanks!

Many, many thanks!

This is most recent hal trace of "y" axes. This was at 60"/min and max acceleration is at .9 (from 1.0). I will try .8 to see how much changes.

many thanks!

When you make changes to the ini file with a text editor. You have to exit Linuxcnc and restart it for those changes to take effect. (It doesn't look like your acceleration is changing.)

You can make temporary changes to an axis' max_acceleration while Linuxcnc is running by using halcmd (either from the command prompt or the Hal Config window) to setp the pin ini.N.max_acceleration to a new value (N=the axis number)

This is the last screenshots with .7 velocity and 25.0 acceleration:

with .8 velocity and 25.0 acceleration:

with .9 velocity and 25.0 acceleration:

I plan to try tomorrow, and fresh, use restart each time.

Many, many thanks!!

The reason I believe you are not actually changing the acceleration, is because the slope of the velocity command (purple line) is not changing. The slope of that line is your acceleration setting, and from those halscope shots it looks like your acceleration is set to approximately 30 ips^2.

Next time your working on this, open a HalMeter window, and If you are working on the Y axis check the value of the pin "ini.1.max_acceleration" (or for X use ini.0.max_acceleration).
Then using the "Test HAL Command" box in ShowHalConfiguration you can use the command "setp ini.1.max_acceleration 15" (or what ever number you choose) to test a new acceleration value for that axis.

Once you are happy with the results you can edit the ini file to make the change permanent.