Set up using AMC AB15A100 drives, brushed DC motor Prototrak Plus with Encoders

I think you might want to have a 2 channel scope to monitor both the signal input and the current monitor. Maybe something like this.
www.ebay.com/itm/394146873835

But I have no experience with one to say if it would truly be up to the task.

Todd, thank you for the help and support! I looked at the scope link on Friday, by Sunday the link was down, for opportunity to buy, I researched the story and the approach the company took sounds great, I will need to keep my eye open for next time. I was busy tuning, it looks like some overlap of what traces are represented by the SW2 & SW3 settings, including the tweaking Pot 1 & Pot 3 for each group of settings. The best trace so far is attached, the file name has the settings not viewable in the pic, example file: ys2 1.817 s3 40 p1 13.25 p3 11.25 = ys2 (y-axis motor on the x-axis), s2= SW2=1.817; s3=SW3=40; p1= Pot 1, 13.25 turn; p3=Pot 3, 11.25 turn. I have several pics (all with uniform units) that look similar to this pic, naturally with their own settings. None of the traces close the gap at the beginning of the trace in the corner, the angle of the 1st part of the trace is nearly the same in all traces that I can get close to this sample.

Many thanks!!

Edit: When or how to know when to edit .ini file, from 7 to 10 in the "max_acceleration" area of .ini file? There seems to be a spot where the motor is full speed (then goes to 20"/min) for only a short area of trace, before the test trace is over.

Many thanks!
 

That is looking a lot more promising. The drive is not accelerating the motor at the rate that is being commanded, but at least now it is starting to accelerate the motor as soon as it is commanded to. The slope of that trace is the acceleration. Right now with the settings you have in the drive, that is the max acceleration your drive and motor are capable of. It looks like that slope would be approximately 1.6inches/sec/sec. You should probably decrease your max acceleration settings in your ini file to be about 25% less than that (1.2 or 1.3) to give the pid some headroom to work.

What happens if you attempt a move a a faster rate say 60 or 120ipm? (You might have to increase the length of the move to give it time to get up to speed.)

Things that could possibly help increase the acceleration:
increasing the current limit (Pot2).
Increasing the proportional gains in the drive (the resistances settings.) So Pot1 for the vel loop gain, and SW3 (1-5) for the current loop gain. If maxing out the resistor settings for the proportional gains in the drive isn't enough, then you may have to look into adding an additional resistor to the solder point on the drive (like described in current loop tuning sheet from AMC.) But I don't think this is advisable without an o-scope for properly tuning the current loop.

This is the kind of scope I have access to at work. They are normally $3-400. But here is one for only $99. Sounds like a too good to be true deal though.
www.thebeastshops.com/products/byijjzca1...=1603342-0-0-0-0-0-0

Todd, thanks!! I called the number & email about the scope, I do not think it's a real item to purchase.
I am working your suggestions in when I tune. I may see if the Pot 2 will change the slope, and understand this Pot2 will affect the other Pot 1 & 3.
When you talk about "(You might have to increase the length of the move to give it time to get up to speed.)" I will pay close attention to that. The .ini file is back to 10, but I will edit to 1.2 max_accelaterion.
Many thanks!

Todd, thank you for the help. How much over the 11 turns (as set per your suggestion) on Pot 2 would be ok, if I go with 11.5 the motor (depending on all of the settings) turns really quick, gets up to a cruse speed, quicker than 20"/min that it is set. Usually I feed back (using the arrow key, unless the motor joint error out, then will hand crank) to start so only record test in 1 direction.
If I set feed rate to max 60"/min & have as best tune for the settings at the time the motor will go even quicker, but usually joint error out.
I have nothing better to show that the last pic. How much additional Pot 2 or what to look for as too much. What I notice is a jagged trace, it seems.
Many thanks
Edit: Just to review the procedure, Pot1 CW until nosey, back up 1/8 turn, or less (as not to see any oscillation on trace): then Pot 2, try to go CW, very small increment 1/8 turn until trace gets jagged: then Pot 3 CW or CCW depending on where the trace is in relation to the red trace. Pot 3 & Pot 1 try as much CW w/o oscillation. Pot 3 & Pot1 try yo increase each as you go to as high of values w/o oscillation & Purple (shown in white) trace to match red as best as possible, like if lay 1 on top of other trace. If this sounds ok or does one of the pots need to be adjusted in a different order.
Many thanks
 

The pot2 setting is the current limit, too high and you could cook your motor. It isn't really a "tuning" setting.

Todd, Many thanks! Attached is a pic of one of the better traces, I am about 1/2 way through the chart. What I seem to find is some small groups of the chart, (the SW2 & SW3 all the possibilities) that group of settings are quicker & the trace shape is better match to red trace. It appears several areas of the SW2 & SW3 produce traces that are close to what the pic shows. Pot 2, I found back off, as much as 1/4 turn, sometimes help.
I was thinking, I would find a group of settings that (this was just the beginning edge of the correct sets of values) just go to next sets of values and would just keep getting better trace by after finding the beginning of the sweet spot and work it.
The settings that are friendly (did not require a lot of time or a bunch of hi-low tweaking) to tune (really need Pot 1 to be 12 5/8 or a bit higher) got the best shape.

How smooth does the trace need to be??

The trace attached compared to the one at (6 posts up) 15 Jul 2022 15:47 #247395 is smooth, but the corner is not filled. The one attached has good shape but some ruff edges. The motor is on the thin edge of oscillation, has real faint noise, probably could not hear in most shops because of background noise. I have several more hours to document all the settings in SW2 & SW3. If I find that ideal set of settings, that allow the trace to lay on top of red trace w/o any jagged trace, that is what I am in search of.

Many thanks

 

I think it should be fairly smooth. The smoother it is, the more precisely you'll be able to tune the position loop, the motors will run cooler, and the quieter the motors and drives will be at rest.

Have you tried any moves at faster feeds? What were the results?

Todd, thanks helping! Over the weekend I was in the tuning process and after repowering up for the next set of settings, nothing on the trace would work, after some pondering noticed the LED on the 24 volt power supply was not on, so I checked that power was going to the power supply & that was ok, so the new power supply will be here as late as this time next week. The only thing I can think of is that during this tuning process I have the power off & then on, a lot, for the next group of set of settings. The new power supply is 24v, 3 amps.
You asked about at 20 vs. 60"/min feed rate, the 2 pics are the same settings for the drive, but the trace units were changed, read file name for settings. It is obvious now that I should have changed the trace for better information. There have been settings when the motor preformed as well as you would want by the way it picked up speed & speed of motor, not varying. This was as I watched and listened until the power supply went bad, I am over 1/2 way through the SW2 & SW3 table.

Many thanks