AASD15 Alternative - Thanos

That would depend on what you are using for a controller. The AC servo systems will do exactly what you tell them to do. The cogging comes from rushing to the next trajectory point, getting there too early, slamming on the brakes, rushing to the next point. This is easy. Smoothly following a trajectory is more difficult.

Are you mostly flight simulator?

Have you checked that there are two different parameters for the torque threshold? One of them is called "torque limit" and is related to the overtorque alarm. And there is a second one called "torque warning level" or "torque reaching reference" which is related to the "torque reach" output. Unfortunatelly, I'm not an expert for the HLTNC drives. I have tested the P100S, JMC and Lichuan drives. Although some features have a little different names for each brand the functionallity is basically the same.

Some drives have a switching function where an input or parameter can select one of multiple sources for the torque limit value. Make sure you select the correct source.

And yeah, often the manuals are not very precise. Sometimes you have to find out how it actually works by trial and error because even the support doesn't know everything. I just had to figure out what the bits of the status register really mean because the manual doesn't tell anything about it.

They call them external and internal. I want to go back and check things with fresh eyes. That could be the issue. What I ought to ask support is the exact definition of the "switching" function is because the current manual sayss "range 0-2". I did tell then what I was doing and expecting but that has goone down the drain at this point. Can't expect much when you have a potential volume of 5 or 6 units.

Of course the manual is a reference manual so its mostly lists of parameters alarms and front panel settings. In general though it is the most useful maual I have seen coming out of AliExpress.

I will post here is I have a breakthough. I still haven't tried the same test on my second unit.

I may be wrong but my interpretation of "internal" and "external" torque limits are that the internal limit is a fixed value set with the parameters and the external is an (analogue) input pin or a value set via fieldbus communication, i.e. it can be set on the fly from an external source. There must be a third value that is lower than the actual limit so that the "torque reached" output can be activated without triggering an alarm.

Thanks for the offer of help.

I don't think the manual is mine to post but read through the manual again today and the only relevant information is this JSON representation of my variables that I have set. I also asked support specifically for documentation on P-064 because I think it was ommitted from the manual by accident.

BTW: I vibed a MODBUS app in Windows for the T3D. I think its specific for that controller but one gets tired of pushing the tiny buttons.

"P-064": {
"value": 0,
"name": "Torque Limit Selection",
"range": "0 to 2",
"default": 0,
"unit": "",
"applicable": "ALL",
"description": "Sets the torque limit mode."
},
"P-065": {
"value": 30,
"name": "Internal positive rotation (CCW) torque limiting",
"range": "0 to 500",
"default": 250,
"unit": "%",
"applicable": "ALL",
"description": "Sets the internal torque limit value in the CCW direction of the motor."
},
"P-066": {
"value": -30,
"name": "Internal counter-rotating (CW) torque limitation",
"range": "-500 to 0",
"default": -250,
"unit": "%",
"applicable": "ALL",
"description": "Sets the internal torque limit value for the CW direction of the motor."
},
"P-067": {
"value": 80,
"name": "External positive rotation (CCW) torque limitation",
"range": "0 to 300",
"default": 100,
"unit": "%",
"applicable": "ALL",
"description": "Sets the external torque limit value in the CCW direction of the servomotor."
},
"P-068": {
"value": -80,
"name": "External reversing (CW) torque limitation",
"range": "-300 to 0",
"default": -100,
"unit": "%",
"applicable": "ALL",
"description": "Set the external torque limit value for the CW direction of the servomotor."
},
"P-069": {
"value": 100,
"name": "Trial run torque limit",
"range": "0 to 500",
"default": 100,
"unit": "%",
"applicable": "ALL",
"description": "Set the torque limit value in the trial operation mode."
},
"P-070": {
"value": 300,
"name": "Positive (CCW) torque overload alarm level",
"range": "1 to 300",
"default": 150,
"unit": "%",
"applicable": "ALL",
"description": "Set the torque overload value, which is a percentage of the rated torque."
},
"P-071": {
"value": -300,
"name": "Reverse (CW) torque overload alarm level",
"range": "-300 to -1",
"default": -150,
"unit": "%",
"applicable": "ALL",
"description": "Refer to the description of parameter P-070."
},
"P-072": {
"value": 10000,
"name": "Torque overload alarm detection time",
"range": "1 to 32,000",
"default": 10000,
"unit": "ms",
"applicable": "ALL",
"description": "Refer to the description of parameter P-070."
},

Yeah, I got hold of a manual of the T3D driver and I agree it's terrible. Lots of ambigous translations and some parameters are missing. The table of contents is a mess, too.

Please check out parameters P157 and P158: arrival torque and arrival torque return. I think, that are the ones that control when the ATRQ (torque reached) output go on and off (difference between them is the hysteresis). Try setting them to 40% and 30%, for example.

BTW, I also use MODBUS to tune the parameters. I've written my own code for this and integrated it into my CNC control software.

It's so much more convenient than pressing buttons on the front panel. But I have to find out how to save the changes to permanent storage. This is done automatically when parameters are modified via the front panel but not when done over MODBUS.

On the T3D there is a MODBUS command to save the parameters to EEProm.

I would think this would be at standard. On T3D some parameters do not get saved automatically when you change them. For these you have to manually save them with another command. Maybe this is only certain commands that require a power cycle.

Thanks for the tip I will try the arrival torque (ATRQ) vs torque limit (TRQL). I prefer both directions but since I will typically only be hitting the lower one I can deal.

Do you have the V2.3 version? It’s in the name of the PDF.

Yes, I also have V2.3 of the manual. But I no longer own a T3D servo. I have P100S drives in Sven's rig, original AASD drives for my own simulator and Lichuan drives for my CNC projects. I've tested serveral others (T3D, KS300 and JMC) but I sold the ones I no longer need shortly after.

The arrival torque works but in one direction. Is that enough for Thanos? There is a T-DIR input that I can set, in your mind is that the standard way of doing things?

TRQL seemed like a good alternative because you can set the torque limit pushing up higher than the pushing down limit.

EDIT: Gemini hallucinated the T-DIR input. TRQL probably doesn't work because it hits the position limit and decclares the drive stalled before I see the DIN change (scanning at about 1Mhz).

Unless you build an emulator of the servo actuator, it's hard to understand it. But hey if you are bored and have nothing else to do, sure, experimenting with actual high speed, high torque and dangerous servomotors is one way

https://youtube.com/shorts/Pej4fOOBxlY?si=GQZt7460kQvp8rLa