Motor setup question with r net

[Gregrb]

I have Kolector swissdrive brand new motors. The lh side one lacks power / torque to even make it up a wheelchair ramp. The rh has lots of power. They were swapped out from old motors that worked fine till other issue. Bit settings changed but when showing motor company they daid:

The motors have specifications about the output torque and speed, based on input voltage and current. The problem is most probably on the input side, so motor controller.
Can you measure the inputs; current, voltage?

Any ideas what and how to do that setup?

Chair is etac e880 with rnet system control etc.

[slomobile]

The company is trying to not be the ones responsible, so they are asking you to test something else, hoping you will give up.

All you need to verify if the problem is in the motor, or the controller is to switch the motor wiring side to side. Connect the left wires to the right motor and right wires to left motor.

If the problem changes sides when you change the wiring, the motor company was right, the problem is with your controller, or its program, or possibly the wires.

However, if the problem remains on the same motor even with different wiring that has been proven to work, you can be certain the problem is with the motor.

If the above test indicates a motor issue, one problem I have seen is failed brakes on brand new motors. If your chair puts out 12v to release the brakes but the new brakes on the new motors require 24v, one brake may not be releasing fully. Or if your chair is sending 24v to 12v brake coils one of them may have failed. That is probably still the fault of the motor company for supplying the wrong part, unless you told them to order the wrong part.

Another possibility on new motors is poorly seated or grease contaminated brushes. They will work ok with no load but be weak under load.

[Burgerman]

Bit settings changed but when showing motor company they daid:

What does this mean?

The motors have specifications about the output torque and speed, based on input voltage and current. The problem is most probably on the input side, so motor controller.
Can you measure the inputs; current, voltage?

Any ideas what and how to do that setup?

Chair is etac e880 with rnet system control etc.

Very easy.
Plug in the programmer and look at the real time motor current as you use the chair and motor voltage (ignore battery voltage and battery current) and do them a screen shot. M1 and M2.

See below:

[Burgerman]

ABOVE.

Resistance (R) = 0.093 ohm (Ω) Or about 90mOhm.
Calculated from the figures in the R-Net graph above.
This is why they want the figures. It tells them the motors impedance. So would identify a bad brush, bad connection, low output etc.

Power (P) = 1227.29 watt (W)
Not bad for a 350W motor...

Steps: Ohms law...
10.7 volt
114.7 ampere= 0.093 ohm (Ω)

Power = V x Amps...
= 10.7 volt × 114.7 ampere
= 1227.29 watt (W)

Now the actual MOTOR impedance is 45mOhms. The rest of the 90 calculated here is the battery and motor cables and the connectors. And some innacuracy due to how its measured. This is the thing they want because it tells them the condition of the motor. Or if there is a bad connection etc. So drive up to a wall, try and push it down to stall the motors, and when the Amps are at MAX then do a screen grab.
Both should read the same or similar. Mine above is my own chair doing a turn in place on a thick carpet. Those were the motor current it pulled and volts that it took to do that. From this you can calculate the motor impedance with ohms law.

[slomobile]

The live motor voltage and current from both motors would go a long way towards making Rnet more suitable for "program control" features like semi autonomous ramp navigation, sidewalk following, doorway threshold traversal, hill control, wheel slip control, autonomous unoccupied navigation like "call to bedside" or "load into van" and "unload and maneuver to driver's door" or "leave commode" and "return to commode".

Is anyone aware of methods to grab that data sent from dongle to Rnet Windows computer program and redirect it into another program for altering the control inputs, like CAN2RNET?

Are there any restrictions to operation of the chair when in that live data mode?

[Burgerman]

No. And no.

[slomobile]

Bummer. I was thinking of something like this https://learn.microsoft.com/en-us/visua ... ew=vs-2022 Spy++ tool
or running the dongle and Rnet software on ReactOS and piping the live messages into my app.

Unfortunately I have very little knowledge about how to do that.

[Gregrb]

Bit settings changed but when showing motor company they daid:

What does this mean?

The motors have specifications about the output torque and speed, based on input voltage and current. The problem is most probably on the input side, so motor controller.
Can you measure the inputs; current, voltage?

Any ideas what and how to do that setup?

Chair is etac e880 with rnet system control etc.

Very easy.
Plug in the programmer and look at the real time motor current as you use the chair and motor voltage (ignore battery voltage and battery current) and do them a screen shot. M1 and M2.

See below:

How do you open PM Status

Then what do you change to match lh to what rh does

[Burgerman]

In the top menu. I am using OEM not sure what you use or if that exists in the dealer version.

What do you change? You dont change anything. The amount of current and voltage depends n the motor impedance, cables, brushes, motor windings etc and the position of the joystick.

So both sides will read almost the same if the motors are matched and healthy. If you keep joystick straight ahead or straight back. Againds say a curb or wall. To load up the motors. But whatever the readings are its possible to use ohms law to work out impedance and see if theres a problem.

If you dont have OEM access, and its needed (not sure) then you can measure this the old fashioned way with a clamp Ammeter and a voltmeter too. But R-Net makes it easy to comply with their request.

The oyher thing you can do is unplug the motors and use a QUALITY meter that can measure down to mOhm levels and actually measure the motor resistance. Again both are healthy they will read the same. Around 30 to 50 mOhm. If decent 4 pole. Or higher if not. But both the same.
You can also try lifting the wheelchair and giving it max speed, and counting wheel revolutions per minute. Again both should be the same.

Theres many ways to diagnose a problem and find the cause. Likewise if a brake is not relesing for e.g they will sound very different to one another. And you can check that the brake is actually releasing and measure the voltage the PM applies.

[Gregrb]

See these images both m1 and M2 show quite different when driving straight line. Which is lh and which is rh?

What do I need to do??, these are brand new.

https://ibb.co/9sy2qBQ

https://ibb.co/xzxZGq1

[Burgerman]

Well first of all you need to do something that draws enough current to actually notice.

And then you need to be sure that BOTH motors are recieving the same voltage. And that depends on things like the stick position and motor load and subsequent compensation added by the controller.

Reverse to a wall.
Pull the stick back straight, and as you STALL THE MOTORS you will find the motor compensation increases the current (because the wall is stoping it move and so the compensation tries to move the chair against the load) and then move the joystick left/right slightly untill voltage at each motor is similar. At his point the CURRENT at each motor will be high, and similar. If its not then each motor has a different impedance. Caused by ad connections, damaged armature, stuck or burned brush or whatever.

You only get a few seconds to do this as the BOOST current will decay after a few seconds. So as to not melt wiring or motors or overheat the pwer module.

You should see up to 120A if its all programmed correctly and the motors are half decent quality. On each. Battery voltage will drop a little and battery current with good low ipedance motors will be quite low like 30A or less. With crappy motors it may be much higher.

When motor voltage is maxed out and current is high press PrtScrn button. And then release joystick. Open an image editor and then right click on screen and choose "paste"...

[Gregrb]

I got told not to do that by motor company. Does my differences in above images not show enough as there is bug differences even though driving straight

[Gregrb]

See these under full load against wall. Lh motor does not spin while rh motor spin skids (on a laminate floor)

Is M1 or M2 lh motor?

What does the above mean. How do I fix abd what do I tell motor company as brand new.

[Burgerman]

Both are pretty much the same impedance.
Both are healthy.
You cannot know which is which as it ust depends on what connector each one is plugged into.
UNLESS you watch the display, and load one motor (push joystick 45 degrees forwards/right so that the LEFT motor does all the work. Then the motor that shows highest amps is the one that is the left one.

But it doesent matter they look relatively normal.
Question... Why no battery amps shown?
And those are not very low impedance motors.
At around 10 volts the one that wasnt spinning should have pulled around 115 to 120A if they were.
The one that was sliding and turning will take a little more volts and pull a few less amps as shown. So M2 was likely the one that was spinning here.

So it looks healthy. Not spectaculary low imedance. But fine for what they are.
What motors are they?

Your first two images show so little current flowing through a pretty innacturate measuring method that 1mm of joystick movement would make a massive difference to the readings. The only way to compare is to max out the readings so that both are stalled. Not really spinning on lino. But that was close enough to know they look reasonably healthy. Looking at that tells me they are OK.

So next job is to LIFT the rear of the chair or wherever the wheels are, and run both at maximum speed. And COUNT revolutions in 30 seconds. Both left and right should be very similar. Be SURE the joystick is in the straight ahead position. Or they will turn at different speeds...

Both should sound similar too.
Did you check that the brake is releasing properly on each motor?

[Burgerman]

I got told not to do that by motor company.

Why are you even listening to them?
Of course they say that.

[Gregrb]

The screenshots showed m1 and M2 having quite big differences between current and voltage. Does that not show motor Co issue with LH motor? As was straightforward so should be almost equal.

As lh stops but rh spins is there not a torque setting or something to adjust to match?

Can't lift chair up.

What can u do?

It doesn't make it up vehicle wheelchair ramp due to issue currently.

[Burgerman]

The screenshots showed m1 and M2 having quite big differences between current and voltage. Does that not show motor Co issue with LH motor? As was straightforward so should be almost equal.

Had you done that test on concrete so it didnt spin (and unload) then the current would have been the same. Or as close as you can get it because if the joystick is 1mm to the left then one motor gets more power/the other gets less.
A dc motor at a given voltage (your joystick position determines the voltage in the form of a pulsewidth) will draw whatever current its impedance makes it. But that is at STALL. If you do this on lino and a wheel spins hen that reduces the load, and so motor compensation drops away (less power needed) and so you read a lowr current.

As lh stops but rh spins is there not a torque setting or something to adjust to match?

When you set off hard in a car usually one wheel will spin. The one that spins may be because that tyre had less traction. That can be because of dust or tyre pressure differences, or because theres more mass over one wheel or i your case the joystick not being exactly central. Once spinning it takes less power to keep it spinning. So less amps. In any case as the motor is turning it needs a higher voltage to read the same amps because a dc motor is also a generator! As it is turning you need enough volts to overcome that generated voltage in order to maintain the same amps. So no.

If there is an RPM difference when you lift the chair, and set it at max speed, then yes you can make an adjustment. But theres no reason why you would ever do this on 2 new or even old healthy motors. Only if you were to use say a 4mph one with a 6mph one on the same chair. If you need that then you have bigger proplems. What I can see already on your screenshots is that the motors are likely not the problem, as long as RPMs match when free running lifted off the Deck.

Can't lift chair up.

What can u do?

It doesn't make it up vehicle wheelchair ramp due to issue currently.

What can I do? Nothing. I am the wrong side of the atlantic! I think?
What I would do if it was mine would be to find the fault or what was happening if there is one, and fix it. That involver a little troubleshooting, logic, and actually testing everything. It might be a tyre binding against something, a wheel where you forgot to fit a key, a slipping gearbox, a brake that isnt releasing due to a connection error or something. A caster bearing failed. I would feel all those things in the first 5 feet of movement even if I wasnt sat in it.
And then follow up on the clues until I find the issue.
It deosent appear to be the motors themselves. Do same test on concrete and the motor voltages and currents will more closely match. I think. But I am not there to spot the clues.

If you can do the tests and analise things or lift it up, check for tyrs or casters moving freely, test brakes etc then you need a man that can. I would confidently redict that if there is a fault and it isnt a driver issue then I could find it in 5 mins flat. So it cant be that hard or expensive even if you had to pay someone to look at it.

[Gregrb]

You say yes you can adjust torque or similar but shouldn't have to. But where in program do you adjust as that will help me as well.

[Burgerman]

It doesent adjust torque!

Try and understand how a motor works.

You feed it a voltage. (The position of your joystick).
This is fed to the motor. Its actually not a voltage its a full battery voltage chopped up waveform. But it behaves exactly the same way as a voltage.

So if your controller sends 3V to your motor it draws a current. That current is DIRECTLY PROPORTIONAL TO TORQUE. So double the current = double the torque. Half the current = half the torque. At a given motor impedance. And motor RPM.

So when you move your joystick in the forward or backward direction, the controller sends that same voltage to each motor. Half stick is roughtly equivelent to half battery voltage. Thats around 12V. Since the programming means your reverse is slower than your forward speed this is an approximaton. You may in fact be sending just 6 volts to the motors at FULL STICK in reverse.Or less. Or when you turn. Because the programming reduces this output in accordance with what you set up.

So if you send say 3V to both motors in reverse then that draws a very large current. Why? Because the motor is stopped. As the motor begins to turn the current drops away. To almost zero. Unless theres a load. At which point the current will stay high. And will climb as motor compensation kicks in to help you move. It thinks your wall, is a curb, hill, or a rock. It adds power to help the chair move.

Remember VOLTS = SPEED or rpm, directly.
Volts causes Amps, which is determined directly by the motors impedance and this is exactly proportional to torque.

If you apply say 6V to your motors and allow the chair or motor to run free. In an extreme example with the wheels off the ground even so there is literally no load then the Amps drawn by the motors will be extremely low Just a couple of A. So rolling along at constant speed your motors pull a very low current from the controller. EVEN FLAT OUT. Nothing of significance maybe 5 to 10A each at max speed. And the motors will be at 1/4 speed at 6V. Since 6V is 1/4 of the full battery speed voltage. Remember Volts = RPM directly.

Now if you send the same 3V to the motors, and stall the motor, so it cant turn it will draw a very very high current. Around 60A or so at 3V. And make a lot of torque. This is actually increased now even further by the motor load compensation which is a positive feedback loop to make sure that the motor can make full torque or close to it at low voltages (small stick movements or slow programmed speeds). At around 120A and at 6 to 10V typically the controller is maxed out. This all depends on motor resistance (ohms law) and isnt determined by the controller. The level of compensation is, and it can be adjusted. Too low and both motors have inadequate torque. Too high and the chair becomes undrivable and can run away or spin in circles on the spot uncontrollably with no way to stop it.

So please do as I ask. Do the current test somewhere with grip like concrete and read the motor voltages and motor currents. When theres no wheel slipping... Under load, central joystick. They will not be exactly the same, they never are.

Then test that the motors rotate at the same speed within say 5% when the stick is CENTRAL and forwards with wheels off the ground. A 6 mph motor will be approximately 160 to 175 rpm at the wheel. The actual speed is unimportant the DIFFERENCE is what we are looking at here. If they are similar, and both drawing just a few amps and at around 21 to 22V volts at this point then theres absolutely nothing wrong. Because the motors are running as expected, and the controller is feeding the full voltage to the motors. Conversely if there is, then it is not a programming issue but some mechanical or wiring thing or even a controler problem. But unless you do this. as well as look at and evaluate casters, tyres dragging or brakes dragging and not releasing etc then the rest of this conversation is pointless. There is a setting that sets a slight difference in speed per motor. That IS NOT TORQUE and is intended for extreme issues where you have 2 motors installed with different gear rations. If you set that in your case it will do absolutely nothing for torque. It will screw up the steering and ability to drive in a straight line. So dont!!!

[Burgerman]

When you fitted these did you put the key into the shaft when fitting the hub?
Are the brakes connected correctly?
Are the brakes releasing when they should?
Are any casters binding or bearings failed?
Do both motors sound the same?
ARE both motors the same? Check the numbers...
Is the gearbox slipping and engaged correctly?
Has the cuh drive failed or jamming?
Can you rotate a motor freely by hand?
ETC.

[Burgerman]

I have Kolector swissdrive brand new motors. The lh side one lacks power / torque to even make it up a wheelchair ramp. The rh has lots of power. They were swapped out from old motors that worked fine till other issue.

Could be that one brake is not releasing. Diid you check?
Do these have encoders or anythig? Are both connected properly?
What other issue?

[Gregrb]

OK but where in rnet program do you find settings to adjust what's sent to the motors to equal up an issue. Regardless of if its voltage etc. You said you can adjust in the programming so where?

All fitted just like the other 6 pairs my chair has had by Pro engineer fitter.

Please let me know where in program I can adjust between lh and rh as all correct
You said v and c all looked OK. Motor company not helping motors cost me thousands. I need to adjust between lh and rh as all works good till wheelchair ramp or small curb see these vids

https://www.dropbox.com/scl/fi/ejiotkzi ... yx2qp&dl=0

https://www.dropbox.com/scl/fi/vrvp8gfl ... sxxkg&dl=0

[Burgerman]

Right now your controller is doing everything correctly.
That video shows me nothing, what am I supposed to be seeing?

Both sides, both motors are being sent the same voltage. It went straight before right?
So if anything is different now then it is nothing to do with the controller or its programming. All I can see is that you are trying to get a small wheel to climb up a curb that is a bit too high. It hits the curb and stops or skids depending on traction.

Question. Does it dive in straight lines on a flat surface?

If so, then its NOT a programming problem and changing that will not fix your problem. It wll however create several others.

You have some other issue that you must find. Both sides get the same electrical signal. But you claim they respond differently. So your job is to find out why that is. I already explained how to do that repeatedly. But you keep ignoring this and wanting to ttry to fix a physical mechanical problem by skewing the power delivery... That will not work.

[Gregrb]

OK but it's the motor company issue. So what should I tell them. They told me to test voltage so does my readings I posted show difference to show the£4000 brand new motors crap and need replacing

[Burgerman]

But they dont apear to be faulty. At least as far as I can see from your wheel spinning flawed test. Do it on concrete against a wall. See if currents and voltages match.
Do that test properly as already explained. You will see both motors take the same current at the same voltage within 10% which is perfectly normal/healthy.

What you showed me so far is that they look perfectly normal.
There MAY be some mechanical or electrical connection issue causing some other problem. not nessasarily with the motors themselves. There may be a mechanical problem in a gearbox, cush drive, hub mounting or something. Or a bad electrical connection that cuts power under load. But before you can claim a motor is bad you must find the fault if any exists. The video showed nothing other than a motor(s) struggling to climb a too high curb.

As already explained. But you must find out using normal fault finding methods and diagnostics, and possibly disassembly and testing to know what is actually going on. If anything.

Can you demonstrate a fault?

I also ask for other information such as the previous "issues/fault" which you ignored. Have you changed anything else? Can you show me a fault or what it does that is wrong? What happens on a steep slope?

[Burgerman]

Again.

Right now your controller is doing everything correctly.
That video shows me nothing, what am I supposed to be seeing?

?

Both sides, both motors are being sent the same voltage. It went straight before right?

? Elaborate!

So if anything is different now then it is nothing to do with the controller or its programming. All I can see is that you are trying to get a small wheel to climb up a curb that is a bit too high. It hits the curb and stops or skids depending on traction.
Question. Does it dive in straight lines on a flat surface?

?

[Gregrb]

If my previous motors work without this issue and when swapped by engineer to these motors there is an issue then the motor obviously has issue. The brake and gear etc all built in to this hub motor. I just need bit advice on how to get motor company to swap the faulty motor with new one.... They cost me 4 grand.... I understand you telling me to test but I I just want help to get swapped to working one as cinokeatky ripped of. Motor cimoan8tikd me not to do what you are telling me to do. So can't do that then report to them as they will say I broke motor instead then.

[Burgerman]

As far as I can see wit the flawed limited tests that you have done theres nothing wring with the motors.

How is swapping them going to change that?

Why were they 4 thousands?

Are these hub motors?
What do they look like?
Stock 4 pole with gearbox and brake?

Why do you never answer any of the questions that I ask? Several times now...
You are fixated on swapping the motors long before you have found the real problem. Its POSSIBLE that its a stuck motor brush on a 4 pole motor reducing impedance on one motor. The tests I ask you to do properly will show this. So far its not showing that.
Its possible a brake isnt releasing, due to being siezed or electrical wiring issues or bad connection, burned coil etc. Again you wont examine this and find out. Or answer my questions.
Its possible that it has a gearbox that jams up under load, or a cush drive rubber that does the same. That would show high current and look normal and so would need actual careful examinatin and testing and you refuse to do that or even answer my simple questions.

But non of those three things are very likely at all. Especially on a motor that runs straight and doesent make unusual sounds in a straight line on a flat surface. Again I ask this several times and no answer.
ALL of the things I ask are a way to let me diagnose the thing without actually getting my hands on it so that simple logic and understanding will allow me to diagnose the actual problem. But randomly swapping motors isnt a way to fix this. I completely agree with the comany that suppled the motors as they know that they are healthy. They build and test these before shipping. And most of what you will tell me doesent add up or make any sense.

As to what you tell them, say I wont analise the problem and find the cause and wish to jup to the conclusion that one of your motors is faulty. Obviously they wont want to swap them.

If you properly diagnose the ACTUAL problem, and can show them how and why then they will have no problem swapping a motor for a new one. You will need evidence to show them. And you refuse to do it. So what are you expecting? I sugget you get someone capale to examine the chair, use actual tools and a test bench an a power supply, to properly test and find the problem if one actually exists on the motors. To me that would be the obvious thing to do.

I could measure impedance on the bench. Can do the same for the brake. I can test motor RPM start voltage and current. I can test free running current at all voltages. I can measure stall current and torque if needed and compare the two motors. But if the previous stuff checks out theres really no need. I can test that whenbrake is operated that they can be turned by hand. I can LOOK at the motor coupling physically, same with geabox internals and make sure nothing is wrong. If you do this and find anything that is wrong then they WILL swap them.

If you are guessing, they wont. And then when they test them and find out theres no problem then they will likely charge you. And your problem will likely still exist.

Again what was the original problem you aluded to?
Again do the tests
Again does it run properly on a flat surface or go in circles?

Please answer!

[Burgerman]

If you really think theres a problem, and you cannot do the above, then you must get someone such as rover on here, a DECENT tech and most are not to take a look at it. Motors are not magic. They are actually very simple things IF you understand them.

And so equally simple to properly test and evaluate. I or someone like rover on here could figure out if theres a problem, and exactly what it is in just a few minutes. And likely fix it or dissassemble the offending part and photograph the evidence be it in parts or on a multimeter.

Minutes. Less time than all these messages!

If you cant do this. You need a man that can. Note most chair techs are clueless. So be careful! But if you get a report from a tech that says faulty motor they will have to swap them. They are unlikel to do that based on your opinion. Because you are guesing.

Not sure that it will help you however. They appear fine from the test you already did. But hard to tell if you let the wheel spin. Find a more grippy surface. You motor company must know that trying to climb a curb loads up the motor in exactly the same way as testing against a wall? Or are they idiots too? The current limit is 120A and limited by the controller and they will see this in service regardless. Be it your test or a big curb.. Tell them that they are clueless. Or you are talking to some numpty instead of an engineer?

[Burgerman]

Just one small clue, that may be unrelated. 1 thing that is a little odd. Your screenshots show 0 battery Amps. It should have a reading. I do not know what this means. Never saw that happen before.