PINNED - PROGRAMMING - Make it steer! R-Net + others

[Burgerman]

Because its possible to set a thing that can damage brake, motor, or set a chair to run away, and break your legs with no way to stop it. So they think that OEM should only be for Original Equipment Manufacturer. Use.

[steves1977uk]

I, for one would never program a chair with dangerous settings, common sense tells me not to unless I see the actual chair to see how it responds in person with the user in control. Sure I've had PM's sent to me to re-program for the user, but I always ask if their chair has 2-pole or 4-pole motors and use my knowledge to make sure it's safe for them to drive.

Steve

[greybeard]

Because its possible to set a thing that can damage brake, motor, or set a chair to run away, and break your legs with no way to stop it. So they think that OEM should only be for Original Equipment Manufacturer. Use.

That's a pretty feeble reason IMO. The chairs belong to end users, not CW, and as owners they should be free to do as they wished with them - including killing themselves with them if that is their desire. All it takes to protect CW from claims (which is probably what's behind the policy) is to enclose INFORMATION about the possibly dangerous consequences of messing with certain options in the programmer, and explaining WHY, and a disclaimer with each programmer sold. Then it rightly becomes a case of each owner being responsible for his/her own actions

Would you have accepted a similar ban on tinkering with any motorcycle you owned or even the one on which you were injured? I doubt it. Would any rock climber accept a ban on climbing itself, or some vital piece of climbing equipment because they might get injured? Again, I doubt it.

So why should any of us accept such a restriction simply because we are the unfortunate users of power wheelchairs? Particularly as stock programming makes the damned things quite dangerously uncontrollable?

Having vented all this I do realise there is sod all we can do about it except to encourage the early production of illegitimately obtained cloned programmers. CW and any other manufacturer that follows this principle will ultimately be the losers. I would love to own a programmer but I'll be damned if I'm going to cough up £400 - £500 for one.

[Burgerman]

I absolutely agree. They cant really complain then, when we reverse engineer, and copy and crack the OEM software for our own essential use to actually improve our messed up lives! They have left us no alternative.

[shirley_hkg]

John , would you please explain more about stall motor amp ?

You demonstrated a low impedance motor can draw 240a at stall. What is its potential difference across its terminus , and what is the corresponding ampere at the 24V battery ends ? ?

One motor or two ?

[Burgerman]

Start with 1 motor.

The CONTROLLER limits the stall current to its maximum allowed, or temperature, stall rollback settings etc. But a 100A controller will never allow more than 100A per motor.

SIMPLE figures to make it easy to undertand.
If the stall current on a motor at 24V (when connected to a big battery directly) is say 400A, (which will rapidly destroy it) then we know that a 100A controller MUST limit the motor to 25% PULSEWIDTH, or 6V at stall in order to stay at 100A limit... The battery current will then be 1/4 of the motor current at stall. So is 25A.

As speed increases - remembering that the motor is a generator - the pulsewidth is increased if that same 100A is to be maintained. Until at some speed the motor needs the full 24V, to draw 100A. At this point motor Amps = battery Amps. Per motor.

So at max acceleration up a hill, you can draw 200A at the battery, and 100 each motor.

[shirley_hkg]

Thank you and got it.

[Burgerman]

Also, this does not really apply to brushless on your chair. They are higher impedance. So they dont draw 100A at 6V, but at around 20V. So they take 100A per motor at stall/low speed under load such as when zero turning, and also almost that much from the battery. So they murder batteries indoors or turning. And they are super efficient at max speed.

[steves1977uk]

Here's an interesting but odd R-Net settings file that I downloaded from the 120A PM I bought recently off eBay.

I assume this was off a 4MPH 4-pole HD NHS chair, the speeds are programmed to a max 50% (obviously it had 8MPH motors!). Motor Compensation was set to 120mOhms! Luckily when I tested this on my test bench setup, the 4-pole AMT motors didn't take off! Going to re-program this with much safer values.

Steve

[Burgerman]

Some 2 pole really are 120mOhm, they NEED a mass of compensation because they are just crap motors.

No its 2 pole/4mph programmed to 2mph and a lot of other programming oddities.

[steves1977uk]

I agree BM, it certainly looks an odd setup! Wouldn't 120A kill 2-pole motors faster though? I guess not if it's programmed like the above.

Steve

[Burgerman]

I doubt that they will DRAW 120A at any time with that impedance and with 4mph gearing, so not an issue.

They will draw around 1/3rd that current of 40mOhm motors, plus battery volt drop, cable resistance losses etc, so I doubt that there will be adequate response from the motor compensation to reach 120A. Ohms law says that 120mOhm, could draw 200A in a perfect world with a stalled 120mOhm motor (0.12Ohm) at 24V.

But batt volts will be about 18, and the cables have nearly as high resistance as the motors.

[Burgerman]

Even on low impedance 4 poles, (which naturally pull more Amps due to impedance) and with compensation increased to a non recommended 50, on my super heavy salsa chair with all fully loaded options, (185KG + my 20 stone) it draws this:

Zero turn in my hallway from a standstill shown.
Note: M1 and M2 Amps, and M1 and M2 Volts.

[Burgerman]

Look at one motor.
It is pulling 113.7Amps, at 10.7Volts.

What does this tell us? It tells us, using Ohms law, that the TOTAL system impedance, of motor, connectors, wiring, is 0.094. Call it DOUBLE the actual measured motor impedance of 45mOhm (0.045A) Why is it doubled? Cables, connectors, etc. These are adding the same level of resistance, as the motors themselves do. In resistance. And wasting HALF the power at stall. As heat. So a 2 pole, with its higher impedance will draw around 1/3rd that current. The high 120mOhm motor compensation will help to a degree, but it will be unlikely to get near 120Amps.

This is why a 48V system with the same vehicle speed gearing, is way way more efficient. Half the amps, at double the voltage means half the HEAT resistance losses. And then because motor speed is doubled the gearing can be double the reduction, giving same speed as before, and same torque (at half the current) as before.

As they say in EV forums, volt up, gear down!

[steves1977uk]

Thanks for explaining that BM, learn something new everyday!

Steve

[stefanturbo]

Were can I find a manual about the Q-logic 2 system parameters?

[woodygb]

Try this ..not 2 but should be very similar.

http://javafoundry.com/home/Q-Logic_Tec ... Manual.pdf

Standard manual.

https://www.quantumrehab.com/pdf/basic- ... %20boi.pdf

[stefanturbo]

Try this ..not 2 but should be very similar.

http://javafoundry.com/home/Q-Logic_Tec ... Manual.pdf

Standard manual.

https://www.quantumrehab.com/pdf/basic- ... %20boi.pdf

Thanks

[stefanturbo]

Is it possible to use a CJSM2 as a attendant control?

[Burgerman]

No its a different manufacturers system.

[stefanturbo]

No its a different manufacturers system.

Its al Rnet so it is the same system. On Permobil wheelchairs is it possible.

[Irving]

Actually on r-net you can have multiple joysticks. The master joystick is the one that powers on the system. The controlling joystick is the one with the earliest serial number. The deciding process is described, badly, in the R-Net technical manual. I've not tried it yet though.

[stefanturbo]

Actually on r-net you can have multiple joysticks. The master joystick is the one that powers on the system. The controlling joystick is the one with the earliest serial number. The deciding process is described, badly, in the R-Net technical manual. I've not tried it yet though.

I have a Omni as main control and I want the CJSM2 as attendant control

[Burgerman]

Yes, on a permobil, that uses an r-net system, you can have a remote joystick. Not 2 master joysticks I think. Never tried that though! Depending on how its programmed it MAY be possible. Omni plus a joystick module should work. But it WILL need careful configuration.

[stefanturbo]

Is there someone who has experience with Now Technologies Glory headset or other products from Now to drive your wheelchair?

[Burgerman]

Not me. Never heard of them. But I have normal hand function. But the programming side of things in the way the chair works and steers is pretty much the same regardless of input method.

[woodygb]

I think that he means...

https://nowtech.hu/gyroset-glory/
https://nowtech.hu/actuator-direct-controller/ etc

[rover220]

No problem to have cjsm2 as attendant with an Omni. With correct programming you can have 2 master joysticks aswell. I have some experience of the glory headset.

[stefanturbo]

No problem to have cjsm2 as attendant with an Omni. With correct programming you can have 2 master joysticks aswell. I have some experience of the glory headset.

i know how to setup the CJSM2 as attendant control, I've asked it at pgdt how to do, Can you tell more about the headset?

[stefanturbo]

Because of my progressive muscle disease I have now not enough strenght anymore in my hands to control the joystick. I use now a Mo-vis micro-joystick but its to heavy. So is there someone who knows good alternative controls?