Invacare gb motors

[Ashley G]

Ashley, Assume your chair is facing N. When you place the stick in NE which way does your nose turn? When you place the stick in SE which way does your nose turn? On every chair I've ever seen, the users nose will be turning toward the right in both cases. If you do the same thing in a car, your nose will turn toward the right in the first case, but toward the left in the second. Ciao, Lenny

If I place the stick at NE, my nose turns right.
If I place the stick at SE, my nose turns left, Lenny.

Ashley,

This is the map of a joystick...does it match yours?

No Woody ! On your diagram, the SE and SW positions are showing the chair turning in the wrong direction, compared with both my chairs. I hasten to add that I haven't changed that - it's just how they always were and how I assumed all wheelchairs were

Regards

Ashley

[woodygb]

Cheers for that Ashley ...

it's just how they always were and how I assumed all wheelchairs were

I'm as surprised as you!


THIS is your joystick setup!?

ashley.JPG (32.84 KiB) Viewed 13520 times

[Ashley G]

Yep, that seems right, Woody

That's something new I have learned then, which I didn't even know was there for the learning !

Regards

Ashley

[Burgerman]

Every bit of tank steer electronics, JCBs etc all do the same thing as far as I am aware. Cant see any logical way of ever doing anything different.

Do me an experiment. Go outside in a big space, and stixk your joystick as far right as it goes. In the centre. Chair will rotate right seen from abobe. Keel it right pushed over to the right.

Now move it forwards and backwards while STILL keeping it right. The chair, every chair, will (should) just continue rotating right but now go either back or forth too.

Theres no way electrically or mechanically for it to do anything other than this. As far as my brain says! It cant start rotating the other way just because you reverse, it would act weird. And how would it turn when you were not going back or forth? The right way or the other way???

[woodygb]

Theres no way electrically or mechanically for it to do anything other than this. As far as my brain says! It cant start rotating the other way just because you reverse, it would act weird. And how would it turn when you were not going back or forth? The right way or the other way???

That was my initial reaction.... but Denis modified one of my pics and came up with the following for steering direction ( ignore the motor direction notation )... ...then Ashley chimed in with the confirmation that his chair followed that pattern and I also recalled a thread on this forum where the swapping motor / wire logic didn't sort out the chair direction as I percieved it should be.... thus doubt was sown on the "universal" joystick direction concept that I believed.

It's possible to come up with any electronic map mix and I'd guess that Ashley's results will be

Everything above the center line as "normal"

Right stick center spin clockwise...then as you pull back ...joystick still hard right...and just past center.. it will stop spinning clockwise and slowly reverse direction.

[Burgerman]

Cant be.

>>> Right stick center spin clockwise...then as you pull back ...joystick still hard right...and just past center.. it will stop spinning clockwise and slowly reverse direction.

Because 100 times a day you pull the stick back to slow fast, or to negotiate a steep ramp, and as you did, steering would decrease, then reverse itself. Effectively the amount you were steering around an obstacle would change with thottle position! It wouldnt be drivable. And would be absolutely counter intuitive.

[woodygb]

Over to Ashley then.....

[ex-Gooserider]

Ashley,

This is the map of a joystick...does it match yours?

For whatever it's worth, my Select 6 matches Woody's picture - the nose of the chair moves in the left/right direction the joystick points, with forward and back speed added depending on the fore/aft part of the position. Can't tell if my 1100 or the 626 does the same for certain since those are in pieces, but all three did just exactly what I expected, so I think all three match the map...

I don't recall any other joystick vehicle driving experience, but I used to work as a repair tech for a pinball / video game company, and got plenty of joystick time on that job. I didn't have any problems when I first got in a power chair, as the stick did exactly what I expected it to do...

ex-Gooserider

[Burgerman]

They should or in fact must match that picture unless I am completely losing the plot!

Or the steering would need to suddenly reverse as you pulled the stick back since when stopped it turns as you expect!

[denis.b]

All wheelchairs that I used to guide follow this pattern:

Cattura.JPG (30.85 KiB) Viewed 13430 times

It is probably another way of driving.
On the site "http://www.hagon-shocks.co.uk/catalog/config.aspx?TypeID=M" Shocks must be chosen depending on the brand of motorcycle.
how to know which one to choose?
thank you
Denis

[woodygb]

What happens along the yellow line between clockwise rotation "spin" on the spot ( both wheels driving in opposite directions ) and anticlockwise rotation?

Cattura.JPG (23.64 KiB) Viewed 13270 times

[Burgerman]

You crash, quite obviously.

I USE that part while slowing down to hit tight doorways for eg.
Can you even imagine trying to steer towards a doorway, while slowing and the steering swapped from left right as you pulled the stick back to decelerate?
Ouch!

Its not possible/usable. I just flew around the house and watched my thumb! I spend around 15 percent of the time with the stick pulled back, to slow, even if I am always traveling quite fast forwards! If the steering kept reversing itself I would be in hospital with broken legs!

[woodygb]

It may be odd and perceived as dangerous ....this system however appears to exist ...therefore I wish to understand it.

It might make some sense if there was NO SPIN just a tight turn pivoting around one stationary wheel.

Cattura.JPG (23.52 KiB) Viewed 13248 times

[Burgerman]

It really cant exist? Can it? Its illogical, and obviously going to cause out of control moments. How can a system exist that allows your steering wheel to reverse its sense of direction if you decide to slow down for a padestrian or doorway...

I can program my RC transmitter to do this for a laugh. But I am not trying it indoors!

Think about this. You are sailing along next to the edge of the train platform, and heading slightly for it. You decide to stop or slow drastically because someone steps in your way. Now the steering reverses sense! And you are heading for the edge while still slowing down. Not pretty. Nobody would make a system like this.

[Ashley G]

Mea culpa ....

Somewhere along the way, I got my nose and my direction of travel mixed-up and I stuck fast to that in my subsequent explanations.

Now I must apologise and confess that, being unable to understand why both my chairs should differ from everyone else's, I actually dragged my bum into gear and sat in one today. I was wrong

As soon as I was in it, and without even moving it, I knew I had misdescribed it When I pull my stick back and to the right, my nose turns right, not left as I insisted previously.

Sorry for the confusion guys. I don't know at what point I convinced myself I was right, but I should have checked sooner, instead of just re-explaining what I thought I meant

Regards

Ashley

[Burgerman]

Its all part of the fun!

I just finished programming the mix in my transmitter while watching TV. Will see how dangerous it is later!

[woodygb]

NP...

[Burgerman]

Went to pub so only tried it for about 3 mins. Dont go there! Its impossible to drive unless you are extremely careful and dont try braking. A plainly silly idea!

[LROBBINS]

I think that it could work, but you'd have to get use to always moving the joystick on a diagonal when going from forward to reverse. We do quickly adapt to that in a car, turning one way when going forward and the other when going back, but we usually mostly or completely stop moving between forward and back when swinging the steering wheel from one side to the other. I suspect it would fairly quickly become automatic in a chair as well, but why do so? Ciao, Lenny

[Burgerman]

No that doesent work. Eg, I am driving along a narrow path fast and making corrections etc, and steering most of the time. If I have to brake/slow I actually move the joystick back well beyond the centre while still steering. I would never get the correct amount of "reverse" steering, at the correct point...

I have it now so it STARTS to reverse steering at centre point. And by 25 percent reverse its fully reversed. At 12.5 percent there is NO steering since its crossing over. If I choose say instant reverse at x point it feels violent if you are already steering one way. So only pull back slightly to slow a little, and you lose all directional control and fall off a curb. Or reverse slowly and no steer... No way to make this work.

[denis.b]

I have a problem of alignment of the engine speed between front and rear wheels.
To drive the two stations simultaneously with a single joystick takes the signal from a (output of the decoding CAN) and I apply it to the second unit.
Everything works fine but the engine turns back than the front legs are very different.
It may be guilt that the two units are not the same model?
1° Controller : MKIV GB-HD model : 1116589-engines running on this unit the fastest-
2° Controller : MKIV GB model: 1109528 - engines run slower-
thank you very much
Denis

[Burgerman]

If they are programmed the same, then it must be motors that are different.

[woodygb]

swap over the controllers and see what happens to the motor speeds.

OR ...and I feel that this would give a better result in diagnosing the error .... wire up a front motor and a rear motor to ONE controller and see if there is an rpm mismatch.

[woodygb]

Denis are the motors all the same or odd pairs?

gbmotors.jpg (49.53 KiB) Viewed 10479 times

[shirley_hkg]

MKIV GB HD controller is for HD motors that is 7 MPH , with bigger torque.

MKIV GB only controller is for old version motor that is 8.5 mph. It has 1 less line for the hall speed sensor.

They don't seem mutually competitable.

[shirley_hkg]

One feature of the INVACARE GB controller is TRUE - TRACK .

IT keeps track of the speeds of the left and right motors , and it will keep both motors running in accordance with the joystick command ; by adjusting the speed and torque of the 2 motors . Say ; controller will automatically increase power of the right motor , if it came to an obsticle , while keeping the left motor unchanged.

How do your system work , with 4 motors ? They tend to pull each other apart AT TURNS .

You shoul have picked ordinary 4-polee motors for your project.

[woodygb]

1° Controller : MKIV GB-HD model : 1116589-engines running on this unit the fastest-
2° Controller : MKIV GB model: 1109528 - engines run slower

MKIV GB HD controller is for HD motors that is 7 MPH , with bigger torque.

MKIV GB only controller is for old version motor that is 8.5 mph

The two statements seems to contradict each other.

EDIT ... The possible work arounds seem to be:-
Reproggramming the faster controller to go slower...approx 20% slower
or
Bigger tyres on the slower motors again 20% bigger on the diameter...
or
Buy /source / find 4 off matching motors and controllers.

The other alternative is to give it up as a bad job.

[Burgerman]

Unlike the P and G stuff, I think the programming is in the joystick? So not possible to set different speeds for fifferent sets of motors.

[woodygb]

You could be right ..

However the purchase of a replacement joystick would mean that you'd need to reprogram it each time... that doesn't seem logical seeing as how the joystick is a part that wears out.

On that basis I'm going for the brain in the controller.

[LROBBINS]

Dynamic keeps a copy of the program in the PM that automatically uploads to a replacement joystick pod, but the brain is indeed in the pod (or other Master Remote if using some specialty controls other than a joystick). Ciao, Lenny