Still finding the joystick over-sensitive

[DannyB]

I'm finding it hard to steer my Frontier V4 in a straight line at anything other than the slowest speed. It's not as bad as the Meyra Optimus, which had the tank steer issue thrown in, but the V4 still seems to veer at the slightest movement. I'm beginning to think maybe the slight tremors in my right arm (better than my left and I'm right-handed) are responsible. Although I don't have a problem steering my extra-small footprint indoor powerchair precisely enough.

I'm practising every day and starting slow. I love the tiny turning circle and find the seat super comfortable.

Any tips please? I've read about how to use the joystick properly and my fourth and fifth fingers are securely curled around the R-Net controller as advised.

Sorry to sound whingy...

[Burgerman]

Did you set turn acceleration to 100?
Did you set turn deceleration to 100?
Did you set miimum turn acceleration to 100?
Did you set minimum turn deceleration to 100?

This prevents the delays and overcontrolling.

And then, did you lower the minimum and maximum turn speeds to a rate that is controllable and comfortable for you?
That Is also essential. The minimum sets the turn sensitivity at low speed. The max or "turn speed" sets the sensitivity at the higher speeds.
And then test. And re-test until you get this how you prefer it. If not all of the above is done, I cant steer any powerchair properly. And neither will you.

Send me your profile?

Then to steady it further your arm shakes can be damped down with tremor damping
Set low it means fast almost instant response. I have this at zero. Set too high it causes a delayed response as it averages the joystick positional changes over time. But that also smoothes out shaky hand / arm control and may be a nessasary evil in your case.

If all the above is true, then we can later, check out the stability settings meant to stabilise unstable front drive chairs. Theres an algo built into the control system that can help you. Also do you have any previous experience of joystick control? For e.g. flying model airplanes etc. Computer games maybe.


And do you have the joystick positioned correctly? If not things get very difficult. Do you have "normal" hands?

Look at the height, of the joystick here that martin my carer is using below. Note that for control stability the joystick is high enough above the arm top, and slightly inboard of the arm top. And has a GAP between the arm top, and the joystick. So the palm/fingers are correctly positioned as a reference, so that he can accurately move the joystick with forefinger and thumb to millimeter accuracy. If this is not all true, you need some modification work. It is essensial that you get this part right.

Note he has the footplate too low. And so is looking like he is sliding out. Short legs syndrome...

Pic: Because of wrist, arm, and especially hand position, which need the GAP, Height, and maybe 2 inches inboard jotstick position, and because the arms are solid (double uprights) and because his hand is cupping the side of the joystick comfortably, then the joystick knob cannot move from the straight forward position unless his fingers CHOOSE that. No banging, wobbling or bumps move the joystick knob around.
Enlarge and look CAREFULLY.

[Burgerman]

If no GAP. Then the joystick must be higher. Like on my salsa. Below.

Because it also allows a comfortable position to hold the joystick. This means a few spacers and a bit of drilling Etc. Note that the outer edge of the joystick lines up with the arm centre. So it sits around 2 inches inboard.

Zoom in to underside of mounting bracket. To see a few round spacers to lift the joystick. And the whole swingaway was mounted differently to move it inboard.

Details like this absolutely matter. I cant control the damned things once programmed to be linear and proportional otherwise. Neither can anyone else.

In pictures here its still 0.5 inch too low. Another 3 additional alloy spacers were added later. 4 in these pics. 7 eventually.

[steves1977uk]

I'm guessing Danny doesn't have a programming dongle BM, so he would need to buy one or take the chair to someone who has one. But it's better to buy your own and take time setting it up properly.

Steve

[Burgerman]

Then thats the problem garanteed. Its not over sensitive its overcontrol caused by all the delayed turn accelerations/decelerations all stock chairs are lumbered with. Cant hit a barn door with any of them.

Dealers generally will not set this as I just explained above. And in most cases even if they will, and if they even know how, they generally only have dealer programmers and so cannot remove the walls and you end up no better off. So you need a dongle, and some free software to deal with it.

[Burgerman]

His IP adress is virgin media. So UK. Wonder if any of us with OEM programmers are close? I am up 5 hours a day half the week at the moment...

Also. He will never drive that chair properly with the joystick in this position. https://postimg.cc/vDmDL1HF
Its too low. Too far to the right. And theres no gap needed to drop your hand into to properly hold the side. See my long post above. You will need to breakout the hacksaw, drill, hammer, or whatever it takes to rejig everything.

[DannyB]

Thanks for the excellent advice.

Yes I'm in north London and no, I don't have a dongle. But I'll try to get one through the people who sold it to me.

I'm very encouraged there is a solution and it's not just me, so thanks for that.

I think the joystick is at the right height but could come inboard an inch or two.

[Burgerman]

No. It needs a gap. Like in the picture above with my carer. Or higher. like the Salsa pits. As it is you would need to be a contortionist to have a decent hand position and I certainly couldnt drive it properly that way..

[DannyB]

I'll try and move it forward tomorrow.

[Burgerman]

If its in the right place move the arm back instead. All takes a lot of fidling about and inginuity. And move it higher and more inboard at the same time. It may mean breaking a few eggs. And then once properly programmed you will be in business.

I also note that your arms seem very low altogether. Mine are at least 3 or 4 inches higher. That may or may not help - it might - but if it were me I would raise them till your arms rest comfortably at the elbow like this download/file.php?id=15599&mode=view

[DannyB]

Thanks BM.

The Magic Mobility guy calls the V4 "twitchy". He's sending me a dongle and disk but it cost yet more dosh. This is turning out more expensive than I expected...

[steves1977uk]

That will be a Dealer version, but there's a workaround that let's you write the OEM settings using the Dealer dongle.

Steve

[Burgerman]

It is the same as every single powerchair with all the stupid default turn acceleration settings. Its not "twitchy" is programmed badly.

It can be non "twitchy" if you do EXACTLY as I say above in this thread. In that order. As can every single powerchair made.

[DannyB]

That will be a Dealer version, but there's a workaround that let's you write the OEM settings using the Dealer dongle.

Steve

No Steve, it's the OEM dongle apparently.

[DannyB]

It is the same as every single powerchair with all the stupid default turn acceleration settings. Its not "twitchy" is programmed badly.

It can be non "twitchy" if you do EXACTLY as I say above in this thread. In that order. As can every single powerchair made.

Thanks. I looked at the joystick and there seems to be a male slider inside a female square tube to which the armrest is fixed, adjustable for this purpose and a bit of slack in the connector cable, so it won't be a problem.

[Burgerman]

No Steve, it's the OEM dongle apparently.

Well if it is then I will eat my hat. Well I dont wear one but you know what I mean.

They call it "the" programmer. It will have an A on the dongle. Thats Dealer, not OEM. (OEM has a B on it). Its the only one most of them ever knew about... You are talking to an ahem, "expert" arent you?

[DannyB]

All I know is what he said, which is

The V4 is a twitchy chair but can be programmed to suit. I do have a dongle, lead and disc (oem) version. This is the top programmer as the 2 below it restrict what you can adjust. This will then allow you to adjust to your hearts content until you are happy with it.

[Burgerman]

He is selling you an OEM level programmer without the usual arguments/denials? If true I am amazed!

[steves1977uk]

Danny, what was the price for the OEM dongle kit?... Just curious.

Steve

[DannyB]

Danny, what was the price for the OEM dongle kit?... Just curious.

Steve

£180 Steve. But I figure that without it the massive investment in the chair itself is compromised - and I want it sorted pronto.

[Dan]

The OEM ones normally sell for £400+
The dealer ones about £200

[steves1977uk]

Danny, what was the price for the OEM dongle kit?... Just curious.

Steve

£180 Steve. But I figure that without it the massive investment in the chair itself is compromised - and I want it sorted pronto.

At that price it's definitely a Dealer dongle you're getting, new complete boxed ones are around £250. An OEM kit would be about £450.

Steve

[Dan]

At £180 for an OEM dongle I would take two! For what its worth the dealer one using the work around is ok in my book, especially if its not going to be used much.

[Kssisk]

hi all
i am having the same issue. the hair is so jumpy. it was given to me, only used about 10 hours from its former owner. its a mid drive Rovi X3
i have woody's dongle and the oem programer. i keep running over my service dog because it is so jittery. the issue is it fishtails everywhere

any advice is appreciated

[Burgerman]

What control system are you using on that chair?
VR2?

If so you need to go to the ABS settings (walls) and remove any. Set upper to 100, lower to 0 everywhere in there.

Set turn acceleration to 100.
Set turn deceleration to 100.
Set minimum turn acceleration to 100.
Set minimum turn deceleration to 100.

These four ACCELERATION/DECELERATION settings above will make the chairs joystick operate in almost real time. Like a pencil, or the steering wheel of your car. They may make it FEEL more sensitive initially when you set them to 100. Thats because it now does what its told, WHEN its told, and so the frequently high settings for turn speed below will catch you out! So next:

set:
Minimum Turn Speed set to say 12. This is the speed it turns when set to the chairs slowest speed in each profile.
And Turn Speed to 25. This is the speed or sensitivity that the chair has to the joystick movement at max speed.

You will want to set these faster than 12 and 25 eventually, I suspect, but this should be super easy to control.

But you MUST have the hand control positioned correctly, as per the start of this thread. Read from post 1 VERY CAREFULLY!

[shirley_hkg]

I will reduce forward acceleration and torque too.

Reduce max speed when in indoor helps most.

[DannyB]

Thanks all. I'll let you know what arrives and how I get on.

[DannyB]

OK, I've got the dongle and OEM Windows version of R-Net, as promised. I'll try reprogramming the V4 shortly.

[Burgerman]

See pm.