Configuring a new chair (essential!!!)

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Re: Configuring a new chair (essential!!!)

Postby Burgerman » 15 Nov 2022, 13:48

Thats no problem on mine. Even when sat with lift high up. Its not as tippy as the salsa. Because on that chair the footplate and therefore seat can go back another inch or so.
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Re: Configuring a new chair (essential!!!)

Postby Toro » 15 Nov 2022, 13:54

Really, I thought it was, I'm not against setting the seating back, I just worried in falling, it's something that freaks me out, took me awhile to get used to tilting in the beginning.

Haven't had a rear drive chair in 20 years either.

I'd be looking at setting it up like your new one, but the control setting a little different
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Re: Configuring a new chair (essential!!!)

Postby 700R » 15 Nov 2022, 16:18

Toro wrote:What appeal to me is the wider forks on them like the salsa, I'm wanting a middle footplate and the Q700R is a little narrow unless you shift the seating back like you did.

Problem is I think that will be too tippy for me especially to tilt being a c4/5 quad.


The seating shifted back is only done for centre of gravity purposes not clearance. It actually makes the centremount closer to the front castors the further back the seat is. It all depends on how you feel comfortable where you have the seat positioned in relation to your feet. Of course the further forward the more weight is over the front end making it feel like a boat but I'm currently testing my seat one hole forward of maximum and can get a better closed angle on the centremount before it touches the castors. It hasn't made any noticeable difference to the handling so I shall try it for a while.

At present I am fully reclined in mine, as I was earlier before the seat was moved, and rocking like a demented loony and there's no-way I can get it to tip. You will absolutely be safe, in my opinion, certainly with the seat down. The chair is way too long to be tippy.
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Re: Configuring a new chair (essential!!!)

Postby Burgerman » 16 Nov 2022, 16:18

You must TEST.
Set it up as you wish. Then recline, tilt and get someone to try and tip it see what it takes. Do it with your bed behind you and actually push it over.

If you have seat elevator, also test that the same way. And do so with tilt, and reclive as well. If its too tippy then adjust things until YOU feel that its safe. It really doesent tip far back onto a bed and can easily be righted.

In the case of the salsa its not tippy with just recline/tilt. Maybe a little bit. With the legs lifted that goes away. As legs are heavy! So no problem it just makes you aware. The salsa IS instable if lifted, and tilt/recline. Only takes maybe 4 lb of force to make it tip back. So I dont do that!

The Q700 is less tippy altogether. But on that chair I angled the set lift forwards. So that it moves the seat forwards as it lifts. So the CG is moved forwards too. Not tippy when lifted any longer. In order to get my preferred seat dump angle of around 6 degrees back I added a couple of spacers under the front of the seat base, on top of the lift module. I intend doing this to the salsa too.

EVERYTHYTHING is down to how you configure the chair. It takes time and thought and TESTING to get everything right. No chair is ever even close to right as it arrives. In so many small ways.
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Re: Configuring a new chair (essential!!!)

Postby 700R » 16 Nov 2022, 16:48

All valid points, BM, but you and I have the chair to test and alter as we like. Toro and others interested in the Q700R can't test without spending thousands on a chair they're uncertain about. The Q700R won't tip with the seat back or there wouldn't be a hole there from factory.
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Re: Configuring a new chair (essential!!!)

Postby Burgerman » 17 Nov 2022, 00:27

Well the salsa has a hole there! It certainly does tip. Without moving.

These things are meant to be configured to suite very different people. Some no legs, some really long or short thighs, some that can only be is certain positions and from 5 stone up to 22 stone on the same chair.

And frankly as the too close together casters or the rediculous stock programming (on all chairs) or the flimsy wobbly arms and swing aways, or the standardised rear drive nose heavy oil tanker setups, swing away footplates ahead of casters, or the silly marketing department "swinging" leveling (spirit level tecnology as they call it) shows they really do not have much of a clue! Added to which the same seat mount and various different lift or tilt modules allow very different CG positions to each other... And are identical parts used across the rear, hybrid, front or mid drives.And even different brands. Some lift modules are just standardised parts used across brands. So I dont think the hole position means much at all.

Certainly not safe limits. That stuff must be configured by "your seating expert" they will tell you. For what they think is safe or best. The trouble with that is that the "experts" or in thi country the WCS for e.g, dont or cant think. Usually a bunch of old ladies with zero grasp of physics or mechanics. Theres around 5% of them that have a clue. The rest know about as much about chairs as the answers they gave you about your seat height adjustment. Two man job? I did my own as half a man in a wheelchair. As I keep on saying to people do not ask the "experts" use your own brain. Because they just make shit up to cover their ignorance.
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Re: Configuring a new chair (essential!!!)

Postby 700R » 17 Nov 2022, 10:38

Burgerman wrote:Well the salsa has a hole there! It certainly does tip. Without moving.

You're talking when the lift is right up? That's still surprising from factory. I can't tip my Salsa on full tilt and recline.

Burgerman wrote: So I dont think the hole position means much at all.

It should, despite allowing for many variations, be safe on any hole from factory with leeway. If not it's plain stupidity and incompetence.

Burgerman wrote:The rest know about as much about chairs as the answers they gave you about your seat height adjustment. Two man job? I did my own as half a man in a wheelchair. As I keep on saying to people do not ask the "experts" use your own brain. Because they just make shit up to cover their ignorance.

How did you adjust the floor to seat height alone? I wasn't aware you've altered yours. That I would like to see! :shock:
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Re: Configuring a new chair (essential!!!)

Postby Toro » 17 Nov 2022, 10:53

I don't tilt and lift at the same time, neither do I have leg extensions.

As I've mentioned my main concern is not tipping back as if I go with a Q700R I'd want a center footplate.

As I've been using a mid wheel chair, tipping over is not a problem when tilting.

Is shifting the seating back on the Q700R for CG or because a middle footplate won't fit otherwise.

I understand BM you believe they are to noise heavy if it's not shifted back, and don't drive right, but just curious to know why or if it's essential?
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Re: Configuring a new chair (essential!!!)

Postby 700R » 17 Nov 2022, 11:16

Toro wrote:I don't tilt and lift at the same time, neither do I have leg extensions.

As I've mentioned my main concern is not tipping back as if I go with a Q700R I'd want a center footplate.

As I've been using a mid wheel chair, tipping over is not a problem when tilting.

Is shifting the seating back on the Q700R for CG or because a middle footplate won't fit otherwise.

I understand BM you believe they are to noise heavy if it's not shifted back, and don't drive right, but just curious to know why or if it's essential?

Adjusting your seat right back is not essential for anything other than getting your weight over the drive wheels to maximise performance and drivability. It will also shorten your chair considerably. The centremount will fit better with the seat base further forward but you'll compromise handling somewhat.
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Re: Configuring a new chair (essential!!!)

Postby Toro » 17 Nov 2022, 11:48

Thanks 700R, everything is compromise, especially in the disability sector.

Been a long time since I've used a rear wheel chair. It was what I felt most comfortable with, but then in Australia for a long while rear drive chair were lacking in the choices, and mid drives are pushed hard.

I do like the ability of mid wheel to spin on the spot, though when I first jumped in one it felt like I was doing fishtails all over the place.
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Re: Configuring a new chair (essential!!!)

Postby Burgerman » 17 Nov 2022, 12:01

The centremount will fit better with the seat base further forward but you'll compromise handling somewhat.

I dont understand that sentence.
The swing awy footrests make the seat have to be way too far forwards.
The Centre mount ones, and there are about 6 different ones here, all allow your heels to sit further back between the caster wheels slighty. The swingaway ones mean your heels must be much further forwards, beyond the (rear facing) caster wheels.

So you can move the seat back further with a centre mount plate. And if you fit the 8 inch tyres, guards removed, you can gain another inch on heels and seat position. Mine is as far back as the adjustment allows. Its OK. It could be better is the casters were further apart but I would need to drill extra holes. And then LIFT stability would be compromised, but it woud drive better.

Its still a little too far forwards for my liking, but a million times better than any swing away setup if carefully configured. This applies to ALL rear drive chairs. Every one is as long as an oil tanker and as nose heavy as hell, with hovercraft programming as they come stock. ALL of them. Making all STOCK rear drives completely hopeless. Hence the centre drive popularity. But they are really the best option for anyone that hopes to go outdoors and have any stability and control ONCE SORTED! But you wont get that short, nimble controllable rear drive chair unless ou are repared to do a little work.

The Q700 rear drive is not as good as the Salsa or Jive. Same with the Q500R. Because the designers (obviously a committee/marketing dept) ruined it!
They fitted flimsy seating compared to the salsa. They moved front casters around 3 inches closer together making it extremely hard to get a rearward seating position, and sensible knee angle. And they fitted a STUPID swinging hinged REAR axle. In order to attempt to keep both drive wheels on the deck for control while the chair is so stupidly nose heavy with stock setup/swingaways. This makes no sense when CG moved back to where it needs to be, as the chair then flops from side to side. It needs to be bolted up and that allows the normal rear suspension to work as it should.
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Re: Configuring a new chair (essential!!!)

Postby 700R » 17 Nov 2022, 12:09

Toro wrote:Thanks 700R, everything is compromise, especially in the disability sector.

Been a long time since I've used a rear wheel chair. It was what I felt most comfortable with, but then in Australia for a long while rear drive chair were lacking in the choices, and mid drives are pushed hard.

I do like the ability of mid wheel to spin on the spot, though when I first jumped in one it felt like I was doing fishtails all over the place.

I wouldn't have a mid-wheel drive chair if I was given one. The manoeuvrability of a rear wheel drive chair with the seat right back, centremount and programmed properly will steer, turn and generally be as good as a mid-wheel is indoors. Also you'll have no blind rear overhanging castors to worry about taking out furniture or people's feet. It'll be far superior outdoors too.
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Re: Configuring a new chair (essential!!!)

Postby Burgerman » 17 Nov 2022, 13:55

Agreed!
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Re: Configuring a new chair (essential!!!)

Postby Burgerman » 12 Jun 2023, 18:40

test
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Re: Configuring a new chair (essential!!!)

Postby ex-Gooserider » 12 Jun 2023, 23:53

Burgerman wrote:test


Pass!

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Re: Configuring a new chair (essential!!!)

Postby ex-Gooserider » 12 Jun 2023, 23:54

Possibly I spoke to soon? First time I tried to post the above, I got an error -
Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator at webmaster@wheelchairdriver.com to inform them of the time this error occurred, and the actions you performed just before this error.

More information about this error may be available in the server error log.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.


The second time it worked fine...

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Re: Configuring a new chair (essential!!!)

Postby Burgerman » 13 Jun 2023, 01:47

That happens when the server is too busy. Like when I am doing a backup and getting it to ip 20Gb and letting me download it maxed out. So it has a little nervous breakdown. Or when hundreds of requests (like a denial of service attack) happens. Hence the test... Because I disabled the bad IP request filtering, VPN filtering etc.
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Re: Configuring a new chair (essential!!!)

Postby Burgerman » 27 Jul 2023, 11:01

test
Attachments
65_Myr_Climate_Change_Rev.jpg
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Re: Configuring a new chair (essential!!!)

Postby Michalych1974 » 24 Dec 2023, 10:14

Burgerman wrote:Thats no problem on mine. Even when sat with lift high up.


Question: at the moment of starting the electric motor of the wheelchair under heavy load, the controller outputs a maximum current of 175 A, but for some reason does not increase the voltage above 6 V? The joystick is fully tilted forward/backward. Or is that how it should be? Electric motor 700 W, 22 V.
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Re: Configuring a new chair (essential!!!)

Postby LROBBINS » 24 Dec 2023, 10:35

Yes, that is how it should be. Motor speed is controlled by voltage (using pulse width modulation). When just starting out is rotating very slowly - low voltage, very high motor current, much lower battery current = motor current X PWM percent.
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Re: Configuring a new chair (essential!!!)

Postby Michalych1974 » 24 Dec 2023, 11:02

LROBBINS wrote:Yes, that is how it should be. Motor speed is controlled by voltage (using pulse width modulation). When just starting out is rotating very slowly - low voltage, very high motor current, much lower battery current = motor current X PWM percent.


The fact is that the wheels cannot turn. What is the reason: the controller or the motor?
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Re: Configuring a new chair (essential!!!)

Postby Michalych1974 » 24 Dec 2023, 11:37

Should the controller raise the voltage to a nominal 23 V if the motor cannot turn the wheels. The current increases to a maximum of 170 A Meyra Optimus 2 stroller with CAN bus
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Re: Configuring a new chair (essential!!!)

Postby Burgerman » 24 Dec 2023, 11:41

The controller limits the CURRENT to whatever is programmed as maximum. So the voltage cannot increase as the current would rise above the maximum. The voltage or rather the pulsewidth is the thing that the controller is reducing in order not to exceed the rated current.

Since the motor is also a "generator" as the speed increases the current naturally drops and then the controller will use a higher pulsewidth to maintain the rated current.

As to why your motors dont turn I have no idea. What is stopping them? Do they have too much load? Brake is on? What is the motor fitted to?
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Re: Configuring a new chair (essential!!!)

Postby Michalych1974 » 24 Dec 2023, 13:00

Burgerman wrote:The controller limits the CURRENT to whatever is programmed as maximum. So the voltage cannot increase as the current would rise above the maximum. The voltage or rather the pulsewidth is the thing that the controller is reducing in order not to exceed the rated current.

Since the motor is also a "generator" as the speed increases the current naturally drops and then the controller will use a higher pulsewidth to maintain the rated current.

As to why your motors dont turn I have no idea. What is stopping them? Do they have too much load? Brake is on? What is the motor fitted to?



wheelchair MEYRA Optimus 2, cannot overcome the threshold of 6 cm. without acceleration, My weight is 50 kg.
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Re: Configuring a new chair (essential!!!)

Postby Burgerman » 24 Dec 2023, 13:21

Right. Then you need better system.

To increase torque you need lower shorter (slower) geared motors. Or a controller that can provide more Amps. Or both.

The myra optimus is not really a wheelchair. It doesent use "tank" style mixed steering/drive algorythm. As such its a special power module that isnt normally used on a powerchair and has both its drive channels linked as a single channel output. You are already reaching its maximum Amp (current) limit. Adding a more powerful module, would help if one were available. Its not... So theres no easy solution. In any case that may also burn the motors...

With normal powerchairs this is also a problem. When I buy powerchairs I always specify 10kph max speed. And 4 pole motors. This gives the greatest level of torque. Faster motors are problematic. Lack adequate torque for curbs and for good steer control. (tank steer).
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Re: Configuring a new chair (essential!!!)

Postby Michalych1974 » 24 Dec 2023, 13:38

[quote="Burgerman"]Right. Then you need better system.

Thanks
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Re: Configuring a new chair (essential!!!)

Postby LROBBINS » 24 Dec 2023, 16:05

You might also be able to reduce the rolling resistance of your tires and/or reduce the torque required to overcome the obstacle by shifting the center of gravity.

If pneumatic tires, you can reduce rolling resistance by increasing tire pressure.

Shifting the center of gravity rearward will reduce the load on the front wheels, making it easier to get them over the obstacle. If your chair has tilt, you can see if tilting back shifts the weight enough for this. If not, you may have to move the seat back - easy or difficult to do depending on design and possible interference with foot plates.

BTW, if you turn around does it more easily climb the obstacle going backwards?
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Re: Configuring a new chair (essential!!!)

Postby Michalych1974 » 24 Dec 2023, 17:23

LROBBINS wrote:You might also be able to reduce the rolling resistance of your tires and/or reduce the torque required to overcome the obstacle by shifting the center of gravity.

If pneumatic tires, you can reduce rolling resistance by increasing tire pressure.

Shifting the center of gravity rearward will reduce the load on the front wheels, making it easier to get them over the obstacle. If your chair has tilt, you can see if tilting back shifts the weight enough for this. If not, you may have to move the seat back - easy or difficult to do depending on design and possible interference with foot plates.

BTW, if you turn around does it more easily climb the obstacle going backwards?

Going backwards into the curb is even worse.
Tire pressure 2.5 kg/cm
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Re: Configuring a new chair (essential!!!)

Postby LROBBINS » 24 Dec 2023, 18:25

That tire pressure is certainly high enough - is that the pressure in both the front and rear tires? Do front and rear tires have the same or different diameters?

Is the backward speed programmed lower than forward?
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Re: Configuring a new chair (essential!!!)

Postby Burgerman » 24 Dec 2023, 18:30

https://www.meyra.com/wheelchairs/produ ... roduct-47/

Servo rear steered single channel motor controller based on a special single channel parallel connected drive channel r-net power module. Large group 27 battery (heavy). High speed motors, low torque garanteed! On slower versions they just program for lower speed and keep the same gearing. So still low torque. Lots of mass at both ends. Basically a servo steered scooter. Actually low tyre pressures help on curbs.
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