Weight! (A continuation, sort of, of my Storm 4 review.)

[Burgerman]

Suspension adjustment isn't scientific. Its totally down to your own preference. Depending on what you are doing, what you are trying to achieve, and why. And yes I adjusted the suspension to my own preferences as I do on most chairs. As well as tyre pressures if they don't have those horrid solid flat free things on. However as I have tried to explain already 101 times, suspension has absolutely ZERO affect on the programming accelerations and delays or on the affect of CG position that we are discussing here. None. Zilch. It is simply not involved. I can feel that acc/delay within 2 seconds of touching the joystick, and before the suspension has moved a mm. The fact that you cant see this totally baffles me.

At this point, especially when I read things like this suspension question, and the fact that you would even ask this, I realise that you are so far away from being able to understand any of this stuff that I have to say that I am wasting your time and mine.

Like teaching your grandma physics.

[greybeard]

It's taken long enough, BM.

[Burgerman]

And have a read through these 1500 posts about programming, safety, control, (and writing the firmware, building the joysticks and safety equipment from scratch, and actually building all the stuff that the chair manufacturers just "buy in"). And configuring a much more powerful robotics controller that was never intended for this purpose to get just a slight idea, of quite how much many of us understand about these things on this forum.

viewtopic.php?f=2&t=2436

Here's a picture under the seat of a chair I designed, And I don't just mean the frame as the big manufacturers do, and this is a small fraction of its technical details. http://www.wheelchairdriver.com/BM3-con ... ronics.jpg

A PDF of a chair I knocked up in my bedroom with a development fund of about half a powerchair... http://www.wheelchairdriver.com/BM3-con ... lchair.pdf

When I say I have forgotten more about any of this stuff than anyone you that could possibly ring up or talk to from a manufacturer or dealer I am really not kidding.

As for your programming, it is exactly as I said it is. I have seen all these same parameters on EVERY stock production chair I looked at or reprogrammed over the past 17 years. Every one. But if you don't want to improve it, wont listen to those that do know better than you do, then feel free to get on with it. Your loss!

[sakima]

So when you 'tested' these chairs at the shows you go to, like the Storm 4. What 'exactly' was done to the chair/s to adjust it for your weight and how long did this take?

[Burgerman]

I give up.

You obviously don't read what I write, or don't understand what I write, don't care what I write, don't listen, and don't have a clue about chairs or physics. As such I am wasting my time replying.

Some people just will never get it and are not capable of doing so. There's nothing left to say. You have demonstrated very clearly that I am correct already. And your suspension never entered into it. (Oviously!)

[greybeard]

BM, I respectly suggest that the guy is simply a troll who enjoys winding you up. If I was the site owner I would delete his membership. In fact, I would have done so long ago!

[Burgerman]

NO, I think he either genuinely doesn't get it. Not equipped either engineering, knowledge or speed wise.
Or now does he does get it, and just refuses to be wrong because he wants to save face. And is digging a deeper and deeper hole.
Its painfully obvious but he claims not to see it. And keeps going off at a tangent (suspension??? !)

[sakima]

So when you 'tested' these chairs at the shows you go to, like the Storm 4. What 'exactly' was done to the chair/s to adjust it for your weight and how long did this take?

You need to adjust the suspension so that any setting change van be effective.

[Burgerman]

Explain using your knowledge and experience of electronics, programming and physics how on earth the suspension on any chair, if fitted, can make even the slightest difference to the time delay that is turn acc or turn dec?

If you cant provide a logical answer (and there isn't one) then I will lock this thread. Nobody could be this stupid so you are just wasting my time.

[robnnorthaustin]

I would suggest locking OP and not the thread. I have not posted as I cannot add anything to discussion but it is clear to me that OP has gone way past ignorance and into trolling. I really like the fact that discussions on WD are absolutely genuine....Have of this thread fits that.

[Burgerman]

Well I wont ban anyone for an opinion no matter how misguided. If he is genuine. But its hard to see how he can be. Some of the stuff makes absolutely no sense to anyone with an ounce of logic and is not remotely connected. But some people just don't understand things, and maybe he really does think adjusting suspension can have some affect on the programming or something... Lets see.

[sakima]

Why don't you answer my question?

[sakima]

It's simple enough!

[Burgerman]

Because there's no relevance whatsoever to the thing we are discussing. Its like me asking what colour your wallpaper is. And serves only to show you don't have a clue about the subject.

And that you are just wasting my time, changing the subject, endlessly repeating the same stuff I already explained many times etc. Over and over. You don't know when you are out of your depth.

Repeat:
Explain using your knowledge and experience of electronics, programming and physics how on earth the suspension on any chair, if fitted, can make even the slightest difference to the time delay that is turn acc or turn dec?
If you cant provide a logical answer (and there isn't one) then I will lock this thread. Nobody could be this stupid so you are just wasting my time.

[sakima]

You are right about the electronics not having an effect on the suspension and I apologize for that.
I was blinkered and was focused on something else entirely.
WEIGHT of the user.
Which is what this thread is about and you have made some comments on this.

If you sat in my chair, the settings, suspension and tyre pressures would be no good for you.
Your WEIGHT would create more rolling resistance.
You can add more air to the tyres, but adding too much would make the tyres burst, so that alone would not be enough. So you would need to adjust the settings quite a bit.
Now those adjustments would be far to aggressive for me and other lightweights, making the chair very jumpy, but for you and other heavyweight users it would feel ok.
And the HEAVIER you are, the more nose heavy a chair would BECOME.

In this thread, you have said;
So it turns and fits better in crowded places, vans, houses, pubs or allows me to turn around in a small toilet and come out forwards. Where your chair can barely fit in. 
I have said that the Storm 4 is a lwb chair.

Now while most wouldn't want a powerchair this tippy, I do! This is too extreme for most. 
Which means, your chair would be totally useless carrying shopping on the back or going up hills.
That's why I NEED a lwb chair.

Everything is set to super delayed.
1. No. It is set for Mr Average.
An independent wheelchair distributor, with over 30 years experience, said;
I would say that it has been set up for Mr Average and that setting suits most people .

I ever saw or tested. So trust me …..
2. But that is the perspective of a 20 stone man.

My turn acceleration is set to 100. 
My turn deceleration is also set to 100. 
I also have forward and reverse acc set to 100 too.
3. Because you are HEAVIER. Remember;

Your WEIGHT would create more rolling resistance.
You can add more air to the tyres, but adding too much would make the tyres burst, so that alone would not be enough. So you would need to adjust the settings quite a bit.


but begins to turn afterwards when it wants, not when you tell it, then speeds the turn up and does long after you wanted it to. It means you slam the stick fully left or right to make a correction and it gradually starts to accelerate into a turn over about 2 seconds period... The turn RATE increases as you wait. Yawn. Instant small accurate corrections are impossible. So you are heading for a door frame at speed, and no fast correction is possible. So in the panic at the lack of affect a few mm of stick had, you give it some more... Now the first bit starts to take affect (late) followed by the extra stick you also added in panic as nothing was happening... And the chair turns too much, too late. And then you cant STOP it turning because of:

Turn deceleration... This is a delay is STOPPING the turn. Once its going left nothing you do stops that. So you have turned too far due to the above, and so slam the stick the opposite way in panic. But it has no affect as decelaration delay makes sure that it cannot! So you now hit the opposite door frame to the first one you were scared of. This is followed by the chair lurching at the opposite side about 1 second later and you guessed it, you cant stop that either. Yours is set to 40. Also totally un-drivable - and worse than turn delay.

You get a SMALL instant response which then accelerates (builds ever faster) to catch up with the amount of stick you initially  gave it, later on.

And you then suddenly zero the stick. Let go. Now. at a 10% TURN DECELERATION setting, it takes approx. 4 full seconds before the turn command dies off to zero. You rotate maybe another full revolution or so. It does not stop rotating as seen from the window, instantly, as you release the stick but it slows down gradually over 4 seconds to a stop. But it isn't now pointing the same way as when you released the stick. 

Now, imagine you are at full speed along a curved footpath, you are turning on the curve so you have some "turn" stick held in too. And now need to stop turning and go dead straight instead for an instant. To miss a pot hole, someone that steps out in your way, or to hit a narrow doorway opening. You have a fraction of a second to do this.

You want it to STOP TURNING right NOW. You do not want a further 4 seconds of turning that begins to reduce then gradually decreases until it goes straight. Because you will hit something. You will now tell me that your chair DOES stop turning. It does not, it BEGINS to turn less, the rate of turn decreases instantly, but ALL of the turning still takes a few seconds to cease altogether. That's why its called turn deceleration. Because its not instant.

But to make it stop turning WHEN YOU CHOOSE this has got to be set to 100. Or SOME turn continues after you let go. Making steering accurately (or in fact stop turning instantly) impossible. It will continue turning for a short time after you zero the stick...

Then as it rotates on the spot, let go of the stick instantly. It should stop turning left or right almost INSTANTLY.

 Its a liability at speed in areas where you need accurate control.

Because it keeps on turning after you decided you were aimed correctly or overshoots (overcontrols) because you gave it "some more" in response to a slow turn acc as not enough was happening. The net result of all this is about 4 seconds of over controlling and correcting. 
Could you respond to all the points above, as the videos show clearly;[url]
http://www.timsstroke.co.uk/#/proof-is- ... 4587264903[/url]
4. That it doesn't turn when it wants.
5. It doesn't take about 2 seconds to turn-accelerate.
6. Instant corrections ARE possible.
7. When the stick is zero'd, it doesn't take 4 seconds to stop turning so it is facing the wrong way.
8. If it is 'super delayed' how come I can swerve around people and pot-holes etc.

The 1st video shows almost nothing but a blurred joystick that you barely move about. And you are turning and changing direction so slowly that even if the camera was in a sensible position that showed the scenery too, that it still wouldn't show any delay. Because you are moving and manoevering / turning way to slowly and gently to show up any delay or accelerations...
9. Look at the trees. I guess I am doing about 6/7mph and making millimetre adjustments to the stick.

You need a reference for your hand.
 He NEEDS his palms resting on the controllers case to have the fine 1 or 2mm movement skills required.
10. You can clearly see, in the videos, that my hand is resting on the side.

But he is going to need to move a lot faster than that to show that it steers properly. He moves the stick almost slower than the acc/dec so disguises it. But he has no urgent need to change it if he only moves about slowly as shown in the video. But even at those speeds it will "feel" more accurate and give more user confidence if set to 100 or even 90. 

Its ok if all you want to do is creep about slowly inside like my granny,
I go about walking speed in the house. The video shows that. I slow down for the external door, as there is a metal threshold of about 1.5 inches. If I were to hit this at speed, the chair would jolt and subsequently, cause my hand to move the stick and the chair would respond accordingly and as there is only 1.5/2 inches either side, I do not want the chair to move, so I MUST drive slowly.
As for the bedroom door. I park right by the door wall, so I have to do a sharp right to exit, so I go through the doorway at about a 45 degree angle! The chair JUST fits through with mm to spare.

11. If they are so “crap”, why do people buy them.
12. Do you not think end users would have complained about them being so “crap” to their distributor and they in turn, would have told the manufacturer.


Please answer 1 – 12.


Anyway, this is MY Storm 4 with ME in it!


Could you now weigh more than 20 stone? IF you do, you may be too heavy for the chairs.
When did you last weigh yourself?
I last weighed myself in 2007 and I was JUST over 12 stone. I had a 34” waist then, now it's 32”.
I see you go to the pub. 4 pints is about equivalent in calories as my total daily intake.
I realize that we are all different, but I know, only too well, how easy and quick you can put on weight once in a wheelchair.

[Burgerman]

I have explained all of this countless times already.

Weight is not relevant for reasons already explained that you just don't understand. You are only armed with a bit of the knowledge you need to make this assessment.
And yes your chair, in common with every single mainstream production chair has horrible non linear and delayed action accelerating controls, that cause any user with good skills to over control and panic as you go faster in tight spaces when the chair doesn't follow the commands directly.

No matter how many times you keep repeating the same confused physics and other rubbish. And yes most users think that that's "how it is" and don't complain because just like you they simply don't know any better. This must account for at least 90 percent of all users, and the also "dealers" and "techs" (I use the word extremely loosely) in most cases, and most of the people you get to discuss this with at the manufacturers also don't have a clue. I have even had Sunrise Medical sending their own customers to ME to reprogram because while they might know whats is required by people that complain about it, they cannot fix it for various reasons relating to conformity and certification.

I will answer one question (yet again) as it negates all of the rest... Try and understand this.

>>>If you sat in my chair, the settings, suspension and tyre pressures would be no good for you. Your WEIGHT would create more rolling resistance.

Yes, Slightly, so what? It has no other affect. Rolling resistance doesn't affect programming accelerations and decelerations and subsequent crappy control. Even the workshop manuals for rear drive chairs only mention changing suspension setting for "comfort" reasons. Even the Storm 4 one is the same. No mention of weight, because those with any grasp of physics know it doesent change control at the speeds we move at one tiny bit! And the CORRECT setting is the one you prefer.

Your chair and every other chair, is sold to people with BOTH much less weight, and much greater weight than you. And sold with solid non adjustable flat free tyre options. Increased Rolling resistance causes more losses (marginally), and this eats slightly more precious battery power and reduces range. Has pretty much zero affect other than this though. Rolling resistance doesn't affect the delays or the steering. The added MASS has some affect on decreasing turn acc and increasing the turn deceleration even further however. Due to added inertial MASS requiring more AMPS to follow the stick. Not - rolling resistance.

But this too is not by enough to matter or detect easily if at all. Because of something ELSE you don't understand. Motor Compensation. This is another bit of built in programming that all control systems have. It detects the extra load as a form of a feedback system from the increased motor amps due to added load as you move or steer. And it adds power almost instantly and CORRECTS the acceleration rates on the fly to match the stick position (and its programming) seamlessly. Without the user knowing.

So response remains just the same regardless of user weight or terrain (grass etc), slopes, tyre pressures etc. So these changes (inc weight) do not change the chairs response to whatever is programmed in to the system one bit. Its barely detectable or measurable. As such my own chairs (and yours) drive exactly the same with my 20 stone on board or when totally empty by RADIO CONTROL. There isn't any change in driving characteristics at all. Making your entire post of repeated assertions above invalid through ignorance.

One of the other things in programming I also tweak incidentally (if needed) is this MOTOR COMPENSATION. As this also improves steer accuracy in some difficult circumstances and reduces the need for any extra "stick" in difficult turn or curb climb situations.

And... adjusting the suspension on your own chair is limited to simply increasing preload (which I did), which only actually affects ride height in any case. It does NOT stiffen up the suspension spring rate, or increase compression or rebound damping. As such ultimately pointless anyway. But it sits the caster barrel at the best angle at 90 degrees to the deck. It may prevent caster shake if it becomes an issue.

All of which make the rest of your arguments totally invalid. But you don't want to learn, cant see, tell, or feel the difference, don't understand what I am telling you and only want to try to argue to win points or something. When anyone that truly understands this stuff knows you are plain wrong or bewildered.

Non of which you will understand So I give up. Thread locked.