Q6000 Quantum 8mph Torque

[Burgerman]

http://www.wheelchairjunkie.com/forums/ ... #Post31677

In this thread above is the exact issue that I keep trying to explain to everyone that thinks 8mph chairs are a good idea!

The REASON that the typical 8MPH powerchair has little torque or power (in this case not even enough to turn the casters straight!) is because of the following 4 things... + Why faster isnt always a good idea! http://www.wheelchairdriver.com/powerchair-speed.htm

a) Taller geared 8mph motors need MORE power in Amps to give the same level of power or rather torque at the wheel. Now generally they use the same or very similar motors to the 6mph powerchair. So less "stall" torque is available.

b) Even if a BIGGER motor is used to try to regain that lost torque or pulling power it has to be fed Amps! That means a BIGGER amp control system.

c) The bigger control system even if fitted cannot get any more amps from the typical group 24 Gel batteries installed as they are simply incapable oif doing so without the voltage dropping. As it drops the controller folds back and reduces amps to save the batteries or wiiring loom.

d) Programming. The Q6000 chairs (and most Quantum powerchairs) are spectacularly bad here. Most stock powerchairs are not programmed to actually give you any sensible torque or control anyway. There are things that can be changed to help matters and give more urgency (to a degree) with an OEM level programmer. See http://www.wheelchairdriver.com/powerch ... amming.htm

[CPguy]

I do not have a very high opinion of Mr. Smith. He is a manager at Pride and generally not helpfull despite being polite and ending all his posts with "thank you". If you do not praise products of Pride and have a dissenting view in his forum you get banned.

Besides, his "tech articles" on his web page are extremly superficial often even wrong (I least in those topics where I can judge). He is just a waste of time.

And no, I shall not pitty him just because he is a fellow spastic.

[JoeC]

What do you suppose would be the most spectacular way to get banned there? Links to a set of demonstration videos on youtube? A picture is worth a thousand words, and a video could forever change people's minds about how acceptable their chairs are. There's a grassy hill here that is approximately 4:1 slope. I once climbed it in the 7.5 mph P200 to see if I could do it, and I kept good control. A video of that might be a good demo of what powerful electronics, good batteries, efficient motors, and a proper center of gravity are capable of!

[Burgerman]

While most agree about Mark Smiths "technical" knowledge seems very limited (other than facts and figures via pride) and his holyier than thou attitde on his forum he isnt really to blame for the physics of torque, gearing or batteries! The same thing applies to all 8mph chairs although some slightly more than others.

The real root problem is the group 24 gel battery doesent have the current /voltage capability to provide the amps that a powerful controller and taller gearing needs. Not without the controller "backing off" or folding back due to voltage falling under load.

But Quantum chairs seem slightly more gutless and easy to stall than the rest for some reason be it programming, wiring resistance or a combination of things.

I dont think the motors ever see that full 100 amps that the controller says is possible on any Gel batteried powerchair unless they are new and fully charged on a warm day. Even if they do, the total number of watts (power) is drastically reduced due to the low battery voltage. My clamp meter shows they struggle with 80 amps as the voltage drops considerably. After that the protection cuts in limiting what you can get further still. Hence the "stall".

Added. If you were to connect motors DIRECTLY to the batteries rather than via a safety nazi and super safe controller then the same motors would pull up tree stumps... Because the controller wouldnt limit what happens. This is one reason JoeC was asking about what difference "battery cable" settings make in programming on another thread.

Its a different story on most chairs once you fit a set of odyssey batteries and get the thing programmed properly. I suspect that would help, and the Q6000 would be as good as most 8mph chairs. But they will always be a compromise due to the gel MK batteries. And even if you give them the best chance then range sufferes and battery longevity suffers.

[Burgerman]

There's a grassy hill here that is approximately 4:1 slope

I think thats 12 degrees? or 1 in 4? My 6mph chair goes up the ramp in the pub with good control and can start/stop easily. A ramp THAT I BUILT! After the regular pub across the road said that it wasnt possible for years.

That IS exactly 12 degrees since there was no other way to do it other than chopping and changing a listed building...

Thats with a 20 stone guy and 6mph motors. Its seriously steep! Mark smith is correct when he says users over estimate angles / steepness. 12 degrees in real life looks unfeasable!

I cant do it forwards as I would tip out the back. When reversing up I feel like I will fall out the front. When I fit the the 8mph motors I suspect that given a bigger properly programmed controller and odyssey deep xycle and starter (with starter being the key) and bigger 10 sq mm (7 gauge) cables it will still be OK but not quite as good as now. I will photograph this ramp so you can see how severe 12 degrees really is! Looks like 30 degrees in real life. Wheelspin is the biggest issue in my own chair. And the "brakes" dont quite hold it with my weight if I stop on the way down...

[Burgerman]

Looks much worse when you actually see it! A 12 degree ramp looks way too steep. Most users will not attempt it. And wouldnt get up if they did.

Look at the 1 in 4 level. 25 percent gradient. Or 12 degrees. You would never get up that on grass without my or the x5s all terrain tyres. Just not enough grip. When you see a hill at a real 12 degrees its way steeper than you expect and looks like a wall!

[JoeC]

I will have to post a photo of the hill I have in mind. It's a piece of landscaping- I would estimate that it's about four to five feet high and reaches this height in a horizontal distance of fifteen to twenty feet- so I estimate that the slope is somewhere between 5:1 and 3:1. Looking at it I'd be very doubtful of getting up it, and most people wouldn't try it. You're right though, hard to put a number on it by eye!

The only way I was able to get up it and get the right traction was by leaning far forward with my chest on my knees, so as to keep my center of gravity somewhere between the front casters and the drive wheels, instead of landing on my back. I won't be able to try it again in the chair until next thursday.

[Burgerman]

Will take camera to the pub tonight and get a picture of the ramp to the bar. Its all black and dark though... And difficult to get far enough away to take a picture.

Another issue with 6 wheel platform chairs is actually getting on to a ramp like this. there comes a point with dead straight lines where the drive wheels either leave the ground completely or have so little weight due to the casters and their springs that traction prevents it ever happening...

[TwoTeasChris]

I think 1 in 4 is actually 14.48 degrees. (0.25, inv, sin, on the calculator??)

That chart is scary. I held a protractor to the screen because I thought you had got it wrong!

This is Mt Pleasant Rd in Caterham, the steepest road I know of. But I don't get out much!
I thought I remembered a 1 in 4 gradient sign but I can't see it on Google Earth.
(Tilted to make the lamppost vertical-ish.)

[Burgerman]

>> I think 1 in 4 is actually 14.48 degrees. (0.25, inv, sin, on the calculator??)

Could be my maths is crap!

That street doesent look 1 in 4 though. More 1 in 5? Although I bet it drains pretty well!

[JoeC]

This is the hill I was thinking of. This is from a standing perspective with my lens at 55mm on a Nikon D40 (so equivalent to 82mm on full frame). There are things that could have been done with perspective to make it look more impressive. Anyway, it's more than waist high so at least 3 feet high. Placing my foot end to end, it took about 12 feet to get from the bottom to the top. If my math and height estimation is right, I think I stand by my rough estimate of 4:1.

hill.JPG (119.31 KiB) Viewed 50638 times

[Burgerman]

Well its pretty steep. I think the ramp at the pub looks steeper than that though! But not much. Not very wheelchair freindly either way. I will get a picture later in about an hour...

[Pete]

This is the hill I was thinking of. This is from a standing perspective with my lens at 55mm on a Nikon D40 (so equivalent to 82mm on full frame). There are things that could have been done with perspective to make it look more impressive.

I don't know how a normal wheelchair would handle it, but my Frontier X5 would handle it without a problem.

[JoeC]

Not surprised- the X5 has the same Dynamic DX controller with twice the current (twice the torque) as most chairs, and it's not hampered by worm gears. I think that a lot of chairs would have trouble getting up this hill, just from the angle of it with a reasonably large person driving.

They would also have severe problems if they weren't going up it completely 100% straight. I tried to drive on a much shallower hill with the Permobil C350 demo just to see if it could do it, and it absolutely couldn't- no traction at all. The X5 is also set up to put the weight where it does the most good.

Oh, and the OmegaTrac would also handle this hill with no sweat- but only driving backwards.

[Burgerman]

My worm gear chair would easily go up there. Power isnt an issue at all. Its staying sat in it that is. It has plenty of torque to spare - so much so that I can stop and restart easily with good control even though the brake wont hold it. And I can accelerate upwards noticibly at will so can climb it fast. Not just "move".

Your slope is about the same or not quite as steep as the ramp I use daily about 4 times to get beer. Nothing keeps me from my beer! Couldnt get a picture due to a wedding in the hotel but will try again today.

I honestly think worm gears compared to non worm gears makes so little difference compared to every other loss that its pretty unimportant in the full system. And depending on design it may not even be worse since there is only one gear where some systems use two or more.

And its single gear is 6 inches in diameter. Increasing diameter means much lower sliding forces on the gear teeth. Compared to several and smaller non worm gears. The difference if there is any may be lost in the noise or even lower depending on design. Remember there are also losses in motors, matching rpms and windings, brakes, controllers, batteries, cables, too. There cant be a huge difference if any since I dont get better range from other 6mph chairs like the q6000 or x5. If anything they seem worse as well as less torque.

And I am about 20 stone! Decent batteries, proper programming, heavier cables, heavier motor windings etc all contribute to torque. Mostly batteries. I am surprised if an X5 can make as much torque as my own chair with the gel batteries they come with regardless of gear type or control system since the batteries cannot provide!

Added I have to reverse up. Or would overturn...

PS A stock f55 would look at it and stop... Maybe wouldnt even move on the grass if the casters were facing the wrong way... Making a few small changes, like the 20 amp bigger controller, programming, cables, Odyssey batteries etc as well as losing a few lb of iron makes a huge difference to the end result. So much so that its hard to comprehend the difference or believe its the same chair.

[Burgerman]

A true 1 in 4 ramp. Actually just slightly more. If thats 12 degrees then this is 12 degrees! I think its the same thing almost exactly.

It goes up by 18.5 inches in 55 inches exactly. I know because I built it as a tempory ramp in my kitchen after the boss said it was not possible... and dropped it in place, and still have the measurements here. They then built around it! Bodge job... But it works. Looks even steeper in real life. Cant get far enough away for a better photo though - not enough space. Certain nameles staff members "ski" down it in shoes on the way to the kitchen! They have competitions now.

[Burgerman]

The stock f55 (with gel batteries, crappy programming, thinner battery cables, smaller 80 amp controller and heavier weight) cannot even get up this ramp to my van from a standstill. It simply stalls and cant be steered. The 6mph Q6000 is the same, along with most powerchairs. The 8mph chairs are even worse.

Suspension not lowered here, and it is still much less than HALF as steep as the pub ramp... Remembering that in both cases it has me as an occupant and I am about 20 stone too!

The difference these small changes make whan added up are huge. Both in torque and accurate control. With the better batteries, heavier cables, better programmong and bigger controller it simply flies up either ramp without trying.

This was me going to fly an electric powered thermal glider on sunday just loading up...

[JoeC]

That is very steep- I think it is about the same as my hill. My wife is fearless enough on the court, but I think she'd ask for me to stand behind her for that one.

[Burgerman]

Quite.

Im the only one that can use it. Several others have tried in powerchairs and they just stall or get scared and give up.

Power on my chair even with a fat me on it isnt an issue. Its just a safety thing... I am expecting that the 8mph motors will be JUST as good with decent controller/cables/batteries. But I may stick with group 24 batteries due to the weight -- presisely because of ramps like this, even though I can actually fit group 31 batteries. Lightweight lithiums are way overdue...

[Foz]

is your car knelt down?

[Burgerman]

That chart is scary. I held a protractor to the screen because I thought you had got it wrong!

I didnt make the chart I just spotted it on the net and borrowed it rather than steal the guys bandwidth. And will delete it in a few days... But it seems right. 12 degrees doesent sound much until you actually see it does it.

[Burgerman]

After sticking my portable ramp on bricks, (I went into the back yard to test). I can actually get up to just over 15 degrees, before traction rather than power, becomes the issue. On my aluminum portable ramp that was going upwards to nowhere! So probably good for about 17 degrees before power with a 20 stone guy stops play.

A stock F55s fails at much less than half of that due to it "stalling" and then folding back much like most stock chairs would. Pretty damned useless when the world is full of thresholds, ramps, pot holes, thick grass or carpets! But they are like that because the manufacturers think its "safer" as well as cheaper to make and most users never get out so expect nothing else.

[JoeC]

In pursuit of further knowledge, I just called Pride USA to ask what the maximum power is for their Q-logic controller. They said they didn't know, didn't have anybody to refer me to, and wouldn't tell me. Not very helpful. They did admit that they do not manufacture the Q-logic electronics, but when I asked them who it was they said "that's proprietary". What a load of bull! If it's not on external sticker on the control module, the OEM will absolutely be printed on the circuit board- so all one would need to do to find that out would be to crack open a dead Q-logic controller. Proprietary, ha!

Anyhow, since I wish to understand the details of this controller, both as a possible source of sport gear (though it seems unlikely with the attitude I encountered on the phone), and in the case that my wife picks an R4000 for her next chair, I have registered at another forum where Quantum and Pride gear is the norm.

[Burgerman]

Judjing by the amount of torque and control most of the chairs they sell actually have I wouldnt count on it being much good anyway! But report back any interesting findings! The R4000 chair drives just like the q6000. Soggy, gutless and hard to guess where its going... May just be programming though.

[JoeC]

I still haven't been able to get anybody associated with Pride to talk to me about Quantum or the Qlogic controller, but a little googling did yield this press release:

http://curtisinstruments.com/index.cfm? ... essRelease

This suggests very strongly that the present Qlogic system is made by Curtis, which in my opinion is a good thing. I had a nice conversation with Curtis, and they were willing to send me to a distributor that would sell me what I wanted for controllers and programmers. Based on a conversation I had, their top enAble40 controller does a true dual 70 amps, 140 from the battery. They also told me that their ramp rates are no faster than the 0.2 seconds I've found anywhere else, so I didn't pursue it farther.

Of course, Qlogic still has the problem of programming. Dynamic may make Invacare's stuff, but the Dynamic programmers won't talk to Invacare modules. All it takes is a small firmware difference for the controller to be incompatible even if the hardware is largely unchanged. Likewise, Qlogic may or may not talk to Curtis programmers. It would be interesting to find out though, since Curtis programmers are available from many golf cart supply shops!

[Burgerman]

I still get the same response from Penny and Giles regarding the power output though. They CLAIM that the 120 amp R-Net for eg; does do 120 per channel and it is equal to or better than the equivelent dynamic system. According to a Mr Roger Brickliff whos job it is to know. He even checked with the engineers. We agreed to disagree quite strongly judging by my simplistic tests! Which leaves me with a bit of a problem...

Do I go with the P and G that I prefer and understand or do I go with the Dynamic and accept its voltage limitation when it comes to Lithium batteries... Or look elsewhere.

[JoeC]

If they are that insistent that R-net will do a dual 120 amps, would they be willing to sell it to you on the condition that if it doesn't deliver then you can send it back? If we weren't talking about wheelchairs, that would be a TOTALLY reasonable proposition! You're selling me a grade 8 screw and it fails at half the rated tension? Returned! You're selling me a gallon of milk that only has a quart inside? Returned!

Another serious option to consider is the Curtis enAble40 system:

http://curtisinstruments.com/index.cfm? ... y&catID=10

They list 36.0 volts as being the highest point that you can set the battery meter, so I presume that the system can survive 36 volts, even though the "maximum motor volts" is maxed out at 28 volts. The most powerful system they make is 70 amps, which of course they tell me is per-motor simultaneous, 140 amps from the battery. If I'm right about P&G's rating scheme, this would make their top system stronger than R-net's top, but less than DX2's.

I also found their sales engineers to be friendly and helpful, and willing to guide me to a distributor (of golf cart parts!) that sold the OEM level PC programmer.

[Burgerman]

I have thought about all of those points...

P and G over voltage = 35v no warnings before that point I am led to believe.
Dynamic 32v with warnings well before that point...
Curytiss? Dunno...

I really want 200 amp, 36v nominal (45v peak) and full programability, different battery logic, and safety...

But until they all wake up to the 21st century like the hobby people did 8 years ago we are a bit stuck.

[JoeC]

I was just reading after lunch... Curtis shuts down at 38.5 volts- looks like the highest voltage you'll find. Too bad their highest "max motor volts" setting is 28.0.

I'm writing letters to Dynamic and Curtis explaining the need for lithium compatibility, more programming options, adjustable joystick exponent, and shorter ramp times. Dynamic has already told me that the next generation (DX2's replacement- DX3?) is in development right now, and that they welcome suggestions. If P&G wants to stay in business, they're surely developing R-net's replacement right now as well. I don't know how to get them to listen...

[Burgerman]

The big control system manufacturers only really listen to their biggest users. That means people like sunrise and pride, so since they dont really get it or care about development expect more of the same old...