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andrew
Joined: 16 Jun 2004
Posts: 3110
Location: Castle Hill, Sydney. N.S.W
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Ha ha, 45 km/h wheelchair
Shes a woman driver so thatd be ......very bad.
The idea is not to make a manual chair into a power chair, i can get second hand power chairs at will from work no problems.
Its mainly just when in a manual chair them brief moments where the environment throws u a curv ball and u need to get up stuff.
Id like to keep the manual chair as stock as possible minus hill assist mech as pushing herself around in the manual chair may help in building up muscle and actively pushing herself from a to b may assist in her losing a smidge in weight to which would help her in that shed have less weight over her bad knees and less pain.
That wheelchair hub kit is crazy expensive, still alot cheaper than most solutions tho but out of price range for me. Look up e motion wheels, sorta like hub motors but only assists when u push the hand rims and such, bout 10 grand tho.
I saw this today as well, some badass who build a power chair from scratch using roboteck controller and A123 style batteries
Been pondering the plausibility of some form of super light weight powerchair using just hobbyking parts. Theory wise use as joystick the setup marto has done for his demo ants of a modified transmitter, lipo batteries and gearing down some large brushless systems in theory you could make a pretty badass power chair that weighs less than some manual chairs
Another idea also is if u search on alibaba you can get some fold up power chairs but im a little cautious as the few ive seen at work are a bit flimsy and reliability not great. _________________ Andrew Welch, Team Unconventional Robotics
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Fri Sep 20, 2013 3:20 pm |
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maddox
Joined: 21 Dec 2006
Posts: 786
Location: Belgium
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quote:
Originally posted by Nick:
@ Maddox: Now that you mention it, yes. If this was on the front wheel, would you even need suspension? The only problem with replacing the front wheels is disengaging the motor drive when its not active - trying to turn that output shaft is near impossible!
The solution is given on the same site as where the idea of the omniwheel back-drive comes from, the "free-wheel" in front. Just use a small linak to lower the "powerdrive" and lift the original front wheels a tad.
If a "free swinging front wheel" is used, 2 brakes on the back wheels are almost mandatory, toggling a joystick requires a hand.
I don't think a gaspedal is the best solution in this case.
@ Andrew, I'm in far away Europe, so my contribution won't be that much, except spewing idea's.
But it feels to me that a "el cheapo" add on drive for wheelchairs ain't a bad idea.
Also, the website we're taking the idea's from says their kit ain't water, dust or gritproof. Especialy the omniwheels are vurnable.
Let us see what we need "at least".
To avoid omniwheels or other vurnable "5th backwheel approach", I like the idea of a front wheel puller setup. Less prone to wheelies too.
A brushless outrunner in the 2 kw range, like the Rotomax or NTM 50-60, with a low KV.
Speedo that can handle the power.
Control , or a servotester or some homebuild control mechanisme (can be a RX/TX set)
Batteries.
Gearbox. Limiting the top speed to 10 km/h or so, that's a fairly brisk walk or slow run.
Wheel. Preferably a wide 8" or bigger airtyre, for comfort and terraincapability. Climbing hills and such on a colson seems a sure way to wear it down fast and uncomfy.
Motor and controller+ servo tester= $100
Batteries
In short, batteries, 1 set of
6S 8000mAh
LiPo ain't that expensive. Add another $100
A 8" minimoto wheel (ask Glen about this) can be gotten from alibaba for $35 or so
The only expensive bit then is the gearbox. With a 280 KV motor @6S and a 8" wheel reaching 10km/h, you'll need a 24-1 gearbox. Maybe that a high batterydrill gearbox can handle it. But that will be noisy and the maybe is in the bearings of the axle.
But I think we can design/make something that works.
I think it can be done for under AU$500, especialy if the community kicks in.
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Fri Sep 20, 2013 5:40 pm |
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