Re: Automatic Wheelchair Turntable

[nobody@xxxxxxxxxxxx (Dave Houston)]

That's why I suggested bearings under the entire surface. With central
bearings like a lazy susan, the weight will be applied far outboard of the
bearing.

"Patrickg" <pboch@xxxxxxxxxxxxxxx> wrote:

>No way I can see a turntable working, I use a full size van, however I have
>a couch/bed so I'm a bit cramped with turning room....He can go back and
>forward and worm around. But for me I go in backwards, out forward...Much
>safer to go backwards then come out. Your turntable would need bearings not
>only centered but mid points and outer..Just can't see that.
>"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote in message
>news:_rydnR8CpccKQ6beRVn-hw@xxxxxxxxxx
>>I just got my Dad a wheelchair van with an electric ramp but we've hit a
>> snag.  There's not enough room to turn the wheelchair around inside the
>> van.
>> If he goes in forward, he has to come out backwards.
>>
>> I toyed with some automatic guidance systems to make sure the backup
>> procedure didn't run him off the ramp, but I don't think that's a wise
>> solution.
>>
>> I decided that since there's almost a 4X4 foot flat area inside the van, I
>> would take a 4x4 sheet of 3/4" plywood and make a turntable on the van
>> floor.  When he transfers to the driver's seat, I want the turntable to
>> automatically rotate 180 degrees to position the powerchair so that it
>> will
>> go down the ramp front first.
>>
>> I'm not sure how I would contstruct and power the turntable, however.
>> It's
>> got to be as thin as practical - there's very little extra headroom in
>> these
>> types of vans and it's got to have some sort of autodetection of exactly
>> 180
>> degrees - probably some sort of limit switch.
>>
>> Should I rout a channel in the outside of the circular-cut plywood panel
>> to
>> run a belt?  That why I could mount a motor in the corner and still have a
>> pretty low overall height.  Sort of how some belt-driven record turntables
>> are designed.  I could also cover the ends of the belt that are likely to
>> drag loose seat belts into the works pretty thoroughly with a motor
>> mounted
>> in the corner.
>>
>> Does anyone know if they make commerical turntables for this purpose?  As
>> much research as we did on vans, lifts, ramps and options, it kind of
>> floors
>> me that we didn't realize there would be a "wrong way out" problem.  Just
>> a
>> reminder to always model things, even if they seem trivial.
>>
>> Well, any suggestions, inputs, discussion or ideas where to post for good
>> feedback will be appreciated!
>>
>> (posted to:  comp.home.automation & alt.support.wheelchairs)
>>
>> --
>> Bobby G.
>>
>>
>>
>