Seat bracket big
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Seat bracket
huge
This is the plate that I had made (drawn on a tatty bit of paper a few images
below) to allow me to move the seat back in small stages (all those holes) to get the correct C of
G position for the whole powerchair. It is VERY important for a large number of
reasons. I finished up using the most rearward one. The front one is in the same
place as a stock power chair. That means that the seat is moved back 2 and a bit inches
and that's all it takes, But don't even consider comfort padded backs or
automotive style seats! They move you so far forwards the wheelchair is all but
un-drivable.
The more rearward the C of G is positioned the better and easier your steering
control is. This is because the rear drive and control wheels actually do the
steering and having to drag the front from left to right with a lot of weight
over it is very difficult to do especially on grass, carpet, or on slopes or
ramps. Plus this extra effort requires battery power! Battery power is limited,
and it takes MANY more amps to turn on a carpet than it does to drive on a flat
surface at full speed.
Range and speed. Apart from the above extra amps a front heavy chair needs while
turning or even trying to "stay straight" when travelling it also causes many
more amps to be wasted (and slows the chair down) when travelling along any
cambered road or pavement. As an example try to push a manual wheelchair along
with its push-rims along the edge of a road. Most are cambered to let water run
off. The wheelchairs front casters try to do the same, and it always heads down
towards the curb. Same on pavements. Now, the more nose heavy a wheelchair is
the more it tries to do this.
You will find in some situations you are actually having to PULL on one
wheel and push twice as hard on the other just to go straight and its bloody
hard work! The same thing happens with a power wheelchair its just
that you don't "feel" this. But all that wasted energy is still happening.
Moving the C of G back reduces this waste, moving it forwards increases the
wasted energy. I you were to move the C of G right back to the rear wheels axle
then the effect is eliminated completely! The chair will just go straight and
not be interested in heading for the kerb at all. But it would be too tippy! You
would fall out of the back! The correct position is -- just like a manual
wheelchair -- where you feel the most comfortable. I like to be able to wheelie,
tip the chair back at will on to its anti tip wheels, and have the lightest and
most accurate steering possible.
Another advantage is that you have so little weight over the front caster wheels
that a puncture does not matter. That's right, you can actually remove one wheel
completely and carry on with your daily business. All (most) of the weight is
over the almost puncture proof rear drive wheels. Which also means that they
stay in contact with the ground for full control over tree roots, uneven
ramps/pavements etc. Before, the chair seemed to have a mind of its own as a
REAR wheel would leave the floor at times meaning no control.
Said bracket fitted (and powder coated!) with polished, greased stainless steel
Allen bolts...
Seat plate fitted medium
|
Really big
image large
Here is the bit of paper that the engineering company got from me. So if you
wish to do the same print this!
Another rear view showing the same bracket -- I use the very rearward hole for
seat position and hinging (it tilts). If you do the same be VERY careful you
don't go out over the back of the powerchair either while wheeling or slightly
more unexpectedly when going up a ramp. If a ramp looks steep I have to run at
it or go up backwards! Just like a manual wheelchair. You soon learn how steep
is too steep! It hurts though... Take care! I am not advising anyone to do this
just showing you what I did!
Bracket medium
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Bracket large
Starting to look a bit more like a powerchair again. Vaguely...
wheelchair
medium
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wheelchair
large
And its shiny. I like shiny things... See the seat bracket again. That's
zero to 3 inches rearwards. It looks unimportant doesn't it. Well it drastically
changes everything! Also the seat back uprights are moved to the rearmost
holes. The net result is a powerchair that is as tippy as a sports manual
wheelchair with all the advantages (and disadvantages) that this brings.
power wheelchair detail
medium | power
wheelchair large
swing
away medium
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swing away
large
Above: This is a parallel swing away "pod mount" see the parts PDF at top of
page. Its not cheap, and this is an old one that's been stripped and powder
coated. They are a million times better than the crappy standard swing away
linkage! They all wobble about like a drunken sailor and make it hard to control
the chair! They are fine for the first week but after that buy one of these.
They really are essential and should be fitted to stock new chairs. But the been
counter won again.
The pod has been stripped, re-sprayed satin black and re assembled too... A good
few bolts still to add and or polish though.
swing away pod mount
medium |
swing away pod
mount large
wheelchair arm
medium
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wheelchair arm
large
OK, arm rebuilt and fitted. Brand new uprights are needed as
they last about a year as they are a bad design. They start to wobble and rattle
about slightly after just a few months on my chairs. I order them in black and
don't get these coated. I also replace the big ugly square arm tops with
these soft comfort ones from the parts PDF at the top of the page.
The T bar at the top is powder coated. The bolts are
polished stainless steel, and the silver home made alloy bars replace the big
plastic flat plates that stock chairs use. This is lighter, prettier, stops the
sweat caused by a square foot of plastic causes on your legs and allows access
to your pockets. What were they thinking!
Close up of powder coated arm "bars" that now replace the big flat heavy plastic
things it came with. (See green standard chair at top of this article) Also a self portrait!
See the bolts! You can see four copies of me and my other black powerchair!
Still no rear light carbon fibre thingy, or Cushion (Jay2 in my case) or wheel
trim discs fitted. But basically 95 percent assembled. No arm rest "bars fitted
yet either here... And the dog has managed to get in this one too.
electric
wheelchair medium
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electric wheelchair
large
The back. Without its lights fitted yet. But you can see how clean and shiny and
the small skate board wheels to replace the horrid big rubber ones. And you can
see that the push handles are shortened since they serve no purpose other than
for my young lady to hang her shopping on. Please note that there are NO marks
other than shadows on this 2 year old carpet. Contrary to the opinions of
certain other self proclaimed we "experts" black tyres do not mark carpets
unless either the tyre or the carpet is wet.
This carpet sees me for many hours each day and so far the only marks were on
the white paintwork where I hit it many times. (it wipes off gloss paints) but
never yet on any of my carpets although the rest are darker. And these are
normal tubeless scooter tyres. Of course if you skid and try to mark them you
can. But with a little common sense no issues.
Of course your experiences may well be different but those are mine and I am not
particularly careful...
electric wheelchair rear medium
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electric wheelchair rear
large
Same as the above two images. Still not finished. The thing on the seat just allows me to drive it
about by radio control... Its how I get it about without sitting in it. It works
for all powerchairs that use a Penny and Giles control system. Its a very
involved bit of electronics that takes the radio control receivers output and
converts it to something the wheelchairs control system understands and its
portable. It allows me to get into
my van in my own
powerchair and then drive an empty one into the space behind if I need to take a
powerchair somewhere else for example. The dog did it again.
wheelchair and dog medium
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wheelchair and dog
large
And another. The dog is scared of an empty wheelchair
driving around on its own. As were many of the people I met when I followed it
in my other powerchair to the local college the other day to get some machining
work done. I drive my own chair that I am sat in with my right hand, and this
(or any other) empty powerchair with the transmitter below with my left hand.
Requires some practice but after a while its easy enough. People are a bit
surprised to see one crossing the road empty though. Pedestrian crossing are a
laugh as you watch the cars stop for a waiting empty chair. I'm going to video
it! Watch this space.
powered wheelchair
medium |
powered wheelchair
large
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Detailed PowerChair Only Menu
