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The F55s
powerchair has a bunch of design problems that turn a really
excellent chair into a useless almost unusable device...
Below is a list of its issues, some of which are related.
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Its Centre
of gravity is far too far forwards. This
particular one has a Recaro seat making it much worse still.
It causes serious control issues, batteries to die fast,
overall chair length to be too long. Easily fixed!
This may be a "legislation / safety thing but it buggers up
a seriously good chair...
-
Recaro
seating is a bit of an afterthought... Its FAR too
high as well as too far forwards, but both these can be
fixed easily. So WHY don't "they" do it already???
-
Programming is nothing short of dangerous (my own
opinion of course, for legal reasons but I have now
reprogrammed so many other desperate peoples that obviously
most other users seem to think so too...) It makes the chair
all but unusable. This requires the PP1b programmer to
fix, and a little knowledge. Takes about 15 minutes.
But the PP1a programmer that most service agents have
CANNOT do it - regardless of what they tell you. This
programming issue effects almost EVERY chair, not just this
one...
-
Control
pod mounting. It uses a stupid "swing away" hinge.
This consists of a single rivet that soon wears and allows
the pod to flop about uselessly, and causes control issues!
Easily fixed though. So you have to ask yourself why they
don't do it already???
-
It uses
"Swing away" footrests too, like many powerchairs do.
Whilst they may be a good idea for some people most of us
can't stand so need to "transfer" by sliding to car seat or
bed. Well they are in the way, and can't be removed
because the weight of my legs is on them! Plus they
make the chair look like it came out of the ark, they take
up too much space while trying to turn, as they stick out
and are simply too wide. When will they learn that
every inch, and every pound REALLY count when you don't have
a choice? And every one you see is twisted and bent...
Weak design as well.
-
Motors...
Use open bearings (shielded only, allowing carbon dust,
water in but not the rubber greased for life sealed ones, as
would be expected. They run dry of course! And expire
as you would expect! So fit sealed bearings! They are
cheap. So why don't the manufacturers do this???
Brushes last around 2 years total if you use it all day
every day, and are actually available (whoohoo) - Nothing
else is though, so if ANYTHING goes wrong with motor or
gearbox or cush drives you have no choice but to replace all
as one unit. You don't want to know the price...
-
The "cush
drive" fits onto both the motor and the gearbox shafts
the same way. A "D" type drive, or if you prefer a shaft
with a small flat in it. Well its useless and wears
out causing that familiar clunk / clunk as you turn left
right. If you take your chairs motors off and remove
these BEFORE they wear, and refit using permanent stud lock
or bearing lock (I use the "green" Loctite) they never will
wear... But you only work this out when its too late!
Parts are of course unavailable! so prevention here rather
than cure is your only option. They last 9 months to a
year on my powerchairs if you do NOT Loctite them first!
-
Gearboxes
- They come with two factory built in defects... You CAN fix them
though. After a few weeks you will begin to notice
that your chair goes clunk/clunk as you go left/right...
Its not in your mind its caused by a very small amount of
backlash in four places! But its enough to drive a
full time user to distraction.
1) the wheel fits on the round shaft with a small
"square key" to transmit the power. This is fine for a
load in one direction. But you actually go left/right,
forwards/backwards hundreds of times every day. So although
it had only a very very small amount of free play when new, it
very soon wears.
Minute amounts of movement here cause a
clunking and a sensation you feel rather than hear at first
and its horrid! And it gets WORSE with time slowly.
They do this from day one.
2) There is a big gear that fits on this same
shaft INSIDE the gearbox and it too uses a similar
key... The problem is now compounded, and is much
harder to fix.
3) The "cush drive" wears where the thing fits on
the motor, (the rubber shock absorber meant to "smooth" the
motors pulses, shown on the end of the gearbox input shaft
in both these pictures. This one though is "fixed" on
with serious "stud lock" by me.! If you don't do this
they screw up eventually and then cannot be fixed.
4) And Ditto the gearbox...
To stop the clunking and noise you must fix ALL of these
problems together. A keyway should NEVER be used for
reversing cyclic loads. Ask any good engineer. But they are
here! But lots of wheelchairs do this... I
told you they were designed by idiots? There IS a fix
though.
-
There are
lots of MASSIVELY overweight (weight matters!!!)
and over complicated bits that are simply bewildering.
For example there is a "bar" that holds up the front of the
seat. Its made from SOLID steel bar, encased in a bit
of thick wall steel tube and has machined and shapes ends,
and uses four bolts, four washers, four nuts. It
doesn't do much, but I can hardly lift it! Why??? I
just replaced it with a single alloy bar with two holes
drilled in it! Lighter, cheaper, neater, does not
rust, no need for paint, cheaper to produce... There
are lots of strange bits like this. (Idiots??? Or is
there a reason I can't understand...)
If they
sorted these issues out as I do on this page then this would
be by far the best powerchair for active users as an in /
outdoor chair. But we all know how wheelchair
companies love advancement, or constructive criticism. Beats
me why they don't ask me! But there you go.
What I
intend to do to this used F55 powerchair:
-
Strip and
rebuild its motors and gearboxes PROPERLY so the damned
thing is smooth and quiet, with bearings, brushes, etc.
Now Done. See HOW

-
Strip and
clean everything PROPERLY, and have any parts that are
not perfect either replaced or modified, improved, or
powder coated or all three!
-
See if I
can get on with that Recaro seat. It may not be
compatible with my backside, but we will see! And
move it rearwards by 4 inches, and lower the back of it
1 inch, and the front by a massive 4 inches! At
the moment as standard its 27 inches from the floor and
leans backwards far too steeply! Who designs these
things anyway Now done. See HOW
-
Throw
away those awful antique footrest hangers - fancy paint
does not make a good design...
And saw off those ugly mountings >>>>
-
Throw
away that awful curb climber. I can get up bigger
ones without it anyway after reprogramming and moving
the seat back.
-
Design,
construct a LIGHT cheap SMALL narrow, rubber mounted
single footplate - >>>>
-
Pull all
those Nancy stickers off - they look gay..
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Throw
away the front lights, (C of G, Weight) because they are
cheap nasty, heavy, oversized, and unused. If I
really wanted lights I would fit tiny light carbon fibre
LED powered ones from a Motorcycle catalogue. But
I don't!
-
Fit a
"parallel" type pod mounting, they may be heavy but they
actually work.
-
Replace
the "arms" and mountings as these are (as usual on this
design) worn and rattle about. The locking pin wears in
the alloy of the arm.
-
Throw
those multicoloured tyres away. Fit proper (black)
pneumatic front ones, and tubeless "trailer"
wheels/tyres on rear. These are less puncture
prone, bigger diameter (so faster) and CHEAP! On
home made hubs, so as to eliminate that backlash
"keyway" problem for good.
-
Fit 100
amp controller in place of the 80 amp one (I happen to
have one...)
-
Reprogram
totally so it drives like it should have from the
beginning, with PROPER control. (Drive it like you stole
it!)
-
Then I
hope to use it while I REALLY go to work on my original
F55S CHAIR... That one will be 48v, 270 amp robot
controller, on board Honda suitcase silent generator,
etc...
OK I am
rebuilding now super clean of course and properly!
Below is
the new 8"x 3" trailer wheel fitted. This comes
very cheaply with a strong tubeless 3.5 inch wide tyre
already fitted. Its about an inch or so "bigger" than the
stock F55s tyres, giving a higher top speed, better ride due
to more sidewall, and less or zero punctures due to its
stronger carcase and tubeless construction.
Kinda makes you wonder why they don't just fit these as
stock doesn't it... It fits using a 20mm
Taperlock fitting, so that the typically worn keyway, and
gearbox / wheel backlash problem is eliminated.
And a specially machined (by me) V belt pulley so I can bolt
the wheel straight on... Also shown in this picture is
the new "anti tip" wheels, which came from a new £5
skateboard! They are smaller, harder, lighter,
fit straight on, look better, are harder wearing.
And make a nice whooshing sound as you wheelie!
Those trailer tyres look better than stock ones do as well
as they are "chunkier" and definitely better than those
multicoloured foam ones were! All those stickers are
gone too.

That
skateboard wheel! I use these while wheelying
sometimes the full length of the street. Every day. They
don't last very long!
But they DO last a damned site
longer than those nasty rubber ones that it came with...
This
picture shows the 20mm "taperlock" that clamps to the shaft.
And the V belt pulley before it has been machined down and
"tapped" to allow me to fit the wheel

(After
machining - click)
Now, with the seat moved back by
4 inches or so, when you reverse to a wall its the headrest
that touches first. And it was lowered 4 inches at the
front and around 2 inches at the back as well so that
transfers were easier, and the seat height is the same as a
"standard" seat version at 23 inches at the set front from
the ground.

It makes
for a VERY compact powerchair now those awful swing away
footrest efforts are chopped off!
Also the
arms are 2 inches closer together now due to losing
those 2 one inch thick unnecessary side plates. On a
Recaro seat they just get in the way, and make the chair
wider than need be. And as I already said the
narrower, and shorter a chair is the better! Its
amazing how much difference an inch here, or there really
makes. Shame the manufacturers don't quite get this...
Saves some more weight too.
Ughhh ORANGE
tyres! That Owen guy had no taste!
While size
is very important, I have a box with all the overweight
or unneeded parts in it. (except wheels of course) Now
I can't lift it! Really. There are brackets,
oversized bolts, all that rubbish I cut off the seat frame,
curb climber, swing away footrests, lights and indicators,
etc etc... WEIGHT matters. It effects
both performance "usability", range and therefore battery
life expectancy, hill climbing, carpet and tyre wear (which
in itself requires some power!) Must get off this soap
box...
Don't worry those orange tyres will soon be gone!

New footrest plate. Nice &
small (I drew around my training shoes rear half) compact,
light, small & will soon be fitted. Shown here
it is sat on the new front black tyres. On it is the rubber
(car exhaust) rubber mounting blocks. They are simple
small cheap light strong things. 6mm & 8mm threads.
It will be rubber mounted to
help stop the jolts from bad roads and surfaces causing me
to have muscle spasms.
Now with this fitted the
furthest thing back is my head, or if fitted, the headrest.
(I may take it off.) The furthest thing forwards is my
toes. And they are as tucked back as its possible to be.
This means it can turn in a TIGHTER space than most
manual chairs because the wheels do not get in the way.
 OK
THEN!!! Time for a break!!!
For
fun, I fitted my home built Radio Control interface, and
it was just "borrowed" from my 4x4 Robot Powerchair
(Here)
I have not got the
footrest fitted yet, and it still has those horrid coloured
front tyres, but who cares!
There is actually a real
reason for this messing about, in that I can work on
this purple chair, and move it about, such as onto the vans
lift for easy access like a car ramp! And I can plug
the same "box" into any Penny and Giles control system on
any chair and drive it home, or to my workshop. Or I
can scare my dog, and cause strange looks as an empty
powerchair zig zags all over the shopping centre avoiding
walking obstacles... I took it for a walk to the pub
last night! Anyway, not bad for around 600 UK Pounds
so far, and it looks like new, and then some with all the
crap stripped off and shortened etc.
Download the short 5 Mb
movies below, it looks very odd! The downloads may be
slow, because they are living on my desktop computer and its
connected via NTLs cable...
Right click, choose "save target
as" to save.
1 movie
2 movie
3 movie
4 movie
Playtime now over!
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Start
(looking at the mess! And sorting it all out
starts) |
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Part 2
(On board four stroke petrol power begins!) |
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Part
3 (The modified smaller lighter
footplate design continued) |
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