have a slower F55 the 4 mph version and you would prefer it to go
faster then you will only (!) need to change the pair of
Motors/gearboxes as a complete assembly. You do not
need the "full power actuator" that they talk about,
because this simply works the lights! But it still
PROBLEMS and how to fix them!
.1. It has an
incredibly weak, wobbly cheap, and nasty "swing away"
pivot for the control pod. Consists of a bit of bent tin,
and a wobbly rivet - have looked at loads of these on other
peoples chairs over the years and EVERY ONE is loose
and needs replacing! Fortunately there is a
"parallelogram" version which is also available (at a daft
price) to replace it. Although everybody at sunrise
has no idea what you are asking them for... So actually
getting one is almost impossible! It is a part that is
in the parts list - a .pdf file that you may download from
here! (1.3Mb) Give them the part number and I guarantee
sunrise or your dealer will only send you the wrong part
about 5 times... I have one and its strong and solid.
Recommended urgent fix!
2. The same
pod is strangely located on the OUTSIDE edge of
the chairs arm. Meaning that the chair is wider than it
needs to be and with daily use it gets banged on doorframes
and this is the main cause of that other previous part to be
b**g***d! Who the hell designs these things?
Fortunately if you raise the armrests a "notch" it can
easily be moved to the inside edge, making it less liable to
be damaged and more comfortable at the same time!
Which is a massive improvement in use. Another essential job
that fortunately takes only a few minutes - my chairs total
width is now two and a half inches narrower as well! 2
inches is a lot when you are manoeuvring on trains, inside
restaurants, pubs, small loos or doorways at an angle.
3. While we
are still on the "pod" area, we have another problem!
the "charging socket" is an XLR type connector - usually
used for microphones and tiny currents. These can (they
claim) take up to 10 amps for charging purposes. When they
are new and making good contact they do this "quite" well,
but are on the edge of their capability. Stupid design. This
is not sunrises fault actually but Penny & Giles who make
the control system (its a Pilot Plus 80 amp unit). It causes
BIG charging problems with some types of chargers though. It
starts to wear after a few months, and gets hot during
charging. This is the key... It goes fairly high resistance.
Not helped by also having a long thin cable also of high
resistance, connecting the pod to the controller under the
seat. Now, the clever intelligent charger (that senses the
voltage accurately) "sees" higher voltage, and less current
so it thinks the battery is more charged than it really is!
My trusty digital multi-meter tells me this can be as much
as 2 volts difference between batteries and the charger!
So poor charger drops back to a lower charging current too
early in its cycle for fear of damaging the sealed batteries
by "gassing"... In reality it either never finishes
the charge before morning, or goes onto a REALLY long
final stage! So your battery cells never get equalised or
properly charged and your batteries are useless. Simple
solution, if you feel any heat here when charging, swap both
the socket inside the pod, and the plug on the charger for
new ones. Or better still, fit an external directly
connected to the battery, charging harness with a proper
Programming of the PowerChair is nothing short of
unbelievable! This is a much bigger problem than ALL
of the others! As it is delivered to you it is all but
un-drivable, If you can:
a) get it to turn at all on carpet its a miracle! Or
if it does it goes too fast and hits something...
b) get it to go through a doorway without you losing
fingers or smashing into first one side and then the
Its as if the joystick is connected by a very loose rubber
band! It bears no resemblance to what the chair does.
there IS an easy cure! But it cost me 270 Pounds and I had a
massive fight to get it! It is the PP1b "programming
box" DO NOT confuse this with the completely useless user
version the PP1a programmer that so called
"wheelchair techies" wave about. They LOOK the same. They
are definitely NOT! You NEED the PP1b
and some skills and understanding to use it safely and
properly. Hence my problem getting one. I had to sign
disclaimers, jump through hoops, etc and lie! Anyway, if you
want your chair to drive properly you need to reprogram it.
It will be faster, accelerate and brake better, turn slowly
and precisely in direct proportion to what you do with the
stick with LOTS of torque, and you will never hit another
doorframe! If you want me to reprogram your own chair, (ten
and I will discuss. For full details go to
MY REVISED SETTINGS ARE NOW IN
A CHART AT THE BOTTOM OF THIS PAGE
5. The motors and gearboxes are only supplied (Via EMD)
as complete units. No spares
are available other than motor brushes (these last two
years maximum with full time use). They have two
SERIOUS problems. I have had maybe 30 emails about
the backlash or "clunking" that soon develops. It
becomes "very tiring" to drive it like this. Although in
reality it will never leave you stranded. The first
thing to wear out is a tiny, easy to get at, rubber
"cush drive" Pictures say a thousand words so see below.
motor to gearbox bolts. Easy, and no mess. This
separates the motor and gearbox. This is how you
get to the rubber cush drive bits. This is
serious problem one.
Separated (four Allen head bolts) with the new
in this case rubber cush or "shock absorber".
This rubber bit is what drives your chair! It
removes shock, vibration from the driveline
making the chair smoother and quieter. Shame its
crap then... They always disintegrate, and drop
out as dust! Then we have clunk clunk, metal on
rubber bit put back into the motor side... You
can use four bits of round Hoover belt (OK
vacuum cleaner then!) If yours are ruined...
Suggest you superglue them in to make assembly
simpler, and maybe last longer.
with rubber cush removed.
close up of the part that fails and causes all
the clunking... The middle bit is only needed to
hold everything in place when you put it back
Only the four round bits do anything. So any
four bits of rubber that are the same size work
ok. (Vacuum cleaner belt... and a sharp hobby
Mine now has four harder "nylon" based material
(unknown name) now. So they don't fail any
longer. Polyurethane or something...
SECOND problem to check for is actually
the easiest, but usually happens later on, is
the wheel where it fits onto the shaft. It uses
(incorrectly! Ask any engineer!) a
square "dowel" or key to transfer power from
shaft to wheel. This can and does become worn,
and the wheel retaining bolt does nothing to
help here. Although tightening it up really
tight "disguises the sound, so it can make it
quiet for a short while. Also if these wheels
are not put on correctly, with some copper
grease or similar you may NEVER be able
to remove them. Check now BEFORE you get
a puncture! If this is the cause of your
problem then the official repair is to replace
motors as a pair, and the wheels! Your bank will
not like this! Its seriously expensive.
the SHAFT AND KEYWAY WEAR PROBLEM - I had this problem
as well. So I fixed about 3 problems at once! This
requires some skill and engineering work, but allows
standard trailer wheels to be used instead. These are freely
available, cheap, slightly bigger, tubeless (far less
punctures), and harder wearing. The tyres are also of
wheels were 350 x 8 tubeless tyres on steel 8" x 2" rims
with four mounting holes at 115mm PCD or 107.5mm radius if
you prefer. After several days staring at all the bits a
cunning construction plan filtered in to my brain... I
wanted Tank steering, with chain drive to the wheels, simple
compact and elegant engineering construction. No yucky steel
brackets, added on bits etc, much thinking, but little
cutting!!! I chose these wheels because they are readily
available, cheap, chunky, strong, tubeless (less puncture
problems!) and I spotted them in a local car accessory
wheel, now fitted on a turned down, and drilled and tapped
ex pulley using a "taperlock" shaft fitting, because keyways
are useless for reversing torque loadings... Ask any of
those people who have all that clunking on a powerchair.
They wear and fret! Why they don't do it like this is beyond
Better pictures of how
this was done on my home built Robot / Powerchair 4x4 base
are here Once done no more keyway wear
problems... And cheaper bigger (faster!) tyres...
I hate those standard "swing away" footrest bars! (See
standard F55s picture) they stick out too
far, and are too "wide" meaning that you get stuck when
trying to get in and out of loos, or turn in tight spaces.
It also gets in the way during transfers. So I made a alloy
T shaped mounting so I could fit a "Viva" powerchair
footplate. Opposite. This is narrow, rounded, and shorter.
Means easier transfers, better
manoeuvrability in tighter areas like trains, loos etc.
Definitely a major improvement.
Later on I made a
still Aluminium chequer plate version....
MOVING THE SEAT BACK
On the face of it pointless but...
wheelies which whilst may not seem essential, allows me to
"lift" the front wheels at will at low speed, so as to be
able to get over thresholds, 3 or 4 inch curbs etc really
easily with less of a jolt. And when leaving the pavement
you can lift the front so as to land smoothly on the rear
battery life or range loads. Did you know it takes more amps
to turn than to go flat out? By MILES! This is because with
most of the weight on the rear driving wheels the front
takes less power to "swing" around.
on thick carpet - less weight over casters
to sink casters in sand/mud/snow or whatever.
control on uneven surfaces. When you go up/down a ramp or
over some bump in the path for example, on a standard F55
one of the rear wheels leaves the floor! These are
controlling both your progress and your direction! So it
spins around or goes in the wrong direction. Mine lift a
FRONT caster instead as all the weight is over the rear. So
I stay in control.
If a front
tyre gets a puncture, it matters very little, because it
just runs along merrily, on the other one! And the rears are
very difficult to puncture since I now use stronger trailer
On an F55 the
only thing that stops you moving the seat back further is a
small black steel bracket that is triangular in shape with
three holes as shown in the picture. You just need two new
1/8 inch (3mm) plates with the holes drilled as shown in the
drawing. You can see this bracket or rather my new stainless
steel polished multi hole adjustable one in the other
photograph just... Should have scanned one before I fitted
Dimensions shown need to be cut out of a new bit of
metal and fitted as photo below shows.
below shows the new one with all the extra adjustment
holes allowing the seat to be relocated rearwards. In
the picture it is using the second to last hole to the
rear. This allows controllable wheelies at will.
NOT RECOMMEND ANYBODY TRIES THE FOLLOWING - unless they
have a very real understanding of the possible
consequences. These include fire, danger to public,
danger to users, damage to wiring, controllers or blown
motors or gearboxes. Remember a simple thing as a blown
gearbox (Nylon gears!) can result in the chair doing a
sudden turn off the path and into the traffic! Be
warned, there are many other nasty possibilities too.
intend to fit a 100 Amps per channel controller (in
place of the stock 80 Amp one) as fitted to the new
8.5Mph Pride "Blast" 850 powerchair. This requires
heavier battery and motor cables for fire and safety
reasons, and to prevent voltage drop under load.
Actually I had already done this for performance
Theoretically since the only time the chair ever reaches
(draws) 80 Amps anyway (read with a clamp over cable
type test meter) is when accelerating from a standing
start for the first half second when trying to pick up
the front wheels, it will not make any real difference
to anything other than wheelies. But this is not the
real reason for doing it! See other modifications
planned later below. This mod is
now done, makes wheelies REALLY easy! Otherwise
performance unchanged as expected. See 2) below for real
Picture 1 shows how simple
it is to retrofit as they look identical.
Picture 2 shows the simple (and inadequate!) plug in
Fitting much taller geared higher current draw motors.
Now you think you know why I want more "power/speed" Now
the motors I am looking to fit will be good for approx
15 mph and are much MORE efficient than normal motors.
These are the brushless, gearbox less type that actually
form the wheel itself. Some need a completely different
controller. As yet I have not heard back from the
suppliers. But if that fails then there are plenty of
other options available. The reason I want no gears, and
therefore no gear backlash, and lots of power is because
I am currently working on a simple (!) circuit board
that is programmable, and has a solid state "heading
lock" type gyro, and wheel position/speed sensors. The
Gyro is actually looking at pitch - not yaw as in the
model helicopter it is designed for. I want to cut off
the wheelie/ant tip bars and let the software and the
sensors / gyro balance my chair for me! So it will
balance on the rear wheels, and let me drive about in
this configuration as I wish at up to 6 mph only. The
reserve speed and torque is simply to allow it to
balance as a reserve of power is needed in case it needs
a burst of extra power to keep it's balance. Initially I
intend to let my circuit override the control stick, and
the Pod will plug into my circuit. Everything is small
so will be under the seat and invisible.
balancing it will of course now be able to go much
faster! Now does anyone have any ideas where I can get
some real motors for this project? All info helps!
Advantages of a balancing chair are numerous, but
include "laid back" comfort (while at the bar, or
watching TV) and pressure relief. Also battery range
will increase as the heavy front end will not always
head "down" the camber, which requires extra power
(lots) to keep going straight. And also when turning, or
trying to keep straight you use energy to "swing" the
forward weight about. By balancing all this disappears
as the Centre of Gravity is directly above the drive
wheels point of contact.
those horrid uneven pavements and surfaces that make the
small front wheels chatter and cause me much muscle
spasm is reduced as the big drive wheels travel over
these surfaces easier. Plus, going up and down ramps and
slopes your seat will remain level - no more falling out
the front, or tipping over backwards.
can (have to!) cut off those anti tip bars that stick
out the rear, as the gyro will not allow you to tip out.
This means a shorter chair that can turn in smaller
this Idea of course from the
. Balancing has LOTS of advantages, and I don't think it
is that hard to do. We will see! Right now we have a
B.A.E Systems solid state gyro, (Futaba radio control
use them!) An electronics guy who is out of his depth we
think... And a good programmer, most are useless believe
me. ANY suggestions or help or offers of suitable
motors (even with gearboxes!) is very welcome at this
point, as I am not sure what is available yet.
Since this was written I decided it may be better to
experiment on a unmanned ROBOT Radio controlled chair Base
- Click to see!
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