Mobility Scooter transaxle

[toylander]

Does anybody have any experience with mobility scooter rear axles, its a motor and gearbox/diff assembly, and i can't get the wheels off, they appear to be of a pull off design but i'm stumped. hopefully they might just be coroded on. I'm trying to get them off with out too much damage.....

Anyway on the electricity side of things the motor is rated at 200W  What kind of speed controller do i need to make this work, the one from the scooter was damaged when it burst into flames..... thats how i got hold of it...

Speed controllers for small motors on DC seem to be one of lifes Mystery's ..... and i'm an electrician....

[markh15]

Hi James,

The wheels should have a central bolt holding the hub onto the shaft. Once this is removed, the hub should slide off the key-wayed shaft.
If it's a little reluctant to part company, spray a little WD40 around both ends (inside and out), and try gently knocking the hub from the inside with a blunt bar and a 2lb hammer. That should shift it.

As for the electronics, have a search through the forum topics for '4Qd' controllers. From what I can remember, there are two basic types, with different ratings. One of these should be compatible with a 200 w motor.

I was fortunate to have the motor's controller when I built Harvey's car, and so didn't have this problem.

If you know the make of the scooter, or the controller, you could keep an eye on Ebay for one. There are several people who break scooters, and advertise varying bits on a regular basis, so you might be lucky.

Hope this has helped a little,
Keep Busy,
Regards,
Mark.

[toylander]

Well one broken rim, a few minor cuts and a couple of choice words,
"The wheels are off"
 reluctant wasn't the word here, they wouldn't come off when i first got the thing, nearly 2yrs ago have been soaked in WD40, Ezzzit, 3in1 a blow torch and everything else i could think off including cillit bang!!!!! Nope they would not budge....

Hammer and bar, lump of wood and wedges ....nope.....the final solution was a puller, when i eventually found it, and a few words to the man upstairs  

And now i've measured it it a little short LOL

[markh15]

Hi James,
I could have told you that the axle would be short!

Sorry about that, couldn't resist! 

What I did with mine, was mount the transaxle flat in the motor compartment, so that the motor was behind the diff / axle, with just the axle ends (where the wheels fit), protruding into the wheel arches.
I then mounted sprockets onto the hubs from the scooter, and a chain from these to specially modified trailer hubs, on the rear axle of the car.

I know that Walter (multisync) used a similar set-up, but mounted his transaxle in an upright position (motor above the diff / axle), with chain to the standard 'Toylander' wheel / sprocket combination. Because of this, he had to fit small spacers the seat base to gain some clearance.

There are some pictures of my axle set-up in the gallery (red bodied T2), have a look at these to see what I mean.
You could also have a look at my website, it details how I did the modification. Just click on the 'Globe' icon under my username (top left) and that will take you there.

It is easier (I think) to use a scooter for the motive power, and if you have started with an 8 mph version of the scooter, you'll have 'Soft Start' built in to the controller, along with Lights, Indicators, Hazzards, Reversing Beeper and all sorts of other things too.

Hope this has helped a little,
Keep Busy,
Regards,
Mark.

[markh15]

Hi Mike,
When I said the Transaxle didn't make much difference in the legroom department, I meant compared to the standard Toylander setup.

I'm pretty sure that the motors on the 4 - 8 mph scooters are slightly more powerful. This is because I'm using the electronics from an 8 mph scooter, but the motor from a 6 mph scooter, and with the gearing (1.3 : 1) it will only reach 5.7 mph according to the cycle speedometer I have fitted.
The gearing figure was a 'guestimate', but it works really well, and will pull away with me (18st) and Harvey in the car, and will cope well with some quite severe inclines....



The top is about 10 ft above the other field, and about 20 ft long, and there's no problem with the speed either.

As for pushing the car, I simply dis-engage the motor from the axle with the 'Freewheel' lever (usually on the end of the diff unit), and away we go.

Walter (multisync) or Brian will be able to tell you how to use a micro switch to by-pass / cancel the electric brake, but if it's draining the battery, it sounds like a problem somewhere.

If you're having trouble sourcing chain and sprockets, try 'Technobots' (www.technobots.co.uk), or 'Bearingboys' (www.bearingboys.co.uk) who can supply these in a variety of sizes and pitches. I found that 3/8 th pitch chain is heavy enough for the job, without breaking the bank.
I have used Technobots for some of the bits for Harvey's car, and although the P+P looks expensive, there is no weight limit for the packages, and they are delivered pretty quickly.

You will need access to a lathe to modify the sprockets, as they come with a central boss, but you might be able to use this to your advantage.

Hope my ramblings have been of some help,
Regards,
Mark.

[multisync]

Hi
All mobility scooters are fitted with some sort of free wheel device to enable scooter to be pushed in event of battery failure.
There are two types
One is a lever that disconnects tthe drive train itself, this is done within the transaxle unit and the lever protrudes at rear of scooter.
The other type actually lifts the brake off the motor, and operates a micro switch as well. The micro switch disconnects trhe brake circuit and this prevents the controller starting up.
Best wishes
Walter

[Tombraider]

Hi All, well here's where I'm up to. The Pride Hurricane scooter transaxle was shortened and fitted with the sprockets supplied by RLT by a local machine shop. Richard suggested using a roll pin and/or grub screws so the machine shop guy decided to hold the pins in place with the grub screws either side (I had actually planned for the grub screws to be at right angles to the roll pins for additional retention as Richard said the roll pins can shear when using high torque motors but hey ho).

The motor, ECU and onboard charger have all been mounted under the seat. Space is a bit limited and I'm a bit concerned about the heat generated in such a small enclosed space so may have to fit cooling fans as Mark has done. The charger is at the top right of the picture and has been mounted upside down (the aluminium plate is its base).

(Richard look away now) - I've made chain guards out of shock horror - plywood!

I had all the power leads nailed to the underside of the floor when a neighbour came up and offered me some plastic toilet overflow piping with right angled connections. I went and bought a 45 degree elbow and it has neatened it up a treat. The smaller dia tube is a piece of copper plumbing pipe and carries the wires for the rear lights and indicators to protect them. Will have to add picture in another post as I've reached the limit of 4 now. He also bought me a black and silver Landrover badge about 1" long from the wheel centre cap of a Range Rover which is superb scale for a Toylander badge! Not sure whether to mount it on the grille or rear panel yet.

I accidentally shorted out a battery whilst wiring up the power leads so took it to a scooter service centre and sure enough it was damaged. I bought a new 40Ah one from ebay and it goes again now but only very slowly. Although they said the other battery was ok, the repair centre said they must be replaced in pairs and they are right - the 'good' old battery is dragging the new one down so I'll have to get another one this week. Before I shorted the battery, a few weeks ago I did having it running down the road and 8mph was a bit too fast even for me!! (now aged 50) and I'm making it for a lad who will only be 3 next weekend.

Anyway, does anyone have any experience of taking apart the electro-magnetic brake? It seems to stick on really hard after long periods without use and I'm wondering if it is going rusty inside?

I'm using the knobbly (open tread) tyres and the other thing I'm struggling with is to stop the right tyre fouling the inner wing on full lock. I've relieved the inner wing and put an angled bracket on the swing axle to limit the lock but am still having trouble on full lock and right wheel fully up (hitting the bump stop which has also been relocated to limit axle travel).

Regards
Mike 

[Tombraider]

[markh15]

Hi Mike,

I had to strip the electro-mag brake down when building Harvey's T2. They are quite simple to dismantle, just be careful not to loose the small cylindrical spacers, which are around the securing screws. These stop the two halves of the assembly crushing the spinner / rotor, which (usually) locates on the extended motor shaft.

Plenty of WD 40 and some 'scotch-brite' will have the components rust free in no-time!.
If you're woried about loosing small bits, take it apart in an old 2 ltr ice-cream tub, then if anything should escape, it won't go far!

When re-assembling the unit, try and get the rotor as central as possible, then the housing screws will line up for final assembly.

Hope this has helped,

Good Luck,
Regards,
Mark.

[Tombraider]

Thanks Mark. Yes, it looks like it should dismantle easily with just 4 miniature socket head screws. I was just a bit worried in case it was one of those devices that needed a special tool to get it back together again if it was spring loaded with a strong spring.
I'm encouraged to take it apart now that I know you had to do yours. I bought the scooter several months ago and the motor hasn't been freewheeled much during that time. The rotor does locate on a hexagon on the end of the shaft as you rightly say.
Regards
Mike

[Rickster]

Just received plans and am new to the forum.
Intending to build a Toylander II using motor and transaxle.
Has any one had any success with running 24V motor on 12V rather than chain gear reduction ?

[multisync]

Hi Rickster
I've not tried using a lower voltage but electric motors can be strange things!
Most speed controllers will get the lower speeds by sending pulses of the full voltage to the motor, not by sending a lower voltage.

Just consider your car engine, there is a particular rpm at which it is most economical and produces the best output in terms of value per gallon of fuel, hence we have gears so that the engine is always running efficiently, and at it's best rpm.

In the same sort of way, an electric motor will generally run best and give better power and battery life if it is free running at its design rpm, than if it is struggling to work at a lower voltage.
Have you made a start yet? How's the build going?
Best wishes
Walter

[quadra]

Just received plans and am new to the forum.
Intending to build a Toylander II using motor and transaxle.
Has any one had any success with running 24V motor on 12V rather than chain gear reduction ?

You can run a 24v motor on 12v but the current drawn will double, which isn't so good.

[Tombraider]

Are you sure that is correct? V=IR, resistance of the motor R is a constant so if V is halved, the current will be halved too? Speed is directly proportional to voltage so if you run a 24v motor on 12v it will run at half speed (but won't get anywhere near as hot as it is drawing 1/2 the current).
Power = VI so with half the voltage and half the current, the power will be a 1/4 of that on 24v.
Regards
Mike

[electric4fun]

when you run a 24V motor on a 24Vcircuit , and the motor is e.g. 240W , the amperage dranw is 10A,
when you run the same 24V motor on a 12V battery , in order to produce the same Watts , it will draw 20A as the wattage is the only constant (by desing )

in DC
W = IxV
or
for 24V => 240W = ? x 24 (where then  ? = 240/24 or 10A)
for 12V => 240W = ? x 12 (where then ? = 240/12 or 20A )

 modern regulators do not 'half' the voltage they send out chopped blocks in a certain modulation  of 24V ,the so called PWM regulators , thats the 'humming' sound you sometimes hear.
some think it the motor put is is actually the modulator you hear




more details on PWM > http://www.netrino.com/Embedded-Systems/How-To/PWM-Pulse-Width-Modulation


regs,
Luc