Workshop Index

Trike Index

3 Wheel Mobility Scooter Clone Version2

  A couple of years ago I built a large mobility trike a lot like a Palmers Industries Independent version. 

 The web page for that one is here :
 You can see the Palmer version at this link : 

 Mine worked fine but I didn't put the two 100 amp batteries in boxes which I should have. They were setting on a rubber mat above a stainless steel deck but over time battery acid leaked from them a few times when the charger did an equalize charge on them and it managed to get past the mat to the regular steel tubing frame on the trike.

 It corroded the frame pretty seriously in a couple of spots. as you can see in the picture below.  It might long look too bad in the picture but I easily pushed a screw driver through the lower frame tubing right in front of the first upright tubing for the top frame there.  I'm really surprised it didn't try to fold in half with me sometime when I was going down a street!

 Since I knew it was going to have to be rebuilt anyway I took the chance to extend the rear so I could install a basket the roughly the same size as a large grocery shopping cart.   The picture below shows the differences between the old and new trike on length.


Old Version

New version

new extended version pic


I used the same twin 24v 500w motors and lawnmower tranmission I used in the first trike. The only difference was I mounted the motors vertical and the transmission horizontally this time like it is supposed to be mounted. I had it mounted sideways in the first trike.  It's kind of funny. Even using two motors on this, I still don't have as much power as I do when using my little small mobilty scooter. The motor on that is rated 1.5 hp while both these two motors together only put out a maximum of 1.3 hp.

 A big change I made in this model was I used two 12volt  100 amp hour marine deepcell batteries in the first trike and they were mounted beneath the seat.  This trike is using two 12volt 32 amp hour sealed scooter batteries mounted at the back end.  This time instead of worrying as to whether I have enough battery power to get somewhere I simply solved the problem.

 Under the seat is mounted a 5.5 hp vertical shaft lawn mower engine I bought from Harbor Freight and it's running a 24 volt 100 amp alternator through a jackshaft in front of the transmission.  If my batteries get low I can simply start up the engine and run the electric drive motors on the alternator.  I doesn't get the best gas milage doing that but it doesn't leave me stranded with a dead battery either.

 Another change was I made and installed some large rear disk brakes on this version. The front brake and transmission brake on the other trike did an OK job but I wanted a little more stopping power this time.

The trike has a maximum speed of 15 mph. I geared it down on purpose to comply with the mobility scooter laws. It could probably do about 20 mph with different sprockets on the transmission.
The only laws I can find about mobility scooters here in North Carolina in the law books are it can't go faster than 15 mph and has to weigh less than 1000 pounds.   Otherwise the same rules go for a pedestrain as far as sidewalks, etc...   I normally run this on the edge of the road instead of sidewalks but I use one now and then if it's safer to be there.




 My original plans were to be able to run it on either the electrical motors or the gas engine through the transmission but it turned out that the freewheels I used couldn't handle being freewheeled about 2500 rpm.  They died on me almost immediately. So I switched the engine over to driving the alternator and only the electric motors driving the transmission. It will at least regen to the batteries this way when going down long hills and I get the same end result as far as range goes so I'm more or less happy with it.

I started out using belts from the motors to the transmission this time because I wanted it to be quiet.  It didn't make any difference as the noise I thought was coming from the chains turned out to be coming from the transmission itself.  That thing is noisy!  I took it apart to see if I could find out where it was coming from but nothing in the transmission was broken and after cleaning up the gears and inspecting them throroughly it was wasn't even worn in from what I could see. So far it hadn't even worn off the orginal machine marks on the gears.  I just have to assume that lawn mower transmissions are noisy and you don't normally notice it due to engine noise when they are being used.

 Picture of the transmission when I took it apart.  It had plenty of lubrication and showed almost no wear on the parts.

Here's a picture of the frame before I started adding all the parts. It's not as heavy as it looks.

Top view looking down at internals. Those motor pulleys abd belts have been switched over to sprockets and #25 chains.
The V-belts caused too much drag. I gained back 3 mph when I switched them to chains.

Front view

Running/turn signals, headlights and a mechanical speedometer.

I have another very bright led headlight mounted beside the speedometer now and have
replaced those small mirrors with motorcycle dot style mirrors that are a bit bigger.
The strip lights are set to shine directly in front of the trike now. It helps to see potholes, etc...

Rear view

The trike is straight. That pavement there is angled down.

The black cable wrapped around the lower center post is the aux power in/out line.
It has a 75 amp connectors on it.

The pin type trailer hitch is capable of use all my various bike trailers.

Brake lights and running/turn signals use seperate light pairs.

Left side

The gear shifter is on this side

It simply moved forward and backward   4-3-2-1-N-R

The small throttle knob under the seat is the engine throttle control. I simply set it to run at one speed for the alternator.

The trike has a full lighting system including head lights, tail lights, turn signals and emergency flashers.

I used a boat seat this time instead of a lawn tractor seat.  This one should at least handle the weather better. 

Right side

The engine brake release is on this side - lawn mower engines like this one don't use an electric kill switch. 
The handle operates a cable that releases the brake and the handle latches
into the top of the frame to keep the brake off and allow the engine to run

The power switches are [aux power in/out] - [alternator]  - [main battery]  in that order.
They are not labeled on purpose. People tend to leave them alone that way.

You can just see the parking brake knob there on the front  of the frame below the seat. It's more visible in the front view
It rotates down and has a swing latch that holds it down. It acts on the transmission brake.

The foot pedal operates the rear disk brakes.