My New Vehicle: 30 LBs/HP, Aluminum Tube Frame, Not Street Legal
 

Over the past few years I've spent much of my time working on car projects (not the least of which has been Tina) that I have kind of missed messing around with other crazy endeavours. In the midst of fabricating a few things for the RX-7 I decided to take a break and build something I have been thinking about for a few years.

https://www.rx7club.com/forum/attach...1&d=1251916102

The battery pack is made up of 4 12V 7AH lead acid gell cells in series for a total of 48V at 7AH. I have used lower voltages in the past but they lack the punch you get from packs of 36V or greater. 24V is OK for kids and 12V is for Power Wheels toys.

https://www.rx7club.com/forum/attach...1&d=1251916102

I built the frame out of 3/4" 6061 square aluminum tubing with some 1/4" and 3/16" plate used for flanges when necessary. The front end is from a Rage (Razor knockoff). I cut off the existing wheel forks and then welded on a bit of 2.5" square tubing with the bottom cut out. The aluminum forks then bolt to the tubing vertically. The tires are 6" x 2" pneumatic "speed wheels" from Princess Auto. To drive the rear wheel I had the machine shop machine two hubs to fit inside the wheel hub and I welded them in place.

https://www.rx7club.com/forum/attach...1&d=1251916102

The motor started life as a 350W 36V motor but was rewound a few years ago with thicker wire to support 500W. Run at 48V, I would expect it will be putting out about 800W or just over 1HP. and something like 60 FT-LBs of torque. There is a 11 tooth sprocket on the motor with a 44 tooth sprocket on the rear wheel. Honestly that ratio is a little soft. I think I am going to go to a larger sprocket on the wheel. In the past I have used simple contactor controllers but this time I wanted a variable speed controller so I purchased a 48V 1000W controller from ElectricScooterParts.com. In addition I picked up a twist grip throttle.

https://www.rx7club.com/forum/attach...1&d=1251916102

Overall I'm pretty happy with performance though I think I will change the gear ratio as I mentioned above. I think I may be lugging the motor, so even if I go to a larger sprocket and raise the ratio I may bring the motor into a more efficient RPM band and gain both top speed and acceleration. At the moment it will do 25 KM/H flat out, which doesn't seem very fast until you actually try it. :) No idea on range yet as the longest I have rode it is about 2KM but I don't see the problem with assuming about a 10KM range.

Looks nice. Quality welds and finish. Love the jackstands;) If you find it is a bit squirrly at speed you could try playing with the rake angle of the forks. I've noticed a difference with that on bicycles. So is Tina's little sister going to take on White Zombie?

the more / angle on the front end aka castor the better it will handle at high speeds...such is the same with cars


oh i love you, princess of auto POWERFIST IT

I've found that small scooters are fairly stable with minimal rake. I think the reason, at least for battery electric scooters, is because of the low center of gravity. With all that lead down at the deck it doesn't want to suddenly change directions. Previous scooters I have built have mounted the batteries higher, or used a large gas engine and could certainly be described as a bit challenging to drive due to their twitchyness.

Annoyingly, as I was coming home from the Wortley Village Cruise Night on Tuesday (the first long trip with the scooter) I lost a front tire. Luckily it was at the end of my street so the walk was not far. Looks like a manufacturing defect and I intend to return it to Princess Auto. I happened to purchase an extra set when I bought the wheel for the scooter as they were on sale, so it was a quick swap and I was back up and running.

Range is somewhat less then I thought at around 5KM. I am definitely lugging the motor so it's time to find a larger rear sprocket.

Moved to the Fabrication forum. I think that's a more appropriate place for this.

That's a neat little project, how long did it take? What is with all the pics of the Wilson manifold on the wall?

Why batteries? I understand its a toy but if your going through all that trouble, why not a stihl chainsaw engine or a 80cc 2cycle dirtbike engine? Looks like it would be alot of fun though
'

I don't have an exact hour count but I started at the beginning of August, and finished at the end of August. I had the basic frame and wiring mockup done around the 2nd last week of August so I could work out any mechanical/electrical bugs before I installed all the body pieces.

The manifolds are on the wall because it's probably the best welding done by a human that I have ever seen. I realize that he goes through a ridiculous and totally impractical process to get those beads, but it's still damn impressive.

Because small 2 stroke engines are:

-torqueless
-smelly
-loud/obnoxious
-messy
-unreliable

On the contrary, electric power is:

-quiet
-efficient
-torquey
-reliable

hell yea, electric power! cool project. nice fabrication. nice choice of power.