Hand powered speeder

[duckman903]

Well the speeder has been fun for all the ages of kids (6 to 72+) , at the club they're in the process of connecting the outer and inner tracks, so the speeder is going to be converted into a semi box cab (electric) that way it won't impeded the traffic, I have a right angle gear box, ordered sprockets and chain, and then buy a darned expensive battery.

[duckman903]

Pictures to follow, the speeder has been stripped down and ra gear box mounted, sprockets bored and keyed/mounted, 2 electric motors, PWM controller, all the parts are mounted and it's been test run off my battery charger, now the battery, and seat with false engine hood, then a test run at the club to see if I got the gearing right, fingers crossed.

[duckman903]

OK got it together, kinda just tossed together just to try the gearing that I've chosen, well we took a trip to the track in Holliston (Washakum Live Steamers) well my figuring was way off, my GD jumped on and away she went at a breath taking 1 MPH, well it looks like I have to remove some gearing.

[steamin10]

Somewhere around 7-10 MPH seems pretty common. I had a gas goose that was geared for 12, and I never ran it wide open, as it was just too fast. If you do your gosintas, and takes aways for the wheel diameter, you can get a pretty good final drive by doing the chain ratios. The fifth grade math aint so bad, its getting things in order.

[duckman903]

Well got home and ripped it apart, lose the right angle box, lose the #40 chain and sprockets, took both motors and made a mounting bar to hold them in position, using the #25 chain and sprockets cobbled them together, was all set to go try the new gearing and remembered the club track has "HILLS" both up and down, so discretion being the better part of valor I thought that I'd put a brake on the new engine (not a speeder any more). So now I get to use the old grey matter and make something that works.

[steamin10]

I made mods to the goose engine, a pancake briggs of 3.0 through a rider trans. three forward and one reverse. #40 chain and sprockets for final. I removed the governor, as it proved to be a pain, as it over rode the throttle on a down hill and caused a gallup (ON _OFF) glitch. Rear was single axle, with small 2.5 wheels on the front short truck. A coupler with a broken shank was fitted to the rear and towed a flat for operation. It was set up to ride on with the body , and footplates and pedals for stop and go. I never completed the body, had to sell it for survival back then.

Too many irons right now, but some day it will happen.

[duckman903]

OK got the brake system done block of oak pinching on the tread of a wheel, went to the track for a try out, am using a 10 amp PWM control made it about 50' and blew the Chinese fuse the filament looks about the size of a hair, went to the car parts place got a box of 5/10 amp fuses , put in new fuse took off and got about 10' blew a fuse, opened the hood and cut a wire going to 1 of the motors, new fuse made it about a 100 yards then it blew/popped, about this time decided to go back to the truck, picked the engine up and put it on the down hill section of the outer loop shortest way back, went flying down the hill and gave it just enough juice to make it about a 100 yards guess what blew another fuse, decided that a 10 amp controller didn't cut it, looked on Amazon and found a 40 amp controller got it installed and will go to the track tomorrow/Sunday for the monthly meet and give it a go, going to fuse the positive wire with a 40 amp fuse, if this doesn't work gas engine is next.

[duckman903]

OK put new controller on rated 40 amps, put in a fuse holder with a 30 amp fuse wahoo all day on the same fuse, still need to get the ratio a little higher right now it's about 3 1/3 to 1, need to get to 4½ to 1 or 5 to 1, it's pulling a little hard going up hill, and gets scary going down grade.
Now for the electronic guru's, the controller can handle input of 12V, 24V , and 48V right now I'm running 2 14V PM motors on 12V wired in parallel, if I put the motors in series and feed the controller 24V will it work, I would like a little more power which I know a little higher gearing will give me, if I fry these motors I have 2 more waiting in the wings, or would I just be better off getting a scooter motor.

[steamin10]

You are not giving enough info, that has to be right on, to know the real answer. Too much guesstimating here. But what I know is, voltage up, Amp draw is down for the same work. Less Amps means less heating, and you only have 40 to draw on. Starting from dead stop, or rapid control increases, may ad overload spikes to the draw on your controller. If you have been running successfully on your 40 amp controller, then gearing down to 5-1 will help as it will allow more motor spins for each axle turn. It is less work on the motor.

IMHO parallel batteries for long running in 12 volt. 24V feed will allow higher outputs to the motors without high amps, at the controller. On the draw side, putting the motors in series makes them mutual resistors, and cut the voltages down, while generally raising amp draw. In other words feeding 12 V to the series wired motors will have the effect of running 6 volt motors to do the work, and heating will result. I have run 12 volt permag motors on 24 volts, and they are happy. (24 volts are never attained as that is wide open, so they will cruise at about 18 or 20 volts, and reasonably lower draw.) Gearing is important, and I ran 12 tooth brass pinion on 100 tooth steel gear, and was most happy with the speed, my problem then was a suitable controller, which are much better, and less expensive now.

[tornitore45]

I am a little worried about wiring motors in series. sharing power may be problematic.

I do not know if they are on the same shaft (same RPM) or are free to slip.
On the same shaft there would be different voltage across, if the magnet strength (or field) are not equal the back emf would be different .

If they are not locked and one wheel slip, the voltage one that motor will rise.

Best bet is to wire the motors in parallel, and feed at 24V (series batteries). The controller is more efficient at lower current. Switching losses do not change but RI^2 losses are reduced by 4.

Charging batteries is best done in parallel or one at the time to avoid cell overcharge.

[duckman903]

I've decided to leave the electrical stuff alone and just change the gearing , will be going from 3 1/3 to 1 to 4½ to 1 that should help with acceleration and what ever else it helps.