Project E-Mini Bike, Using an Outrunner

[Metallover]

Originally Posted by BL_RV0

Awesome! That's the same bike I'm doing the gas conversion on!!

No Way! That's awesome... Honda Minimoto?

Have you managed to fill up the rear tire? How did you change the rear sprocket? Those are the two things I need to know, besides the throttle.

Originally Posted by J57ltr

Break out your meter and measure the wires on the pot installed on the servo tester. The outside pins should read about 5K. The middle is the wiper, it moves along from highest to lowest. so if you are on one of the outer pins the resistance will rise (or fall) as you turn the pot. The leads on the throttle will be the same if they both are the same resistance then you'll be OK. basically you will have to just remove the pot and replace it with the throttle control. Although since most ESC's have to be in a neutral position and the throttle is probably maxed at one range or the other so the ESC might not arm.

A pot is nothing more than a resistor that has a sliding wiper that when centered on the resistor will read half of what the total value is. So if you are in the middle the outside (lets say left) leg and center will read 2.5K and from the other outside leg (lets say right) and the center it will read 2.5K. As you move more to the right the left and center will start to increase in value while the right side and center will decrease.

Jeff

So will my throttle work? Maybe yellow in the middle and ground to the right and pos to the left? Do I need to make some circut crap or get a new throttle? I hope it's easy as soldering on the wires in place of the pot..

[BL_RV0]

Originally Posted by Metallover

No Way! That's awesome... Honda Minimoto?

Have you managed to fill up the rear tire? How did you change the rear sprocket? Those are the two things I need to know, besides the throttle.

Yah, the minimoto. I used an angled nozzle attached to my air compressor to fill the tire. The way the big plastic pulley is held on is just fuckin' stupid. It is glued on to a small freewheeling sprocket on the rear wheel. I took it off just bu cutting it into quarters and prying each section off. I put a different sprocket on, simply by welding it next to the existing sprocket, then welding the freewheel mechanism closed, so the drive is locked, having the motor drag help slow the bike down. If you get on AIM we can talk about the bike and such.

[J57ltr]

Originally Posted by Metallover

No Way! That's awesome... Honda Minimoto?

Have you managed to fill up the rear tire? How did you change the rear sprocket? Those are the two things I need to know, besides the throttle.



So will my throttle work? Maybe yellow in the middle and ground to the right and pos to the left? Do I need to make some circut crap or get a new throttle? I hope it's easy as soldering on the wires in place of the pot..

There is no way of knowing till you test it. Never guess going by wire color. it tells you nothing, There is never a "cut the blue wire".

I am guessing it was already an electric bike, since the throttle is wire and not cable. 5K ohms is pretty much a standard value in a lot of items that use a pot.

But you need to get a meter (DMM,VOM, Ohm meter their called by a lot of names). Select it to the ohms scale. There are a lot of different styles of meters but it;s going to be the same test. Set the meter to read ohms around 20K to start, then read between and 2 of the leads coming out of the throttle. Record your reading. Leaving the leads in the same place Move the throttle through its range and see what the meter does, does it increase/decrease or stay the same? (BTW if the readings are like only 5 or 6 then go down to a lower scale on the meter, then again some are auto ranging).

Do the same with the other wires.(Red/Green, Red/Yellow, Green/Yellow).

At some point you will have a high reading; this will be the value of the pot located in the throttle.


Scratch out most of this because the pot is basically just set up as an adjustable resistor.

Just measure between the 2 pins that are tied together and the one by itself. Fully CCW should have the highest resistance, and CW will have near 0 ohms.


This part is more for how a pot is set up in circuit.
((Now take the reading between the pot located on the board on the outside legs (the 3 that connect to the board) Turn the pot all the way CCW record your reading. Turn the pot all the way CW and record the reading.))

The higher reading will be the value of the pot and should match the one for the throttle control.

Looking more at the board I can see that the center and outside legs are tied together. This makes this a little easier. You still need to figure out the throttle. Then when you have that straightened out you will just configure the throttle wires in the same manner.

If you increase throttle it should read the same as the pot that is already there, so if with the servo tester you crank it CW to make the speed control increase speed and you already know (because you checked that earlier, with your or someone’s meter), which way the resistance needs to go in order to increase the throttle. Wire the throttle to correspond with what you found out while testing.


It sounds harder than it is. As far as soldering buy a flux pen you can find them at better electronics stores.

Jeff