Project E-Mini Bike, Using an Outrunner
 

Well, I'm already head deep in this project. I got it a couple days ago and since the stock battery was dead, I decided to go right at it with the brushless stuff. Should be faster then the stock 150w brushed motor. Using the stock gearing for now; It's probably overgeared though. It's a 250kv HXT outrunner made for 36v, running on 24v sla with a supersimple controller. Might do a 9s lipo in the far future.:intello:

I got the bike for $30 plus $8 gas. In the honda I got 32mpg, pretty good for the thing. It's got a 2.2 i4 iirc. Average is about 28-29.

The first major problem came up (besides the shotty pinion boring and filling up the damn rear tire) and it's the throttle. I have a servo tester here and it really sucks to use. I want to use the twist throttle that's already on the bike. It has 3 wires and I really want to replace the pot on the servo tester with the thumb throttle. Let me know how I can do it, please.:whip:

It looks sweet with the body on, I'll get some body on pics when I'm done.

chassis after stripping
http://i345.photobucket.com/albums/p...1/S7301952.jpg

motor and mount
http://i345.photobucket.com/albums/p...1/S7301960.jpg

servo tester
http://i345.photobucket.com/albums/p...1/S7301962.jpg

http://i345.photobucket.com/albums/p...1/S7301961.jpg

want to hook up this throttle,, Guessing green is ground, yellow is signal, and red is +
http://i345.photobucket.com/albums/p...1/S7301963.jpg

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

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

Also had a idea for the throttle:
Get a twist throttle for gas conversions (I ordered this one: http://cgi.ebay.com/ebaymotors/ws/eB...m=360176795063 ) and make a arm for the pot on the servo saver, then attach the throttle cable to the arm.

No Way!:lol: That's awesome... Honda Minimoto?:party:

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?:neutral: 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..:angel:

Might have to do something like that. I'll either use a bike handle or mod the thumb throttle to turn the pot. Hopefully I can just solder this on..:whistle:

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.

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

Those little bikes usually come with a nozzle extension hidden inside one of the handlebar grip ends. Pop 'em off and see if it's still in there. Also.. for the $$, there's much better ways to go about this albeit not brushless..

Tired out the ohm thing. Never could get the reading to change by moving the throttle...

20k
Black/Red (contacts)

Green/Yellow 7.64
Green/Red 9.08
Red/Yellow 1.68
Yellow/Red 1.69

200k
Black/Red

Green/Yellow 53.2
Green/Red 55.1
Yellow/Red 1.6
Red/Yellow 1.6

2000k
Black/Red

Green/Yellow 433
Green/Red 433
Yellow/Red .1
Red/Yellow .1

None of the other wire combinations got a reading except the ones listed above. I think I may have a different type of throttle then what's required?

to find the overall resistance rating put the probes on the outer pins on the pot. that is your Pot resistance. you need a pot with the same resistance for it to work properly.

Looks like tht throttle is a 10K pot, and may be broken, if the reistance does not change while rotating the grip.

Yuo didn't give specs on the pot located on the servo tester.

Jeff

With the pot on the servo tester, two leads are together and when I put the probes one way I get 5.29 and if I reverse them I get 11.49 while on 20k.

I might take apart the throttle thing to see what the problem is.

Ok you are getting different readings because you are "reading" other parts in the circuit. The 5.29K would indicate to me that's a 5K pot. Do one more thing. Place your leads where you read 5.29 and adjust the pit and see if the resistance starts to decrease.

Jeff

The pot on the servo tester works fine, it decreases when I turn the knob.

Theory with the throttle: I think it has a few levels of throttle position. All the way down is neutral, then when you push it a little it goes to "step 1" which is something around 1.68, then it goes to "step 2" as you increase throttle some which is probably either 1.69 or 7.64, and so on. It doesn't use a pot but rather different resistance switches to give a few speeds rather then a full spectrum.

So now I'll try to incorperate the pot into the mechanical throttle mecanism.

That would probably be best, sounds like the old mech. speed controls.

Jeff

Using just the servo tester for the throttle, I am pretty sure I am geared too high. Minimum throttle is probably 10 mph. Got a broken pin and some good, long squeals from my motor too. I'll look into gearing down with new gears...

What would I need, 3/16, #35 roller chain? Where do I get sprockets? Could I weld a gear onto the freewheel after cutting the stock plastic pos off?

Mcmastercarr.com

You can get Sprockets from a local industrial salvage yard. Yea you can weld a sprocket to the freewheel. You can also try sprockets for #25 chain, will be easier to get the reduction you need...

Looking around I found a 90t #25 sprocket ($20) I can use with my 13t "pinion", or I can get a "pinion" from mcmaster car with set screws ($5)... Chain will cost me $10 from mcmaster, I need probably 2.5-3'. It would be nice to get all three Items ($35). I'm working 16 hours this weekend so I could get this stuff as a reward...

I found a 5k ohm sliding pot that could be hooked up into a throttle pretty easily. Just put a small rubber band on it (gluing the ends) to return the throttle to neutral and I'm set..

http://www.electricscooterparts.com/images5/POT-5KS.jpg

Can you give me an example of an "industrial salvage yard"? I live by a city of 200k and there's nothing even close to that around here... jesus it's probably 400 miles to a place like minneapolis or Kansas city. :angel:

Got a link to this sliding pot? I get alot of entertainment out of electrifing/motorizing things, so I'll probably so a lot of these conversions, and that would come in handy. Oh also, nice find on the #25 stuff! The place I went to doesn't have a website, but it is basically a place that buys stuff from industrial companies that are going out of biz usually, with a old guy behind the counter, where you just go, pick out what you need out of piles and shelves of crap, and the guy gives ya a price (usually real cheap) and you walk outta there..

There's a tool place kinda like that around here... But the stuff isn't strewn about and the prices aren't quite as low.:eyes:

The 90t sprocket I found at monster scooter parts - http://www.monsterscooterparts.com/9...-scooters.html

I found the pot at electric scooter parts .com under the throttles section - http://www.electricscooterparts.com/throttles.html

they also have the 90t sprocket but it's $10 more. Everything is a little more expensive here then at other places. I'd go with mcmaster for everything, but they don't have the 90t sprocket.

I'll take the wheel to a bike place and see if they can screw off the old freewheel. I have anoter freewheel I can bolt a sprocket on off of another scooter. It has a 72t #25 sprocket, but I'll need a little bigger one. Want to gear for about 20-25mph on 24v, and the 72/11 combo I have now will get me 27mph, too much.

New Plan
I can get a 9t sprocket from mcmaster carr, use my 72t sprocket, and add some chain to the mix and then I'll have saved $20 on the 90t sprocket. How much do you think a machinist would charge to machine a 1/4" hole to a 10mm hole?

sprocket is part number 6793K1 and chain is part number 6261K283. McMaster Link is 6261K108

What pitch is your 72t sprocket?

#25, 1/4". It's from an old electric scooter. I sent an email to a couple machine shops getting quotes for modding a sprocket.

Cool. Is the shaft on your motor 1/4" though?

Assuming your motor has a 8mm shaft, you can get this sprocket:
https://sdp-si.com/eStore/PartDetail...63&GroupID=649

My shaft is 10mm. The #25 sprocket from on old scooter I had has the same shaft, so it must be pretty common in china.

http://www.hobbycity.com/hobbycity/s...idProduct=5144 - This is supposed to be my motor, but it looks longer and has some screws in the bell now. The shaft might be 12mm on the newer ones... But mine is 10mm.

OMG. I test drove it today. You have to be rolling at 2-5mph depending on battery charge to make sure the motor doesn't lose sync at start up. That's one of the problems of being overgeared...

The brakes didn't do much. They are crap because if I tighten them any more they rub a little...

Once you got going, it was a great ride. First, top speed was 10-15 mph. My friend could sprint beside me. We charged up the battery for an hour and a half, and top speed was MUCH higher. Probably 25+. It's faster then it sounds on a little bike like this, especially with no brakes. I'm charging the battery right now, and I'll see if I can try it out tomorrow with a full charge. That will be fast.

Temps were averaging 90-105 on the motor/controller and about 90 on the battery. I don't think I'll be running 36v on this motor any time soon.

I am still planning the #25 chain conversion. I'll re-do the rear wheel so that will be smoother, and replace the off-centered pinion. The belt is already showing signs of wear and the whole setup is iffy. The chain will be nice... Can't wait.

I'll post up a video once I get a chance to open it up will full batteries. That might be tomorrow, monday, or tuesday.

And Ian, I hope the detta comes tomorrow; didn't get it today.

NICE! You got it running. About the detta- I wasn't able to get to the post office till the day after I said I would. Sorry about that- it should come today.

Hey that's fine, I got it today. A good gift after getting up 4 hours early and working 8 hours.:sleep:

I will order the gear and chain from mcmaster soon. Then it should be a really tight bike.:intello:

Now just get yours done and we can compare them. :whip:

Well, yours is 10mm, so hopefully his will be larger... :rofl:

Doubt it.:na:

I messed around with the settings on the esc a little. I don't know what the timing was set on before, but I changed it to 15* for 10-14 pole outrunner motors.

I have the option of 1* for 2-4 pole inrunners, 7* for 6-8 pole motors, 15* for 10-14 pole outrunners, and 30* for 10-14 pole high rpm outrunners. If one of the other settings would be better for me let me know. Startup is much better now though, but still not perfect.

Since this setting change and the improvement on startup, I think I'll just run my 11/72 gears I have now geared for 27.27 mph. I'll see how it goes and I always have the option of gearing down later. Right now I'm geared for low 30s.

Since I don't need the sprocket from mcmaster, this will allow me to try and find the chain locally to save some money. Would your standard lowes/home depot have #25 roller chain?

I dobt it would. You could probably pick some up from a e-scooter store on the cheap, though.

Placed an order at electric scooter parts dot com. It was a little more expensive then I could have found, but they have the pot there so I went with it. I hope it arrives fri-sat. I'll post some pics. I can't wait!

Code Item Qty Price Total
POT-5KS Sliding 5k Ohm Potentiometer (POT-5KS) 1 $4.95 $4.95
CHN-25140 140 Links Of Standard Duty #25 Chain With Master Link (CHN-25140) 1 $16.80 $16.80
CHN-25ML #25 Chain Master Link (CHN-25ML) 2 $0.95 $1.90

Sweet man!
I got the elecs in for my e-bike today, I'll make a thread tonight probably.

Oh yeah, saw you're doing a brushed bike. I was working on my General Lee before this popped up, and I hope to finish it or do a different bike in the future. It will be transportation oriented; not recrational. I don't know what the heck I'm going to run; brushed or brushless....

I'm getting some experience under my belt with this pocketbike first. :yipi: Can't wait till it's done. :whip:

Out with the old, In with the new. The old freewheel had to be completely dissasembled to be removed, so I'm not sure if I'll ever be able to put it back on. It's a pos anyway, so I guess I don't need to worry about that now! 8)

Awaiting chain, a few bolts, and a new throttle pot. Can't wait. Hope it's here by the end of the week.

Sorry for the blurry pics too; my $70 camera sucks.

the old freewheel
http://i345.photobucket.com/albums/p...1/S7301986.jpg

http://i345.photobucket.com/albums/p...1/S7301987.jpg

http://i345.photobucket.com/albums/p...1/S7301988.jpg

http://i345.photobucket.com/albums/p...1/S7301989.jpg

I can fill up the tire now!!
http://i345.photobucket.com/albums/p...1/S7301990.jpg

http://i345.photobucket.com/albums/p...1/S7301992.jpg

just awaiting chain
http://i345.photobucket.com/albums/p...1/S7301993.jpg

here are some other pics I have. The guy on the bike is my friend troy, I am about as big as him if you're wondering. I'm 5'7".

http://i345.photobucket.com/albums/p...1/S7301985.jpg

http://i345.photobucket.com/albums/p...1/S7301966.jpg

charging setup. I just swap out the series connector for a parrallel connector and charge the packs with a car battery charger at 2a. I'm not sure if the batteries will take 6a which is the next step up. Let me know if they can. They're 10ah 12v sla batteries.
http://i345.photobucket.com/albums/p...1/S7301970.jpg

Got some stuff done today. I hope my chain and pot come in the mail soon...

http://i345.photobucket.com/albums/p...1/S7302000.jpg

[the chain in the background isn't long enough]
http://i345.photobucket.com/albums/p...1/S7301994.jpg

http://i345.photobucket.com/albums/p...1/S7302001.jpg

http://i345.photobucket.com/albums/p...1/S7302002.jpg

Better esc location and mount. It's solid as a rock.
http://i345.photobucket.com/albums/p...1/S7301995.jpg

I also spent 89 cents on nuts and bolts and bolted up the rear sprocket to the freewheel. I need to put on the chain and hook up the pot and she's done for good.

is that the hobbycity 85a-95a esc? i was using one for my savage conversion and it worked better and more reliably than other other esc i have ever had.........until i damaged it in a crash lol.

That looks awsome! I have wanted to do something like this for a while but with a go cart. I have a huge 24v motor. its about the lengthe and width of a truggy chassis. but its only 900rpm. Can i have a list with links for your electronics?

i think someone here has a signature that works perfect for your dilemma.

"when in doubt, overvolt it" try running 48v or 72v. if not, just gear it to the moon.:intello: