Ross' bike pusher (trailer) project...

[rossfree]

Hi all,

I'm a newbie... and love to start things I never finish! Ha!

I'm dieing to build an EV bike but for getting my feet wet and keeping costs low I've gone the pusher route. I've not found very many projects using the pusher and that surprised me. Would love to see a video of someone using one. Any links?

So here's the plan:

MY1070 Motor 36volt 750 watt
(2) 24 volt 75 amp/hr deep cell marine batts from Wally-world
16" wheels taken from a CHEAP kids bicycle... the bearings won't last.

I plan to over-volt the motor with 48 volts. Only one wheel will be driven on the trailer. Two sprocket drive (no secondary reduction).

So far I have about $230 in the project. I still need two sprockets, chain, motor controller and BRAKES BRAKES BRAKES!!!

I worked on this on Saturday. Bought some additional steel at Home Depot, did a CAD layout at work and cut the steel on their band-saw, and tack welded the frame together when I got home. Not bad for a days' work!

Except I tacked the battery frame on the opposite side... have to move that. :-[

I've attached some CAD views below. They are VERY rudimentary but allowed me to get started.

The motor came with a #25 - 11th sprocket. If I wanted the pusher to go 30mph I would want a 4:1 ratio. I'm not sure if I want it to go that fast (not even sure it could push me). And this is where I would like some of your thoughts. I know I would like a larger sprocket on the motor anyway. Something in the range of 20 or more teeth to hold down wear and noise.

What ratio do you guys recommend for the sprockets and what size chain. Is #25 ok or should I use #35.

Second... can you recommend a controller that's reasonably affordable. The choices are daunting. I'll even consider one that might require modifications. I'm capable and have some electronics background. (this is a poor man's first project).

and Third... I have an inexpensive 26" bike with lousy breaks. Are there any reasonable generic kits for putting better brakes on bikes? I know this is a big issue for me.

Would love your comments and advise. I would like this to work first time out with a minimum of upgrades later... seems like I spend a lot of money replacing things that I should have just bought in the beginning.

Remember I'm a newbie... be gentle.

6" of snow just fell outside... I have a little time to work on this thing! Bother!

Ross

[diver]

hi, newbie here. I am thinking the same thing and using a old golf cart motor with a 48 volt programmable controller. i have the controller and the twist throttle for the handle bars. I will watch this close.
thanks butch

[Miles]

Hi Ross,

A chain running that fast will wear rapidly - it would be a good move to make an enclosure for it.

The smaller pitch #25 chain will run more smoothly and be quieter but will wear quicker than #35

How about 16t to 90t using heavy duty #25 chain? This will get you to about 25 mph...

Here's a reference on chains: http://www.roymech.co.uk/Useful_Tables/ ... chain.html

Source for sprockets: http://www.electricscooterparts.com/sprockets.html

Here's a power calculator (scroll down to 3rd version): http://endless-sphere.com/forums/viewtopic.php?t=538

Miles

[iberkt]

Source for sprockets: http://www.electricscooterparts.com/sprockets.html

This is good for the #25 sprokets but if you want to go up to the #35 they don't have much.

You can look at Robot Marketplace they have sprockets for #25, #35, and #40 chains.

http://www.robotmarketplace.com/marketp ... ckets.html

They also have the #25, #35, #40, #50 roller chains.

http://www.robotmarketplace.com/marketplace_chain.html

Just for as a guide look at the size difference of the chains
<a href="http://photobucket.com" target="_blank"><img src="http://i63.photobucket.com/albums/h140/iberkt/store_chains_lg.jpg" border="0" alt="Photo Sharing and Video Hosting at Photobucket"></a>

[vanilla ice]

You can get the chain speed down by using a 9, 10 or 11t sprocket on the motor, but I'm not clear on whether its worth doing this or not. The sharp turn the chain has to make is not good either.

I don't think theres such a thing as a generic cheap brake kit. I think pulling off a cheap donor bike is the most inexpensive way?

[Miles]

If you need something bigger than #25 I would use #219 chain and go-kart parts: http://www.accelerationkarting.com/219.html

Best to use a drive sprocket 16t or greater - as you mention, smaller sprockets wear the chain quicker and are less efficient - linear chain speed goes up with the drive sprocket size, though....

The Extron "kevlar" sprockets might be good to keep the noise down a bit...

[Miles]

Have you seen these two?

http://www.rqriley.com/b-pusher.htm

http://www.geocities.com/vancyclist/PT50.html

[rossfree]

Thanks for all the great feedback ya'll! I'm leanin towards the #25 for now with a 20 or so tooth sprocket. I'm kicking myself for not getting the 600 watt motor with gear reduction. That would have put this issue to bed right quick. But I wanted POWER.

I like the HTD timming belt reduction that some have done. A bit more complicated and added expense of the pullies, belt, bearings and framework.

Can someone recommend a reasonable motor controller for 48 volts and say 40 to 60 amps?

Thanks for the feedback!

Ross

[vanilla ice]

TNC has one for $35, but as others have pointed out the amp rating is likely overstated when you look at the components. Still a good buy I think.

For the easiest/cheapest way to do a one wheel trailer, I still think buying a used razor dirt bike from the classifieds, and using it as a base to build from, is a good option. Provided you can find a good deal on one, which shouldn't be too hard.

[iberkt]

TNC has one for $35, but as others have pointed out the amp rating is likely overstated when you look at the components. Still a good buy I think.

Do you mean this one?

http://tncscooters.com/product.php?sku=101210

LB37 - Technical Parameters
Rated Voltage 48 Volts
Rated Current 10 - 50 Amps
Rated Motor 800 - 1500 Watts
Rated Charger ≤ 3.0 Amps
Conversion Efficency 95%
Under Voltage Protection 41.0± 1.0 Volts
Speed Control Available
(Twist or Thumb Throttle) Hall Effect
Dimensions 11.1 cm x 6.9 cm x 3.8 cm

[vanilla ice]

Yes that one, and I think there is one more. The other one that says 100amps max is the one I meant that is probably not rated realistically. I was thinking about getting one of these TNC controllers too because my Currie controller doesn't work over 36v.

[wetdog]

chain
http://www.surpluscenter.com/powerTrans ... powerTrans
the 44 inch #25 chain is #25H and is loop, 88 inches of chain

sprockets
http://www.mcmaster.com/

[rossfree]

Thanks again for all of the feedback.

So... I've made a change. It was really bugging me that the motor would be turning at 2800 rpm, creating noise and wearing out my chain. Sooooo... I purchased a MY1020Z3 gear motor. A little less power but about 500 rpm output. Much nicer to work with. I really want a quiet ride.

I have ordered the $35 LB37 Yi-Yun 48v controller from tncscooters. com and a thumb-type speed controller.

Presently I'm trying to select the sprockets... I'd really like 30mph but don't know if I'm pushing safety/motor loads... etc. :-I I have a few hills but don't mind pedaling here and there. I'd also like to put a slightly larger sprocket on the motor. I think an 18tooth on the motor will give me room to play with speed up or down.

I'm looking to order Bulldog brakes for the bike. I've heard they work pretty well. Still... would be nice if the motor could do some braking for me and take some inertial forces out of the trailer. I might look into that.

I have really really cheap wheels for the trailer. I don't mind that but worry that the bearings might wear out prematurely. Any thoughts? I have my eyes open for a beafier 16" bike second-hand.

I hope to finish up the frame and get the wheels mounted tonight... still have to wait for the motor.

I've been trying to absorb the huge amount of information available in the forums here. It's daunting! I do wish the search engine would allow me to only search in the subject line instead of bringing back posts with my search word buried in some ten or twenty pages. Still... awesome website!

More pics as I get them...

Thanks for the feeback!

Ross

[vanilla ice]

I have a different unite geared motor, the 1018z, but I can tell you its loud. In fact my non-geared unite is much quieter at the same motor rpm, even though the chain speed is much higher.

Miles, whats the compatibility of the #219 chain, and what are the power limits? Is it the same pitch and roller diameter as #25 just thicker side plates? That would open up that selection of rear sprockets for the guys running #25. For example on motorcycles IIRC you can run 520 sprockets with 530 chain. I found this:

<i>The first two numbers in a chain size are the length and width of the link in increments of 1/8. So a 530 chain is 5/8 long and 3/8 wide, and 520 chain is 5/8 long and 2/8 (1/4) wide. It only gets a little complicated with say a 525 chain. This chain is 5/8 long and 2.5/8 (two and a half 1/8's) wide----which figures out to 5/16.</i>

[jerryt]

I believe it was Xyster who suggested using the Google search engine.

1.Use the "advance" search
2.Ttpe in what you want
3.Use the "domain" feature and paste in
http://endless-sphere.com (or any of the forum categories)
as the place to search

You may be able to fine tune it to what you are looking for