MB-1-E Part Fourteen: The day after ...

MB-1-E's picture

Yesterday was my first E-bike ride ...
What a blast!

Although not very refined looking, this is how the MB-1-E looks with all the elements.
The wiring is not too pretty to look at, but it perfomed without any glitches.
You can't see it well here but I do have a DPDT switch wired in so I can charge at 12V and run at 24V. It also has an off positon.
This adds to the complexity of the battery wiring, thus a lot of wires in a small space.
I used quite a few wire-ties to make sure it was "one with the bike", as I like to say. I don't want a branch snagging any wires.

I'll place something over the battery terminals and the mass of wires eventually, so it looks a little better and insures that they are well protected ... but accessible.

I really like the placement of the batteries now after several tries, I think the weight (although about 48 lbs. heavy) is well centered and low enough so that once rolling it's easy to manouver and doesn't feel top heavy (just heavy). In a future build, I might consider NiMh's but it would be expensive to get 72Ah at 12V or actually 36Ah at 24V, which is what I have now. I'm glad to report that the batteries are "One with the bike", rock solid and don't even want to move.

The V-belt and pullies will be replaced by a 5mm pitch x 15mm wide HTD timing belt and a 16 tooth drive, belt sprocket with 62 tooth driven, belt sprocket.
This will take some machining as the stock bore of these is smaller than my motor or jackshaft diameter.
Since machining a keyway is quite costly, I will probably bore the sprockets then use machine screws to mount it to a pulley that is already keyed. I think the shafts are plenty long so I can do this and the end result should be plenty strong.

As you all must know by now, the controller fried on my first day. It's a 100A max. 30A continuous controller. There are some modifications that I will make to insure that I reduce the load, and will try the same controller again. I don't really know if the controller was rated higher than it's actual capacity or if my design was flawed, but I have some ideas that should help.

First: I will gear the bike down from it's current 10:1 ratio to 12.68:1. This should really help although I will lose some top end speed I'm sure.
I think the motor will be more efficient if it is running at a higher RPM.

Second: I will incorporate another heatsink that Sturdly gave me (Thanks Sturdly, I should have had it on there the first round ... live and learn). I suppose I could even incorporate a blower to kick-in when I'm moving slow and there is a chance of overheating. Maybe water cooled ... like the CPU cooling efforts of some back when we were overclocking our 486's. We shall see ...

Third: I have an awareness of the limits of the controller now that I didn't have prior to the BBQ.
With this in mind, I will tend to know the signs and back off if needed.

Fourth: I probably need some fuses that will blow before the controller has a chance to. I'm not sure where within the system I should have them but maybe someone more electrical than I can help me there.

Here are some pics of how the bike sits now.

I threw in an interlude, some pics of my wolfdogs.
When I get the ebike perfected, they will be running with me (or at least the dad Timber and his son Lobo will. Ivy is a bit more timid and likes to stay home with my wife.

FRONT VIEW (I'm pleased that the conversion doesn't change the appearance of the bike too much)



BATTERY WIRES (Made from a 12 ft long set of jumper cables)

And now the INTERLUDE (OT)...

TIMBER (The dad - we've had him about 10 years now)

IVY (The mom - she's almost 4 years old, hanging out under the bushes)

LOBO (One of Timber & Ivy's pups (she had seven) - he's almost two and the only pup we have left)

In Loving Memory of SILVER (Silver died earlier this year ... he was Lobo's brother and pal)

As you can see, they are all losing their fur by the handfulls, adjusting to the Summer weather ... we can brush them and one day later they need brushing again.

They do love to run, I think the backroads here will provide us all with some fun times.

before comments


Can you tell my why you don't harness the animals and let them pull you, Sgt. Preston style? Sorry to hear about losing Silver. Pets are always hard to part with.

Wow, you sure have a lot of shrink tubing to install :D. Glad it's you, not me.

If you're having a hard time finding and need some bigger heavy duty stuff PM me with diameter(s) when shrunk and roughly how many feet. I have some left over that should fit and could be donated.

Makes me nervous seeing all those amps so close to the family jewels, just looking for the path of least resistance.

Chin up and slog on my friend.

MB-1-E's picture

Can you tell my why you don't harness the animals and let them pull you, Sgt. Preston style?

The thought has definately crossed my mind.
I do take a pair skijoring on occasion.
(For those of you not familiar with the sport, skijoring is harnessing the dogs and letting them pull you on cross country skis with a stout bungie section between you and the pups)
It's a bit wild since I haven't really trained them on a regular basis ... but we all have a heck of a lot of fun.

I'm just not sure I want to try it with a bike though ... snow is much better to fall on. :D

I don't know if you can really see it or not, but I do have clear heatshrink on each of the lugs, not over the connection screws though. I also have extra layers of thick, tough plastic insulation wire-tied over any place where a wire could potentially rub on a terminal. I've been quite conservative in this regard, 72Ah DOES have considerable potential ... I agree! (those would be good spots for the super-duper, Boing recommended, RTV as well)

I will probably have a need for more heatshrink as I make some improvements, I'll certainly keep you in mind. It gets pretty darn expensive getting it at NAPA. :jawdrop:

I'll keep you posted on how the warranty issue goes ... manufacturers are usually pretty good about these things and they do state a 12 month or 2000 hour guarantee on their "fully protected" DC motor controllers.
I'll tell you what though, if the new one starts to cut out "at all", I'll stop, analyze the situation, figure out exactly why and give it time to cool down.
I think with the several changes I'll be making it will work fine.


Electric - Bridgestone MB-1 Mountain Bike
Icon Photo of lighning striking Eiffel Tower Jun 3, 1902, taken by MG Loppe'

Dave B

<a href="http://visforvoltage.org/book-page/996-mountain-bike-conversion-24v-3-4h... - Bridgestone MB-1 Mountain Bike</a>

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