Safe's Electric Bike Project #003

Unbanned?

I figured I would check back here after the election and it turns out I was "unbanned" all the way back in the middle of October.

Ooops! :lol:

Anyway, I started up my threads over here:

http://www.ebikehub.com/forum/viewtopic.php?f=4&t=550&start=15

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My new battery has a different more compact design and I've done all kinds of changes over on #001 too.

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On #001 the new battery configuration basically gives me two sets of parallel battery sets. The SLA's are in parallel as are the NiCads. The effect is that the "runt" is always balanced by other cells. I've in effect eliminated the "runt cell problem" without needing a balancing system. I got 17 miles today and the SLA's ended at 12 volts... before the switch if I did that one of the SLA cells would be at 10 volts.
 
You should send Aussie Jester a PM and ask him to come back.
 
where did you get that sprocket for the unite motor? And how is it mounted? And that is regular bike chain, so regular bike sprocket on the unite motor?

Answers Safe.....Answers!
 
TPA said:
where did you get that sprocket for the unite motor? And how is it mounted? And that is regular bike chain, so regular bike sprocket on the unite motor?
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If you are talking about the "idler sprocket" I just took something laying around in the garage and welded up something and bolted it on. It's not even using a bearing, just a smooth metal on metal contact, so it will likely be replaced later on. I just wanted to see how an idler would work and it seems to be a good idea. The chain is a standard wide BMX chain. (super strong)

The stock sprocket is a 9 tooth regular chain size.

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Not All Things Perfect...

I've decided to build some better dropouts for the rear end of my bike. Today I tried making one that is really thick, in fact it's a full 3/8" thick which is three times the minimum I could get away with. The reason is that my 8-Speed has a slotted axle and it needs to be kept from spinning. Rather than use their little axle adaptor I want to custom match the dropout to the axle and make it super wide for extra strength.

The first try today is too heavy and I never completed it. This is the picture of todays unfinished work.

People need to realize that you can often use up a whole day just pursuing ideas and have to shift course at the end of it. (I've abandoned an entire summers work recently... Project #002)

Two steps forward, one step back. :roll:

Things only look easy after they are done. :lol:
 
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This time of year I can weld, but not do fiberglass. I have a couple other things that need to be done other than the dropouts. I need to weld on a rear disc brake mount and also a shifter cable mount. While I add the dropouts I'm going to be checking the alignment and really spend some time being careful and getting it right. The crank looks okay after all, so that's a relief. (maybe a little truing of the front sprocket) I need to get the motor and chain all aligned perfectly and become more certain of how I'm going to bolt on the motor. (there are a few possible options) Also, I still need to mount the battery which itself needs stuff welded for it so I can attach it to the frame. (one piece will be on the battery, and the other the frame)

So I've got plenty to keep me busy while the weather outside is bad...
 
Time Flies...

I couldn't believe it when I looked up and it was 4 o'clock already. :shock:

Anyway, this is the new idea I have for the rear dropouts. As shown the surface area that the axle touches is very large (about 3/4" wide at the moment) but I do plan on reducing that somewhat. The axle fits so tightly that I don't need a no-spin washer on the slotted axle. I used some angle iron that was really thick and I'm using the natural bend in it to form the bend at the axle. This should produce a very stong result and a heck of a lot more precise than if I tried to cut and grind it.

rear dropout 02.jpg
Tomorrow I'll look into welding this to the frame and then after that I'l be measuring where the disc brake mount needs to go as I whittle the dropouts down to a practical size. It's better to weld with the excess on there and then grind later because you get a smoother finish.

Getting the alignment tomorrow will be extremely critical because if it's off there is not as much that can be done to wiggle it back in line. There are plusses and minusses with having it precise. The plus side is that if you get it right it will be perfect every time you put on the rear wheel. The minus is that if you get it wrong then no matter what you do it's out of alignment.
 
I try so many new ideas and many do work, but every once and a while they don't. This one should work very well with a slotted axle because it makes the slot part directly touch the frame.

It has to be perfectly aligned though... that has me a little nervous for tomorrow. It's getting the alignment right that could make this a problem.

Sloppy construction prefers loose fittings.

:idea: This idea might be useful for hub motor people who are having troubles with their axles slipping.
 
Why do you need such strength around the axles? Since your power is transferred via chain your axle won't have any torque applied other than the force of the motor trying to shorten the chain length. You just need to worry about axle slippage, not spinning.
 
johnrobholmes said:
You just need to worry about axle slippage, not spinning.
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This is an eight speed internally geared hub, so that will amplify the torque on the axle. It's probably not a major issue, but I was switching from one type of dropout to the other anyway so I figured I might as well improve on the design.

AussieJester thanks. :)
 
Does the gearing actually affect the axle? I would think that it would just be transmitted from input gear to hub shell directly. Interesting thought though.
 
I don't think it would. Considering the kind of force a human's weight could potentially exert on the axle if that were the case would be far greater than even an overpowered X5 could produce, the normal dropouts internally geared hubs are made to fit on would snap in an instant.

Yeah, looking a few diagrams, there's no torque on the axle at all:

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Wait...now I see it. Stupid uncolored diagram.>_<

Still, that kinda seems like overkill...
 
There must be some benefit...the new dropouts could add speed going downhill :lol:

As Safe suggested, it could be a nice strong mount method for hubmotor ebikes or EVs. However, fully enclosing the axle seems even better, using a 'torque plate'.

As an aside, my Shimano Alfine 8 speed internal gear hub has little anti-turn washers and uses different types depending on the dropout used (horizontal, vertical, or semi-horizontal) but they are quite little and would not stop the axle from spinning if serious torque was applied to it.
 
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As I see it the modification was both needed and also overkill. The torque situation will rise, but not to such a degree as to warrant much extra strength, but it's not going to hurt to have a set of dropouts that are better.

It's actually less weight to do the "L" shape than to do a really thick dropout like I first tried. This is actually a fairly good idea if you happen to be using a slotted axle.

The negative is that if I ever want to revert to a solid axle it won't work because the width of the slot will be too small. (the width of the slot is maybe 1/4" rather than the usual 3/8")

So this ties me to a slotted axle solution...
 
Improvised Alignment Technique

I had a bunch of the angle iron laying around and decided to just clamp it all together and that gets the front and rear rims into alignment. I then welded the rear drops while the frame was in it.

It seems to have worked. :)

(trying to eyeball alignment is really hard because your mind starts to play tricks on you and my frame has a kind of odd asymmetrical rear wheel attachment so all the normal line of sight tricks don't work)

rear dropout 03.jpg
 
Went to the hardware store yesterday to get some bolts and nuts for the bike. One of the bolts turned out to have been wrong, so I went back again. That's about it. (a rest day) The weather is foggy and that doesn't give me much enthusiam to work on the bike. (it's always cold now... like 50 degrees in the garage)
 
Dusty Nasty Stuff

Grinding in a confined space is not a lot of fun when it comes to the dust. But it's better to at least be warm and surrounded by dust than freezing cold and in the fresh air.

Later I will be welding the disc brake mount. I was hoping that I could have done it along the way, but no such luck. It shouldn't be too hard though. (I'm thinking of a long slotted piece so that the disc can be adjusted in parallel with the dropout)

rear dropout 04.jpg
...it's a work in progress obviously. On the positive side the alignment looks very good. :)
 
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