Link's first ebike. (Now: The S-Go)

[Link]

So:

Smoker's hub (thanks, man ) arrived today, along with my Watts Up (or Doc Wattson?), and 25 pairs of Andersons.

The only thing that I didn't have was the wire, so I ran down to my local Radio Shack to see if they had some. They only had reasonably sized rolls of 16ga, and giant rolls of 14ga. Lamesauce. So, instead, I ran down to my local (not) Fry's and snagged some 12ga speaker wire. I got a pretty good deal: 50ft for $20. Works great. I also got some 14-10ga ring terminals for the batts.

Now, construction begins. Most (pretty much all) of what I was doing was rigging up the PowerPoles. I swear, I'm gonna slap the person that decided on the housing's inner dimensions. You CANNOT fit the stupid contact into the housing when you crimp it properly. After about an hour of of screwing with the crimping tool trying to make the damn things fit, I was like, "F*** this." Instead, I just stuck the wire in the contact and filled it with solder. I did it with a small torch, so I figured it would work fine. It did. Because the torch was much hotter than an iron, I could work quicker and not have the insulation on the wire melt. The finished product was just as strong (if not stronger) than a good crimp. I did this for like 6 pairs of PowerPoles.

I already had two new PowerSonic 18Ah batts, and I ordered two more from eBay. Not a good idea. One is so bad it only holds 11.25V open circuit and sags to less than 6V with a 4A load. I have my suspicions about the other. In any case, I'm going to have to run down to Orvac and grab another for $50. Oh well.

Anyway, the semi-bad one works, just not as good as my original ones. So, I made up some wires with the ring terminals to connect them all up in a 36V string. Simple enough.

Before I attached them, I stuck all the batteries together with mounting tape. You know, the crap that's practically invincible if you do it right. I witnessed its effectiveness firsthand when I stuck the last battery on wrong. I had to really work the thing off with a giant automotive flathead screwdriver. Oddly, I managed to salvage the tape and stick the battery on the right way. The wiring went on after this.

Now that all the connector business has been dealt with, on to mounting the wheel. I have worked on my bike quite a bit, so this was no problem. I was able to completely remove the old rim, switch the tire and tube onto the new one, and mount it up in less than 15 minutes. My only problem was front disc brake, which had to come off. There is no provision for a disc on the hub, but this isn't really a problem. I can put the front disc brake on the back, and there is a bracket for a caliper brake in the front.

I connect everything up and turn the bike upside down for a test. I turn the throttle and...

Nothing. Dammit. I twiddle the throttle and it suddenly jumps into action. WTF? I mess with it and the thing is spazzing out. So, I take the throttle in and have a look. I pop off the cover and peek in. From the way it was behaving, I thought there was a frayed wire in it. Luckily, it was much simpler to fix than that. The middle hall sensor leg kept touching the negative leg. I bent it back, and fixed it in place with some hot glue. (FYI: I use hot glue and mounting tape the way Xyster uses duct tape.)

Okay, so now I'm ready to test the thing. At 1:30AM. I stuff the batteries and controller, and Doc Wattson in my backpack. Heavy as hell, but still not as heavy as the schoolbooks I used to have to carry. The straps need to be shortened, but otherwise it's fine.

So, I take a test ride at nearly 2:00 in the morning with no front brake, wires are all untidy, I don't even have the other half of the throttle on, there's no torque arm, and it's like 40 degrees outside and I'm in thin pants and a tee shirt.

And it's friggin' AWESOME. Even at 36V, I can only really do much good for the motor during acceleration in the highest gear. Amusingly, the throttle is a little sticky. This is actually pretty cool, because I can just set it at a speed and cruise without messing with it.

All that's left to do is tidy up the wiring.

Now, a couple questions:

According to my Doc Wattson, my peak amperage draw was 33A, and the voltage sagged all the way down to 31V. For less than 2C, this seems a little drastic. Does this sound about right, or are my suspicions about that third batt confirmed?

Because of the way the forks and drops are shaped (it's a mountain bike frame), it basically has a built in torque arm. The drops are basically 3/8 in steel plates that vaguely resemble triangles. These continue several inches up the fork tubes. What do you guys think: torque arm or no?


Anyway, because the library's closed, I don't have work tomorrow. I'll see if I can get my friend from bowling to come over and bring his camera. I'm sure I can do it if I offer to let him ride :wink:.


EDIT: I am SO lucky I copied this before I hit submit. The site went down when I was typing, and I nearly lost all of it.

 

[Link]

Dammit, it's NEXT Friday the library is closed.

 

[TylerDurden]

The sag sounds typical (to me, anyway).

You might check out the desulfinator, desulfator, desulfinationerama or whatever they're called:
http://endless-sphere.com/forums/viewtopic.php?f=4&t=3264&p=48168&hilit=sulfate#p48168

might be cheaper and keep you flying in the future.

 

[Johnbear]

Great Idea on the mini torch for the andersons, I may try this! Ypedal also has a great post on crimping andersons.

 

[Dr. Shock]

Hi Link, good documentation. On the Andersons, you can get a tin of plumbing solder flux and dip the ends of the wires in, then stick them inside the andersons and move them back and forth a little. A good soldering iron will then heat solder enough so that the flux will make the wire act like a wick and suck it inside the connector just like sweating joints on copper pipe.

As to the torque arm, what I did on my bikes, one of which has dropouts like yours, was to cut steel tabs about half an inch longer than the dropouts and drill holes equal in diameter to the width of the narrow flat part of the hub motor's axles. Then, with a grinder, I cut from the edge of the tab to the sides of the holes. That turns the holes into slots big enough for the narrow side of the axle to slip in.

Once that's done, I wire brushed the paint off the dropouts, set the tabs against the outside of the dropouts, and brazed them together. You get really strong dropouts this way without ugly looking torque arms.

If it turns out that you made the slots too big and the axles start to turn, you can also fix that by laying down a braze bead inside the dropout and grinding and handfiling till the narrow part of the axle just slips in.

 

[Link]

I got ahold of some spray paint and cinch ties last night.

I sprayed all the wires and connectors (except the Andersons) that were exposed black. Looks MUCH better than before. The spray paint doesn't seem to like the speaker wire insulation, though. It should have dried a long time ago, but still feels wet. It isn't actually wet, but it doesn't adhere well to the insulation. I'll give it a day. If it still feels like that...well...I still probably won't do anything about it .

Cinched it to the frame as discreetly as possible. You probably wouldn't notice unless you were up close. All the wiring is hidden in with the brake and gear cables.

I'm still not sure whether or not it needs torque arms.

Now, instead of replacing the front brake with calipers, I think I'm going to work on a plug braking setup. I've been testing the motor's braking power and it's very impressive. At higher speeds it's probably just as good as the disc. Pretty sure I would be in danger of endo-ing if I slammed it on at full speed. I'd DEFINATELY need torque arms for that, though.

Everything (as permanent as it seems) is just temporary. I plan on putting the setup into a BMX bike and hiding all the wiring in the frame. I'll put the motor in the back. This will make the pedals useless unless I can find a freewheel, but I don't pedal much anyway 8).

I would think the torque would be incredible. At 48V, it's already pretty good in a 26" rim. In a 20", I should be able to out accelerate anything short of a Viper. At 72V (when I get the money for lithium), I might have to be careful of wheelies .

 

[Link]

Ah, dammit. I made my controller splodie.

Was setting up for a ride at 48V. The 48V pack's terminals are identical (it was designed for something else) and I had an Anderson-Spade adapter. I plugged it in, realized I hadn't done it right, and was reaching for the wire when I heard that fatal POP.

I took it apart. I had blown the positive side of the PCB's main power trace ( ). I didn't see any damage to anything else, so I fixed it with a bunch of solder (beefed up the power traces while I was at it). I tried it and...

Still doesn't work. Weaksauce.

So, since the caps still work fine (I think), I figure it must be the transistors.

I'm gonna have to get a new controller. Which is really lame, because I had some Andersons on it and I had extended the throttle cable.

I'll think about making this one into an Ubercontroller.

 

[fechter]

That's a pretty sure fire way to blow some FETs.

If you're lucky, the drivers and the logic parts will still be intact.

It needed 4110's anyway

 

[kbarrett]

According to my Doc Wattson, my peak amperage draw was 33A, and the voltage sagged all the way down to 31V. For less than 2C, this seems a little drastic. Does this sound about right, or are my suspicions about that third batt confirmed?

SLA sucks ... that sag is normal.

 

[Link]

According to my Doc Wattson, my peak amperage draw was 33A, and the voltage sagged all the way down to 31V. For less than 2C, this seems a little drastic. Does this sound about right, or are my suspicions about that third batt confirmed?

SLA sucks ... that sag is normal.

I don't know. Here's why:

The giant 18Ah SLA pack sags from 37V all the way down to 31V. That's about a 19.5% reduction in voltage at 2C.

The much smaller 4.5Ah SLA pack sags from 50V down to 41V. That's an 18% reduction in voltage, but that's at 7.3C.

So, the pack that's four times the size of the 48V pack is sagging more than these tiny batteries that are being run at slightly over their maximum discharge rate.

I'm going to have to test that suspicious batt separately to make sure. Also, it rests at 12.3V. The other two rest at 12.6V.

 

[Link]

Tested the batts.

Batts 1 and 2: Sags to 11V @ 3A.

Suspicious batt: Sags to 11v @ 2A.

Blah.

Also, the spray paint doesn't like the insulation. It's still kinda sticky-feeling.

 

[Ypedal]

gotta use special paint for flexible rubber.. otherwise the solvent is disolving the rubber and eating away at it.... IF it ever dries.. it will just flake off.. doh.. lol

 

[Link]

Yeah, that's what I thought. The paint was supposed to be for plastic, but I guess it doesn't like what the speaker wire is coated in.

The thing is, the other wires I painted (throttle signal/brake signal) are fine.

:?

 

[Toorbough ULL-Zeveigh]

I plugged it in, realized I hadn't done it right, and was reaching for the wire when I heard that fatal POP.

Hey you popped your first controller!
Congrats on becoming a man young Hyrule.

This is a rite of passage that will establish how deep in the veins the obsession is embedded.

 

[TylerDurden]

This is a rite of passage that will establish how deep in the veins the obsession is embedded.

...and how deep in the wallet.

 

[Eric G]

I think something is up with those batteries...or charger...
When I charge my 12volt/7ah sla they charge up to 13.35 volts. An hour or so later they're 13.26volts and after sitting for 24 hours they'll drop to 13.22volts.When I hook up a 12volt RV light bulb to them they'll drop down to ~12.8 volts.(the current draw from the RV light bulb is 4.25 amps).
As far as I know sla batteries should be around 13 to 13.5 hot off the charger.

What kind of charger are you using?

Eric

 

[D-Man]

Battery discharge curves suppose to look like this if the batteries are new and charged. Are your batteries new or used?

 

[ngocthach1130]

...and how deep in the wallet.

How true. Last time i heard that pop, I dunno if i lost consciousness and moved by instinct or what. When i came to, another controller was bought, as well as a dozen IRFB4110 Mosfet, Schottky diode, Capacitor, resistors, was racked up on my credit card. It's terrible how tiny components can add up. These days, for minor replacement parts like blown gate resistor, i just stop by the stock room of the electronic lab at my school and social engineer some away from the attendant.

 

[Link]

Yeah, I did kind of find the voltage drop a little steep.

Two are pretty much brand new (bought them ~6 months ago and they've been sitting around fully charged) and one is new old stock (by like 6 years). The new ones have the sticker: QA/08. The new old stock one says: QA/02.

I'm using a Vector 2/4/6A charger to keep them in balance and a 36V charger made by YiYun, the same guys who made my controller. They seem to do a good job on what they make. The chargers are used on both packs, so it's not those.

Resting voltage hot off the Vector charger is just over 13V for the new ones. Something like 12.7V for the suspicious one.

This is a rite of passage that will establish how deep in the veins the obsession is embedded.

...and how deep in the wallet.

Tell me about it . I got paid today, so I'm gonna go look for a suitable BMX bike tomorrow. Then find some spokes. Then upgrade my controller. Then get another motor (dual wield BD36! 8)).

 

[kbarrett]

Tell me about it . I got paid today, so I'm gonna go look for a suitable BMX bike tomorrow. Then find some spokes. Then upgrade my controller. Then get another motor (dual wield BD36! 8)).

And then you go compare what you have spent to the cost of a used +500cc motorcycle on craigslist ... and seriously consider beating your own head against a post ...

 

[Link]

Tell me about it . I got paid today, so I'm gonna go look for a suitable BMX bike tomorrow. Then find some spokes. Then upgrade my controller. Then get another motor (dual wield BD36! 8)).

And then you go compare what you have spent to the cost of a used +500cc motorcycle on craigslist ... and seriously consider beating your own head against a post ...

...then you see that gas has gone up AGAIN and not feel TOO bad.

 

[ngocthach1130]

I don't really compare my ebikes to my car or other transportation since i think of it as a hobby rather than alternative transportation. It'd be hard to ride my bike in 20 degree F weather here in the northeast right now. Even if i were to compare i would have to factor in insurance, registration, license, gas, and maintenance. That would drive the cost of ownership of these gaser way up. I'm sure electric bike have maintenance too, but since i'm not very familiar with motorcycle or car repair. It's cheaper to do self repair on the bike.

 

[Drunkskunk]

Tell me about it . I got paid today, so I'm gonna go look for a suitable BMX bike tomorrow. Then find some spokes. Then upgrade my controller. Then get another motor (dual wield BD36! 8)).

And then you go compare what you have spent to the cost of a used +500cc motorcycle on craigslist ... and seriously consider beating your own head against a post ...

...then you see that gas has gone up AGAIN and not feel TOO bad.

I'm not doing this to save money. Its a hobby. and I'm not saving money, either.

My batteries cost me $850, I get an average of 25 miles out of them. They are good for 500 cycles. Thats 12,500 miles total range or 14.7 miles a dollar.
Thats roughly equil to 40mpg on a car, but a car can do that three times as fast in town, and have an AC, or a heater, and room for passangers and cargo.
Heck, my Durango with a 350 HP Hemi gets 20mpg, and can haul my bike, 7 other passangers, a weeks worth of camping supplies, and a boat.
Thats 350% more power for only twice the cost in fuel. I can carpool places, and by taking a pasanger, I'm dead even on the cost of the bike for transport. I can haul 6 months worth of food in the truck for one grocery trip, if I chose. On the bike, I'm lucky if I can haul everything I need for one meal.
And have you ever tried to pick up a Date on a bicycle? Or make out in the back seat of a Schwinn?

Its a hobby, not a solution.
But its a whole lot of fun!

 

[Link]

Uhh...

No comment.

 

[Jay64]

And have you ever tried to pick up a Date on a bicycle? Or make out in the back seat of a Schwinn?

*forty year old virgin*Do you have a big trunk, cuz I'm gonna put my bike in it. */forty year old virgin* :lol: