Dirt Cheap DIY eBike

Show off your E-bike creation here.
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RebelRider.Mike   100 mW

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Location: Washington, US

Re: Dirt Cheap DIY eBike

Post by RebelRider.Mike » Mar 01 2019 4:13am

Finally got my 3A fuses in the mail!
Still working on the next video, but in the meantime, I took a bunch of pictures.



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Organising cells via repacker.



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Ready to solder!



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First two series are connected.



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The tape is there to make sure I don't solder the wrong cells.



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The left side is done. Now it's time for the right side, which will have fuses. Here I've got 3 of the 8 series done.



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Done! Still waiting on the BMS, and I just realised I don't have any 8s balance cables. I'll have to order some. Soon it will be time to build a protective box.


In other news, I have 2 fans, 2 heat sinks, and some thermal compound for the motor. I'm also putting together a cowl to move the air across the heat sinks more effectively. It looks like the freewheel I bought will be adaptable as well. I have an unrelated project I need to finish up this month, before I can work on that though.
Mike

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RebelRider.Mike   100 mW

100 mW
Posts: 44
Joined: Oct 13 2017 4:05am
Location: Washington, US

Re: Dirt Cheap DIY eBike

Post by RebelRider.Mike » Mar 03 2019 2:50am

A short video on how I test cells:
Mike

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RebelRider.Mike   100 mW

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Posts: 44
Joined: Oct 13 2017 4:05am
Location: Washington, US

Re: Dirt Cheap DIY eBike

Post by RebelRider.Mike » Mar 09 2019 3:04am

Here's part 6: An intro to the bike I'll be using, a ton of battery design, and a little about the actual real life battery I made.



The BMS board is finally in the US, so I hope to get it next week some time. I've also got connectors, threaded rod, shrink wrap, and nylon bits. I'm about ready to start building the box!
Mike

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RebelRider.Mike   100 mW

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Joined: Oct 13 2017 4:05am
Location: Washington, US

Re: Dirt Cheap DIY eBike

Post by RebelRider.Mike » Mar 23 2019 9:49am

I spent some time refining the gadgets I'll have on the ebike, and how to wire them up:
Image

I've decided to add an old bicycle headlight I fixed up, though I won't be powering it from the main battery. I also found this cool dual display, dual probe temperature gauge. I'll use it to monitor the temps of the motor and battery box while I ride.

Yay, more video:


Seems the motor and battery are the vast majority of the work on this bike. I'm back on the motor, fitting a freewheel cartridge and a roller bearing. Also a couple miscellaneous things. I've actually got a lot more footage to go through. I intended to make a final motor video ending with it on the bike and running, but that would have been way too long. But I'll give you a spoiler: The motor is on the bike and it (mostly) works! :)
Mike

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RebelRider.Mike   100 mW

100 mW
Posts: 44
Joined: Oct 13 2017 4:05am
Location: Washington, US

Re: Dirt Cheap DIY eBike

Post by RebelRider.Mike » Mar 30 2019 5:13am

Finally got the motor mounted to the bike:
Mike

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wturber   10 MW

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Re: Dirt Cheap DIY eBike

Post by wturber » Mar 30 2019 10:51pm

The driven sprocket on the wheel seems to be wobbling in the video - like it isn't square to the hub. That may be the main cause of the chain skipping. There may also be some flexing of the rack that the motor is mounted to. So anything you could do to make that more rigid might help. And finally, adding washers or shims to fine tune the distance between the motor and the drive sprocket might also help by letting you make small adjustments to the chain slack/tension.

One last note. You may want to test how hard it is to throw your leg over that motor when you mount the bike. Adding the milk crate to my bike forced me to change my standard motion. I now have to hitch my leg up and drop my knee down as I swing my leg out - sorta like a high jumper clearing the high bar - in order to clear the milk crate and get over the seat.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

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RebelRider.Mike   100 mW

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Joined: Oct 13 2017 4:05am
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Re: Dirt Cheap DIY eBike

Post by RebelRider.Mike » Jan 14 2020 3:58pm

Refurbishing my motorcycle has slowed down a bit because of winter weather. I may work on the eBike again.

I made this video a while back, but forgot to publish it. It's basically a lecture on how I'm keeping my battery safe. For all you folks who already know about safety features, this will probably be really boring. But for anyone considering building a battery and you're interested in making it relatively safe, I hope the information is helpful.




Not every battery would need these features, and some batteries may benefit from features I've not included here.
Mike

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