Lord Gruntfuttock

LG's ebike prob-never-happen project

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28 minutes ago, Lord Gruntfuttock said:

Awesome project idea! 

Assuming you're riding Invercargill, front hub drive will be sweet. They don't love steep up hills. There's a place in Russia that seems to have success sending li-ion cells. Will see if I can remember where. Do the hub suppliers also sell a speed controller? Helps get rid of the few compatability issues that can arise. Awesome project! 

 

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Hard to say. Depends on the 18650 cells. The 10S gives me 36V, but only have 3 in parallel so if I have 2600mAh cells that'll give me 7.8Ah. 3400mAh cells would give 10.2Ah.

I don't know what the 350W rating actually means (constant, peak?) but assuming face value figures, it will draw around 10A at full noise, so should run for around an hr at that. Real world figures will be far different I expect...

Of course more batteries is better, but there are huge cost, size and weight considerations. 48V may have been a better option too, I just went for something not too bulky I can hopefully conceal in a saddlebag or similar. And the no-solder battery pack kit came in that 10S 3P configuration. (I'm fine with soldering but apparently it can damage the cells and spot welding is better)...

If I had access to unlimited cells and a spot welder I would look at different methods...

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Don't see why not, as long as correct voltage motor. I even looked at using my DeWalt tool batteries... :)

There's a few calculators out there, this is a screenshot of electricbikesimulator.com.

Electric_bike_power_calculator_and_3_more_pages_Microsoft_Edge.jpg

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They are 3.7 nominal voltage per cell so would be 37v. I get mine from revolectrix. They happily ship them and are pretty good price, wouldn't even need the fancy high discharge rate ones

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12 hours ago, Lord Gruntfuttock said:

Hard to say. Depends on the 18650 cells. The 10S gives me 36V, but only have 3 in parallel so if I have 2600mAh cells that'll give me 7.8Ah. 3400mAh cells would give 10.2Ah.

I don't know what the 350W rating actually means (constant, peak?) but assuming face value figures, it will draw around 10A at full noise, so should run for around an hr at that. Real world figures will be far different I expect...

Of course more batteries is better, but there are huge cost, size and weight considerations. 48V may have been a better option too, I just went for something not too bulky I can hopefully conceal in a saddlebag or similar. And the no-solder battery pack kit came in that 10S 3P configuration. (I'm fine with soldering but apparently it can damage the cells and spot welding is better)...

If I had access to unlimited cells and a spot welder I would look at different methods...

@Ghostchips made a battery tab spot welder once

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22 hours ago, Lord Gruntfuttock said:

I don't know what the 350W rating actually means (constant, peak?) but assuming face value figures, it will draw around 10A at full noise, so should run for around an hr at that. Real world figures will be far different I expect...

350W tends to be the constant rating, and a pretty conservative one at that. The 350W motors we run will hit 750W under acceleration. We run 24V and 40A fuses...

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13 minutes ago, Lord Gruntfuttock said:

Good info, cheers. I'm flying blind here, just bunging things together to see how it goes... 

Our 48V 1kW motors actually run a 2.2kW speed controller, again with a 40A fuse - not great for the longevity of the motors, but good for performance! We don't have pedal assist, so the bit of extra oomph to get you off the line is a winner.

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Did an inventory of bits in the shed yesterday. Got a new set of Sun Ringle CR18 26 x 1 3/4" alloy rims looking for a home...
PRZ90R8.jpg

And a 1972 Sturmey Archer AW 3-spd hub that looks ok...
qgynFZu.jpg

And some packages arrived today, batteries from Dunedin...
oEtT1EO.jpg

Think these are pretty good spec, Panasonic 3200mAh...?
Ovmecy7.jpg

And most exciting, hub motor has arrived, 11 days from order, pretty sweet...
MElhs6o.jpg

Except, it's bloody 48V. Checked and def ordered 36V. Wouldn't be a major but I've ordered BMS, batteries, battery holder system and charger all for 36V configuration. Have notified Mr Ali, will see how we get on (could be a win, could be a PIA)...

It came with this fitting from motor (3 power and 6 Hall effect connectors?) guessing there's a socket to suit, don't think the cable included fits, only had a quick look. [edit, yep has appropriate connector, was looking at wrong end)...
GEB6G3M.jpg

Good thing is I can measure up hub for spokes, looks like 5mm wide flanges, 42.5mm apart, 119mm flange diameter (haven't looked at any offset yet). The Sturmey AW is 65mm flange diameter and 27mm from centre to each side. So until I hear back from Ali I guess I can order spokes and look at controllers...
 

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Worked over the weekend, but did some foraging for bits amongst the junk at home (after seeing the stupid prices on trademe for vintage bits). Pulled this ratty seat off an old Raleigh in the shed...
QvQtBQj.jpg

And looked like it would suit the 70s? vinyl Brooks cover I scored for $10 on the tard some time ago...
L2gZGC2.jpg

Sweet...
OpExwGT.jpg

And on the spare Ali seat post I bought for my Raleigh Twenty, was too short for that but perfect for this...
7BJN5ag.jpg

After I cleaned up the hub I found some other bits I had squirreled away for just such a project, thought I had a shift lever somewhere, glad I didn't buy another one...
9kpQvZt.jpg

Still need some pedals and a carrier, but things coming together... :thumbleft:

[Edit] Found a couple of carriers on donor bikes I could use, and have ordered these...
BBA7TqU.jpg

MKS for $19US. Far better than the junk ones I've seen elsewhere, and should look great in white with that seat...

 

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