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bmc trail fox with puma hub motor

I need you as my consultant. Great build!
 
update on torque arms. did drawing in autocad and sent the .dxf to a nice guy who did laser cutting of stainless steel for $30 for all four :)

on the picture it looks a bit strange because of the grinding. but it all looks nice when you turn them a bit.
the open arms go on the inside directly to the frame, and on top of them there will be the closed type.

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i soldered the two arms together so it's easier to install. i did polish them with grade 400 sand paper to look nicer. they really shine *ggg*

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izeman said:
update on torque arms. did drawing in autocad and sent the .dxf to a nice guy who did laser cutting of stainless steel for $30 for all four :)

That's extremely cheap, considering they're custom made.
Comment: I'm no mechanical engineer, but I can't help wondering if you really need 2 on each side. Looks to me 1 is more than sufficient.
Question: Why not have all four of them closed?
 
SamTexas said:
izeman said:
update on torque arms. did drawing in autocad and sent the .dxf to a nice guy who did laser cutting of stainless steel for for all four :)

That's extremely cheap, considering they're custom made.
Comment: I'm no mechanical engineer, but I can't help wondering if you really need 2 on each side. Looks to me 1 is more than sufficient.
Question: Why not have all four of them closed?

yes. he's a guy form a german ebike forum and does that as a favor to the community.
those are 3mm thick. i'm quite sure that one closed arm on each side would be enough, but the space is quite limited, and i have to move them a bit away from the frame to install the closed arm, and so i use the open type as spacer :)

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SamTexas said:
izeman said:
... away from the frame to install the closed arm, and so i use the open type as spacer :)

Ah, expensive spacer! ;)

it's not ONLY a spacer. it serves as torque arm as well :) and as you already mentioned: the whole set was really cheap. so all four came for the price of two.
i got it installed today. a really tight fit. really nice. i'll put connectors on it tomorrow and post some pictures.

btw: i lost the m14 nut :( any idea where to get them cheap?
edit: just found it in the pocket of my working trousers. :)
 
update: torque arms installed

right side. nice tight fit and polished to shine :)

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left side. with cabeling. i also swapped the disc rotor for a silver one.

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safety first. thanks to china those are $1 only and quite loud. *ggg* ppl just don't expect a bike rider to be that fast.

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installed a 3 mode switch. this does limit the power to 30% and 60%. don't think i'm gonna use that really often. also swapped all those cheap screws for stainless steel.

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new cabeling. how do you like it? i'm sure if i go for the spiral look.

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bike in all it's stealth glory. i'm finished with it (at least for that season)

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this is the bag opened. there is a lot of space between the batteries. two of them perfectly fit on the top side, the other two fits in the corners. so this builds a triangle, leaving enough room for bms and cables.

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i still have to do thru holes and cabeling. ths bag just arrived a few minutes ago and i was too excited to wait any longer :)
 
Nice light! I like it, have you compared it to the 900 lumen Magicshine? I wonder how it compares?

NICE build by the way, I like the batts in the center MUCH better!
 
i wanted to buy the magicshine, but it was too big, and requires a seperate battery which has to be stored somewhere as well. so i went for that torch. the magicshine should be better, as specs of the xm-l drop-in say 800 something lumen - and as we all know - they lie :(
but it's ok for me, easy the detach, and enough light to find my way home at night in the forest.
 
If your setup is reliable, simply solder/shrinkwrap them and put them into the spiral loom..
 
Whiplash said:
If your setup is reliable, simply solder/shrinkwrap them and put them into the spiral loom..
this surely is by far the most reliable solution, but in case of maintenance it's hard. even to unmount the rear tire it's not very practible with the cables attached. but ... i could solder cables to the motor, as i can detach the saddle bag, and will only have connectors for thumb throttle and battery.
 
izeman~ how totally stealth...so clean and lean. Congrats.
Since yer talking abit about batts in the frame...thought I'd shoot you couple pics in case you're interested. Even with your partially obstructed triangle, I could build one've these for ya pretty easy. Go Jolly
 

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update: during xmas holidays i had some time for improving some things and for upgrading.

first project was the remote shunt for my turnigy/gt power wattmeter which will be installed on the handlebar.

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then i bought a smart bms. first 2 6packs are connected in parallel, then in series. the balancer leads have to be connected the same way, so i can controll each voltage seperately.

i soldered a connector board and put some epoxy on the back side for insulation. i'm missing a picture of the finished project - i'll add one later :)

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next was recableing of the controller and installation of an anti spark circuit.

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the controller is now attached to a much smaller topeak saddle bag. this is a perfect fit

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i also changed all screws to inox screws and installed a water proof switch.

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the cable coming from the motor will be cut near the axle and 4mm goldies will be installed. this is the controller side

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any comments welcome :)
 
today i installed the smart bms in the battery bag. it's nice how easy working with wood is :)
i wanted to do that with aluminium but didn't have access to an aluminium welder, so i chose wood.

the bag is bigger than 4 batteries, so i had to put something between the batteries to hold them in place.

the balancer parallel harness is installed in the middle where it can be reached easily

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this is what i looked like before. you can see the empty space

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holes drilled and cable ties in place to secure the batteries

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i also added 39ohm resistors to the bms to push bleeding to 200ma.

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everything in place, ties attached, and now that (of course), when i checked the voltage of the single packs before paralleling them

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it was a loose balancing cable, that was fixed. everything ok now.

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i also installed goldies for charging only, so there is no chance for putting wrong connectors together. all other connectors on the bike are xt60.

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all done :)
 
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