build thread: klein mantra hs3540 5kW 70km/h 20" (done)

[izeman]

thanks i'm still struggeling with radial lacing. there is another thread by me about that:
http://endless-sphere.com/forums/viewtopic.php?f=2&t=46618
i just hope it works as expected and won't break

atm i'm a bit frustrated. i finished my clamp board, just to find out that the case (pelican im2075) should be too small to hold all 24 cells.
and i don't need to write much about those victpower cells. you're in the same boat am i the first to realize this extremely high IR??

 

[izeman]

this is the clamp board for 24s a123 20amp cells. balance wires are attached, but not jst-xh connectors, as i'm not sure about which side to guide the wires.

 

[neptronix]

Wow, this build is coming along nicely. You're making all the right moves here IMHO.

I still object to that specific bike. It's going to be a wheelie machine. Do you have the means to extend the swing arm?

 

[izeman]

Wow, this build is coming along nicely. You're making all the right moves here IMHO.

I still object to that specific bike. It's going to be a wheelie machine. Do you have the means to extend the swing arm?

thanks for the flowers. that makes me wish to complete that
this could be a wheelie machine. but the 13kg weight at the handle bars should do the best to keep it down. and if it still will wheelie, than i can tame it with the CA-V3 features.
the swing arm will be extended. not too much. i thought about 10cm in length and 7cm in height to compensate for the smaller wheels and high some pedal clearance. on the other side this will make steering angle steeper. will see how it rides. should still be 2-3mo till completion. my full day job and 3 kids ain't give me much spare time ...

 

[neptronix]

I doubt the handlebars will do much for you. I tried using handlebar extenders and leaning on the front and that didn't work for me. That motor in a 20" wheel will produce pretty good torque; you can tune it down a little bit via the cycle analyst, but the CA might not react fast enough to throttle the amperage down to prevent a wheelie. 10cm ( 4 inches ) is a good extension, but maybe you'll need more. Just consider that.

I forget what you planned for the front wheel, but a 24" front will help balance out the geometry.

 

[izeman]

i got the battery finished. took me almost the whole weekend

i now also know now that LiFePo4 CAN burn, but not that explosive as LiPo. at first i was drilling holes in the tabs. to do that, and to know where to drill, i inserted the cells in the board, bended the tab and then drilled through the cell, and used the holes in the board as guide. 2 cells went well, and then i drilled to far down, and drilled in two cells some smoke coming from the cells. i reacted in panic and removed the cells from the pack. there was a 3mm hole, and i was glowing inside. i pushed wish my thumb near the hole. no good idea. flames started to come out, but luckily went out after some seconds. those two cells now are in the outside of the house. no damage to expect.

here is a pic of the assembled battery. 4x 6s balance tabs. 4x6 cells wrapped in pvc heat shrink. this gives good stability and some kind of protection.

 

[izeman]

we'll see how good that calculator is (c) ebikes.ca.
i hope it's ok to post that screenshot

 

[vodk1c3]

I know it's already posted out there but I would like to know what is called and where to find that blue tape for the battery pack.

Edit : Ok, pvc heat shrink... where to look for? any hardware store?

 

[izeman]

you asked for it, this is no ad by any meaning:
http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=320788251180&ssPageName=ADME:X:RTQ:US:1123

 

[crossbreak]

Nice build, I like the frame. Perfect for mounting a battery. Will you install a longer damper to equalize for missing ground clearance?

Btw. I guess it wont wheelie with the battery in front. If it does you could go for a 24" front wheel and a shorter 80mm travel fork. Taming the motor is no solution, it's just cosmetics

 

[izeman]

first of all i'll leave all geometry as is. fork has 80mm travel. i will have to pre-load the spring to it's max to compensate for the heavy load at the handle bars. but different wheel sizes is a no-go. it's only 55mm/2.2in lower than with 26" tires. this should work. and i will add some height at the rear with the new rear triangle to compensate the smaller tires.

 

[crossbreak]

[...] different wheel sizes is a no-go[...]

why? many enduro bikes have different wheels size. Drives a lot better IMO.

 

[izeman]

because i already bought the rim and tires, and laced them.
it may drive better, but i like the look of two same tires better - like the supermoto look.

 

[MattyCiii]

I was able to dial down the torque on my wheelie machine using the CAv3. I'd love to have a guarantee in geometry of the rear swingarm, but I'll wait till the summer supports long warm days for welding in the garage.

Is that Magura HS33 brake in the rear? I use HS33 on the rear and it works really well. I spliced a hydraulic e-brake cutoff into the hydro line, but it's finicky and I've recently had to unplug it from the CA.

 

[izeman]

yes. good ol' hs33
can't use it anymore as tires are 2.75" wide and i prefer hydraulic disc over rim brakes anyway.
i thought about this magura hydraulic brake switch but fear to open the tube, as this would require service to the brake.
i still try to install an electronic brake switch based on a hall sensor. didn't succeed yet, switching to a reed switch now. will see.

 

[izeman]

battery done i bought some 1.5mm thick aluminium plates. one is U-shaped, and two single pannels for the side. all wrapped in icehockey tape.

guess what company i'm working for nice handles to carry the battery, and take it out of the case.

top view. power cable are not attached yet, as i want to avoid any shorts.

 

[izeman]

i have to install a fuse next to the positive connection. but am i asking for trouble with this one?
it's rated 40a, and i wil have a 30a nominal setup. but those are 40a and 12v (for cars). will they stand 80v and 30a?

 

[izeman]

installed a electronic brake switch. after experimenting with hall sensors, and the very unprecise switching characteristics, i moved to a tiny reed switch.

this is the elixir3 brake. drilled a 3mm hole for the cable:

a little magnet super glued to the lever:

the installed reed switch. switching is VERY precise, and 100% reproducable. just start pulling the lever and the switch closes. that way i expect the regen braking to start before the disc pads attach to the disc.

the switch is secured with some epoxy, and is 100% waterproof.another advantage over hall sensors is, that there don't need any power supply. so a shorted line just would enable braking, and not burn anything.

this is the other thread where i discussed my problems with hall sensors:
http://endless-sphere.com/forums/viewtopic.php?f=2&t=43680&start=15#p689035

those are the reed switches ordered - highly recommended supplier. fast shipping and good prices:
http://www.ebay.de/itm/330671622238?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

[hjns]

Nice build. Thanks for the link to the reed switches, I will try it myself.

edit: are you sure about the correct switches? For my controller, I need an open circuit to allow the throttle to work. When the circuit closes, throttle is deactivated, and the regen is activated.

With a reed switch that closes the circuit when the magnet comes close, you should have the magnet moving towards the reed switch in order to activate braking. Is this the case for your controller? Or do you use reed switches that are normally closed and will open when the magnet comes close?

 

[izeman]

good point. to be honest i didn't think about it that much
i just assumed that shorting the 2 brake pins would stop the controller and enable regen braking. but now i'm not sure anymore. i plan to use the ebrake input of the ca-v3.:

Digital Ebrake (EBK): This input has an onboard pull-up to 5V to be used with an ebrake cutoff switch. When the signal is shorted to ground, the CA thinks that your brake levers are depressed and forces the CA's throttle output to 0V.

this would mean: you pull the lever (brake), the switch closes (0 Ohm) and the CA cuts the throttle and stops the power going to the motor. i hope it also enables regen that way (if the controller is configured to do so of course).

but anyway: it depends where you locate the reed switch. move it to the outside of the brake, and it's closed when the lever is in it's idle position. when you pull the brake lever, the magnet moves AWAY from the switch and the switch releases and opens the circuit. do it like i did it, and the switch closes when the magnet move into it's direction.

 

[hjns]

but anyway: it depends where you locate the reed switch. move it to the outside of the brake, and it's closed when the lever is in it's idle position. when you pull the brake lever, the magnet moves AWAY from the switch and the switch releases and opens the circuit. do it like i did it, and the switch closes when the magnet move into it's direction.

Ah. Are you saying that in your case, when the lever is idle, the magnet is away from the switch. When you pull the lever, the magnet moves towards the switch, closing it? That makes sense. thanks!

 

[izeman]

yes. correct. the position of the switch determines the switching "logic"

 

[Sunder]

yes. correct. the position of the switch determines the switching "logic"

I am about to do the same thing, and I'm twisting my mind around this... All the micro reed switches I can find close when the magnet moves close, and opens when it moves away, as per your description... But when I look at my braking mechanism, I can't see any way to make the magnet move CLOSER when I pull the lever. Where did you attach the magnet/switch?

 

[izeman]

see red circle. north/south of the magnet is perpendicular to the movement.

just open a thread, and post close up pictures of brake levers - maybe we'll find a solution.
if you wish i can post a picture of the re-assembled brake.

 

[Sunder]

see red circle. north/south of the magnet is perpendicular to the movement.

just open a thread, and post close up pictures of brake levers - maybe we'll find a solution.
if you wish i can post a picture of the re-assembled brake.

Will do. Will link the new thread in a few minutes.