Farfles Iron Horse build

Farfle

100 kW
Joined
Jun 27, 2010
Messages
1,759
Location
Redmond OR
Hello all, i have been browsing ES for awhile now and have taken the plunge into buying some parts and have been too lazy to post any stuff on ES, so here is a couple days of build :D .


2x 8s 25c 5.8 AH turnigy cells

1x 18 fet controller from Lyen

1x 5304 from Maxwell going on a 26" rim

heres a couple cad pics
 
The battery box being built, can anyone tell me what this stuff is? it looks like a layer of waxy plastic sandwiched in between two sheets of thin aluminum.

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here is the batteries and ghetto charger setup

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Yay! no bad cells!



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So hey, are you building an eBike on an 'iron horse' bike?
Just thought i'd warn you that Iron Horse went bankrupt over perpetual welding defects in their frames.
I found this out when i was comparing trek, giant, iron horse, gary fisher etc frames.

If it's an Iron Horse, you may want to look into whether or not you had one of these potentially failing frames.
 
One name for that material is Promolyte. Is used as sign board and packaging.
The trick to corners is to cut 2/3rds of the way through with circular saw or router, not through the outside layer, then fold by hand. Even better if you have a 45deg router bit, then you get perfect miter corners. This is excellent stuff for building battery cases, switch boards and the likes.
 
If you're really going to be running <40v, you can have a crazy cool controller if you use this FET:

http://www.irf.com/product-info/datasheets/data/irlb3034pbf.pdf

It would be an extremely cool running controller. Like cold as ice. :) A 12fet with these would run cooler than an 18fet made from IRF4110s. :) But the ultimate current limit would be roughly identical, as either way it's package limited.
 
Thank you for the info on the frame, mine seems very solid and if it was going to break, it would have broken already :twisted: I have cased a good many jumps on it and only broken rims and an ankle :cry: . i am running 16s for 59.2 volts @3.7v per cell. Right now my goal is power not range. so definately more than 40v especially when i add a third batt and go to 88 volts :twisted: . and i have no idea how it will perform because my motor has not showed up yet : ) and as how i got it into Sketchup, i wheeled it into the office with me and sat down for about 4 hrs with a measuring tape and a protractor :roll:. hopefully my motor should show up tomorrow. :?
 
No motor yet, but i did get my 0-100 volt voltmeter and my spokes from Jon Holmes yesterday. On the receipt he left me a note saying "perfect for a 1x lace" I am assuming that he means a 1 cross lace, and what is everyone's opinion on different lacing?
 
motor is still not here yet, but setting up the dash panel right now, i have a couple of relays i may be able to use as a "contactor" , do you think these would be up to the task?

relay.jpg

and is this good for continuous duty? i know it will handle the amps :D
its a minibike starter solenoid.

Solenoid.JPG
 
Got the motor from max today :D :D :D! . Not his fault, but the disk brake holes were drilled a good 1/16" off center, all in perfect alignment :roll: so, with a set of transfer punches, i have managed to get the locations for the new holes marked out, i will try to drill and tap them tomorrow. I have no metric taps that are anywhere close to the disc brake holes, and 10-24 is too small, so i may be drilling the holes out a bit and tapping them out to 1/4-20 :twisted:. have some nice SS cap screws for em too. Going to build the torque arms tomorrow as well as going over to one of my dads friends places and lacing it to a wheel, when my controller from lyen shows up, i *should* have a functioning bike :D
 
Did you ever find out if that solenoid will work?
 
well, i did find out the hard way, no the starter solenoid got noticeably hot in 10 mins or so, and right before i unplugged it i heard the "click" of the coil burning out, the bosch relay is working just fine, but at the moment i am just running a keyswitch to the on-off lead, as my controller plugged in in the off pos. only runs about 3 milliamps.
 
Where did you get the relay?
 
The black relay is a car headlamp relay, and you can get one at a local auto parts store, NAPA, shucks etc... the little starter solenoid can be bought online on minibike stores.
 
OK so the headlamp relay is the one that is working right? How many volts and amps are you running?
 
The headlamp relay has worked for a couple days now, and seems to be running just fine. i run 16s of lipo @64 volts fully charged. with very little current limit i have no idea how many amps im pulling, probably in the 100-150 amp range. You may have to pick up a resistor to drop the voltage for the solenoid coil, they are normally 12v and if you run them on 60, they tend to go bang really fast :roll: .
 
Ah, so that's the trick. So I need what kind of resistor and where do I put it? I am not a real E-guru, so I am learning!
 
oooh boy, not so good with ohms law :oops: , as i am taking physics this year :D . i believe that you take the amp draw of the relay on 12v, then do V=IR where voltage equals current times resistance, if you need to know resistance you find V/i=r so 64(battery voltage)/.280(280 milliamps) is 228 ohms, but i am not sure whatsoever, and 288 ma requires a resistor with pretty high wattage, like a 5 or 10 watt resistor, but i also have no idea if i am correct or not :oops: .
 
Alternately you can use a 12V-14V zener diode across the coil to prevent voltage from ever being too high across it. The anode goes to the ground (negative) side of the relay, and the cathode to the supply side. Use a resistor from that point to the actual pack-supplied voltage to limit current thru the zener to below it's max, which needs to be above whatever the relay coil is going to need to hold in position.
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what all does a zener diode do? i have heard that they are like a typical diode, in that they limit electricity in one direction, but that they "break down" at a certain voltage, how does this work? and what effect does it have? also, how much power can they handle?
 
Basically a zener is used as basic voltage regulators, just like the circuit above. They can also be used as overvoltage protection, in that a (short) pulse above their rated voltage will be absorbed instead of being passed to the device down the line in parallel with them. Often enough, that mode is used for FET gates, by sticking a 9.1V zener on there if they have a 10V gate max, so that spikes from noise, commutation, etc., don't end up blowing the gate and latching the FET on or something. :)

Exactly how they work inside I don't exactly know, though I'm guessing that the Wikipedia entry for them either explains that or it has a source link to a place that does.

Power ratings vary. I have some 5W zeners in various voltages, and they're around 3mm in diameter and maybe 5 or 6mm long. I've also got a bunch of tiny glass ones that are half a grain of rice, which are probably 1/8W if that, mostly pulls out of PC power supplies and UPS boards. There are sizes between those, and also even bigger ones.

I think the largest I have in anything is in a very old linear power supply from a teletype, and it is about 1/2" across, 3/4" long, and one end is a nut with the other end a threaded cylinder, basically being a bolt into a heatsink, with a regular nut securing it on the threaded end, one wire out each end. I dont' know it's wattage, but the power supply itself does 5V and 24V at something like 20 or 30A. The zener on each rail also has a resistor to it that is very large, with a metal heatsink that bolts to the big backplane heatsink. I'd guess the zener is 10 or 20W or more.
 
Could a Zener be used to drop the voltage from my battery pack (64v) to my voltmeter? (12v)? On 12v the voltmeter only draws 64 milliamps. BTW the bike project is done and looks great, i just haven't gotten my camera fixed yet, as they want $60 to ship it to them to get it fixed :( .
 
You can use a zener with series resistor to drop the voltage to your meter, but then your meter will only read 12V. ;) Not much use as a meter at that point, since I presume it is there to read the battery pack's voltage. :p

Unless I am not understanding what you want the meter for, or why you are running 12V to it. (note that I haven't read the whole thread, just bits here and there).
 
The meter is powered off of 5-12v, being a nice back-lit led display, and has seperate test voltage input leads. doesn't matter now, to make a long story short i fried it by mixing up the wires :( . so now i figure i may aswell pony up and get a cycle analyst :roll: .
 
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