The Duty Cycle AWD

Agree. Awesome bike, and brilliant battery mount system.

i found these locking seat-post clamps online (http://www.grovetools.com/) and modified them to work as a quick release anti-theft battery mount. i added 8mm rivnuts to the frame and made 22mm posts that bolt onto the top tube. made 35mm OD, 22mm ID slitted bushings to fit in the clamps. the bushing and clamp is bolted to the aluminum plate in the bag.
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mounting post on the bike frame
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top view of battery clamp
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Click to expand...
 
j3tch1u said:
yep, it climbs like a mountain goat on red bull and can still outrun most of the scooters here
...
personally, i like the symmetry/simplicity/redundancy of identical motors/controllers. for more speed i'd just run two 6T's at 72v /w sinewave controllers. with two motors, the bike thinks it's still on the stand with the wheels off the ground 8)
Click to expand...
I run two BMC V2Ss - equivalent setup to yours (except for the overall weight of the build) and the torque is startling. I outrun most cars across intersections and ran down an ATV on the trails two days ago - boy - was he shocked... The bike tops out at 40mph (64kph).

Two identical gear motors/wheels/controllers is such a simple sweet solution, it's surprising that it's not more popular. With the motors only seeing half the load and the heat loss split across two motors, heat worries pretty much go away (unless you really flog it). With front and rear the same, there's no tricky electronics or power balancing issues - just parallel the throttles and go. The only 'extra' item that I use is a common external shunt for the CA.

j3tch1u said:
With both motors I am able to zip up that hill. It feels like more than double.
Click to expand...
I collected some Analogger data late last Fall and found that my no-pedal 0-20mph times were 12.5sec on one motor vs 5.5sec on two - about two to one. The 0-30mph times were 27.5sec and 9.8sec -- just about three to one. This is with 360lbs of bike and rider so I'm sure you are doing even better - it feels like more than double for good reason :D.

I just got my order from Paul for a build using the same folding bike - he mentioned your build and it's really cool to see how it came out - some very slick ideas there. Outstanding!
 
happy to help and glad you didn't buy something you'd regret. in case you missed it, i used kapton in a criss-cross pattern across the pack (between the spot weld junctions and under the nickel where it bridges the cells). the kapton does not even show a mark if you solder onto the nickel directly above it. if i had the space in the bag, i'd mount pc fans blowing thru the cells. however, the fit is so close right now i can barely squeeze the assembled pack into the bag.

looking forward to seeing your 3d printed cell holders.

knighty said:
that's a good price on cell holders, I couldn't find any on there before just ebay :(
I'll probably play with the printer and see how it goes first then decide later on.... I was thinking if I print them right, they could double up to protect from shorting any of the cells out ?
(come of the cells plastic coating is damaged, where the case of the battery is -ve right up and around the +ve connection

Alan :)

EDIT: p.s. thanks again for the help/info and the link :)
Click to expand...
 
i reprogrammed my controllers and changed all the speed levels to 100% and am now seeing 73kph no-load for some reason (even though the 3-spd switch was shorted for max speed before). some of that is due to having a freshly charged pack. i think i'll be topping out around 65kph now (happy day).

i think you'll appreciate the bang for your buck on the macs. if you wanna replicate my battery, i could send paul my drawings so he can build a pack for you that fits in the salsa bag (which is one of the few bags with the right dimensions to fit the frame perfectly). the white montague looks like a police bike so i'm going to get some official looking police biking apparel (legal of course) and see if drivers slow down when they see me :D

teklektik said:
j3tch1u said:
yep, it climbs like a mountain goat on red bull and can still outrun most of the scooters here
...
personally, i like the symmetry/simplicity/redundancy of identical motors/controllers. for more speed i'd just run two 6T's at 72v /w sinewave controllers. with two motors, the bike thinks it's still on the stand with the wheels off the ground 8)
Click to expand...
I run two BMC V2Ss - equivalent setup to yours (except for the overall weight of the build) and the torque is startling. I outrun most cars across intersections and ran down an ATV on the trails two days ago - boy - was he shocked... The bike tops out at 40mph (64kph).

Two identical gear motors/wheels/controllers is such a simple sweet solution, it's surprising that it's not more popular. With the motors only seeing half the load and the heat loss split across two motors, heat worries pretty much go away (unless you really flog it). With front and rear the same, there's no tricky electronics or power balancing issues - just parallel the throttles and go. The only 'extra' item that I use is a common external shunt for the CA.

j3tch1u said:
With both motors I am able to zip up that hill. It feels like more than double.
Click to expand...
I collected some Analogger data late last Fall and found that my no-pedal 0-20mph times were 12.5sec on one motor vs 5.5sec on two - about two to one. The 0-30mph times were 27.5sec and 9.8sec -- just about three to one. This is with 360lbs of bike and rider so I'm sure you are doing even better - it feels like more than double for good reason :D.

I just got my order from Paul for a build using the same folding bike - he mentioned your build and it's really cool to see how it came out - some very slick ideas there. Outstanding!
Click to expand...
 
if you buy some, please mention you found out from some guy in taiwan using them for an ebike battery mount. he was concerned i didn't order the correct seatpost diameter (35mm). i had to explain that i'll be repurposing his ingenious invention for a different dastardly application.

the battery is still vulnerable though---they can still cut the bag right off the frame. but it's the psychological deterrent of seeing a key lock. maybe add a high voltage sticker for more persuasion.

Hillhater said:
j3tch1u said:
mounting post on the bike frame
top view of battery clamp
Click to expand...

That my friend , is pure freeking genius ! :eek:
...I vote this the..." Ebike Gadget of the Year" ! 8)
Click to expand...
 
glad to hear i'm not the only graduate from lucky lucifer's school of damnation!

plenty of fish in the ocean my ass...sharks and piranhas lol

100 is not enough and 1 is too many.

John in CR said:
Great bike. Sorry about the dogs, but otherwise psycho did you a favor, because you're better off without the crazy bitch...plenty of fish in the ocean. Wife #2 was one of those, and thank goodness that cheating bitch bailed, because my life would have been ruined. Hurt like hell, but it was one of the best things that ever happened to me.
Click to expand...
 
at the end of the first battery cycle: sitting at 45v, used 22Ah and covered 60km. terrain breakdown: 30% up/dn steep mountain on 3x pedal assist, 25% wot up/dn steep hills around my house, 25% thru flat city road 3/4 throttle with lots of stop and go, 10% thru rough dirt/grass, 10% letting friends test ride on flat road.

on assist only, flat road, i think Duty Cycle can break the 100km mark.

full charge time is approx 3 hours.

these panasonic cells are nice--they underrated their capacity @ 2900mah (20.3ah pack actually turns out to be ~ 23ah)
 
Seems like a great choice in batteries Ben. I'll have to find a source for them in the states.
 
I am pretty sure the 18650pd is what goes in the Tesla Model S
The vent design in the same as the patent
When the vent opens it tears the bond wire Tesla uses to connect the cells in parallel
The bond wires are also fusible links
Ingenious
 
you are quite right. my friend in the video worked at tesla for six years. now he is starting his own ebike company. that is his prototype he is riding. it's going to be an awesome bike when it's finished.

flathill said:
I am pretty sure the 18650pd is what goes in the Tesla Model S
The vent design in the same as the patent
When the vent opens it tears the bond wire Tesla uses to connect the cells in parallel
The bond wires are also fusible links
Ingenious
Click to expand...
 
flathill said:
I am pretty sure the 18650pd is what goes in the Tesla Model S
Click to expand...

I doubt that
JB Straubel, CTO and Tesla Co Founder told a conference at SAE International, 12-Mar-2013
"We use a nickel-cobalt-aluminum (LiNiCoAlO2) lithium-ion chemistry for our battery cathode material. We don’t use a titanate, which has about half the energy density but is generally good at high charge rates. Some start-ups are using metal oxides; we fall broadly in that category. At this point we really have heavily customized that cell. We’ve totally custom-engineered that cell working jointly with Panasonic to create. It’s an automotive cell, tested to automotive standards. It doesn’t go into laptops anywhere. What keeps us in that general shape and size is the production and cost efficiency. We’re seeing price points that none of the larger-format cells are able to meet. "
Click to expand...
 
just received my 6T motors from paul. will post results soon enough.

deffx said:
Them twin Macs pull hard and fast up them hills, on the down trip you can see how steep and long it is

For some reason i like to go faster uphill than on the flat, must be a mental thing. Was only marvelling at my single Mac 8t earlier today, flying up a fairly steep hill, twin motors would be awsome
Click to expand...
 
Obviously your gain top speed, and i reckon they will cope no problem will the hill, efficiency will be interesting, and again that depends on the ride speed and terrain, i seem to remember you were going to explore some mountains with this bike originally

Next is to test a six and eight turn together

Shame i have a 20mm through axle fork or id consider the same set up,i would really like to try it, two motors sharing the load only has positive comments on endless sphere

And congrats on a great build
 
sorry don't have any hard data on that. they sag more near the beginning but seem to hold steady after that. they also bounce back quite fast. as for temps, i stuck my hand inside the bag to feel the cans after a ride and they were a little warm. couldn't tell if the tabs were warm because the pp covers are bolted on (no signs of anything melted).

t3sla said:
Any feedback on voltage sag and cell/welds temperature?
Click to expand...
 
Just looked over your battery setup again, since I'm sketching something similar. Happened to notice you have the same tabwelder I've been eyeballing over at aliexpress. Your modifications to have the weld points on wires is pretty much what i had envisioned. My only concern would be if it'd still have the zap to produce decent welds. I haven't used a spot welder before so i really don't know what i should be looking for in a future purchase. Hence the "get the cheapest that will work" plan.

I guess what i am trying to ask is, are you satisfied enough with the welder to recommend it to other hobby builders?
Oh and the black/red wire protruding, is that for "activating" the weld?
 
i wouldn't recommend this welder (i wrote about it earlier in my post). maybe try the 2nd or 3rd cheapest? these little black units will crap out easily if you bring out the electrodes. the small wires are hooked up to a switch that activates the welder when you press down on the spring loaded electrode.

Observator said:
Just looked over your battery setup again, since I'm sketching something similar. Happened to notice you have the same tabwelder I've been eyeballing over at aliexpress. Your modifications to have the weld points on wires is pretty much what i had envisioned. My only concern would be if it'd still have the zap to produce decent welds. I haven't used a spot welder before so i really don't know what i should be looking for in a future purchase. Hence the "get the cheapest that will work" plan.

I guess what i am trying to ask is, are you satisfied enough with the welder to recommend it to other hobby builders?
Oh and the black/red wire protruding, is that for "activating" the weld?
Click to expand...
 
j3tch1u said:
test sequence (edited with premiere pro). originally shot in 2.7k 30fps. still need to play around with the settings in warp stabilizer (turned the footage into jell-o). the tarot gimbal is decent, but definitely works better on a drone than a bike.
[youtube]Lpgzh36POgY[/youtube]
Click to expand...


Beautiful video my friend.
 
thanks luke. this is the first time i've edited a video and i really enjoyed it. i think i've found a new hobby. the music is from Place Beyond the Pines. you gotta see that film.

went for a ride on my new 6T motors. top speed is around 68kph now. torque is still really strong. i highly recommend 6T on this type of dual mac setup.

liveforphysics said:
Beautiful video my friend.
Click to expand...
 
added a thumb wheel pot to the thumb throttle that connects to aux pot on the CA. I have it set to limit current (and also effectively PAS assist power). the pot is a 20k (that's all i could find) and i had to add an 850ohm resister to the wiper or else the CA screen would blank out when the pot is turned up. could anyone explain why this happens?

the pot is secured with epoxy and a 1mm screw thru the tiny center hole. i filed a little slot in the plastic side cover for the contacts to pass through. instead of running 2 cables, i replaced it with a 6-wire cable (for the hall and pot). put grey heat-shrink on the aux pot connector (to differentiate from the throttle connector).

it works well:
- change power levels for beginners
- disable PAS and throttle without having to cut power to the CA and lights
- fine-tune PAS level for physical/environment conditions
- turn off PAS

IMG_0921.JPG
 
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