Thanks ES for helping me with my first build...Pic album

General Discussion about electric bicycles.
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lapd1685   100 mW

100 mW
Posts: 39
Joined: Jul 06 2011 5:13pm

Thanks ES for helping me with my first build...Pic album

Post by lapd1685 » Mar 05 2012 5:46pm

Thanks to...
grindz145
maxwell65
Doctorbass
neptronix
Lyen
And more, for answering all my stupid questions couldn't have done it with out you...

About the bike...

Schwinn Network 7 Men's Hybrid Bike (700C Wheels)
Doctorbass torque arms ( I used JBWeld, so far so good! Its about $3 and has a Tensile Strength of 3960, Not as good as DP420 with a Tensile Strength of 4500 but its cheep and easy to find. One the arms broke from its weld early on but I don't think I used enough that time. I'm keeping a close eye on them I only have about 60miles on them so far but they are holding up.

Upgraded tires and tubes
Upgraded brake pads
40a 60v HS3540 sensorless
15s3p
I'm getting about 34mph.

Pic album...
http://imgur.com/a/IgxoR#0

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grindz145   100 MW

100 MW
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Joined: Apr 07 2009 12:10pm
Location: Rochester NY
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Re: Thanks ES for helping me with my first build...Pic album

Post by grindz145 » Mar 05 2012 6:41pm

Sweet! Nice Job Chuck! We have to get together sometime soon for a rochester gangster-ebike ride. That's a pretty solid top speed.

What is that display unit you're using?

-Troy

lapd1685   100 mW

100 mW
Posts: 39
Joined: Jul 06 2011 5:13pm

Re: Thanks ES for helping me with my first build...Pic album

Post by lapd1685 » Mar 05 2012 6:48pm

The APM is from Crystalyte. It lights up blue and its bright as Hell

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grindz145   100 MW

100 MW
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Joined: Apr 07 2009 12:10pm
Location: Rochester NY
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Re: Thanks ES for helping me with my first build...Pic album

Post by grindz145 » Mar 05 2012 8:43pm

Interesting, I haven't seen anyone else using these. Did you get them from Maxwell?

stewrobb   1 W

1 W
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Joined: Aug 30 2011 4:38pm
Location: Toronto, Canada

Re: Thanks ES for helping me with my first build...Pic album

Post by stewrobb » Mar 23 2012 8:27pm

Schwinn Network 7 Men's Hybrid Bike (700C Wheels)
Doctorbass torque arms ( I used JBWeld, so far so good! Its about $3 and has a Tensile Strength of 3960, Not as good as DP420 with a Tensile Strength of 4500 but its cheep and easy to find. One the arms broke from its weld early on but I don't think I used enough that time. I'm keeping a close eye on them I only have about 60miles on them so far but they are holding up.
I wanted to get my bike up an running tomorrow, rather than wait two weeks for the DP420. I saw this post, with your mention of 3960psi vs 4500psi Tensile Strength and went out to Canadian Tire and picked myself up some JB-Weld, because that difference is realistically minuscule. I attached the torque arms with the JB-Weld about 3 hour ago, and am just waiting for it to fully set tomorrow. I started checking the specs between the two, and realized that the difference was incorrectly stated, wish I had of checked it myself before using it :cry: . Easy mistake to make, I don't blame you by any means, just unfortunate. My intention here is just to let people know so others don't make the same mistake. I would like to hear how yours are holding up though, and how much you used. I figure now that they are on there I may as well just cover em in another thick layer. I'm sure it will work with enough... Right?

What matters is Shear Strength, NOT Tensile Strength, because we are twisting the torque arms on the same plane, not stretching them apart. That difference is much larger, with JB-Weld at 1040, and DP-420 at 4500. That means you require over 4 times as much surface area for the same holding strength, and with my motors 11ga phase wires, I know I'm going to be pushing that limit really quick, starting my first run at 60A... Aluminium dropouts don't help.

Hope to get it up and running tomorrow, will holla back with an update on how the impatient JB-Weld method is holding up.
Gio 500+ scooter - @72v 50A X8M06 Greentime Controller
Delta/Wye - Regen - 20s3p 20c Turnigy hardcase
- Drove until the end, bent frame retired it

Current Build:
Ironhorse Hardtail frame, 120mm Suspension
Front Hayes Hydro Disc, Rear cable Disc
18 FET 4110 60A (for now) Controller
1000w Rear Motor - 420rpm@48v
20s3p Turnigy 5Ah

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dogman dan   100 GW

100 GW
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Joined: May 17 2008 12:53pm
Location: Las Cruces New Mexico USA

Re: Thanks ES for helping me with my first build...Pic album

Post by dogman dan » Mar 24 2012 7:11am

Perhaps possible to add one small, but strong allen bolt to the Dr Bass torque plate? Just enough to increase that shear? Or even a roll pin in a drilled hole that can be cut flush, allowing the washer to fit over the top of it?

Perhaps enough Jb weld could be applied over the edges of the plate, giving a bit larger surface area. I've done impressive things with jb over the years, but the applications were those that required tensile, not shear.

stewrobb   1 W

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Posts: 58
Joined: Aug 30 2011 4:38pm
Location: Toronto, Canada

Re: Thanks ES for helping me with my first build...Pic album

Post by stewrobb » Mar 26 2012 3:56am

I lathered the perimeter of the arms with JB-Weld, but still wasn't satisfied with it. After racking my brain for a short while, I checked this thread. Thanks for responding Dogman, big help. I can't believe I didn't think of that, the bolts that is.

I took your advice, and drilled two holes on each arm for M5 bolts. Then I went down to Home Depot, attempting to get 4 x 5mm bolts, washers, and nuts. Well they were completely out of all the M5 bolts that were long enough, go figure. I decided that was the ideal size (would recommend M6 to others though in hindsight). I got the next closest thing, which was the 8/32 SAE bolts, accompanied by very thin nuts (all they had, so I got 2 for each thread). What I didn't consider was the sharper thread angle on the SAE bolts, which don't allow as much torque, especially when threaded with thin nuts. I ended up stripping enough bloody bolts before I eventually got the appropriate torque down. I then threaded on another as a lock nut to keep em sturdy.

I got her all done about half an hour ago, just after 4am my time. When your that close, you just can't stop. I took her for a spin, and holy crap :shock: . I am very very glad I secured those torque arms well. I was doing wheelies up and down my street, at 60A peak. Was only out there for 5 minutes tops, although I sure was pushing that motor hard, full stop, full speed, wheelie, wheelie, repeat. When I got home I smelled a funny smell, thinking it was just the Pb batteries I was floating for a while. Then I realized it was my windings crisping. She really does warm up quick, I didn't even suspect it at first because it was such a short run. I'm running an 18 FET 4110 Controller, and it was actually cold. Definitely below it's potential, but I guess my motor is just the weak point (1000W Conhis Motor look alike, 735rpm @ 20s no load in 26" wheel). My first thought was "O well, guess I better order another one so I can cook this to the limit". Don't think it will last too long :twisted:. I'm curious though, what temperature do the windings start to make that smell?

Thanks for the advice Dogman, Cheers
Gio 500+ scooter - @72v 50A X8M06 Greentime Controller
Delta/Wye - Regen - 20s3p 20c Turnigy hardcase
- Drove until the end, bent frame retired it

Current Build:
Ironhorse Hardtail frame, 120mm Suspension
Front Hayes Hydro Disc, Rear cable Disc
18 FET 4110 60A (for now) Controller
1000w Rear Motor - 420rpm@48v
20s3p Turnigy 5Ah

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ian.mich   10 kW

10 kW
Posts: 705
Joined: Dec 18 2011 10:14pm
Location: Toronto
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Re: Thanks ES for helping me with my first build...Pic album

Post by ian.mich » Aug 23 2012 11:47am

I'm planning to run dual ebike-kit torque arm ripoffs (2 for $40 on some chinese site) with the two plates of each toque arm secured together with this and a single m6 on each arm and two locknuts and washers per m6: http://www.permatex.com/documents/tds/a ... /14600.pdf
only 3000PSI shear, but there's no way i'm shelling out for dp420 and then waiting weeks for it to arrive, when I got this for under $10 at crappy tire.
plan to do basically the same power and motor as stewrobb on an aluminum rear dropout.

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