Search found 94 matches

by ekline309
Jan 05 2021 10:37pm
Forum: EBike Technical
Topic: Maximizing Copper Fill
Replies: 7
Views: 320

Re: Maximizing Copper Fill

Square wire is great in theory but in my experience it is a huge pain, especially when you are moving from one layer to the next. This is the best article I've ever found about maximizing copper fill: https://ieeexplore.ieee.org/document/651289
by ekline309
Jan 05 2021 10:15pm
Forum: EBike Technical
Topic: Stronger Motor Magnets
Replies: 30
Views: 792

Re: Stronger Motor Magnets

Also I forgot the original post was about upgrading the existing magnets in the motor. Ideally the system (motor core + magnets) would be designed to operate at some optimal point on the hysteresis curve of the steel. Essentially it should be operating right at the top end of the linear region. If y...
by ekline309
Dec 23 2020 9:10pm
Forum: EBike Technical
Topic: Stronger Motor Magnets
Replies: 30
Views: 792

Re: Stronger Motor Magnets

Better cruise efficiency does not make sense because the same forces that cause cogging during freewheeling are acting on the motor when under power too. I don't think this is correct, you actually want a design that has high cogging torque when the motor is running, this is what makes an easy path...
by ekline309
Dec 23 2020 8:49pm
Forum: EBike Technical
Topic: i need help tuning chinese bike
Replies: 4
Views: 193

Re: i need help tuning chinese bike

Chalo wrote:
Dec 23 2020 5:09pm
Understand that your bike's preset limitations may be there to keep the bike from self-murdering.
:lol: :lol: :lol: :lol:
You don't want a repeat of what happened to Simon Cowell, be careful!!
by ekline309
Dec 17 2020 10:44pm
Forum: EBike Technical
Topic: Throttle Lag
Replies: 4
Views: 124

Re: Throttle Lag

From what I know water (with impurities like salt) can cause a temporary short, this short can then cause devices to exceed their max current. Even after the device is dry and the short is removed, damage may remain in the device that was over current. Did you replace the controller after it was sub...
by ekline309
Dec 13 2020 11:49pm
Forum: EBike Technical
Topic: Battery options
Replies: 3
Views: 235

Re: Battery options

Theoretically you can use any cell size you like: 18650, 26500, 32650, etc. Actually I think usually the energy density goes up with cell size which is a good thing. I think 18650's are used most often because they are most popular and so are more widely available. Also you might be able to pack mor...
by ekline309
Dec 13 2020 11:08pm
Forum: EBike Technical
Topic: Bafang M620 new build.
Replies: 3
Views: 304

Re: Bafang M620 new build.

Sounds like a cool build, I like the Bafang mid-drives, here's how I would calculate it: Looks like the cells are: 3.6V nominal @ 3.4Ah so 14s*3.6 V = 50.4V (48V) 4p*3.4 Ah = 13.6 Ah 5p*3.4 Ah = 17 Ah The M620 says its rated for 750W at 48V, so current draw at full power is: 750W @ 48V = 15.625 A So...
by ekline309
Dec 13 2020 10:42pm
Forum: EBike Technical
Topic: Motor magnets
Replies: 5
Views: 201

Re: Motor magnets

If it was me, I would try to find a narrow width rectangular magnet that is a similar length and thickness, then get like 4-6 of them to form an arc. This is assuming you won't be able to find a drop in replacement which is probably unlikely. I like magnet4less.com for off the shelf magnets. Hope it...
by ekline309
May 04 2020 6:36pm
Forum: EBike Build Threads
Topic: My Ultimate Electric BMX Build
Replies: 0
Views: 748

My Ultimate Electric BMX Build

Not sure if this counts as a custom build but I ended up using an off-the-shelf Steps system from Shimano on a 26" BMX: Motor & Drive: Shimano Steps E7000 Battery: Shimano BT-E8014 Bike: Verde Modus 26" low_res_23.png low_res_10.png I'm actually working on a custom hub-motor right now ...
by ekline309
Dec 12 2019 7:10pm
Forum: EBike General Discussion
Topic: Electric Bike Crowdfunding Statistics
Replies: 2
Views: 861

Re: Electric Bike Crowdfunding Statistics

Good point, I wasn't really looking at it from the buyers perspective. It would be interesting to see what the average delivery time was, my guess would be 6 months or more.
by ekline309
Dec 12 2019 1:04am
Forum: EBike General Discussion
Topic: Electric Bike Crowdfunding Statistics
Replies: 2
Views: 861

Electric Bike Crowdfunding Statistics

I've been seeing some interesting ebike crowdfunding campaigns so decided to put together statistics on all the projects on Kickstarter and Indiegogo. For each of the sites I searched 2 keywords: 'electric bike' and 'electric bicycle'. Here are some results: Kickstarter had a total of 110 campaigns ...
by ekline309
Dec 12 2019 12:13am
Forum: EBike Build Threads
Topic: Electric BMX
Replies: 49
Views: 9229

Re: Electric BMX

Man this post is super old and I haven't been around for a while... I don't have a current build to show but there are a few nice BMX-like ebikes on the market now. The best is by far the Billy by Enki which has BMX bars and geometry, though the monocoque-like frame is a bit odd and the price tag is...
by ekline309
Jul 09 2014 9:34am
Forum: E-Vehicles General Discussion
Topic: Powered velomobile
Replies: 272
Views: 20466

Re: How to build a high torque hub motor?

The equation you want is E = Kt*omega, where E is the voltage and omega is the speed in radians / sec. Kt is the motor constant. Generally low-speed motors are hard to do, motors work well at higher speeds. To get a very high motor constant, which is what you want, you need LOTS of turns. That means...
by ekline309
Jul 08 2014 11:18pm
Forum: EBike Technical
Topic: What is acceptable spoke angle?
Replies: 32
Views: 5013

Re: What is acceptable spoke angle?

5 is a fibonacci number so 360/5 = 72, this is the total angle between 2 spokes on opposite sides of the hub. 72/2 = 36 which is the angle from from the top flange to centerline. The actual angle from the spoke to the flange would depend on the diameter of the flange. A larger flange makes for a sti...
by ekline309
Jul 08 2014 10:49pm
Forum: EBike Technical
Topic: How to drive high-side N-channel FET to saturation??
Replies: 13
Views: 2233

Re: How to drive high-side N-channel FET to saturation??

probly should be new post, but heres a bmx hub-motor ive been working on, a little machining left and then testing.. it has #18 magnet wires
by ekline309
Nov 09 2012 9:28pm
Forum: EBike Technical
Topic: How to drive high-side N-channel FET to saturation??
Replies: 13
Views: 2233

Re: How to drive high-side N-channel FET to saturation??

highside n channel??????? why,why would you wanna do that. my thoughts exactly. A 2n2222 connected to a high side P channel FET will drive it just fine this is what I've been using as well. The snag with P channel FETs, though, is that you just can't get them with specs that match those of N channe...
by ekline309
Nov 03 2012 6:27am
Forum: EBike Technical
Topic: How to drive high-side N-channel FET to saturation??
Replies: 13
Views: 2233

How to drive high-side N-channel FET to saturation??

Based on observation, it seems many controls use dual N-channel instead of P-N FET pairs. How can the top NMOS ever be saturated?? I don't get this....
by ekline309
Jan 08 2012 11:42pm
Forum: EBike Technical
Topic: Disenabling Low Voltage Cutoff
Replies: 9
Views: 836

Re: Disenabling Low Voltage Cutoff

I agree gordo, I'm charging @ 36 and everythings great until the pack sags to 32 nominal, which is what the LVC is set to... found the solution here :P

http://www.endless-sphere.com/forums/vi ... f=2&t=7384
by ekline309
Jan 08 2012 12:59pm
Forum: EBike Technical
Topic: Disenabling Low Voltage Cutoff
Replies: 9
Views: 836

Re: Disenabling Low Voltage Cutoff

Heh, I knew that word wasn't right, thanks gow. They are 26650P LiFePO4 cells. I know everyone is all about high voltage, but my speed and acceleration is great @ 32V, and it complies with my size constraint, which is most important to me. My only issue is cutting out of the controller because of th...
by ekline309
Jan 07 2012 8:47pm
Forum: EBike Technical
Topic: Disenabling Low Voltage Cutoff
Replies: 9
Views: 836

Re: Disenabling Low Voltage Cutoff

I'm using 10 3.2 rated cells for 32v at full charge. Why would you think it would destroy the battery? This LVC is in place so you don't run a 36v battery too low, but if its running 32v fulling charged the battery is fine, and its a controller issue. Dumnum, what info would you like? A schematic of...
by ekline309
Jan 07 2012 4:32pm
Forum: EBike Technical
Topic: Disenabling Low Voltage Cutoff
Replies: 9
Views: 836

Disenabling Low Voltage Cutoff

I'm running a 36V controller from conhis @ 32V and the LVC starts coming on as soon as battery voltage starts lagging. Is there a generic fix at the hardware level to disenable this or a particular part to the circuit I should be looking for??
by ekline309
Nov 25 2011 12:32am
Forum: EBike Technical
Topic: Spotting genuine FB4110 MOSFETs
Replies: 12
Views: 1815

Re: Spotting genuine FB4110 MOSFETs

really? posting MOSFET deals?> you must be jewish...
by ekline309
Nov 25 2011 12:31am
Forum: EBike Technical
Topic: Anyone ever crack an axle?
Replies: 16
Views: 1307

Re: Anyone ever crack an axle?

hate when lathe happens... ;_)
by ekline309
Nov 19 2011 1:36am
Forum: EBike Technical
Topic: good dc-dc converter
Replies: 0
Views: 258

good dc-dc converter

i just had a link from some page for a good 24Vin 12 or 15 and 3.3V out converter, but lost it :oops: anyone see this post or can recommend one?