Search found 491 matches

by Buk___
Feb 22, 2018 1:36 am
Forum: Large EV General Discussion
Topic: Tesla PEM heat sink material required
Replies: 1
Views: 21

Re: Tesla PEM heat sink material required

Okay, I have a tesla roadster that has the well documented PEM failure The answer seems to be replacement of the thermal layer under the IGBT's https://teslamotorsclub.com/tmc/threads/roadster-pem-failure.88028/ But there is little conclusion as to what that may be. I'm hoping the collective minds ...
by Buk___
Feb 21, 2018 11:55 pm
Forum: Motor Technology
Topic: Ferrofluid for hub cooling? BS or real?
Replies: 30
Views: 619

Re: Ferrofluid for hub cooling? BS or real?

Chalo wrote:
Feb 21, 2018 9:34 pm
And I have to fault any math that suggests it takes more than 6% extra energy to raise only 6% more mass.
106/113*100 = 106.6037735849056603773584905660377% more mass.
by Buk___
Feb 21, 2018 11:48 pm
Forum: Resources & EV Related Parts and Services
Topic: ?? 100+Amp circuit breakers
Replies: 10
Views: 155

Re: ?? 100+Amp circuit breakers

Normally I'd leave you throwing your troll tantrum, but you *finally* got out one sentence that is interesting: I wrote 7 words, to cover a link; you responded with 400words of misinformation. YOU ARE THE TANTRUMING TROLL HERE. And I'm meant to make allowances for the fact that you didn't read the ...
by Buk___
Feb 21, 2018 4:59 pm
Forum: E-Bike General Discussion
Topic: Q128C specs selection help
Replies: 13
Views: 297

Re: Q128C specs selection help

1N4001 wrote:
Feb 21, 2018 3:56 pm
Correct. But the voltage won't have an influence on that, only the current determines flux.
Unless you can increase the flux, adding more volts won't increase your speed; so will just generate heat.
by Buk___
Feb 21, 2018 4:44 pm
Forum: Motor Technology
Topic: Ferrofluid for hub cooling? BS or real?
Replies: 30
Views: 619

Re: Ferrofluid for hub cooling? BS or real?

The most power efficient motors both now and back when I started messing around with these things are still the big slow direct drive hubs, once you factor in efficiency losses due to reduction gearing. In a 150kg gross weight vehicle, the weight penalty of those is something like 2% of the total c...
by Buk___
Feb 21, 2018 1:36 pm
Forum: E-Bike General Discussion
Topic: Q128C specs selection help
Replies: 13
Views: 297

Re: Q128C specs selection help

I really don't see why a high voltage could bring the motor into saturation. Magnetic flux is soley proportional to current. Or am I missing something here? Cores saturate. With the small (18/20mm wide) and narrow teeth, once the teeth are fully saturated, even if you can get more volts and amps in...
by Buk___
Feb 21, 2018 1:28 pm
Forum: Resources & EV Related Parts and Services
Topic: ?? 100+Amp circuit breakers
Replies: 10
Views: 155

Re: ?? 100+Amp circuit breakers

Your quote "they look like domestic AC breakers, so are no good for DC" is a entirely fabricated. I simply did not say that. This imagined quote suggests that the evaluation was based on appearance and the conclusion of fitness for DC use derived from that "look". The document claims they are AC br...
by Buk___
Feb 21, 2018 7:16 am
Forum: Motor Technology
Topic: Ferrofluid for hub cooling? BS or real?
Replies: 30
Views: 619

Re: Ferrofluid for hub cooling? BS or real?

If the motor runs too hot, it's too small or you're demanding too much power from it. This isn't rocket science; we've had boringly reliable electric motors for more than a century. Use enough motor for the job and you'll have no problem. We've had boringly reliable -- but horribly inefficient -- 5...
by Buk___
Feb 21, 2018 6:37 am
Forum: E-Bike General Discussion
Topic: Q128C specs selection help
Replies: 13
Views: 297

Re: Q128C specs selection help

I want to focus on that 48V/328rpm|36V/260rpm variant. If the thread on pedelecs.co.uk is to be trusted, and my assumption that they are talking about loaded speeds is correct, a 67V battery should suit me fine, giving me 64kph (assuming 7.2rpm/V). Any objections? No objections. I'm as much in the ...
by Buk___
Feb 21, 2018 12:18 am
Forum: Battery Technology
Topic: Altairnano LTO module autopsy
Replies: 6
Views: 123

Re: Altairnano LTO module autopsy

jonescg wrote:
Feb 20, 2018 8:33 pm
XT90000 :lol:
Hope that's an -S variant with a bleed resistor :)
by Buk___
Feb 21, 2018 12:07 am
Forum: Battery Technology
Topic: Would you charge a 4s LiFePo with a "15V" wall wart (intended for charging a 12V SLA)?
Replies: 11
Views: 180

Re: Would you charge a 4s LiFePo with a "15V" wall wart (intended for charging a 12V SLA)?

That's a much more complex regulator system than I've seen on any of the SLA-powered devices I've worked on so far (except UPS units)--most of them depend on the battery smoothing stuff out. It makes it more likely it's got some safety cutoffs, but whether they are appropriate for anything but SLA ...
by Buk___
Feb 20, 2018 10:04 pm
Forum: Resources & EV Related Parts and Services
Topic: ?? 100+Amp circuit breakers
Replies: 10
Views: 155

Re: ebike Breakers and Cutoff / Main Power Switch

Do not use these breakers. Two major problems: They are exclusively meant for residential AC use and have no derated specs for DC at all They are recommended only "for infrequent use" by the manufacturer To discourage you, please see: http://donar.messe.de/exhibitor/hannovermesse/2017/U593078/break...
by Buk___
Feb 20, 2018 7:35 pm
Forum: E-Bike General Discussion
Topic: Q128C specs selection help
Replies: 13
Views: 297

Re: Q128C specs selection help

Any other comments, opinions or information? Is anything I mention incorrect or in need of further consideration? Depending upon who's post you read and when, there is a lot of speculation that the "201" and "328" (and for some motors "260") are not direct readings of the maximum unloaded kV for th...
by Buk___
Feb 20, 2018 7:24 am
Forum: E-Bike Technical
Topic: Cute Q100H Autopsy & Modify 2017
Replies: 44
Views: 1170

Re: Cute Q100H Autopsy & Modify 2017

Note the obvious diameter difference between my Q100H W/15t sun, and the 9t sun in the linked image. I count 8 teeth on the Sun gear in that linked pic, which is what I counted in my 2015 tread; I'd have to concur with Papa that there are 9 teeth on the sun gear in the linked pic: Q100(H)SunGear.jp...
by Buk___
Feb 20, 2018 1:02 am
Forum: Resources & EV Related Parts and Services
Topic: ?? 100+Amp circuit breakers
Replies: 10
Views: 155

Re: ?? 100+Amp circuit breakers

MileHighGuy wrote:
Feb 19, 2018 11:35 pm
Sorry if this is redundant. I can't seem to find any of these on the web. Can anyone point me in the right direction please? Thnx
These guys seem to cover most eventualities.
by Buk___
Feb 20, 2018 12:53 am
Forum: E-Bike Photos & Video
Topic: Single-speed track stealth ultralight
Replies: 98
Views: 3096

Re: Single-speed track stealth ultralight

zro-1 wrote:
Feb 19, 2018 5:45 pm
Papa: you mentioned that you were interested in seeing my Phaserunner settings for the Q100H. This is what I've settled at for now. I might tweak things once I can get my hall sensors figured out.
PR-ScreenShot.jpg
Why do you have regen configured for a clutched geared motor?
by Buk___
Feb 20, 2018 12:42 am
Forum: E-Bike General Discussion
Topic: cable operated hydraulic brakes
Replies: 33
Views: 410

Re: cable operated hydraulic brakes

amberwolf wrote:
Feb 19, 2018 6:45 pm
Maintenance? what's that? :roll:
The money they still must pay to woman who used to do all that stuff for them; but upped and left one day. :?
by Buk___
Feb 18, 2018 5:30 am
Forum: Battery Technology
Topic: Would you charge a 4s LiFePo with a "15V" wall wart (intended for charging a 12V SLA)?
Replies: 11
Views: 180

Re: Would you charge a 4s LiFePo with a "15V" wall wart (intended for charging a 12V SLA)?

It makes it more likely it's got some safety cutoffs, but whether they are appropriate for anything but SLA might be another story. Indeed. That's why I spent yesterday trying to simulate it. So I can try to figure out what circumstances control the "charged" light and associated circuits. BTW: I"d...
by Buk___
Feb 18, 2018 1:57 am
Forum: Battery Technology
Topic: Would you charge a 4s LiFePo with a "15V" wall wart (intended for charging a 12V SLA)?
Replies: 11
Views: 180

Re: Would you charge a 4s LiFePo with a "15V" wall wart (intended for charging a 12V SLA)?

Because the charger trickles, no. Unless it does have a reliable bms. Good excuse to buy a 50w RC charger IMO, like a b6 The device has some sort of cut-off; there's an led that goes from red to green once the (SLA) battery is charged. And it doesn't go back to red until it has been used for a good...
by Buk___
Feb 18, 2018 1:26 am
Forum: Motor Technology
Topic: PM Motor theory - formulae etc.
Replies: 71
Views: 24728

Re: PM Motor theory - formulae etc.

There are also advanced controllers like Lebowski's that can use halls for startup, then run sensorless after that. Indeed. I just need crash courses in: PCB construction methodology; repentance* instrumentation techniques; access to a fully equipped electronics lab and a new set of eyes for the de...
by Buk___
Feb 18, 2018 1:11 am
Forum: E-Bike Technical
Topic: Cute Q100H Autopsy & Modify 2017
Replies: 44
Views: 1170

Re: Cute Q100H Autopsy & Modify 2017

... Here's where things get really strange. What this tells me is that either: The wheel RPM (201 vs 260 vs 328) is determined by the motor winding and not by the gear ratio, or I received a 328 RPM motor, even though I ordered a 260 RPM ... At last I think you are getting to the crux of the matter...
by Buk___
Feb 18, 2018 12:18 am
Forum: E-Bike General Discussion
Topic: E-14 Rohloff "The Ultimate Electric Bike Transmission"
Replies: 5
Views: 254

Re: E-14 Rohloff "The Ultimate Electric Bike Transmission"

MadRhino wrote:
Feb 17, 2018 11:14 pm
...enough power ...
Put a bigger one in.
Bigger what?
Bigger everything!
by Buk___
Feb 16, 2018 12:34 pm
Forum: Battery Technology
Topic: Common pack design mistakes, how to avoid?
Replies: 236
Views: 18599

Re: Common pack design mistakes, how to avoid?

The fuse&bms can handle max 80A. I wil use this pack on a motor-compressor that take maximum 45Amps. I like the way building a pack + coper serie bars and no soldering on top of the cells....this is the way i can make a save strong pack ,cells in holders.The coper wire are on top of the serie nicke...
by Buk___
Feb 16, 2018 12:30 pm
Forum: Battery Technology
Topic: Would you charge a 4s LiFePo with a "15V" wall wart (intended for charging a 12V SLA)?
Replies: 11
Views: 180

Would you charge a 4s LiFePo with a "15V" wall wart (intended for charging a 12V SLA)?

The title says it all. I'm looking to replace a 12V SLA (portable vacuum) with Li***, and would like to reuse the existing charger, because it is a wall mount&charger with bespoke connectors, and to save money. 4 x 3.65 = 14.6; but the 15V is the OCV; once loaded it will inevitably drop. Would you d...
by Buk___
Feb 16, 2018 10:13 am
Forum: Motor Technology
Topic: PM Motor theory - formulae etc.
Replies: 71
Views: 24728

Re: PM Motor theory - formulae etc.

Punx0r wrote:
Feb 16, 2018 7:57 am
They do :)
So, my "must probably" wasn't definitive enough for you :)