Search found 703 matches

by olaf-lampe
Jul 10 2011 2:24pm
Forum: Motor Technology
Topic: Estimating Load/No Load RPM Difference for Gearing
Replies: 4
Views: 840

Re: Estimating Load/No Load RPM Difference for Gearing

Most of us are calculating with 80%
by olaf-lampe
Jul 08 2011 1:44pm
Forum: E-Bike Non-hub Motor Drives
Topic: Custom Build... 2 Speed H.O.B.O Powered e-Cruiser
Replies: 945
Views: 108912

Re: Custom Build... 2 Speed H.O.B.O Powered e-Cruiser

I wonder, if the people feeling a kick in the a** when they shift in second, do shift to late?
IMHO they'd better shift at 50% of max RPM or a little later. That's where the torque curve begins to decrease.
Correct me, if I'm wrong. :lol:
-Olaf
by olaf-lampe
Jul 04 2011 1:14pm
Forum: Motor Technology
Topic: Turnigy CA120-70 8600W Brushless Outrunner (100c eq)
Replies: 215
Views: 42377

Re: Turnigy CA120-70 8600W Brushless Outrunner (100c eq)

How about using an epoxidisk mounted on the shaft with 14 tiny magnets in it? The statorfield wouldn't disturb there IMHO, or at least the field would be in the wrong direction.
by olaf-lampe
Jul 04 2011 3:20am
Forum: E-Bike Non-hub Motor Drives
Topic: TONARO Pedelec Kits
Replies: 41
Views: 18733

Re: TONARO Pedelec Kits

Hmmph, tried to order the 240W version, but they don't deliver to germany. I don't dare to call them, it was dificult enough to stumble through their french_only menus. :roll: Anyone located in france, who wants to order for me and send it to germany? -Olaf <edit> Compared the data with the original...
by olaf-lampe
Jul 02 2011 7:50am
Forum: E-Bike Non-hub Motor Drives
Topic: TONARO Pedelec Kits
Replies: 41
Views: 18733

Re: TONARO Pedelec Kits

I'm interested to buy one of those kits. But the link to eastsunworld is dead...
Where else can I get one?

THX
Olaf
by olaf-lampe
Jun 26 2011 1:45am
Forum: E-Bike Non-hub Motor Drives
Topic: Nice 5:1 gearbox
Replies: 39
Views: 9201

Re: Nice 5:1 gearbox

Not yet,
I started my own business and moved back to germany. I hope to go on with the build pretty soon.
-Olaf
by olaf-lampe
Jun 24 2011 12:58pm
Forum: E-Bike Non-hub Motor Drives
Topic: New Bosch drive system
Replies: 67
Views: 15744

Re: New Bosch drive system

Since I started my own business in may, I asked bosch for a chance to get my hands on the edrive. I'd like to use it for tadpoles and recumbents. BTW it delivers up to 625W and since it's an 3 phase motor it can be tuned for sure with a different controller/battery. I'd also like to build a mtb with...
by olaf-lampe
Jun 23 2011 2:48pm
Forum: Battery Technology
Topic: Headway 40160S LiFePo4 Questions.
Replies: 16
Views: 3381

Re: Headway 40160S LiFePo4 Questions.

The lifepo4 has a bad defect rate according to reports, and also does not live up to it's discharge claims whatsoever. david, it would help if you can document this. i consider the defect rate on the headways to be essentially zero. i just read that someone has just twisted off the negative termina...
by olaf-lampe
Jun 23 2011 7:30am
Forum: Battery Technology
Topic: Hobbykings new 5000mAh hardcase LiPos
Replies: 66
Views: 5431

Re: Hobbykings new 5000mAh hardcase LiPos

*UP*
They're available in the US warehouse now.

http://www.hobbyking.com/hobbyking/stor ... duct=18631
-Olaf
by olaf-lampe
Jun 21 2011 11:48pm
Forum: Battery Technology
Topic: High C-rate LiFePO4 Polymer Battery
Replies: 27
Views: 3993

Re: High C-rate LiFePO4 Polymer Battery

It seems, no one is interested in an european group buy. Then I'll make my own order and report test results gathered with my new cruiser.

-Olaf
by olaf-lampe
Jun 21 2011 12:29am
Forum: E-Bike Non-hub Motor Drives
Topic: Water-Cooled, 63mm, 8kW
Replies: 12
Views: 1468

Re: Water-Cooled, 63mm, 8kW

Why not making a hollow shaft? I thought of drilling holes from both ends, but leave it solid in the middle. Then drill radial holes right next to the solid part, so the water fills the area between shaft and stator. ...or even better: Why do we need a single piece shaft at all? Usually we don't hav...
by olaf-lampe
Jun 17 2011 8:30am
Forum: E-Bike Technical
Topic: BLDC phase timing
Replies: 1
Views: 469

Re: BLDC phase timing

AFAIK the better RC controllers do have an automatic timing algorhythm, but the bike controllers don't.
-Olaf
by olaf-lampe
Jun 13 2011 3:50am
Forum: Motor Technology
Topic: Adding hall sensors to outrunners
Replies: 424
Views: 93026

Re: Adding hall sensors to outrunners

The motor seems to run with wrong timing. But at least, it seems you've found the right firing order. :) Label the hall signal cables in the connector like 1-2-3; then put cable 1 in position 2; 2 in position 3; 3 in position 1. ( position in the connector ) If that doesn't work; put 1 in position 3...
by olaf-lampe
Jun 11 2011 11:18am
Forum: Battery Technology
Topic: High C-rate LiFePO4 Polymer Battery
Replies: 27
Views: 3993

Re: High C-rate LiFePO4 Polymer Battery

The Dow Kokam's are much more expensive than $100 each. And if you were the compare prices/amps Haiyin wins the race. I'm working for http://www.ececars.nl/modellen. We have built EVs with Kokam for more than 3 years. I know what I'm talking about. Maybe you have to build up a reputation first to g...
by olaf-lampe
Jun 11 2011 1:55am
Forum: Battery Technology
Topic: High C-rate LiFePO4 Polymer Battery
Replies: 27
Views: 3993

Re: High C-rate LiFePO4 Polymer Battery

@ EVDragracing I don't want to compare apples with oranges, but the cells you'll have in connecticut are of a complete different kind. Especially cycle life at 30C is a bit disappointing. Also 6Ah isn't very impressive. I like the 18.5Ah cell from FreeGo, because it would fit in a triangle better th...
by olaf-lampe
Jun 09 2011 4:22am
Forum: Motor Technology
Topic: Outrunner: stationary shaft?
Replies: 5
Views: 710

Re: Outrunner: stationary shaft?

You could use brass bearing or needle rollers if you dont have enough room.

-Olaf
by olaf-lampe
Jun 08 2011 3:47pm
Forum: Battery Technology
Topic: Bypassing BMS for High Current Application
Replies: 5
Views: 1147

Re: Bypassing BMS for High Current Application

I just am not sure I understand transistors well enough to understand how I calculate resistors for their required voltages.
Thats why solenoids like the tyco czonka 3 are much easier to use. A bit overkill, but pretty common:
http://relays.tycoelectronics.com/datasheets/ev200.pdf

-Olaf
by olaf-lampe
Jun 08 2011 8:14am
Forum: Battery Technology
Topic: High C-rate LiFePO4 Polymer Battery
Replies: 27
Views: 3993

Re: High C-rate LiFePO4 Polymer Battery

yes the chinese price you receive is the same but transport cost is double or more chiper. Dont know how much tax you should pay on top of that price in Germany?? when you are planing to order that stuff? Usually I pay 2.4% import-fee + 19% tax. I'm in no rush, since the BMS and charger aren't in s...
by olaf-lampe
Jun 08 2011 12:52am
Forum: Battery Technology
Topic: Bypassing BMS for High Current Application
Replies: 5
Views: 1147

Re: Bypassing BMS for High Current Application

I had the same problem with electrifying a scooter with a ping-BMS. I used solenoids that where switched by the BMS power output but the power-lines were wired directly to the battery.
-Olaf
by olaf-lampe
Jun 07 2011 10:54am
Forum: Battery Technology
Topic: High C-rate LiFePO4 Polymer Battery
Replies: 27
Views: 3993

Re: High C-rate LiFePO4 Polymer Battery

I received an offer today. 4* 1765140, 3.2V 8.5Ah: US$17/PC 16​ * 132113156, 3.2V 18.5Ah: US$35/PC 1* active balancing BMS for 16s with 30/60A US$60/pc 1* 900W smartcharger for 48V : US$142/pc 1* 36V rear hub motor FG-R-100: US$69/PC Shipping cost for above: US$169 Shipping is cheaper to germany. ...
by olaf-lampe
Jun 07 2011 10:46am
Forum: Battery Technology
Topic: Doc GOT 100 samples of Titanate LTO cells update 6june 2011
Replies: 63
Views: 16311

Re: Doc GOT 100 samples of Titanate LTO cells update 6june 2

I was wondering, how you want to connect them? Spotwelding or soldering is a bit tricky with aluminium poles. Imagine the horror of building a big pack like in the tesla roadster and then have to exchange some bad ones over the years. :x Did you try to get some Li-Titanate cells from EIG too? IIRC t...
by olaf-lampe
Jun 06 2011 5:17am
Forum: Motor Technology
Topic: HE Cabling: Micro B USB Connectors
Replies: 21
Views: 4110

Re: HE Cabling: Micro B USB Connectors

Am I missing something? Why does the connector has to fit in ( or through ) the nut? You have to solder the hall wires inside the motor anyways. The only drawback I can think of, is: the nut can't get lost when the connector won't fit. :lol:
Or do you replace the nut regularly?

-Olaf
by olaf-lampe
Jun 06 2011 4:58am
Forum: Battery Technology
Topic: High C-rate LiFePO4 Polymer Battery
Replies: 27
Views: 3993

Re: High C-rate LiFePO4 Polymer Battery

I just asked for a quotation about 16pcs. of both celltypes.

Since I'm located in germany, do you like to share shipping cost with me? Or do you like to wait until I tested them?

-Olaf
by olaf-lampe
Jun 04 2011 5:49am
Forum: Motor Technology
Topic: 12 kw rc motor
Replies: 1876
Views: 196536

Re: 12 kw rc motor

sorry to say it arlo1 but i think your statment is not true.. KT (torque constant) is inversely proportional to KV. the delta/wye difference is sqrt3 (1.73). the output watts for both motors would be the same (if the efficiency is the same) but the delta motor has 1,73 times more rpm than the wye m...