Search found 185 matches

Mar 17 2013 10:35pm
Forum: General Discussion
Replies: 93
Views: 8695

I'm a CAD administrator for an aviation company. I manage an install of 70+ seats of 3D design software and an engineering database. My education is in mechanical engineering but I've always felt that I'm a bit more of in industrial designer. My design experience is with automated donut production m...
May 29 2012 10:45pm
Forum: Motor Technology
Topic: Motor Theory Head Check Needed
Replies: 2
Views: 452

Motor Theory Head Check Needed

Yo, I tested a Chinese BLDC and am starting to "run" the numbers. I measured: Kv=27.97 rpm/V Kt=.252 lb-ft/A Rmotor=.043ohms Noload: Io=1A, speed=1324rpm @ 48.6V (batt) So, here's where I need my head checked - if tis motor is stalled then the current at 48V through the .043ohm motor will be 1116A. ...
Jan 10 2012 12:18am
Forum: Motor Technology
Topic: How is KV Affected By Controller Type?
Replies: 1
Views: 341

How is KV Affected By Controller Type?

I've been trying to better understand KV for BLDCs by researching and taking measurements on my motors that I've spun up with a drill. In my research I've read one source that said the measured KV needs to be divided by .95 to correct for trapezoidal voltage wave forms used by BLDC controllers. My q...
Dec 18 2011 10:19pm
Forum: E-Bike Non-hub Motor Drives
Topic: Starting a Build From Scratch - Looking for Input
Replies: 1
Views: 419

Starting a Build From Scratch - Looking for Input

Hi All, I'm planning a <1000W mid-drive build from scratch. What I have right now is a concept and a basic design (more of a cartoon, really). Have a look: http://content.screencast.com/users/CADchannel/folders/Jing/media/358bd3e3-8e3b-4b36-ad09-40cff2d8223d/Iso_View_1.png http://content.screencast....
Oct 20 2011 11:57pm
Forum: Battery Technology
Topic: Low Tech SLA recycling !!
Replies: 16
Views: 1247

Re: Low Tech SLA recycling !!

I think the main point for "Nepal Guy" is that he is getting the battery (ergo lead) back into usage as opposed to sitting on the side of a hill polluting the environment. If he could boost the quality and get his customers to pay for it that would be WAY cool. When I was in India years ago I saw a ...
Oct 19 2011 10:40am
Forum: Motor Technology
Topic: New Controller - Strange Results
Replies: 6
Views: 748

Re: New Controller - Strange Results

I figured it out. Bad phase combo. I rewired and now the motor soins as expected.

Cheers!
Oct 17 2011 10:24pm
Forum: Motor Technology
Topic: New Controller - Strange Results
Replies: 6
Views: 748

Re: New Controller - Strange Results

I was expecting 1.53A because that's what the MFG specified. I'm using an Infineon based controller (Lyen's moded version). I corraborated the CA data with a multi meter as well. They match exactly. My only thought at this point is that maybe there is some weirdness with the controller and number of...
Oct 17 2011 7:41pm
Forum: Motor Technology
Topic: New Controller - Strange Results
Replies: 6
Views: 748

New Controller - Strange Results

I have a new ESC from Lyen, I wired it up and my motor worked on the first phase/hall sensor combo I tried. Yipee! However............. Under no-load conditions the motor spins twice as fast as I expected and draws 12A. Here's the low-down: BLDC (not sure if wye or delta) MFG says I should have a no...
Oct 03 2011 10:06pm
Forum: E-Bike Non-hub Motor Drives
Topic: Nuvinci developer kits for cheap
Replies: 505
Views: 59866

Re: Nuvinci developer kits for cheap

Here's a STEP file version. You'll need to unzip it.

If you spot any errors let me know and I can edit the file.
Oct 02 2011 11:52pm
Forum: E-Bike Non-hub Motor Drives
Topic: Nuvinci developer kits for cheap
Replies: 505
Views: 59866

Re: Nuvinci developer kits for cheap

If anyone is interested I can supply a 3D CAD model I made of the 171. I made it by measuring my Nuvinci. It's acurrate where it counts. There is a bit of guesstimation but not on anything that seems important i.e. flange outside dim, spoke circle pattern etc. If you are a 3D modeler you should be a...
Oct 02 2011 4:32pm
Forum: Motor Technology
Topic: What is the Technique for Measuring No-Load Current?
Replies: 6
Views: 597

Re: What is the Technique for Measuring No-Load Current?

OK.

Sounds like I can use the batt- to ESC current measured on my CA. I'll go with that.

Cheers.
Oct 01 2011 10:34pm
Forum: Motor Technology
Topic: What is the Technique for Measuring No-Load Current?
Replies: 6
Views: 597

What is the Technique for Measuring No-Load Current?

As the title says - what's the technique for determining actual Io? I guessing an ammeter would help but maybe using a shunt would be better. Also, I'm wondering how the different phase currents are handled. I expect an ammeter would measure the RMS value of the current but I'm assuming I would want...
Sep 27 2011 2:42pm
Forum: Motor Technology
Topic: Convert Ke Measured to "Actual" Ke ????
Replies: 5
Views: 682

Re: Convert Ke Measured to "Actual" Ke ????

Ya know, after I read the info i realized that i read all that before and somehow forgot...................it sucks getting old.....

Thanks for the link.
Sep 26 2011 11:20pm
Forum: Motor Technology
Topic: Convert Ke Measured to "Actual" Ke ????
Replies: 5
Views: 682

Re: Convert Ke Measured to "Actual" Ke ????

I measure each phase circuit individually with a volt meter measuring AC voltage.
Sep 26 2011 11:05pm
Forum: Motor Technology
Topic: Convert Ke Measured to "Actual" Ke ????
Replies: 5
Views: 682

Convert Ke Measured to "Actual" Ke ????

I have a BLDC (650W from Golden Motors) that I just spun up with a power drill. I measure the shaft RPM and the phase voltages. Now that I have this data I'm struck with the thought "how does measured Ke relate to Ke used in motor simulations"? My emperical data is: Phase 1 - 26.4 V/Krpm Pahse 2 - 2...
Sep 24 2011 10:15pm
Forum: Motor Technology
Topic: Effective Resistance - How Is It Calculated??
Replies: 2
Views: 444

Re: Effective Resistance - How Is It Calculated??

Cool. I was hoping that would be the case.
Sep 23 2011 11:25pm
Forum: Motor Technology
Topic: Effective Resistance - How Is It Calculated??
Replies: 2
Views: 444

Effective Resistance - How Is It Calculated??

I have a BLDC that I want to simulate in a motor simulator but I need to know the "resistance" of the motor. If I have it right I think I need the effective resistance (not just the winding resistance). I can measure the winding resistance but how do I calculate the effective resistance (so I can pl...
Sep 22 2011 2:30pm
Forum: Motor Technology
Topic: 4 Wire Method Power Supply
Replies: 3
Views: 588

Re: 4 Wire Method Power Supply

Once I get the resistance measured do I just use the average of the three phase resistances for my motor calcs?
Sep 22 2011 12:17am
Forum: Motor Technology
Topic: 4 Wire Method Power Supply
Replies: 3
Views: 588

4 Wire Method Power Supply

Hey All, I want to measure the resistance of a BLDC I have using the 4 wire method but I don't have a constant current power supply. My thought is to use an old cell phone charger for the constant current supply but I'm not sure if it's suitable (rated at 4.75V @ 0.55A). My second thought is to use ...
Sep 10 2011 5:07pm
Forum: E-Bike Non-hub Motor Drives
Topic: Astro motor information
Replies: 13
Views: 1860

Re: Astro motor information

Matt,
Any idea if the 3205 motor will live again? Hi power 3220's are cool but personally I'm more into low profile, moderate power applications.

Cheers!
Sep 07 2011 10:04am
Forum: E-Bike Non-hub Motor Drives
Topic: Cannondale Crimson
Replies: 31
Views: 5331

Re: Cannondale Crimson

Matt,
What shocks do you have fited to the white Hooligan?
Aug 29 2011 9:06pm
Forum: E-Bike Non-hub Motor Drives
Topic: Cannondale Crimson
Replies: 31
Views: 5331

Re: Cannondale Crimson

I've thought of mounting your V4 on this frame but don't know if it would fit. I imagined a 32XX motor could fit in the rear triangle between the tire and seat tube with the reduction sprocket nestled in the main frame triangle. Since you have all those parts there would you minf=d taking a look and...
Aug 27 2011 11:18pm
Forum: E-Bike Non-hub Motor Drives
Topic: Cannondale Crimson
Replies: 31
Views: 5331

Re: Cannondale Crimson

I have a Hooligan too. I like the bike a lot but I'd have to say the steering is a bit twitchy for me. I prefer a bit more trail....but it's still very fun to ride. I've been thinking of electrifying it as well.......

Does your fork setup affect steering geometry?
Jul 17 2011 7:13pm
Forum: E-Bike Non-hub Motor Drives
Topic: Group buy on 20 inch, 47mm wide rims.........
Replies: 92
Views: 11968

Re: Group buy on 20 inch, 47mm wide rims.........

I'd be down for 2 with 36 holes.
Aug 08 2010 6:18pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Motorcycles and E-scooters in China
Replies: 76
Views: 19119

Re: E-scooters in China

China is the land of the ebike/escooter! In terma of adoption they put western countries to shame. but according to that link I posted, this is govt backed forced adoption, and it seems like the main purpose of the gas scooter ban is to force the migrant workers out of the major cities... and keep ...