Search found 265 matches

by oofnik
Jul 05 2009 1:19pm
Forum: Battery Technology
Topic: Nylon lock nuts on battery cells?
Replies: 21
Views: 1383

Re: Nylon lock nuts on battery cells?

I would say metal nuts with lock washers would be best. You'll get more surface area for current flow and reduce the chances of heating at the terminals.
by oofnik
Jun 22 2009 10:01am
Forum: Battery Technology
Topic: Kayo Battery?
Replies: 18
Views: 1224

Re: Kayo Battery?

Thank you for the report Gchassi! It is always good to have positive reports from different manufacturers about their products. Competition brings prices down.
by oofnik
Jun 21 2009 12:35pm
Forum: E-Bike Non-hub Motor Drives
Topic: Friction drive outrunner setup. New DJ bike.
Replies: 360
Views: 70869

Re: Friction drive outrunner setup

Awesome! Glad to hear it's running so well. :mrgreen:
What voltage did you say you're running at? My motor gets quite hot at 36 volts after a few hard miles, almost too hot to touch. A fan sure would be nice :P
by oofnik
Jun 13 2009 6:09pm
Forum: E-Bike Non-hub Motor Drives
Topic: Mongoose DX project
Replies: 208
Views: 27039

Re: Mongoose DX project

Gary, the printer I'm using is a Konica Minolta PagePro 1400W. It was $10 at a thrift store. I'm pretty sure there's nothing special about it besides being super cheap. :mrgreen:
by oofnik
Jun 13 2009 5:54pm
Forum: E-Bike Non-hub Motor Drives
Topic: Fechter's Throttle Interface for RC controllers
Replies: 458
Views: 39408

Re: Fechter's Throttle Interface for RC controllers

Hey Richard, I'm going to use your circuit with the Allegro sensor already on my Eagle Tree logger. But there's a small problem: the +5 supply for the sensor on the Eagletree board comes in 10ms pulses, and so does the output signal. I'm not sure if this will be compatible with the analog input on y...
by oofnik
Jun 12 2009 10:05am
Forum: E-Bike Non-hub Motor Drives
Topic: Mongoose DX project
Replies: 208
Views: 27039

Re: Mongoose DX project

So I'm back in the States, and I had to try the magazine PCB method right away. Here's a picture of my first attempt, which isn't quite perfect: IMG_4709_800.JPG Version 2 will be printed with thicker traces and I'll need to find a drill bit smaller than 1/16". From start to finish this is a pretty ...
by oofnik
May 28 2009 3:57am
Forum: Battery Technology
Topic: 3KWhr/Kg batteries??
Replies: 2
Views: 399

Re: 3KWhr/Kg batteries??

Your link was garbled: http://chemistry.st-and.ac.uk/staff/pgb/group/lio.html

It's frustrating to watch all these new battery technologies emerge in laboratories and have to wait years for them to appear on the market... that is, assuming they actually ever do. :(
by oofnik
May 27 2009 7:15am
Forum: E-Bike Non-hub Motor Drives
Topic: Fans for RC motors
Replies: 25
Views: 3113

Re: Fans for RC motors

I haven't taken my fluid mechanics class yet but I'm sure they cover some of this theory to some extent.. I just followed the design of vacuum cleaner impellers, which seem to work fairly well for their application. They all have either straight or very slightly curved vanes, and most of them are al...
by oofnik
May 26 2009 4:58am
Forum: E-Bike Non-hub Motor Drives
Topic: Fans for RC motors
Replies: 25
Views: 3113

Re: Fans for RC motors

Thanks Miles!
by oofnik
May 26 2009 12:24am
Forum: E-Bike Non-hub Motor Drives
Topic: Fans for RC motors
Replies: 25
Views: 3113

Fans for RC motors

I'm making a new thread about keeping our RC motors cool. Feel free to post your solutions, concerns, or whatever relating to this topic. EVTodd and I are working out the design for a fan for the TowerPro 5330 motor. I'll post a pic of the design here again for reference: http://endless-sphere.com/f...
by oofnik
May 26 2009 12:16am
Forum: E-Bike Non-hub Motor Drives
Topic: Cortina Hard Tail Build
Replies: 51
Views: 10722

Re: Cortina Hard Tail Build

Apologies Roy :oops: You're right.
by oofnik
May 25 2009 2:44pm
Forum: E-Bike Non-hub Motor Drives
Topic: Fans for RC motors
Replies: 25
Views: 3113

Re: Cortina Hard Tail Build

Hmm, can you provide some more details about why the fans didn't work so well? It's hard to judge the depth from your picture but maybe there wasn't enough volume between the vanes to move enough air?
by oofnik
May 24 2009 11:54pm
Forum: E-Bike Non-hub Motor Drives
Topic: Fans for RC motors
Replies: 25
Views: 3113

Re: Cortina Hard Tail Build

I don't remember if I posted the cad file but here it is in STEP format, exported from Inventor 2010. I know Matt writes his own g-code because he's hardcore :P but I think it would be easier to work off of my design in a CAD/CAM suite to compile the g-code. I'm not too familiar with the entire CNC ...
by oofnik
May 24 2009 11:43pm
Forum: Battery Technology
Topic: a123 on ebay again
Replies: 21
Views: 2290

Re: a123 on ebay again

My roommate from Taiwan has indirect ties to A123. He actually spoke with this seller previously and can vouch for his legitimacy. Please don't PM me looking for a deal.. I already tried and it's not gonna happen. I'm curious though about the cells being sold by Voltman. I'm tempted to buy one to ch...
by oofnik
May 24 2009 9:43am
Forum: E-Bike Non-hub Motor Drives
Topic: Fans for RC motors
Replies: 25
Views: 3113

Re: Cortina Hard Tail Build

Bubba, I actually tried that on the bench before I mounted my motor, but I was unhappy with the results. I even put a shroud around it to keep the air flow directed. But no matter what I tried it seemed to create more turbulence than anything. Do you actually notice your motor running cooler with th...
by oofnik
May 23 2009 11:41pm
Forum: E-Bike Non-hub Motor Drives
Topic: High power RC motor and drive unit production
Replies: 1181
Views: 126018

Re: High power RC motor and drive unit production

So, I am a health nut. Can I drink Kefir instead? :mrgreen: Mmmm, kefir... good stuff. Anyway I originally scoffed at the price Matt quoted. But then I thought about all the work that goes in to designing and actually making such a thing, even if you do a production run of several units at a time. ...
by oofnik
May 23 2009 11:17pm
Forum: E-Bike Non-hub Motor Drives
Topic: Fans for RC motors
Replies: 25
Views: 3113

Re: Cortina Hard Tail Build

That's right, I forgot you had the same motor. :mrgreen: Yes it should be identical. About the material, I think Matt mentioned that he made his fan on the recumbent out of delrin and I don't think he had any problems with that. Loc-tite should prevent any potential problems however. The screws have...
by oofnik
May 23 2009 2:22pm
Forum: Battery Technology
Topic: a123 on ebay again
Replies: 21
Views: 2290

Re: a123 on ebay again

I want to bump this thread to see if anybody has checked out these cells yet. Here's the link.
by oofnik
May 23 2009 12:33pm
Forum: E-Bike Non-hub Motor Drives
Topic: Fans for RC motors
Replies: 25
Views: 3113

Re: Cortina Hard Tail Build

No, they will probably be some kind of plastic. Todd, are your motor measurements the same? The OD is 63mm, shaft dia. is 8mm. Mounting holes are 10 mm from shaft center. Bell angle is 20 deg. These measurements were taken on my TowerPro motor and were used for my fan design. He can probably make th...
by oofnik
May 22 2009 5:00pm
Forum: E-Bike Non-hub Motor Drives
Topic: New Castle controllers coming and other ESC info......
Replies: 8
Views: 950

Re: New Castle controllers coming and other ESC info......

Great news, Matt. Thanks for keeping us informed. Looking forward to hearing more about these.
by oofnik
May 22 2009 4:51pm
Forum: E-Bike Non-hub Motor Drives
Topic: Twin motored PK Ripper--A little over the top!
Replies: 358
Views: 41615

Re: Twin motored PK Ripper--A little over the top!

Haha, yep.. it's a step above a random guess at least :D. I think we all try to calculate Wh used for the same reason. You should try the accurate method with some e-logger data some time to see how far off your measurement really is. What do you have your recording interval set at?
by oofnik
May 22 2009 3:41pm
Forum: E-Bike Non-hub Motor Drives
Topic: Twin motored PK Ripper--A little over the top!
Replies: 358
Views: 41615

Re: Twin motored PK Ripper--A little over the top!

Matt, On the topic of Wh usage, I know the Eagle Tree doesn't calculate this directly. It calculates mAh used only. I don't know if you are already doing it this way, but in order to arrive at an accurate calculation of watt-hours you must actually integrate over the interval numerically, either by ...
by oofnik
May 22 2009 3:25pm
Forum: E-Bike Non-hub Motor Drives
Topic: Cortina Hard Tail Build
Replies: 51
Views: 10722

Re: Cortina Hard Tail Build

Hi Roy, very nice work! I really like your build. It is very clean and looks quite nice. A video would be pretty great. :D After I made my plans for left hand drive, I started thinking about the advantages of going the freewheel crank route. It definitely does seem to present an advantage. But since...
by oofnik
May 17 2009 12:59pm
Forum: E-Bike Non-hub Motor Drives
Topic: Using two drive chains to one hub - one on each side?
Replies: 34
Views: 6777

Re: Using two drive chains to one hub - one on each side?

I used Matt's idea on my Mongoose: IMG_4704_640.JPG IMG_4705_640.JPG I machined an adapter on the lathe to fit over the left side brake disc mount. It's done in two pieces so that I could get a chain line offset large enough to clear my chain stays. Otherwise the giant sprocket was too far out and t...
by oofnik
May 16 2009 11:02pm
Forum: E-Bike Non-hub Motor Drives
Topic: Mongoose DX project
Replies: 208
Views: 27039

Re: Mongoose DX project

You know, now that you mention it, I probably could print out the layout on one of those iron-on t-shirt transfer sheets, and then use a copper board instead of a t-shirt. *15 seconds of googling* There are so many ways to do this. Google "iron on pcb" or "inkjet pcb". Fascinating. I'll have to look...