Search found 152 matches

by Erogo
Jul 31 2013 11:12pm
Forum: E-Bike Non-hub Motor Drives
Topic: Friction drive - 1kW junkyard sunday afternoon project -
Replies: 81
Views: 9249

Re: Friction drive - 1kW junkyard sunday afternoon project -

... How about two motors side by side with the tire inbetween (so the motor contact the tire sidewall) ? Less force per motor plus the sidewalls are pretty clean (no grit and dirt picked up from the street) Or, how about the two motors contact the RIM, to get less churning loss? Some frames even ha...
by Erogo
May 31 2012 9:32pm
Forum: General Discussion
Topic: Motorcyclist clocked at 193 mph on NY highway - in the rain!
Replies: 125
Views: 7388

Re: Motorcyclist clocked at 193 mph on NY highway - in the r

Ha ha good call Tyler. Yeah, society sets up laws that reflect the desire of the majority of its citizens. Some of them are preventative, targeting some situations of increased risk - driving drunk, driving too fast, leaving babies at home unattended etc etc. Presumably the citizens of that society ...
by Erogo
Dec 08 2011 7:43pm
Forum: Motor Technology
Topic: Good! Someone finally oil cooled a hubbie!! HS3540
Replies: 130
Views: 25209

Re: Good! Someone finally oil cooled a hubbie!! HS3540

The right epoxy, and the right oil. The oilbath fella tested his oil before sticking it in his motor. Nothing if not thorough, that fella.
by Erogo
Oct 10 2011 9:12pm
Forum: E-Bike Non-hub Motor Drives
Topic: Excel friction drive prototyping tool
Replies: 0
Views: 351

Excel friction drive prototyping tool

I've made a spreadsheet up that does various figuring out for friction drives. It calculates the force required between the roller (motor can) and the wheel, under different accelerations, rider weights, gradients etc. It estimates what the actual RPM of the motor will be, given the kv and the load ...
by Erogo
Oct 10 2011 7:02pm
Forum: Battery Technology
Topic: Very Simple String-Capacity Question
Replies: 28
Views: 1515

Re: Very Simple String-Capacity Question

"String" seems like a bad word to use for paralleled cells. A string would normally imply series cells. Like a string of sausages. That and the fact that you had to say
The Mighty Volt wrote:Hi John, that "s" is meant to be a "p". 12s8p
makes it seem like you're confused between parallel and series! Be careful!

Eric
by Erogo
Oct 10 2011 5:12pm
Forum: Battery Technology
Topic: Please help with Electricity Math
Replies: 23
Views: 1891

Re: Please help with Electricity Math

I'd strongly recommend heatsinking the lipos against the petrol tank. The mass of fluid within should keep the lipo at an optimum working temperature, ensuring you get maximum life from them. Probably using the metal of the petrol tank as a common earth is a good idea as well, you can use your batte...
by Erogo
Oct 10 2011 4:58pm
Forum: Battery Technology
Topic: Please help with Electricity Math
Replies: 23
Views: 1891

Re: Please help with Electricity Math

Hmm, that doesnt sound too bad actually does it vokus! And as Hillhater pointed out, your 700w is probably max, so you'd get more than your five hours out of it. Or you could run somethign else off it at the same time, like a decent sound system. You'd have to power a screen of some sort as well eh? E
by Erogo
Oct 10 2011 3:27pm
Forum: Battery Technology
Topic: Please help with Electricity Math
Replies: 23
Views: 1891

Re: Please help with Electricity Math

700 watts for five hours? You need 3500 watt hours of capacity. If you get your lipo seriesed up to deliver 120V, then your 700 watts will be drawing about 5.8 amps. So you need to deliver 5.8 amps for five hours? 29 amp hours. Most packs are speced in milliamp hours, so you need to get 29000 millia...
by Erogo
Oct 09 2011 3:24pm
Forum: E-Bike Non-hub Motor Drives
Topic: Commuter Booster - <1kg Friction Drive
Replies: 1344
Views: 232901

Re: Commuter Booster - <1kg Friction Drive

Hey Adrian, good to hear the progress! I hope you're having fun, with it so close to completion. My two cents: 1) Youve got wiring to the front already hey, for the display? It might not be too much more hastle to have another pair for the wheel sensor? Would the extra length be subject to interfere...
by Erogo
Oct 07 2011 4:10am
Forum: Motor Technology
Topic: Joby Motors Santa Cruz, CA
Replies: 126
Views: 22293

Re: Joby Motors Santa Cruz, CA

That sucks eh. We're all (ok 99% of all) shopping by cost, buying the cheapest we can find, bleating when the $60 WangFo motor that some kid put together at 2am working for a dollar a day doesn't have it's windings tied down tight, and uses an economy grade bearing. Who was it said: "Noone ever regr...
by Erogo
Oct 06 2011 10:07pm
Forum: General Discussion
Topic: How cr4ppy?
Replies: 14
Views: 970

Re: How cr4ppy?

OK I think it's an ezipp Made in India, rated at 250w with 48v of SLA The one in the shop sold, but get this: There's another one available because the original purchaser has given it away to the local women's refuge, who don't want it either. So they dont know how to get rid of it, being that it's ...
by Erogo
Oct 05 2011 3:43pm
Forum: E-Bike Non-hub Motor Drives
Topic: The Brevette "Winchini": a push baby-trailer
Replies: 10
Views: 1459

Re: The Brevette "Winchini": a push baby-trailer

Did some more sawing and drilling and filing last night. Cause I found that when I bolted the newly secure motor to the trailer, the wheel couldn't go round any more. I traced it to the fact that the new retention plate was pressing hard against the tire. Stink. The thing's getting too big what with...
by Erogo
Oct 05 2011 3:28pm
Forum: General Discussion
Topic: battery health by listening to it?
Replies: 20
Views: 1275

Re: battery health by listening to it?

You're not using sound waves anyway, you're using radio waves. But, go ahead and isolate the charger from the experiment by placing it in a faraday cage if you have one handy, or just shielding it in copper. I'd lend you the copper hat I use to prevent the government beaming their messages straight ...
by Erogo
Oct 04 2011 3:00pm
Forum: E-Bike Non-hub Motor Drives
Topic: Nuvinci developer kits for cheap
Replies: 501
Views: 54989

Re: Nuvinci developer kits for cheap

Hey McLovin - what about the insides ;-)
by Erogo
Oct 03 2011 3:38pm
Forum: General Discussion
Topic: How cr4ppy?
Replies: 14
Views: 970

Re: How cr4ppy?

Ah, but headaches is what life's all about, isn't it? If you can always get what you want, you don't appreciate it any more. Yes, this is just a hubmotor in a small wheel. I reckon it should be midmountable, via some sort of bodgy bracketing and lots of duct tape. As a moped styles, it's also got a ...
by Erogo
Oct 03 2011 3:40am
Forum: General Discussion
Topic: How cr4ppy?
Replies: 14
Views: 970

Re: How cr4ppy?

Yeah the old junk yard hat is pretty well-worn. You've seen my Brevette Winchini build maybe. This could be a good alternative approach to motivating the baby trailer, if I wasn't so far down the current path already! The motor would be a bit tricky to lace, being one piece casting out to the rim yo...
by Erogo
Oct 02 2011 6:46pm
Forum: General Discussion
Topic: How cr4ppy?
Replies: 14
Views: 970

Re: How cr4ppy?

That was what I was thinking last night. If the magnets are really shiny, I'll get it. Do you think there's any possibility they're just using ferrite magnets? I guess anything's possible eh. $250 : approved in advance by my exceptionally encouraging and supportive partner : isn't much more than a w...
by Erogo
Oct 02 2011 3:44pm
Forum: General Discussion
Topic: How cr4ppy?
Replies: 14
Views: 970

Re: How cr4ppy?

Yeah nah, I think I might be wrong about that "Ezee" bit. It wasnt heavily plastered with brandname, kinda anonymous looking. Generic almost. Like they were trying to hide something, or at least not sign their name to it. I think I'll get it. I mean, NZ$250? The batteries alone have to be worth that...
by Erogo
Oct 01 2011 2:52am
Forum: E-Scooter and Motorcycle General Discussion
Topic: lit motors c-1
Replies: 116
Views: 6699

Re: Lit motors C1... gyro, enclosed, electric 2 wheeler

For me that would depend on the total package. On-road costs, warranty, insurance cover, public liability, service agreement etc.

If the price was right.
by Erogo
Sep 26 2011 4:14am
Forum: E-Scooter and Motorcycle General Discussion
Topic: lit motors c-1
Replies: 116
Views: 6699

Re: Lit motors C1... gyro, enclosed, electric 2 wheeler

Hey PTD, I'm not a gyroscope expert by any means, but I don't see what the forces in the other two planes are. My understanding of a gyroscope is a mass spinning on an axis. The axis lays on one dimension. If you apply a torque to the axis in a dimension orthogonal to the axial dimension, a reaction...
by Erogo
Sep 26 2011 3:59am
Forum: E-Bike Technical
Topic: Brushless razor e300
Replies: 16
Views: 2447

Re: Brushless razor e300

Did you say the motor has a 1mm shaft? If so, that seems real small to me. I'm more used to bicycle loads, where I think 8 mm or so is needed. You can calculate the torque that the shaft would need to withstand to achieve the acceleration you're hoping for, then calculate the maximum torque a shaft ...
by Erogo
Sep 24 2011 3:35am
Forum: General Discussion
Topic: How cr4ppy?
Replies: 14
Views: 970

Re: How cr4ppy?

But, but, they were originally trying to sell them for $1000 or $2000 or something, and this is the last one left. Surely it's really good eh? It's called an ezee scooter or something. The name on the forks is "no comeback". Odd.
by Erogo
Sep 24 2011 1:08am
Forum: General Discussion
Topic: How cr4ppy?
Replies: 14
Views: 970

How cr4ppy?

Wondering: "How crappy can an e-scooter get?" The LBS has one new for 250 of our local dollars. That's about, what, US$180 or something? It's 48v, can only assume PbH+, and is probably compliant with NZ law on electric bicycles, which I can't remember (don;t care) whether it's 300w max or 600w max. ...
by Erogo
Sep 24 2011 12:57am
Forum: E-Bike Non-hub Motor Drives
Topic: The Brevette "Winchini": a push baby-trailer
Replies: 10
Views: 1459

Re: The Brevette Winchini: a push baby-trailer

thanks Pony. I got another bit done, which is the main retention plate. Simply a fold of aluminium, screwed to the end of the stub of shaft that sticks into the nylon bit that's bolted to the chain ring, and also screwed to the gearbox housing through a little flange bit I hadnt noticed before, and ...
by Erogo
Sep 23 2011 9:31pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: lit motors c-1
Replies: 116
Views: 6699

Re: Lit motors C1... gyro, enclosed, electric 2 wheeler

Yes (in a standard bicycle at least) it has been shown that the gyroscopic effect of the wheels, while traditionally believed to be essential to self-stability, is in fact not necessary. Gyros designed for the purpose have to be a different story though! I posted a link to a paper describing a test-...