Search found 113 matches

by alan
Dec 23, 2017 11:16 am
Forum: Items for Sale - Used
Topic: FS: Two 26" Bionx P350 kits
Replies: 2
Views: 271

FS: Two 26" Bionx P350 kits

These are older units with all parts, but depleted batteries. Both have the newer bus design. One (grey) is eight years old with about 15K miles and has the throttle integrated with the console display. The other (white) is about five years old with about 12K miles and has the newer quieter and torq...
by alan
Jun 04, 2017 11:02 am
Forum: General Discussion
Topic: The paris accord
Replies: 7
Views: 437

Re: The paris accord

Inot a trump fanboi but he is correct when he sez it's all a money making scam. i would add it's also about further eroding freedom & more government control. any benefit to the environment is secondary & purely incidental. Pollution is real. It is also a scam in that the main polluters don't see t...
by alan
May 04, 2017 10:23 am
Forum: General Discussion
Topic: Resolved: NO SUCH THINGS AS TRAFFIC "ACCIDENTS"
Replies: 3
Views: 187

Re: Resolved: NO SUCH THINGS AS TRAFFIC "ACCIDENTS"

Pretty quixotic to try to redefine words. Accident and collision are two different things, even if they are not always properly used. You can have an accidental collision or an intentional collision. Accident alone is appropriate in conversational English (although perhaps not on a police report or ...
by alan
Apr 18, 2017 9:32 am
Forum: E-Bike General Discussion
Topic: how does this transmission work???
Replies: 5
Views: 441

Re: how does this transmission work???

A motor and generator are the same thing. An applied voltage to a motor/generator determines how fast it wants to turn. If it is turning faster, it generates power (current), which causes a drag that tries to slow it down. If it is turning slower, it pulls power (opposite direction current) to try t...
by alan
Mar 04, 2017 9:56 am
Forum: General Discussion
Topic: ...And that's why I don't like Intersections....
Replies: 7
Views: 418

Re: ...And that's why I don't like Intersections....

This was over 4 years ago on my way home from work (been retired 3 years!). I was heading south on College at a red light on Broadway. I was in the bike lane stopped next to a car. A hedge row blocked nearly all vision for me and the car to the nearest west-bound bike lane to our right. Those shrubs...
by alan
Dec 11, 2016 11:57 am
Forum: E-Bike Non-hub Motor Drives
Topic: Kepler Friction drive comes of age.
Replies: 324
Views: 29904

Re: Kepler Friction drive comes of age.

No spring in this design. Just another complication and unnecessary cost. Although the kick spring has its merrett, I have never been happy with how finicky it made the drive setup. Using a cable activation to get the drive to make light contact with the tire is so much more reliable. Just an idea....
by alan
Mar 22, 2016 7:53 am
Forum: E-Vehicles General Discussion
Topic: What Electric Automobile do you drive? Picture thread!
Replies: 14
Views: 968

Re: What Electric Automobile do you drive? Picture thread!

ELECTRICi3.jpg
(206.11 KiB) Downloaded 4 times
My EV is a i3 spaceship.
by alan
Mar 12, 2016 8:18 am
Forum: Motor Technology
Topic: Conclusive proof gearboxes are awesome.
Replies: 790
Views: 57414

Re: Conclusive proof gearboxes are awesome.

Honda already figured out a clever way to skip the very meaningful low power cruising losses. The result is a huge and heavy full size accord that has better performance and economy than the tiny engine lightweight CRX. This Honda hybrid is not a good comparison for this discussion. Honda started w...
by alan
Mar 11, 2016 12:20 pm
Forum: Motor Technology
Topic: Conclusive proof gearboxes are awesome.
Replies: 790
Views: 57414

Re: Conclusive proof gearboxes are awesome.

Show me a real world example of this and I will edit my comment. Are you saying the whole shaft slides back and forth? Are you saying the gear teeth will catch the two different shafts while spinning at different speeds? I have seen such a tranny used, but not in a transportation application (it wa...
by alan
Mar 11, 2016 12:07 pm
Forum: Motor Technology
Topic: Conclusive proof gearboxes are awesome.
Replies: 790
Views: 57414

Re: Conclusive proof gearboxes are awesome.

I considered the tesla direct drive as in the ratio of motor to wheel is always the same. ... I will quit saying direct drive unless talking about hub motors. You are correct that a hub motor is a direct drive. Even if the motor is connected to the wheel through a drive shaft with CV joints, I woul...
by alan
Mar 11, 2016 11:43 am
Forum: Motor Technology
Topic: Conclusive proof gearboxes are awesome.
Replies: 790
Views: 57414

Re: Conclusive proof gearboxes are awesome.

One side note- I have not seen much high scholastic study of magnetism on a quantum level. The field is fairly stagnant and held hostage imo by classical laws and thinking. I consider matter, magnetism, light, sound, and electricity to all be potentially the same thing- energetic wavelengths. ... I...
by alan
Mar 10, 2016 11:35 pm
Forum: Motor Technology
Topic: Conclusive proof gearboxes are awesome.
Replies: 790
Views: 57414

Re: Conclusive proof gearboxes are awesome.

A simple two-speed tranny can have an input shaft and an output shaft (exactly like a reduction gearset with the same number of bearings, having the same loading based almost entirely on the torque loads and not the mass of the gears) with two gears on each shaft. Say the input shaft has a large ge...
by alan
Mar 10, 2016 8:17 am
Forum: Motor Technology
Topic: Conclusive proof gearboxes are awesome.
Replies: 790
Views: 57414

Re: Conclusive proof gearboxes are awesome.

When ever you have additional gears to select they have friction points no matter how you try to build it. The gears not in use will be rolling on bearings at different speeds then the shaft causing drag/inefficiencies and they will have some sort of device like a shift fork to either move the dog ...
by alan
Mar 09, 2016 10:46 am
Forum: Motor Technology
Topic: Conclusive proof gearboxes are awesome.
Replies: 790
Views: 57414

Re: Conclusive proof gearboxes are awesome.

In the tesla example, if you were to make the motor roughly 3 times the diameter, you would have roughly the same low end torque in a direct drive setup. It should also be able to rev and pull way past the current cars top speed with the same technology. No? Larger motors will have lower max RPMs b...
by alan
Mar 08, 2016 1:35 pm
Forum: Motor Technology
Topic: Conclusive proof gearboxes are awesome.
Replies: 790
Views: 57414

Re: Conclusive proof gearboxes are awesome.

Trannies can be over 95% efficient. Motors can be more efficient, but are easily pushed outside that efficiency band down into the 75-85% range. A tranny can help keep a motor in a higher efficiency operating band, and that could more than make up for the tranny losses. Note that anything other than...
by alan
Feb 29, 2016 11:40 pm
Forum: Motor Technology
Topic: wye to delta on the go m-controller ?
Replies: 24
Views: 1304

Re: wye to delta on the go m-controller ?

The peak efficiency of a motor wound either way is going to be when the motor is loaded down to near one half the Kv no-load speed, assuming the electrical supply and controller are appropriate. No, that's wrong. Peak efficiency is achieved when the motor is loaded to the point where copper losses ...
by alan
Feb 29, 2016 8:47 am
Forum: Motor Technology
Topic: wye to delta on the go m-controller ?
Replies: 24
Views: 1304

Re: wye to delta on the go m-controller ?

I can't speak for locomotive drives, but large industrial AC induction motors frequently used wye-delta switching for start-up and it's purely to lessen the peak current draw from the supply. It's not used on smaller motors because the available current supply is sufficient to start in delta. So ye...
by alan
Feb 28, 2016 10:52 pm
Forum: Motor Technology
Topic: wye to delta on the go m-controller ?
Replies: 24
Views: 1304

Re: wye to delta on the go m-controller ?

I wish delta/WYE or series/parallel switching had the benefits you speak of, but they simply don't. Otherwise every manufacturer would put it on their vehicles. I believe the only reason you don't see winding switches is because you need a pretty hefty switch or relay for gains that are easier to m...
by alan
Feb 28, 2016 12:05 am
Forum: Motor Technology
Topic: wye to delta on the go m-controller ?
Replies: 24
Views: 1304

Re: wye to delta on the go m-controller ?

...they all have the exact same power/torque/efficiency potential when driven by an appropriate voltage/current source. Most people have a power source with a fixed maximum voltage and a more-or-less limited current capacity at (near) that max voltage. Changing Kv will allow one to get the most out...
by alan
Feb 27, 2016 8:27 am
Forum: Motor Technology
Topic: wye to delta on the go m-controller ?
Replies: 24
Views: 1304

Re: wye to delta on the go m-controller ?

Don't think of delta/WYE switching as an electronic transmission, because it's nothing of the sort. Sorry, but it is a speed/torque change exactly like a gear change. The energy in/out stays the same with the Kv and Kt moving oppositely. When the top speed is reduced 58%, the torque at 0 RPM is inc...
by alan
Feb 26, 2016 11:36 pm
Forum: Motor Technology
Topic: wye to delta on the go m-controller ?
Replies: 24
Views: 1304

Re: wye to delta on the go m-controller ?

It is simple to do with a triple pole, double throw switch or relay. Use a normal controller for the 3 top ends of the windings, and tie the three bottom ends to the switch or relay. The switch wiring is very easy to figure out. It works.
by alan
Feb 10, 2016 11:37 am
Forum: General Discussion
Topic: Are Electric Cars Really Green?
Replies: 91
Views: 4633

Re: Are Electric Cars Really Green?

Note that this video data comes from Prager University. Prager U is owned by Dennis Prager, and is an alternative on-line school. It is not a research university as implied. Prager is a well known right-wing Christian fundamentalist radio show host who denies climate change at every turn. A very sma...
by alan
Jan 30, 2016 9:45 am
Forum: General Discussion
Topic: Need Patent for start production
Replies: 39
Views: 1468

Re: Need Patent for start production

I believe that you have much more knowledge than me but let s think about drones! In case I put a 3D scanner on one of those I will be allowed to patent it if anyone did and can ask for rights of my patent if anyone started production? For sure it is more useful thing but nothing new, because quadc...
by alan
Jan 28, 2016 9:58 am
Forum: General Discussion
Topic: Need Patent for start production
Replies: 39
Views: 1468

Re: Need Patent for start production

Hi friends, I had a talk with my layer today and I shown him my problem and my doubts. He said that this bike that I want to build doesn t look patentable! Because it is just Union of several devices like a car or motorbikes. He said that I can get patent for some specific device than like heart ra...
by alan
Jan 28, 2016 9:33 am
Forum: Motor Technology
Topic: Windings: basic questions.
Replies: 276
Views: 11744

Re: Windings: basic questions.

You seem to be stuck with your idea of back-EMF being parasitic.......... I'm not "stuck with it", I simply know it to be so. Read back, follow the links. Stuck with it seems to be a perfect description of the problem. If one were to objectively read back and follow all of the links, one would like...