Search found 2798 matches

by speedmd
May 19 2020 8:56pm
Forum: Large EV General Discussion
Topic: Polaris Ranger EV
Replies: 31
Views: 9518

Re: Polaris Ranger EV

The chassis wire -switches- lights are 12v, and share many of the Ice components. I most likely will leave a second- 12v battery in it if easier. May make it easier to have a onboard LI battery heater connected for those times it may be needed and no outlet is near by for the overnight ac heater set...
by speedmd
May 12 2020 5:22pm
Forum: Motor Technology
Topic: Leaf / leafmotor / leafbike high efficiency 1500w motor
Replies: 1589
Views: 223556

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

It’s consistent across the entire range I’m aware of. But to your point, now that I looked it up in a table, I find that the difference in gauge for a 2:1 cross-sectional area ratio is in fact 3, not 2. :oops: And the 2:1 ratio is exact, not approximate. Yes the 3x rule works, but that leaves you p...
by speedmd
May 12 2020 8:04am
Forum: Motor Technology
Topic: Leaf / leafmotor / leafbike high efficiency 1500w motor
Replies: 1589
Views: 223556

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

the approximate ratio of cross-sectional area is 2:1 Yes, and if your into approximates, that is suitable. Unfortunately that only holds relatively consistently for part of the range. Fine multi Stranding, also makes it difficult to compare physically and the open metal wire gauges difficult to use...
by speedmd
May 11 2020 7:21pm
Forum: Motor Technology
Topic: Leaf / leafmotor / leafbike high efficiency 1500w motor
Replies: 1589
Views: 223556

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

ZeroEm wrote: ↑May 11 2020 10:09am The leafmotor from leafbikes Called "black magic" comes with 3mm phase wires, between 8-9 gauge awg Which gauge converter are you using? The term "Gauge" varies with materials. To my understanding, Tradition is from firearms making balls from a pound of lead. Shee...
by speedmd
May 01 2020 4:27pm
Forum: Large EV General Discussion
Topic: Polaris Ranger EV
Replies: 31
Views: 9518

Re: Polaris Ranger EV

14S, 7 of the leaf modules should be a direct drop in. You may need check the stock controller programing for a suitable low voltage cut off for Li packs. Put a voltage indicator or alarm on the pack so you don't get too low if your exploring. The BMS I am waiting for will take care of that issue. I...
by speedmd
May 01 2020 3:46pm
Forum: E-Bike General Discussion
Topic: Broken Spokes (On Going Problem)
Replies: 52
Views: 1292

Re: Broken Spokes (On Going Problem)

+1 on the stronger / heavier rim. Glad to see your replacing all the spokes. Any of the ones not broken, would most likely have been compromised structurally. The limiting factor to building the most stable wheels is the rim in most cases. It is what limits how tight you can string it also. It is al...
by speedmd
May 01 2020 10:58am
Forum: General Discussion
Topic: Best power to weight hub motor..?
Replies: 25
Views: 730

Re: Best power to weight hub motor..?

I posted some of the motor choices in another thread. https://endless-sphere.com/forums/viewtopic.php?f=28&t=68950 The 20KW would make a good flying motor IMO. Listed at 5KG It looks to be able to run on reasonable low voltage. http://mymobilemms.com/OFFTHEGRIDWATER.CA/images/238-50b.jpg With a free...
by speedmd
Apr 30 2020 7:39pm
Forum: General Discussion
Topic: Best power to weight hub motor..?
Replies: 25
Views: 730

Re: Best power to weight hub motor..?

Flying ebike? :shock:
Image
by speedmd
Apr 30 2020 2:01pm
Forum: General Discussion
Topic: Best power to weight hub motor..?
Replies: 25
Views: 730

Re: Best power to weight hub motor..?

Two 6 - 12 foot propellers? How fast are they turning? Looking like a rc style outrunner would be it as mentioned before if your not needing to spoke or tire it for wheel use. Freewheeling crank set will allow you to direct mount a second sprocket if your planning on adding human power and using cha...
by speedmd
Apr 30 2020 6:01am
Forum: E-Bike General Discussion
Topic: Broken Spokes (On Going Problem)
Replies: 52
Views: 1292

Re: Broken Spokes (On Going Problem)

When your tension comes out of the wheel, you end up with one or two of the tighter spokes taking huge loads rather than spreading the loads out about the wheel through many spokes. As most here now understand, the thicker spokes allow for much less stretch and easier to become unsprung with minimal...
by speedmd
Apr 29 2020 7:37pm
Forum: E-Bike General Discussion
Topic: Broken Spokes (On Going Problem)
Replies: 52
Views: 1292

Re: Broken Spokes (On Going Problem)

It does look like maybe the hole is a bit too big and or thick flange is helping ripping the caps off. All look like that? Is there room for washer? You want the spoke to start load transferring at the spoke bend and not bend and load at the cap base. Your healthy spokes and hole dents should lend s...
by speedmd
Apr 29 2020 2:58pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Observed trials bike designing
Replies: 98
Views: 6067

Re: Observed trials bike designing

For Trials, the pegs are offset to the rear and set high and as inward as you can get for clearance. Crank puts you at potential disadvantage in both aspects. Fresh build could be set near anywhere you wish. Ideal would be a crank set that folds out of the way, and pegs that fold down for segment use.
by speedmd
Apr 28 2020 8:58am
Forum: E-Bike Technical
Topic: Does acceleration affect range?
Replies: 14
Views: 410

Re: Does acceleration affect range?

This one is hard to put a rule of thumb on. Agree, it depends on a bunch of factors and your motor efficiency plot. Wishful that most of the common low cost motors are like a prius motor, but if we use the common plot, we can understand it a bit more IMO. Let say that a moderate target cruising spe...
by speedmd
Apr 27 2020 7:28am
Forum: E-Scooter and Motorcycle General Discussion
Topic: Observed trials bike designing
Replies: 98
Views: 6067

Re: Observed trials bike designing

I sometimes wonder why there seems to be a bit of a black and white division between mechanical / electronic. It has often seemed to me that electronics oriented people want to solve every problem electronically when there can be a perfectly reasonable mechanical solution Thinking most have not fal...
by speedmd
Apr 26 2020 7:33pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Observed trials bike designing
Replies: 98
Views: 6067

Re: Observed trials bike designing

Rotors on most of the electric motors per KW are near equal in rotational mass to ICE race motors. Overshoot! :shock: A bit of clutch mass will mate well. Long term, no doubt that throttle only, with brake and reverse (with the help of more advanced controller brain and proper programing of motion c...
by speedmd
Apr 26 2020 3:34pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Observed trials bike designing
Replies: 98
Views: 6067

Re: Observed trials bike designing

Jr class Gokarts run 28hp 125cc rotex 2 strokes and stall carts movement with the motor revving with gobs of throttle with brakes on and off for some time in the pits before heading out to race and still get many hours on clutch drums. It would not take much pressure to lock them up relatively tight...
by speedmd
Apr 26 2020 1:35pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Observed trials bike designing
Replies: 98
Views: 6067

Re: Observed trials bike designing

Friction is good simple torque limiter for certain. Centrifugal also has the ability to freewheel, roll backwards a bit easier. A combination of the two on a clutch lever could be setup to release motor or engage it if springs were just reversed (compression vs tension) and cable pulled -(compressed...
by speedmd
Apr 26 2020 10:57am
Forum: E-Scooter and Motorcycle General Discussion
Topic: Observed trials bike designing
Replies: 98
Views: 6067

Re: Observed trials bike designing

standard for what? where does it go? is it possible to say "limit torque to 150 N.m ?" Sorry, if you could link to some basic learning resources I'd greatly appreciate it. Sorry, hard to judge where folks are starting from at times. Tons of google results on them, so best to get that at where your ...
by speedmd
Apr 26 2020 10:39am
Forum: E-Bike Technical
Topic: Does acceleration affect range?
Replies: 14
Views: 410

Re: Does acceleration affect range?

Best to give it some extra current to get to cruising speed quicker than to gingerly creep up to it over a much longer time in general within some limits. At starting RPMs you have very low efficiency in the motor, so dumping too much current,will result in a significant amount of it going into heat...
by speedmd
Apr 26 2020 9:46am
Forum: E-Scooter and Motorcycle General Discussion
Topic: Observed trials bike designing
Replies: 98
Views: 6067

Re: Observed trials bike designing

A standard centrifugal clutch with a weaker spring would be a easy way to keep peak torque out and still have some lower rpm torque.
Image
by speedmd
Apr 24 2020 9:22am
Forum: E-Vehicles General Discussion
Topic: 60v battery pack on 48v motor
Replies: 1
Views: 268

Re: 60v battery pack on 48v motor

It will just run faster. No issues unless you run it very slow - uphill for extended periods. That would run the motor in lower efficiency range where heat could start to run away. Other thing you will want to check is the low voltage shutoff of the controller as it may be a bit low for the battery.
by speedmd
Apr 24 2020 8:13am
Forum: General Discussion
Topic: Electric Racing Chainsaw Build, Help Please
Replies: 129
Views: 5543

Re: Electric Racing Chainsaw Build, Help Please

Once you get above the 57- 58 Rc hardness, conventional files skate across the surface of most steels. Some alloying elements will help create this skating effect. At 60 Rc, you are getting into needing silicon carbide stones to efficiently cut into most hardenable steels at hand speeds. Many steels...
by speedmd
Apr 23 2020 7:05am
Forum: Motor Technology
Topic: Roman Kostrygin - Sur-Ron 16kw outrunner
Replies: 66
Views: 8334

Re: Roman Kostrygin - Sur-Ron 16kw outrunner

serious_sam wrote:
Apr 23 2020 6:45am
speedmd wrote:
Apr 23 2020 6:03am
With steady state torque levels, Chain loads would increase with more ratio reduction (smaller motor sprocket) and would bend shaft - motor structure more.
Lucky edit ;-)
Yes. the world is much clearer with that second cup of coffee. :lol:
by speedmd
Apr 23 2020 6:56am
Forum: General Discussion
Topic: Electric Racing Chainsaw Build, Help Please
Replies: 129
Views: 5543

Re: Electric Racing Chainsaw Build, Help Please

Most likely all this stuff is on a glide path until c19 settles into a steadier state of affairs. As far a cutting is concerned, most old time wood workers and chefs can tell you that nothing cuts like sharp high quality steel. Carbides, diamond, ceramics will certainly out last and able to cut more...
by speedmd
Apr 23 2020 6:03am
Forum: Motor Technology
Topic: Roman Kostrygin - Sur-Ron 16kw outrunner
Replies: 66
Views: 8334

Re: Roman Kostrygin - Sur-Ron 16kw outrunner

A larger motor sprocket would certainly stiffen (Increase) the impact of what Aberwolf is describing. A larger rear sprocket would reduce this. Much like jumping on a diving platform vs a diving board. Huge impact force difference if you land wrong on your feet-legs on a ridged platform. With steady...