Search found 134 matches

by BobBob
May 04 2021 2:20pm
Forum: EBike Technical
Topic: Do some motors have more/less torque with the same power levels?
Replies: 17
Views: 393

Re: Do some motors have more/less torque with the same power levels?

With nothing but mechanical gear and winding changes, bike b is going faster while using less power, and not overheating, due to better efficiency due to the motor spinning faster. https://ebikes.ca/tools/simulator.html?motor=MMAC10T&batt=cust_36_0.2_16&cont=cust_150_300_0.02_V&grade=6&a...
by BobBob
May 04 2021 1:53pm
Forum: EBike Technical
Topic: Do some motors have more/less torque with the same power levels?
Replies: 17
Views: 393

Re: Do some motors have more/less torque with the same power levels?

So it's as I thought then. If they are geared to the same max speed (meaning the winding is irrelevant, right?) and powered with the same controller, they should have the same performance, unless one motor is more efficient than the other. In which case the more efficient motor will have better per...
by BobBob
May 04 2021 11:44am
Forum: EBike Technical
Topic: Do some motors have more/less torque with the same power levels?
Replies: 17
Views: 393

Re: Do some motors have more/less torque with the same power levels?

The gear ratio difference also brings up the topic of efficiency. At half RPM one motor will be less efficient than the other at lower speeds. Pole switching frequency plays a huge role in efficiency levels at low speeds so the "Slow Wind" motor converts more power to heat. Efficiency los...
by BobBob
May 04 2021 6:49am
Forum: EBike Troubleshooting
Topic: Blown Controller Mosfets!Is it worth replacing?
Replies: 6
Views: 137

Re: Blown Controller Mosfets!Is it worth replacing?

I would compare the blown channel with the good ones. It is likely that voltages on the control circuits will be similar and you have 6 sets of the same circuit so hopefully can see if something is different. Can you guide me as to what I have to check? I only have a multimeter but I can give the b...
by BobBob
May 03 2021 8:11pm
Forum: EBike Technical
Topic: PowerVeloCity F18-100 controller, not working
Replies: 13
Views: 338

Re: PowerVeloCity F18-100 controller, not working

Could be a bit of dirt but hope that fixes it but if the micro is blown it's probably more tricky. And yes, I agree, not impressive quality I've been looking for higher voltage so have limited options, there's nothing much at 150V and not many at 120v The YKZ120150 is a little cheaper and goes up to...
by BobBob
May 03 2021 7:38pm
Forum: EBike Technical
Topic: Do some motors have more/less torque with the same power levels?
Replies: 17
Views: 393

Re: Do some motors have more/less torque with the same power levels?

The bigger motor can potentially provide more torque or power without it overheating, but only if you provide it with more power. You may have to upgrade your controller or battery to do so. The old motor might be limiting the power If you put in 1.8 KW then you will get out 1.8 KW, some of it as h...
by BobBob
May 03 2021 6:03pm
Forum: EBike Troubleshooting
Topic: Blown Controller Mosfets!Is it worth replacing?
Replies: 6
Views: 137

Re: Blown Controller Mosfets!Is it worth replacing?

I agree, give it a go, I have replaced blown mosfets a couple of times on a dead controller. Most of the circuitry round there is pretty robust as you have high spikes of voltage and current so you may be lucky I've also blown a control chip for mosfets so that might be the next thing to go - there ...
by BobBob
May 03 2021 2:26pm
Forum: Bike Mechanical & Structural
Topic: My model of spoke breakage.
Replies: 19
Views: 731

Re: My model of spoke breakage.

A rims resistance to spoke pull through is simply proportional to it's thickness. It's a little more complex than that: A stiffer rim will flex less and distribute the load at the bottom of the wheel more. This in turn will mean that the reduction in load is distributed across more spokes. It's a l...
by BobBob
May 03 2021 6:29am
Forum: EBike Build Threads
Topic: 3KW / 8KW MXUS & Powervelocity 24S2P / 34S6P ?
Replies: 43
Views: 1672

Re: 3KW / 8KW MXUS & Powervelocity 24S2P / 34S6P ?

Thanks Chalo viewtopic.php?f=51&t=111528#p1653334
Need to work out how strong the rim is somehow
by BobBob
May 03 2021 5:52am
Forum: EBike Technical
Topic: PowerVeloCity F18-100 controller, not working
Replies: 13
Views: 338

Re: PowerVeloCity F18-100 controller, not working

I'm only a hobbyist electronics chap so others could help a lot more and I know this is from a year ago but as you pointed me to the thread I thought I'd note: Top right there appears to be a blown capacitor cap.JPG The location you circle appears to be a DC/DC converter - similar - note the small c...
by BobBob
May 03 2021 12:36am
Forum: Vendor Relations Corner
Topic: Trying to buy a PowerVelocity Controller
Replies: 13
Views: 278

Re: Trying to buy a PowerVelocity Controller

Changed your wording for you. :wink: Kinda like how some praise BMS Battery and others loath BMS Battery. Hi Markz, as always thanks for all the references :) They do seem a bit sporadic but also HAVE SOME return customers singing their praises Having a backup plan seems a good idea so a second con...
by BobBob
May 02 2021 11:19am
Forum: Vendor Relations Corner
Topic: Trying to buy a PowerVelocity Controller
Replies: 13
Views: 278

Re: Trying to buy a PowerVelocity Controller

Maybe if I feign interest in the newest and then change my order at the last minute OK, but let me know what strategy works later, when you are no longer a potential customer and need something. Yeah, I reckon patience and persistance but who knows, maybe buy some accessories but money doesn't seem...
by BobBob
May 02 2021 9:46am
Forum: Vendor Relations Corner
Topic: Trying to buy a PowerVelocity Controller
Replies: 13
Views: 278

Re: Trying to buy a PowerVelocity Controller

You're probably ordering the wrong controller. My observation, yours may vary, is that the fastest responses appear to be to questions related to the latest and greatest "next-gen" controller PS. Others have mentioned that being very persistent may help, so you may need to just keep posti...
by BobBob
May 02 2021 9:44am
Forum: Vendor Relations Corner
Topic: Trying to buy a PowerVelocity Controller
Replies: 13
Views: 278

Re: Trying to buy a PowerVelocity Controller

So you are having all this trouble with them, with simple things and yet you still want to buy from them. I could only imagine what would happen to try and get a response from them if something were to go wrong in any aspect after the controller is dropped off at their mail delivery provider. Yet y...
by BobBob
May 02 2021 9:28am
Forum: Vendor Relations Corner
Topic: Trying to buy a PowerVelocity Controller
Replies: 13
Views: 278

Re: Trying to buy a PowerVelocity Controller

Mine did arrive. A nice 7kw brick. https://endless-sphere.com/forums/viewtopic.php?f=2&t=105551&p=1544179#p1544179 I went through this with my IPS e-unicycle and am on my third controller. The UK seller was a good guy and the middlemen were selling him badly repaired second hand kit as new....
by BobBob
May 02 2021 9:25am
Forum: Vendor Relations Corner
Topic: Trying to buy a PowerVelocity Controller
Replies: 13
Views: 278

Re: Trying to buy a PowerVelocity Controller

john61ct wrote:
May 01 2021 7:13pm
Have you searched for others' experiences with this vendor?
Seems pretty mixed for all the controllers and I've read qulte a bit, but there's a lot to read
by BobBob
May 02 2021 9:23am
Forum: Vendor Relations Corner
Topic: Trying to buy a PowerVelocity Controller
Replies: 13
Views: 278

Re: Trying to buy a PowerVelocity Controller

Thanks everyone. I'm surprised that there's no-one chirping up that they're great The response on the thread about this controller seems pretty good with a few teething problems, mainly on the BT. https://endless-sphere.com/forums/viewtopic.php?f=31&t=85156#p1245133 People seem to complain about...
by BobBob
May 01 2021 11:33am
Forum: Bike Mechanical & Structural
Topic: My model of spoke breakage.
Replies: 19
Views: 731

Re: My model of spoke breakage.

Yours looks kinda cool and a good talking point, mine is just plain wrong. It's also worse because of the bigger hub. If they'd skewed it the other way round I could argue that it evened up the stresses under heavy acceleration but they got that the wrong way round as well I assume they probably jus...
by BobBob
May 01 2021 11:01am
Forum: Bike Mechanical & Structural
Topic: My model of spoke breakage.
Replies: 19
Views: 731

Re: My model of spoke breakage.

If we start from the assumption that the rim is strong enough and the spokes are sufficiently tightened, then what is still wrong with this approach? There's nothing wrong with using thick spokes and a rim that can tolerate proportionally high spoke tension. That's what wire wheel motorcycles do. B...
by BobBob
May 01 2021 10:09am
Forum: Items for Sale - New
Topic: 24F Silent Controller 20kw 100-150v iOS/Android- $299>
Replies: 236
Views: 38301

Re: 24F Silent Controller 20kw 100-150v iOS/Android- $299>

Powervelocity.com wrote:
Aug 20 2020 11:48am
A month ago today you said you had the 15 Kw version in stock and you just had to make a bluetooth controller
I'm still waiting - somewhat impatiently now
by BobBob
May 01 2021 9:58am
Forum: Vendor Relations Corner
Topic: Trying to buy a PowerVelocity Controller
Replies: 13
Views: 278

Trying to buy a PowerVelocity Controller

This is probably not a terribly interesting post for anyone else and is simply another way that I am trying to get a response and purchase a PowerVelocity 15 Kw controller for shipping to the UK. I contacted them on the 7th march and got a response the same day that they "have shipped a lot to ...
by BobBob
May 01 2021 9:56am
Forum: Items for Sale - New
Topic: PV NextGen FOC 130v 200/600A 25kw - $599, Watch Display
Replies: 278
Views: 34680

Re: PV NextGen FOC 130v 200/600A 25kw - $599, Watch Display

Powervelocity.com wrote:
Apr 27 2021 10:54pm
Sorry to cross post - trying to buy the 15Kw for nearly 2 months now, no response for a month
by BobBob
May 01 2021 5:53am
Forum: Bike Mechanical & Structural
Topic: My model of spoke breakage.
Replies: 19
Views: 731

Re: My model of spoke breakage.

Great, hope I'm right, I'll stick with 10 Ga, tightened sufficiently. hope the steel isn't 304ss I have a 42mm wide double walled rim which seems robust 10ga spokes probably won't break, but they'll go slack with every rotation because they have several times too much cross-section/not enough elast...
by BobBob
Apr 30 2021 6:47am
Forum: Battery Technology
Topic: Is it possible to upgrade battery packs?
Replies: 36
Views: 1163

Re: Is it possible to upgrade battery packs?

Question: is it possible to upgrade the battery pack? Answer: Looks like you don't need to, you want 2.5 Kw from a 750W motor - you need a bigger motor. Next steps: choose between an additional hub motor - around 1.5 Kw, A bigger motor that fits the existing system or a new system from scratch. Best...
by BobBob
Apr 30 2021 6:36am
Forum: Bike Mechanical & Structural
Topic: My model of spoke breakage.
Replies: 19
Views: 731

Re: My model of spoke breakage.

The equation is LOG(stress)=-.3xLOG(cycles)+4.12+.072xZ The Z is the normal distribution. If you only have 1 spoke you put it in the middle of the normal distribution which divides it into 2 parts. So if you have 36 spokes you divide the normal distribution into 37 parts. Take 1/37 and put it into ...