tonyontopofabighill said:
I had noticed that the temperature had gotten up to 94 C just before it started to smoke.
Inside will be hotter still. Heating power = current squared x resistance so to reduce heat you reduce motor resistance or motor current.
tonyontopofabighill said:
I am going back to plan A of NOT riding up my big hill and then I think it will last for quite a while. It will give me a bit more leg exercise as well.
Wrecking motors is undesirable but a major reason for having a motor is to get up hills so it is a pity to give up. If you can reduce the motor current sufficiently and add sufficient pedal power to get you up the hill it would be OK.
tonyontopofabighill said:
I don't think you guys should use my experience too much as a guide unless you have to ride up a "killer" hill like me, especially at the end of an hours' ride.
I regard your experience as the best guide I've got and think you have demonstrated the limits but without sufficient instrumentation for precision. I have the same controller and have measured it as limited to 34.5 amps. I plan to reduce this limit. Based on your experience I try not to use max power at low speed for more than a few seconds and ride in the lowest practical gear when using full power. When the motor spins faster, current is reduced by back emf rather than the controller limit. With my set-up I think (not sure because I need better instrumentation) that occurs from about 13 km/h and on most Aprilia configurations it should be slower.
I suspect most people are OK because, with the ultra low 34 tooth megarange sprocket, they don't travel slow enough at full power to run into problems. Despite having their controller current limits too high, they are saved by the back emf from over current rather than the controller current limit.
ikxdf said:
29.6V is not much...and i have see an original engine powered with 36V withouth problems...
Higher voltage raises the speed at which back emf reduces your current but it doesn't increase maximum current because that is limited by the controller.
Samd said:
Heya Tony,
it could be that the heat in the case melted the windings after stopping. After climbing that hill of yours it might've been a good idea to keep things moving awhile to move the heat about.
The insulation was cooking while riding because heat is generated in the windings and dispersed to the casing. Therefore, maximum winding temperature is greater than casing temperature and occurs while powering.
tonyontopofabighill said:
Those colours are my doing Ken. I used KRYTON plastic paint aerosols and white pin striping. I used to ride a Ducati Pantah with these colours.
Looks nice in the photos.
Samd said:
Gday Ken, got another sensor for you. Will pm you in the morning.
Already turned up and I sent some funds for postage. Thanks Sam. I've got to figure out how to use it now. I think it must have an amplifier which I supply with 12volts. This is probably under the blue tape but I'm wondering if there was any electronics in the plug in the bottom of the gearbox? If I just connect 12 volts to it without being sure I could wreck whatever is under that blue tape.
Samd said:
Went through my parts box tonight. I have two controllers ... if anyone needs them.
I'd like a controller, if available. I would destroy the electronics to salvage the black metal cover in which I mount the alternative controller. It would be useful because I've had the old one on and off so many times the thread where the plastic covers bolt on is wearing out. I've also broken the flip up battery cover under the front of the seat through catching it with my boot when getting on if you've got one on offer.
tonyontopofabighill said:
No, not mine, I found it on Google images. Handlebars look a bit like Harley ape hangers.
Looks too much like a motor bike for me. I've been modifying in the opposite direction. I've had the solid front fork for a while now and like it. As well as being lighter it has stopped the bouncing when pedalling hard up hills.
I've also got a little data on my quest for longer distance travel. Over 37 km with an average speed of 27.9 km/h I used 6.4 Wh/km. The speed is high enough for a group ride and the energy consumption is low but it's not low enough with the current battery capacity, which is nominally 9.2 Ah and which I've measured as 7.7 Ah, for an 80 km ride. My own contribution is less than it would have been on an unpowered bike and while I'm 'getting better, its psychologically difficult to put in the effort when a slight movement of the thumb can produce the same result without any pain.
