Obsolete Thread

[EV2Go]

[woody]

Hi EV2Go,

you'll get about the same power from the same weight of thunderskies no matter whether you have 90 x 40Ah or 40 x 90Ah - 72kW - so it's not a magic bullet.

That said, I'd go for the highest voltage your controller will take - mostly because it will let you get more speed and the same torque at higher speed - which you are a big fan of.

Downsides of higher voltage are more BMS modules, trickier charging once you get over 300 volts because you exceed what a 240v socket puts out, more contactors to split up for safety.

Also a motor advertised as higher voltage will probably need more volts / less amps for the same speed/torque, so check that out...

Cheers,
Woody

[AussieJester]

Wondering if you have considered the new A123 20ah prismatic cells for the trike? $US2.50 per ah ~30c rated light and alot smaller form factor than the thundersky cells.

KiM

[EV2Go]

[EV2Go]

[Johny]

....what if I wan't less than peak torque? if I could rev the motor to say 4000 rpm and drop the clutch (say a button clutch) would this be detremental to the motor or better for it?

I don't follow. If you want less than peak torque then don't wind the throttle as far. My belief is that dropping a clutch with a DC motor doing any reasonable revs would hurt the motor.

[EV2Go]

[Nevilleh]

Within the motor limits, torque is proportional to motor amps which is proportional to throttle opening. Small throttle = small torque.
Speed is proportional to motor volts, so if you want to go fast you need lots of volts. A clutch is only useful if you have something like a Logisytems controller which is renowned for jerky starts and - I belatedly find - is not recommended for direct drive systems. Their answer to jerky starts is "use a clutch"! Certainly "dropping the clutch" at 4000 rpm will impose a huge shock load on the whole drive system. Electric motors are generally not designed for such things and you may well shear the motor shaft as it is probably the weakest bit in the drive train.

[Goombi]

at 4000 rpm speed and pedal to the floor when you drop the clutch If the drive will not brake something at best you will finisn ar--e over head.
Recommendation: Cabin Crash bars and rear Skid rails

[Goombi]

Typical DC motors produce peak torque between o and ~2500 rpm Quote
Why is everyone entertaing themselfs with 5000 RPM motors?Knowing that after 3000 rpm your torque drops significantly and all one does is burn the amps and race the bearings to oblivion.
Where is the ecconomy and propriety

[EV2Go]

[Nevilleh]

In your case you can get rid of the jerky start by cranking the amps up to the point where you just get wheelspin.   

[EV2Go]

[Electrocycle]

in theory you could launch harder with a clutch (using the energy stored in the spinning motor) and I doubt you'd break the motor itself - but would be very likely to break drive shafts

If you need a clutch for launch though your controller is not big enough.

[Squiggles]

Assuming you are talking series DC here there is also the risk that the motor will spin to oblivion if you give it full volts and no load....you might not get off the line at all!

[Goombi]

I can see your trike with a   bridge construction to the front wheel about 15 ft away from the seat and 4 bags of cement mounted up front Do you intend to wear gogles?    

[EV2Go]

[EV2Go]

[EV2Go]

[Carv'n Marv'n]

oh yeah.

[EV2Go]

[Hebbe]

I just read your tread and it is very interesting reading.
7 months ago I started building a trike with a Harley Davidson frame and a 11kw 230/400V ac motor and Omron 18,5kw vfd. I had the same problems as you deciding which rear end to go for. First I had my mind set for a Frakenstein rear end, like this http://www.mcworx.com/fstrike33.html. ( a fantastic bike build by Norwegian Lars Eriksen. He has built this from his wheelchair http://www.trike.no/x-rod_bygge.html)

I finally decided on a jaguar IRS. 2 months ago I bought a Jaguar -74 xj6 and a -78 xj12 complete IRS so I have one with diff lock and one without.

This project is ment to be educational with both the mecanical and electrical equipment so I want to have the possibilety to try diffrent settings. My next project will be a car probably with jag IRS.

I am nearly finnished with the sandblasting and paiting of one IRS. Next week I am getting some aluminium parts for the motor mounting and som part to connect motor to axle. I have decidet to go for a 10x36V (360v) Headway 38120S 10ah batterypack. I am looking for 15min fun driving pr charge to get the knowledge.

I am looking forward to see what speed and acceleration I will get from 11kw engine.

Sorry for my bad english. Im not used to write it.

[AussieJester]

Those rear ends look sexy Hebbe and only 3500 dollars
Still like the idea of the Jag rear end IRS on a trike would be huge advantage IMHO.

KiM

[EV2Go]

[Electrocycle]

I think I did suggest S13 rear suspension at some point

I have an R200 from a GTR with a mechanical 2 way center in it, just sitting around