TOPIC:

I'm a bit more hopeful about the battery now, after 5 "cycles" the time it took for the charger to peak & the time the 3 motors took to stop improved dramatically:

1st - charge time: 3 minutes; discharge time: less than 1 minute
2nd - charge: 8 minutes; discharge 2 minutes
3rd - 15m & 6m respectively
4th - 25m, 10m
5th - 82 min charge, discharge ... I got sick of the noise after 17 minutes

More electrical fun - I couldn't work out why the radio wasn't working ... finally traced it to the on/off switch on the TX - I'm guessing that it's a dual pole switch, and the pole that supplies the voltmeter is fine, but the pole that supplies the rest is duff ... switch cleaner & frantic wiggling failed to "fix" it, I've lost patiece for now as further investigation will need the switch body unsoldering

Jonny wrote:

... I think I might have to look at a proper charger/discharger due to the noise & worries about motor wear

How about a (or some) 12V light bulbs? Cheap enough from Halfords and quiet.

Yes, as Martin said, car headlamp bulbs work a treat for discharging NiCds, the halogen ones do the best job as they use more current - I've found that discharging packs quickly, preferrably in use, has the best effect when trying to recover them.

HOWEVER, I personally wouldn't recommend discharging Nimh packs, as any kind of heat buildup kills them in my experience. In fact, I'd lay money that the soldering process in building your pack is probably what's rendered them murdered.

Re the tranny on/off switch - yeah, the AP227 tends to do that, don't know why, but it's usually just tarnishing on the internal contacts & some WD40 & lots of on-off operations usually sort it. Bit bemused about the meter working & the rest of it not though... maybe there's voltage being transferred but not enough current to do the work of powering the rest of it properly? - to prove it, substitute the PCB for a bulb, to see if there's enough beans getting through to light it (You'd be surprised at the number of times people have been caught out by "Multimeter says voltage but nothing works", & the problem only properly shows up when putting the suspect component under load)
You'd be wise to check the Rx switch for the same problem whilst you're at it as these are also prone to it.
Incidentally, these switches are a standard item, nothing special, & are available from Maplin etc. You should also find that the AP227 on/off Tx switch is the same as any other Rx switch, so just replacing it with one from an unused Rx battery harness might be the easier option.

Another trick: Usually, the -ve wire goes all the way through unbroken, & it's just the +ve wire that goes through the switch. NORMALLY, the switch is a dual-pole item, but the wires are only soldered to 1 pole, leaving the other unused. I usually pass the wire through BOTH poles then solder - this way, if 1 pole goes mank/not working, hopefully the second takes over as a fail-safe.

Oh, & you know those old run-back timer chargers? - they have big resistors in them & can be used as dischargers if you short out the 12v connection (Preferrably with a hefty resistor or bulb, but not essential).
Old MSC resistors can be used too, but you'd need to wire a bank of several of them in series & parallel to both handle the current and use it (say 2 lots of 2 in series, wired parallel overall)

Put it together this morning:



Page 3 of the manual - most of the rear end:





Page 4: rest of the rear end:





Page 5 & 6 are a duplicate of pages 3 & 4, just with a 540 motor ...



Page 7: Front suspension:





Page 8 - steering ...





Page 9: MSC ...





Page 10: Fitting wheels, small fittings on the body, and assembling the driver (which I did weeks ago):





Page 11 - windscreen, rollcage etc:





Page 12 - fitting body, decals ... I think it came out ok but the orange is still a bit light for my tastes.

Jonny,

As usual...looks awesome ! Fantastic job

Fianlly settled on an IMAX B6 for 21.16 GBP (posted) from Hobbyking - marginally cheaper than the ones being sold by Stifler's Mom on eBay

Also, the one from Stifler's Mom looks like it's fake.

(interesting marketing gimmick though...)

Fantastic car JR And for me the colour looks awesome, really like the somewhat weird orange!!
For the imax b6, i really had some bad experience with it in the past, charging lipo's. It's rubbish in my experience and destroyed two lipo's
You could have gotten mine for free, never again gonna use it. Bought a Graupner Ultramat 16s which is really great for charging all kind of batteries.

Cheers, Bram