TOPIC:

Martin wrote:

... The current owner has no interest in off-road vehicles. ...

I may have done the man a disservice. Mardave has just released a whole bunch of spares for the Cobra.

Cleaned up the MSC and resoldered a couple of wires:

Looking good

IIRC, the Mardave MSCs were superior to Tamiya units (or at least different) in that in the neutral positiom, the two motor poles were linked, meaning they had a dynamic brake rather than just freewheeling

Brand new front wheels in a joblot from ebay


Coming together:


The end of the battery holder has been cut off for access. I have an replacement (see pic) but I can't see how it will fit without making a hole in it for the cable. The battery barely fits and the cable would be bent at a very sharp angle and would be prone to break.

Jonny wrote:

Looking good

IIRC, the Mardave MSCs were superior to Tamiya units (or at least different) in that in the neutral positiom, the two motor poles were linked, meaning they had a dynamic brake rather than just freewheeling

I've had a poke about with my DVM and I can't measure any connection between the motor wires in any position. Without taking it apart again I can't say if there are tracks there that would allow this.
However I have an Apache MSC (which has a different, but very similar PCB) and the PCB looks like it will connect the two motor wires via one of the resistors at neutral (with zero connection just either side of neutral). I will investigate further.

Mardave MSCs aren't exactly built to take high current loads (Thin tracks, small cross-section point contacts) & I suspect just hooking one up to a tuned motor would fry it.

Use your DVM to measure from one side of a track to the other first (To check for holes/breaks in the tracks), then check across a track to the wire-side of each point contact.
Check across the resistor whilst you're at it.

Most likely cause of no connection will be black/pitted point contacts.
It's also possible that not both of the point contacts are touching the PCB (From memory they aren't spring-loaded & rely on the mounting disk being not-heat-warped, & it still being fairly flexible).
Internally dirty/corroded crimps are a possibility too (Wretched things, I hate crimps...)

I suspect you're missing the point there eddrick ... AFAIK Martin was investigating whether it had a dynamic brake feature or not

Ha, oh yeah.... I tend to miss the greyed out quotes, I struggle to read them