TOPIC:

I bought these ESCs this summer but I need some infos on these.


This one is a RM-70 buggy speed controller item 0600
Made by Aiomodelli France ( Scientific France)
That's all what I know...

The second one



That is a NOVA 18~1. I saw on a website that it was common with the Monster beetle.
I don't know wich motor I can put on these and if they are low or high quality...
Thanks

I love that first one...... The font of the letters "RM" looks much like the fonts on the vintage KO ESC's....

sorry.... double post

Thanks a lot Tommie. Right! the connectors are the same than my EX5 radio gear but the big alloy case seems to be very older

stingray-63 wrote:

Thanks a lot Tommie. Right! the connectors are the same than my EX5 radio gear but the big alloy case seems to be very older

Yes, that's a pre-FET controller. I would guess it has a single power transistor and a couple of relays inside, and to be very very early 80's....

That's exactly that. 2 relays and 3 big transistors. I can't find any info on it. Like wich motor I can put and under wich tension only 6V or able to have 7,2V. It should be nice on my sand scorcher.

Ok.... with three of those old power transistors I would say around 10-15A continous (peak 40-50A) That's based on specs from other vintage ESC's of similar design. The Acoms AP-35 is 6A contionus (peak 30A), but that is with only one of those Darlington type transistors. I know some of the old KO RM ESC's were sold in two versions. One for 6v and one for 7.2-9.6v, so I would stick with 6v, to be on the safe side. But if it isn't working properly on 6v, it could be the 7.2-9.6v version you have. I would not run anything other than standard 540S motors or mildly tuned, like black motor etc.

Those old pre-FET ESC's use Darlington transistors, designed in the 50's, and are actually called "Darlington pairs" or "Super Alpha Circuits", as they contain two separate transistors acting like one, where the second one further amplifies the current from the first. The disadventage is a voltage drop of about 1v from input to output, and that's a problem for RC's. The relays are there for bypassing the transistors on full speed, to eliminate that voltage drop.The newer ESC's with FET transistors have much smaller voltage drops, thus eliminating the need for bypass relays.

A funny thing with some of those Darlington ESC's is that they have a slight delay before the relay takes over, almost like the "turbo lag" on Porsche 911 (930) turbos from the 80's. And, yes, I have one of those 1983, Indisch Rot.

Again I must say that ESC is extremely cool! Fantastic find!

yes, and it would definately be age appropriate for a SRB! The only thing that could be a problem, is if you place it inside the radio box. Those transistors give away a lot of heat (that voltage dropped has to go somewhere, you know). On the Acoms AP-35 that is designed for the SRB's, the transistor is soldered to long wires and mounted to the gear box, for heat disposal.

Not the same as yours, but similar design.

Thanks a lot Tommie You help me a lot. (a 930 that's a beautifull car Mine are only in RC) I will try very gentle on a vintage. Maybe install it on the SS gearbox. I will clean it and make nicer connections.
Still thanks.