Hi Guys,

I'm new to this forum, but I have been working (though a bit low-key recently) on a small remix of the Scout ESC.
I am building a 1/16th scale Leopard 1A4 from Tamiya for which I want to upgrade the gearbox to a fully independent 2-motor setup.
Since the Scout ESC is designed to support also much bigger motors than I use, I thought it would be a nice challenge to make a smaller version of this PCB.

I used the original schematics as baseline, but I changed the motor driver ICs for a different model.
The original motor driver is the VNH5019 (17.2x16mm) and I use the VNH7040 (10x7.5mm).
The Rds,on is a bit higher (40mOhm compared to 18mOhm) but since I use it for a 1/16th scale model only, I expect this to be no problem.
Designing for an acceptable thermal resistance was challenging in this small form factor though, but I think it is in good shape now, especially combined with the way the PCB will be mounted + fan and air ducting.

The control of the chip is a bit different unfortunately, so I have to update the firmware a bit as well.
The ATMEGA doesn't have enough pins to fully support the VNH7040, since the VNH7040 has a lot more control options.
This meant I had to design the control logic to be as close as possible to the way the VNH5019 is controlled by pulling control pins to fixed levels.
I now expect that the rotation direction is inverse, but the rest should be identical.
This now is the biggest risk though, and I can only fully test when I have the hardware on my desk and can do some testing and measurement.

The schematic and PCB design was made in Altium Designer.
It is finished now, but I still need to order and test it.
Because the thermal design involves quite some copper area, I hope to find an affordable place that can do the SMD assembly as well.
This will be continued shortly and I hope to post an update with the assembled PCB soon.

Regarding the fitment in the Leopard chassis, I first designed and 3D printed a housing in which the 2 motors and gearboxes fit and between which the Scout ESC Mini and a 40x40 fan could fit.
To make sure things don't get too hot, I did some airflow design, which uses ducts that will finally output any hot air from the Leopard's original exhaust ports.
This took quite some time and with a 2-year old son, hobby time is unfortunately not so abundant.

Anyway, let me know what you think.
I'll keep this thread to post any updates if I have them.