I think I've gleaned from other posts where the FET's are (getting ready to pipe air over them) but wanted to make sure.

If using HL's plug schematic, they are all on the daughtercard that runs "vertically" next to (roughly) Channels 1, 6, 7, and 8?

Thanks much!

THey are just back from where the motors plug into the board. The cover of the RX18 is pretty easy to remove, and you can see them for yourself. It might aid in the cooling as well. Everyone with a Heng Long should consider the 3:1 gears. I mean this in all sincerity. The 3:1 gears keep the motors out of the stall range, where they draw the most amps, and then heat, and kill the FETs. I run my FOV diecast sherman using an RX18. This tank is heavy, and this is the tank I made this discovery on. When it had regular gears in it I fried one board. I replaced this board and was running the tank without the turret on I noticed the new one was running extremely hot. So hot I could feel the heat escaping from the turret hole. I put 3:1 gears in it, and the heating problems went away. Runs all day long with no heat buildup.

The only thing is you do lose some top end, and if possible you should use the motors that turn 18,000 rpm to make up for this if you are running the lighter faster tanks. Heng long used to have white cap and black cap motors, and I think they ran at different RPMs. 11,500 and 18,000.

Radio shack or the "Source" also catalogs suitable motors at these different RPM ratings as well. I have never been one for the high end motors. I let the 3:1 gearbox handle the torque. I have some old 1/24 scale cox slot car motors. I was going to experiment with those one day. I haven't yet as I am pretty sure they draw incredible amps, and frying a Hegn long board would be a certainty.

YHR you've been incredibly helpful thus far (don't think I'm close to done yet lol) I sincerely appreciate you taking the time. Hopefully I can pay back others in the knowledge that I've gained from you.

I do have a 3:1 gearbox on the way (with my replacement/spare RX18's), and according to what I've seen, it comes with black capped motors. I'd prefer to keep top speed somewhere close to where it was with the white cap HL motors (assuming the "white caps" are still the same in the StuG) but the gear reduction I think will be a bit more realistic in how it gets moving. Momentum would be fun, not quite ready to step up to that stage yet. I'm not going to drive this thing a ton, this is more about executing all the mechanical/electrical ideas I can come up with.

I've got a fan already, working on what I think will be a pretty nifty setup (waiting to see if my idea turns out as good as I think it will, before I publicize my project lol) just at a bit of a standstill when it comes to how I'm going to mount the fan/RX18. I may just end up removing the case from the RX18 and mounting the board on "studs" since the board has holes in it that can be used to mount it without the case, to make my cooling idea work. From what I've mocked up that will be the best option.

You will really like the 3:1 gear reduction. It stops all the jack rabbit starts, and you are able to slowly advance the tank.

Keep us posted.

the 3/1 gears are a necessity for the heavier tanks (especially with metal tracks) but I"m not sure they are really needed for the lighter stugs/panzer III/panzer IV. the white capped motors operate at a lover RPM than the Black cap. a 3/1 gear box with white cap motors is dead slow. You will need to upgrade to either a black cap motor but for best results get a speed 400 motor. Your tank (whatever it is) will be able to climb a wall

I use them on all my tanks. They give way better control and they power thrugh just about anything. Agreed you need the 18,000 rpm motors but you don't need expensive ones becuase all the torque is generated by the transmission.

you must have alot of spare gear boxes lying around (lol)

I make my own out of the Stock gear boxes, so nothing is wasted.

now it makes sense why all yours are 3:1. I have about a dozen tank and all having 3:1 would be an expensive proposition. I'm just putting a Matorro 3:1 in my Panther. It was the one designed for the M41. The Panther required the longer shaft like the M41. However the holes to secure it are different so l will have to use milliput to form a new foundation to secure the new boxes boxes.