Good morning.
@Greg: Here some more pics without the body. I hope you can see what you need. The gearbox itself is part of the frame. But it´s not a big deal. Just two gear wheels sets to get the heigt from the motor axis to the axle axis. The motor itself has it´s own reduction. As I wrote the loader only has one gear.
The oiltank U see is just for the looks so U can get its space. The final motor-pump-tank will be just like the one in my wheel exavator.
In the loader I will have an outrunner motor with a leimbach 450 pump and the same scrath built tank. With the self built tank I can get the most effciant oil volume adjusted to the body. The outrunner saves some milimeters of lenght.
The space for the batteries U can see some pics above. You can change it from the outside of the model.
In my big excavators there are outrunner motors on the pump, so you have to control the rpms with a regular cruise control. So you can choose the preassure in the system as you like or turn it off. I don´t use any special electronics. The same thing is with the normal motors. You just have to programm your rc that the motor only goes one way.
If there are any questions please ask.
bye
Ulrich