I should mention drill the mounting holes in the steel.
I do this on a small and very simple turntable which is sufficiently accurate for such work .
This I can easily clamp in my vise and find with the help of a motor and a suitable drill bit in the chuck the proper drilling position on the pitch circle .

So I can now drill every 120 ° , a 2.1 mm hole in each flywheel.


So I can now mount the flywheel with three M2 screws each on the engines. To secure the screws for easier contact adhesive has been proven .

In the next step I must inertia balancing . In addition I have screwed the motors in the cheek of an old gear and connected to the battery and controller. With a servo tester so I can leave the engine running while I hold the gear cheek with the engine between the fingers. So you spührt even the finest vibrations. The imbalance I am like a simple 2-component modeling clay from the I press the Innneseite the flywheels . With a little practice, you have a quick and good result in this way.


After balancing , I can now finally mount the gear in the tub.


Now I must first deal with it as with the original , the chain tensioner looks. The Tamyia solution is not a solution for me.