custom Zoid: Killer Dome (motorized)

Finding proper motivation

I examined my son's Killer Dome and noted the volume between the upper shell and lower hull. I planned to take advantage of the pancake-like volume there, but first I'd need a suitable motor and reduction gearing. My first attempt in February of 2004 used a motor and gearing from a wall-walking toy (left). First I made room in Killer Dome's main body with lots of hobby saw work. I also modified the Killer Dome gears to accept the new motor. So far so good, but there was a problem: I discovered the hard way that while making straight cuts with a hobby saw is not difficult, drilling co-axial holes in order to mount axles is very difficult. Even with the aid of my father's drill press, I was unable to achieve a reasonable result. Instead, my attempts produced rotational motions that resemble a wobbly off-center cam. Discouraged, I set aside the project for several months.

June 2004. I am in a good mood after completing my Demon Dragon custom. I see my Killer Dome on my desk, and next to it, a partially disassembled BrachioZilla motor and gearbox. I notice how small the gearbox assembly is, and how the output axle is about the same size as axle that is attached to Killer Dome's claws and single traction wheel. I grab my hobby saw and feverishly set to work, and in just a few hours I have mated the gearbox to the Killer Dome claw axle. (I was so focused at the time, that I forgot to take in-progress pictures! So these side-by-side comparisons of the finished work will have to do.)

I rework my wheel and axle from my previous attempt, and salvage the previous work on my second traction wheel. By modification of several Killer Dome parts I am able to mount this second traction wheel on the same axle as the original traction wheel, but on the opposite side of the final drive housing. (Note the dual traction wheels on the Killer Dome at left.)

Quick Switch

The switch at the end of the BrachioZilla motor unit is cut down to fit inside the Killer Dome hull. A (rather crude and hasty) cut is made to access it and allow on/off operation without having to open the Killer Dome shell.

Making room

In order to obtain more useful volume inside, the mounting post for the main Killer dome shell was shortened. This was done by taping some spacers to my hobby saw, then dragging the tip of the hobby saw around the outside of the mounting post. Very slow work and not very fun, but after about 45 minutes, the mounting post was cut. After another cut and some cleanup, the end plate was glued back on, resulting in a shorter mounting post. I gave up the rotating top shell feature (which I didn't like anyways).