Sunday, April 1, 2012

Pegasus 1/48 Martian War Machine--WIP Part 4

Last post was pretty boring, since there wasn't anything to show but a crudely hand-drawn diagram. Since then I've made the support for the motor and gears and temporarily installed the drive system for a demonstration. (Don't look at the clutter on my workbench or it'll drive you mad as sure as getting face time with Cthulhu.) As you'll see in this video, that 1250:1 gear ratio is really necessary to get the heat ray projector to swivel at the stately pace you see in the 1953 movie.

Since last time I made a new support for the drive components from a scrap of 1/4" ABS. I drilled a large hole for the shaft of the heat ray projector and two small holes for the gear shafts, plus a clearance hole for the center post inside the hull and a recessed area for the motor. I installed the gears and everything fit. Hooray! Here are some pics of the drive system.

At left you see the upper hull with the cobra-neck heat ray sticking out, and perhaps you can tell that the bottom of the heat ray lines up with the gear on the right at the tip of my thumb. In the background you see the lower hull of the MWM, and part of an AMT Klingon battlecruiser, painted black and in need of restoration, that will be featured in a future post.

Here is a view of the drive train without the motor.The gear at the lower right (with the wires to the heat ray LED coming out of it) is the gear/pinion that I had to drill through (eliminating the pinion) to be able to slip it onto the shaft of the heat ray. It's still not secured, only press fit and none too tightly. On the left side of the ABS panel is a recessed area to support the motor. Don't mind my thumb; I injured it almost three months ago and it's still unsightly.

Here's the whole drive system so far. The gear shafts need to be superglued into the holes, the gears need to be secured so they don't fall off the shafts, and the motor is just lying there. It will be epoxied in place and strapped down. The worm that drives the first gear is superglued onto the shaft, at least, but the shaft is too long and also needs to be supported on the far end of the worm to reduce vibration.

Next time I'll have all that taken care of, and hopefully have those momentary pushbuttons installed to act as limit switches to prevent the heat ray from swiveling too far, plus all the requisite wiring to lead to the DPDT switch that will be outside the model.

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