Oscar Goldman Builds The DMB-87: PART 9

OMG, ready for more punishment?

Here's that main landing gear swing arm from last time, part 8. One end has been cut off.

This is the side with the tire. A 1/4 styrene rod section is glued on using Weld-on.

The outside is sanded flat.

The inner section is cut away.

The inside of the arm is sanded flush.

Ready for casting. I'll need to do a lot more to get all this to fit together, by making a casting I have free licence to hack away on cloned parts.

I try to bundle up my casting. This means more parts. This is a tool I made to emboss a diamond tread detail onto the tire.

The tire is pressed on. Equal distant tick marks are Sharpied on. The tire is turned on tick at a time and gently whacked with the hammer. 

Like so.

On the lathe I slice off the ends so the pattern is in the middle.

Two sidewalls will be cut and added.

The Snuka has a large under chin blister for the front landing gear. Right now it's important to get all the gear sorted out to get it's stance. Then back to the rest.

Basic shape is cut out in thick ABS plastic.

The pattern is smaller because I'll be pulling .100 thick styrene over the top. Here is the pull cut out. I wanted a shell (there is guttiworks in there) and the thickness will allow me to shape more easily.

To match the fuselage contour, sanding paper is attached to the nose and the blister is sanded to fit.

OK, so here is where things get a little weird. What you are looking at is a mold to cast the swing arms. The part has lots of fragile parts and in order to keep these intact during de-molding I chose to create five inserts. What you are looking at is two walls of the mold before completion.

This is a pretty tricky mold, but most of the fun is figuring these things out and stretching my mold making skills. Here you can see the funnel and sprue. I build molds upside down, so you are looking at the bottom.

The cured silicone mold with all the inserts pulled out. This mold will get sliced open on one end so cast parts can be removed (I don't have a pic, I'll take one so you can see).

I made another mold at the same time, this is to cast the landing spat, gear doors and tire.

It gets cut open like so. The slit goes down to the bottom, but not all the way through.

Like so. The uncut bottom acts as a hinge.

Here is the first resin castings. Rubber bands are used to hold it together.

The parts.

Here you can see the spat and landing gear doors. Being clones I can slice and dice at will.

The first casting from the swing arm mold. Later casts were complete.

One of the spat clones is cut, then a second...

All the bits are carefully sanded and it looks like everything will even fit...

That's it for now, this Oscar is tired. See you in part 10!

Oscar Goldman Builds The DMB-87: PART 8

Lest all you all forget where we are headed:

There are several interpretations of the landing gear door, the model I am creating will be a more detailed version of the CG animation from the show. The blueprint style drawing in the book looks much different. The shape has been drawn out on tape and I compare to screen grabs.

The outline is drawn in Sharpie. I cut inside the lines so I can file a nice edge.

Let your tool do the work.

A rough version of the landing arm and wheel are hacked out. I would like the mechanism to fit into the spat once it is retracted.

Here is the image from the 2199 Garmillas reference book. Very sweet illustration, but sadly the pivot points must be adjusted to work in our world.

Another view. The internal brass support structure ultimately has to find it's way from the wheel to the fuselage core.

A floor is cut to put in.

More test fitting. The placeholders give me something physical to reference as I figure out how this is going to look and get made.

The tire has a unique tread pattern detail, much like a rounded diamond. I do a quick test by grinding the tip of a brass rod itno this shape and embossing with a hammer. This will work. More on this later.

The retraction arm is hacked out. Pivot points will need to get moved around, so the arm can clear the tire when fully retracted.

Gear door is paper. I'll use these dimensions to make the nice parts for the final model.

Studies of the swing arm.

I'll use large styrene rod stock as the rounded bits on each end. Three .100 styrene strips are sandwiched together using double stick tape. One end has an opening for a .250 disc, the other .312.

The part I want as the swing arm is between the two holes. I make three sets (the other two are back ups). One is cut off.

Remember, this made of 3 layers of .100 styrene. The extra material is not cut off until the arm is completely shaped. This acts as a handle during shaping.

Slowly grinding away. Not the metaphorical kind.

Here are the three layers pulled apart.

The arm needs to be thinner, I make a sanding jig to thin down the two outer arm sections.

Sand down flat to the jig.

Like so.

Here are the three sections together. The middle one gets chopped, creating the space between the forks for the tire.

Like so. That's it for now, more fun with bits of plastic in a few days, we'll finish the swing arm and make a tire!

Ghale Garmillon!