Thursday, January 15, 2015

Day 109 - Some finishing touches

I spent some time adding felt to the gunbox holes to prepare them for installation of the exterminator gun and plunger arm.  I masked off the portions of the hole that were not chamfered, and sprayed a layer of carpet adhesive on the bevel.  To achieve uniformity on the adhesive, I took a sponge brush and spread it a little more evenly along the beveled edge.  Then I took one of the globes, wrapped an 8x10" rectangle of black felt around it, and pressed it firmly against the edge.  I let that set while I went to work on the dome light cages.

The only place where I saw to position the light cages I inferred from the NSD plans .pdf file.  It looked like the holes for the bulbs were smack in the middle of the 12cm distance between the top "D" groove on the dome and the dome chamfer line.  So going off that assumption, I measured the distance between those two places on my dome (which wound up being 11.5cm).  I also took a look at some reference photos from the episode "Dalek" which is what Rainier is mostly based on.  The scene with Rose's handprint on the Dalek dome shows how the cages are attached, with the two bolts running parallel to the chamfer line.  Based on these measurements and observations, I pencilled in a line.

I had practiced drilling holes into the edges of off-cut sheets of acrylic to make sure I wasn't going to shatter anything, and then marked the areas on the underside of the light cages where the bolt holes aligned with the Moflash lenses' bolt holes.  Then, very gently, I drilled in two 1/8" holes into both of the cages with the drill press.  I didn't shatter a thing, and they were perfectly lined up with the lenses!  Whew.

I marked corresponding holes into the lines I drew on the dome, and before long the cages were attached.

By this time, I figured that the felt on the gunboxes had set nicely.  And, while it had set, it wasn't a good bond, so I wound up ripping it off quite easily.  It was also pretty raggedly cut (I need new scissors).  I'll try another method later, but this time using felt strips and contact cement.

Felt or no felt, I turned my attention back to the interior appendage retention plates.  After a bit of sanding to remove the dried up bits of newspaper and PVA wash build-up, I test-fit everything.  I found that I needed to bore out the bolt holes on the back-most plate; otherwise, the fit was too tight and the plate would get stuck when trying to adjust it using the wingnuts.

First, I used some 3/4" drywall screws (to mitigate the MDF splitting) and attached the middle plate directly to the back of the gunboxes, remembering to pre-position the alignment bolts first so that they stuck out the back.  I had made pretty deep countersinks in these plates so that the screws would bite a nice distance into the gunboxes without going all the way through the MDF and poking out of the exterior (which would be bad).  I only managed to reach seven of the eight holes, but that's okay.  It's a nice fit.

Next, I positioned the plunger arm and gun (I had to do a bit of mental gymnastics to remember which hole got which appendage, since I was working on this with the shoulder section upside-down).  I added springs to the alignment bolts and slid the rear plates onto them.  Adding washers and wingnuts to the back of the bolts, I tightened the plate until it was snug around the globes.  I'll add the felt later to prevent scuffing, but in the meantime, everything is nice, snug, and now positionable!

I re-assembled the stack, and now I am just getting the shivers.  Rainier's personality is finally starting to shine through!

Monday, January 12, 2015

Day 107 and 108 - Dome work, eye, and plunger

This weekend was a pretty fruitful one, being able to get a good chunk of time dedicated to some detailed areas.

I finally attached the bottom rotation plate onto the neck section.  I evened out the distances of each of the eight struts by measuring the distance from the top of the strut to the top of the upper ring.  There were only millimeters of difference there, so I marked the length of the shortest one on each that were taller than it.  After sanding the rest down to that length, I measured the length of the diameter between each pair of struts.  If I recall correctly, it was something like 46cm and some change.  I took one of the smaller off-cut circles of 3/4" MDF from the initial ring creation (back on day 19; my goodness, time flies) and routed the edge down little by little to match that length.

I was trying to factor in eventual dome rotation mechanics while doing this.  Since my struts were already pretty tall, I decided to cut notches into the plate and attach it to the strut sides instead of directly to the top.  If the plate were attached too high, the added distance of the second plate—along with the diameter of the rotation wheels—would exceed the proper distance between the bottom of the dome and the upper ring.  To prove this to myself, I sat what will eventually be the top rotation plate (the largest of the off-cut ring circles on top, with some spacers representing the distance of the wheels/bearings.  Then I placed the dome on top.  Sure enough, I should be able to get the proper distance by just routing away the outer edge of the top plate, millimeter by millimeter, the way AdamSt did.

I'll cut the inner section of the plate out later once I figure out some other stuff.  For example, I'm not sure which method I want for electric dome rotation (there are so many options that come up when searching the forums).  This will determine which plate I mount the wheels, place the motor, etc.  I don't know what any of that looks like at this point.

Now that I had the cowl in place on the dome, I could start to measure out where to place the eye pivot slot.  I knew that I wasn't going to be exactly centered—but at least pretty close—so I needed to wait to make sure that when eventually fitted the eye pivot is clear of the hole edges, and that the eyestalk clears the sides of the cowl when being moved up and down.  After a combination of relative measurements and eyeballing, and eventually marked out where the slot should be cut.

Problem was, I initially only made it 10cm instead of 14cm, and was quite confused when it proved to be such a tight fit for the pivot.  But I managed to get a couple cool photos anyway before correcting it and cutting out the extra 4cm.

Next, I turned my attention finally attaching the bushings to the aluminum plunger tubes with epoxy.  I used a product called JB Weld, which seems to be a recommended brand.  I used their strongest bond, one that sets in like a day, rather than their quick-bond stuff.

I cleaned all the tubes with 1000 grit sandpaper and Brasso metal cleaner to get them nice and shiny.  I then took a series of photos to make sure that I assembled everything in the correct order before attaching the bushings with the epoxy, because once those are on, they are not coming off without a serious fight (and probably major damage).  The acrylic hose barely fit inside the rear outer tube bushing, so I roughed up the surface of the hose a bit with coarse sandpaper.  But I ran into another problem almost immediately: once I had pushed the coupler into the hose, it expanded the circumference of the hose a fair amount, making it impossible for the bushing to fit around it.  If I had the presence of mind, I would have simply slid the bushing on from the back end of the hose (duh!), but instead, I attached a sanding burr to my Dremel and whittled the hose wall down until the bushing could fit!  What a silly person, me.

I mixed some batches of epoxy, gobbed it onto both the bushing wall and the interior wall of the tubes, pounded everything into place with a rubber mallet, and set it all out to cure overnight.

The next day, the were all completely cured and looking very solid.  I attached the (incomplete) plunger to the front, and snapped a couple more pics of it extended and retracted via the acrylic hose.  Soon, I will add black felt to the gunbox hole chamfers and mount both the gun and the plunger arm with my gunbox mounts.

Since I was working with the aluminum tubing, I decided to take an off-cut of the 1" tube and make an axle for my eyestalk pivot.  On the pivot itself, I noticed that the two-part Gorilla glue attaching the plastic outer skin to the MDF disk is coming loose, so I may need to re-glue it.  Also, the two pieces of 1/2" MDF seem to have detached from each other.  If they fall apart completely, JB Weld might be the answer!  Anyway, I slid the tube into the pre-drilled center hole and made a 5/8" hole using the pivot hole itself as a guide.  Once done, I sanded out the new tube holes a bit so that the threaded lamp rod could easily pass through.  For now, it's temporarily mounted inside the dome just to keep it somewhere out of the way (and to make Rainier look terribly awesome at the same time.)

As the weekend was wrapping up, I finally got around to sanding all the excess ABS glue that had hardened around the seams of the eye section.  Sanding ABS plastic isn't all that different than sanding wood, but I sure hated losing that smooth shine.  Ah well, it will be all smooth again once primed and painted black.  And, now that it was sanded (and then smoothed a bit more with a finer grain), I added the twelve 2.5cm "lugs".  These were cut from Plastruct half-round styrene rods that I had previously ordered with all my other plastic parts.  I initially used Krazy glue to secure them into place, and then ran a bead of acrylic cement to really bond them into place.

Then, for my final detail, I drilled the three holes for the eye piece bolts.  There doesn't seem to be an "official" distance for those holes to be drilled from the rim of the eye, so I measured a length that didn't appear to be too fragile—1cm from the rim seemed fine.  I used a bit more JB Weld to also secure some nuts to the interior for the bolts to be threaded into.  When I got up the following morning, I made sure to take my pliers to remove the bolts form the semi-cured nuts lest they be permanently cemented together!  It seems like that solution worked really well, and I'm quite happy with the results.

Sunday, January 4, 2015

Day 106 - Cowl 2.0 demolding

Today, I spent most of the day's daleking demolding and working on the cowl.  I took special care not to damage this second cowl attempt, unlike the first one.  I added a number of slender wooden stir sticks all around the mold to separate everything evenly, instead of slamming wedge after wedge of thick plastic spreaders and risk warping and cracking the part.

Despite the fact that multiple pulls are supposed to get easier, I managed to literally "break the mold" this time!  I don't think the mold is beyond salvaging; however, it would be wise to just make a brand new mold from a nice, cleaned-up fiberglass cowl.  That is if I ever feel the need to explore this damnable part of Rainier ever, EVER again!  This is the last bit of fiberglassing I needed to do, and for the foreseeable future, I am done working with that itchy stuff!  I'll still be using resin for a couple things, but no more glass fabric!  (Maybe.)

The cowl took quite a while to separate from the mold, but eventually, it did come loose.  The name tag inset made with the cut-up PAX badge came off with it, but it was easy enough to remove, carefully, with a razor blade.  I trimmed most of the fiberglass "fur" off of it with scissors.

I spent the next couple of hours using 80-grit sandpaper to even out all the ripples, bumps, and uneven surfaces.  I haven't yet done this step with the dome; it still has all its unevenness and such.  But the work on the cowl gave me confidence when I get round to sanding the dome.  Much of the gel-coat came off, which is why it looks so patchy in its current state, but once sanded smoother and primed, it should look great.

I was especially proud with how even the multiple layers of fiberglass and resin turned out to be.  I intentionally made the parts that were meant to be cut out much thinner than the rest of the cowl, so that my Dremel tool would pass through all that nicely and easily.  The rest was quite thick and sturdy.  There now appears to be a uniform thickness to the interior walls of the cowl where the eyestalk will eventually protrude.

I was completely covered in fiberglass and gel-coat dust by this point, so I also spent some time sanding the underside edges of the cowl so that it would lay as flat as possible on the dome.  Once done, I carefully aligned the position of the cowl on the dome and used my calipers to make sure the top was centered and that the right and left sides were evenly spaced from the front dome insets.  I used the calipers once more to determine a nice, secure, symmetrical place in which to place the four bolt holes so that the wouldn't be too near the edges (to prevent accidental cracking).

I used a 1/4" forstner bit in my hand drill to make the holes in the cowl first.  Then, holding it in place on the dome, made the first hole I've drilled into the cowl.  I was a nervous wreck (never having marred the dome before now), yet I managed to drill a corresponding hole into the dome.  I pushed one of my 1/4-28 steel button head screws through both the cowl and the dome, and made a pivot by which I could align the other three in place.  Before long, all four bolts were in place.

There were a couple of air bubbles on the cowl that revealed themselves during the sanding process, so I just need to do a bit of Bondo work to clean up the rest of it, and also to smooth out the front a bit more.  Then it will be ready for its eventual paint job.

(I also made plunger number 7.)