Wednesday, April 29, 2015

Days 119 and 120 - Attaching eye pivot / attaching shoulders to skirt

Now that the painted eyestalk pivot was dry, I wanted to mount it into place.  I cut out a couple of rounded pieces from some 3/4" MDF, using my dome former for the arc.  I quickly placed them on the rotation plate and put the dome overtop, noting that it wasn't a flush fit because of the inner indentation of the dome grooves.  I then drilled out the spot where they touched the mounts.

Another thing I noticed was that the mounts wound up right where the upper cowl bolts would be placed.  So, after making a couple marks through the holes and onto the mounts underneath, I later took a saw and flattened the MDF (not pictured) so that the bolts would be unobstructed.

Next was to try and determine just how much of the pivot I wanted to be outside the dome, and how high it should sit.  There doesn't seem to be much in the way of measurements out there telling me what it is, so I just looked at several reference photos, and eyeballed it.  One thing I noticed, though, was that the pivot axle's center point was going to be very close to the surface of the dome interior ... so my original idea of using my spare 1" pipe, in effect, wasn't going to let the pivot poke out of the dome that far.

I decided to plug the 1" hole I had previously drilled with some 1" wooden dowel, with new, smaller holes drilled in.  You can see it here, and I made marks on the dome where it lined up with the center of that dowel (the lower mark was the more accurate one).  Again, all eyeball measurements.

Now it was time to drill the pivot holes, both in the dowel and in the mounts.  Then I sat the mounts back on the rotation plate to check and see how far the pivot jutted out.

Satisfied with that, I carefully put on the dome, the dome cowl, and slid the eyestalk on, to give that a good visual inspection. Everything looks good!

Carefully disassembling the eyestalk and removing it, and the cowl and dome, I duct taped the mounts in place so that I could flip the plate over and drill countersunk wood screw holes.  I had to cut a hole in the rotation plate to make room for the pivot (and threaded rot that will stick out the back)—otherwise it would sit too high and scrape against the top of the dome's pivot hole.

The following day was beautiful and sunny, so I worked outside most of the day.  I mixed up some PVA-water and brushed a few coats onto the rotation plates and mounts.

While that was drying, I decided I would add extra reinforcement to the plate mounts inside the dome (Bondo being the only thing attaching them) and use fiberglass tape and resin to lock them into place.  So I set to work doing that, remembering to use less catalyst in the sun, and pretty soon had that finished.  And only then did I remember that without the fiberglass, everything sat flush and even, and now I just made it all bumpy (and raised the overall dome a couple millimeters).  So I'm going to need to address that somehow later, either by sanding it down a bit, or strategically using washers as spacers to re-level the dome.

I also whipped up a bit of Bondo glazing putty and repaired a few more chips on the dome cowl, which will get sanded back a bit later.

The final major thing I did that was to attach the shoulders to the skirt.  This was a little acrobatic, as I had to climb inside the skirt, lean over the side and grab the shoulder section, and gently lower myself into the skirt, and set the shoulders on top.  Then I had to lean over and grab my drill and bring it inside, being careful not to drill holes in myself as I did it.

I had to drill with the bit facing upward because that was the only angle I could use to assure a 90° hole in both sections of plywood.  I used another bit of dowel (pre-drilled) to make sure that my drilled holes were going to be square.  I did this in four places.

I used threaded inserts (similar but smaller than the ones used in the fender) on the top of the skirt after boring out those holes with a bigger drill bit, and then spade-head thumbscrews with washers for the shoulder.  Now the shoulders are securely attached to the skirt, and the skirt is attached to the fender!

Now I just need to attach the neck rings to the shoulder, and I'll have everything attachable.  Again, I'll draw inspiration from AdamSt's diary, as I can't think of any other way (besides rare-earth magnets?) to firmly attach them from the outside.

Not pictured: I've sanded everything down with 180 and 320 grit.  I think it's just about ready to prime, just need to build a paint booth (or, ideally, find a garage made for that purpose).

Friday, April 10, 2015

Day 115 through 118 - Attaching the dome to the neck (and many other things)

I've been quiet, but I've been busy, trying to get Rainier all ready for Anglicon in June!  Any one of these tasks didn't really warrant a diary entry of their own—except for the dome leveling and attachment bit—but I worked on that whilst working on various other tasks, which you will discover below.

First, though, I want to talk about the dome stuff, as that's what I'm most proud of for this update!

So, in the previous update, I had shown how I sanded the bottom of the dome so that it would be a level reference for when I mounted it to the upper rotation plate.  I didn't want Rainier's head to be all cattywampus when he turns to stare balefully at a potential victim.

I clamped a few blocks to the neck rings in order to hold a pen stationary to the dome rim, making sure it was 8.5cm below the chamfer line.  I rotated the dome on the lazy suzan, dragging a straight line along the dome.  Then I took my calipers to measure the discrepancy.

I was skeptical of my findings shown in the photos, so I instead measured several spots from the chamfer line and adjusted the line (not pictured).  Then I took the Dremel tool and again rotated the dome while I held the tool stationary.  This resulted in a beautiful, straight cut then I then re-sanded in the same way as before.  The dome was level and ready for the upper rotation plate to be fitted!

To accomplish this, I took two spirit levels—one for the dome and one for the plate—and tweaked and bumped the plate until all the bubbled were centered.  Once done, I drew a reference line along the interior, and made sure the line was the same distance from the rim all around the dome (in my case, 53.5mm).

My next tasks was to decide what to use to mount the plate into the dome along this line.  I've seen some solutions use bent aluminum L brackets fiberglassed to the inner surface (I think that's mentioned in the Workshop Manual), but I ultimately settled on AdamSt's method using wooden block sections.

But that raised the question for me of how to cut a curved, angled line that matches both the curvature and angle of the dome's interior.  As I scratched my head, I idly looked around the garage, and my eyes fell on the old practice piece of MDF that I used when I was cutting my neck rings.  From this, I cut four pieces out using my jigsaw, and then belt-sanded the existing 45° angle a little closer to the angle of the dome interior.

I placed the upper rotation plate back in the dome and test-placed the four blocks within to make sure they weren't touching any of the inset details or dome grooves.  Ultimately, I decided to use just three of the four blocks I prepared, as I was able to place them the same distance from each other and not touch any uneven interior wall surfaces.  I temporarily duct-taped them to the other side of the plate to see if they needed to be flush against the plate arc, or if they needed to poke out a bit by a few millimeters.  The latter proved true.  I shone a light inside to verify their placement.

The next step was to use wood screws to secure the blocks to the plate.  Keeping the duct-tape in place, I drilled a screw hole into both the center of the block and through the plate.  I countersunk the hole on the side that would be against the lazy suzan so that the screw wouldn't interfere with the bearing rotation.  Because I was going to be using Bondo to adhere the blocks to the done interior, I taped some paper between the blocks and the rotation plate.

Whipping up some Bondo, I slathered the angled edge of the blocks.  I realized that it would be much easier to place the dome over the top of that while it was on the lazy suzan and neck section instead of aligning it to the inner line I drew.  And I could rotate the dome to see if there was anything askew, and adjust it before the Bondo set.  I let this set for a few hours while I was out of the house, and when I came back, unscrewed the plate from the blocks, and removed the paper, everything looks super fabulous.  I will later reinforce the blocks with fiberglass tape and resin.  Yay!  Level dome that attaches to the neck section!

(I took the opportunity to repair a few of the dome air pockets with the remaining Bondo.)

Although this was done on a different day, now would be a good time to bring up my Bondo-ing of the dome cowl.  Because of the combination of my weird linoleum cowl plug, my crinkly cowl mold, and air pockets that snuck into the fiberglassed finished product, the cowl needed a bit of Bondo repair to smooth everything out, especially the D-shaped sharp line at the very front.  I troweled and smudged some filler onto all those points, and then sanded them down later, using 60-, 80-, 120-, 320-, and finally 1,000-grit (wet) sandpaper.  I'm very pleased with how smooth everything is, and it should look really great once primed.

The final bit of Bondo news involved the top and bottom of the shoulder section, just so any plywood unevenness was filled up and sanded down.  I still have a bit of work left to do here, but I've got it pretty flat.  Might just need to apply a bit of glazing putty to fill in the Bondo holes.

I also assembled and glued together the plunger detailing, using a combination of JB Weld for the metal tube, and acrylic cement for the acrylic and plastic bits.  Afterward, I sanded some of the sharp edges down to smooth it out.

Next, I decided I wanted to prime and paint the plunger detail, the eyestalk pivot, a bit of the eyestalk tube, and the front and back section of the eye.  All these were to be black, so I decided to do them all at once.  Taking some advice from ChristmasDalek, I alternated priming layers as grey, white, and grey again, using Rust-Oleum spray paint.  This also helped to fill in a few of the gaps in the plastic.

Once all that was dry, I sprayed a few coats of black Rust-Oleum onto all the parts and let them dry.  To prevent paint from entering the back eye piece, I put in a circular cut of wood, sitting on top of the spray can lid.

Once dry, I test-assembled everything, and was very pleased with the final result.  I will be adding a few layers of satin clear-coat to protect these parts.  I can't wait to next mount the eye into the newly-attached dome!

Finally, I also messed around a means to make my dome light LEDs look more like actual NSD bulbs.  I Dremeled a hole into a ping pong ball, snipped a few cuts all around it to segment it a bit, and then fitted the ball over the LED bulb.  Then I took some clear silicone bathroom caulking to seal it in place, and hung it upside-down to cure.  The bulb only produces 60 lumens of output, and so its heat is negligible; I'm not worried about damaging the caulk, bulb, or lens casing.

So, there you have it!  A nice huge update to let you all know that I haven't fallen off the map!