Day 92 - Removing the cowl mold

The next day, after work, I checked up on the progress of the dome mold.  It had hardened nicely, so I took it outside for removal.

It was attached pretty securely, so I used the same method to remove it from the dome as I had used to remove the dome from its mold: filler spreaders.  I lightly hammered several of them between the painter's tape and the dome, and eventually the cowl mold popped off.

What a sticky, nasty mess it was.  The spray adhesive was still wet and slimy, which made peeling off the linoleum strips quite a slick chore.  I removed most of it, but there were bits that I couldn't get to.

Additionally, the linoleum didn't behave like the plumber's rubber I used for the dome indentations.  In the case of the red plumber's rubber, the inserts peeled off the gel-coat with the greatest of ease (I even had forgotten to use release agent on them).  With the linoleum, it started to separate from itself, leaving bits stuck to the gel-coat.  The rippling effect is very prominent, as well, but I'm not too concerned with that.  Once I made a cowl from this mold, I'll just sand that down before priming.

Also, I couldn't easily get to the bits of balsa wood I used for the top "lip" portion of the cowl.  They're stuck in there pretty tightly.  ChristmasDalek has generously offered to clean up the cowl with her set of specialized picks and knives, and I'm very grateful for that.  We met to have lunch recently, and I passed the mold onto her.

So that's all the news that's fit to print at the moment.

Day 89 through 91 - Glassing up the dome cowl plug

I found some stuff called Bondo Bumper and Flexible Part Repair, which is a rubbery version of Bondo spot filler.  It also uses a catalyst to activate it, but they are used in equal parts.  Then you smear it on.  Also, it smells like burning tires, yuck!  A few applications of this goop filled up the gaps between the linoleum pretty nicely.

After that cured—which was pretty quick—I took out the Minwax oil-based polyurethane varnish that I had also used to coat and seal my dome plug months ago.  I applied a couple of coats every 4-6 hours or so, around the time each coat got tacky.  Then I left it to dry overnight.  In the morning, I noticed that it was still tacky, so I left it sit while I was at work.  Still tacky.  After chatting with acrodrome, I learned that there was no area for the oils in the varnish to soak into, linoleum being non-porous.  I was thinking that I needed to clean the whole thing off with mineral spirits, or, worse, scrap it all and start over.  For the third time.  But then, the weather turned very sunny, and I left it out in the brilliance for several more hours.  It finally cured!

(In hindsight, I probably didn't even need to do this step.  I remember when I had applied the rubber panels during my second dome attempt, and had neglected to even spray release agent into them, and they turned out just fine in the end.  Rubber and gel-coat seem to work well together.)

So, after that, I sprayed it down with silicone release agent and mixed up a small batch of gel-coat with some dye in it.  I added the catalyst, stirred, and sponged it on pretty liberally.  And, after a few minutes from finishing up, those weird chemical reactions happened again, like what happened when I was making the dome plug months ago.  So strange.  I wonder if it's the Minwax that somehow causes it.

While that was getting nice and tacky, I tore off some pieces of surfacing veil and chop mat from their respective rolls.  I was really hoping that I wouldn't run into a problem with air bubbles given all the sharp angles.  It was starting to get darker outside, so I didn't let the gel-coat get as tacky as I would have normally wanted it.

I spent most of the early evening and night applying the glass—two layers of the surfacing veil, and two layers of the chop mat (give or take).  I tried to work out the air bubbles as much as possible, and give good coverage to the cowl plug (especially on the sharp corners).  I put it back in the garage, turned on the heater, and left it to sit for another 24 hours.

I guess we'll see how it turns out tomorrow!  *crosses fingers*

Day 86 through 88 - Dome cowl

Back at the beginning of June, I started to make the dome cowl.  I was originally going to follow ccain's method of using cardboard, but when I started to Bondo it, I was running into many frustrations.  First, I just don't do a very good job of sanding detailed pieces.  Second, the duct tape I was using to attach the pieces of cardboard onto the cowl were not flush with it, so the arc of the cowl was lifting off of the dome's arc.

So, fast-forward to now.  I took a big break from Rainier (mostly to enjoy two full weekends of other activities and travel), and have been coming back to him slowly.  I had lunch with a friend when it hit me: I don't need to use cardboard!  I could totally use rubber sheets like I used for the details in the dome!  Even when forgetting to apply release agent, the cured gel coat let go of those details perfectly!  This will be perfect for the dome cowl!

I went to Blick, a craft store here in the States, and looked around for suitable rubber.  I needed bigger pieces than the plumber's rubber that I had found at Lowe's for the dome details.  I was directed down an aisle, and I found large linoleum rubber sheets that were nearly 5mm thick.  I bought these, a mat cutter for slicing them up, and some stronger spray adhesive than what I had before.  (I didn't want a repeat of the rubber panels sliding off while gel coat was smothered over them.)

Back at home, tore off the old mess of a cowl, leaving the painter's tape attached to the dome.  I made paper templates to get the general shapes I needed for the new linoleum version.  The linoleum cut like a dream with the mat cutter, and in fairly short order, I had the main outline of the cowl base cut out.  I sprayed some adhesive onto the backs and onto the painter's tape attached to the dome, and let that get tacky.  Then started I attaching the pieces.

Even the stronger version of the spray adhesive was still not sticky enough, and some of the pieces were lifting off of the painter's tape.  However, a little brushing of Krazy Glue solved that problem.

I remade a cardboard structure—this time a little smaller than the plans to taking into account the thickness of the linoleum—for the interior of the main cowl piece.  This is because the linoleum is very bendy; it's basically like rubber.  I needed a stiff inner structure to adhere to the outer pieces.  Then I drew out and cut the front, top, and sides, similar to how I did it back in June.  Spray adhesive and Krazy Glue kept it all together.

Eventually, everything was attached to the dome.  I am extremely pleased with the result, and how sharp the details are.  I still need to fill in gaps between the various linoleum pieces, but I'm not sure if Bondo is the way to go, since the linoleum substrate is so rubbery and flexible. I just learned about another filler called Dolphin Putty that is used for repairing rubber car bumpers, so that might be a thing to try.  It's also sand-able and paintable.  After that, I'll probably throw a few coats of polyurethane varnish—goodness knows I still have a whole gallon of the stuff.

(Note that the front piece has a large semi-circle cut out from the bottom.  This was inspired by MrsCarleigh's 80% scale Dalek cowl.  I didn't like the way the front of my old Bondo version bulged out. This semi-circle will also be filled in and smoothed.  Also, I will be attaching the name tag piece in the eventual mold rather than on this cowl plug.)

OH!  And I would be completely remiss if I didn't mention that ChristmasDalek was kind enough to take my gazing globes in for powder-coating, in exchange for the Imperial dome that I made for her several weeks ago.  They turned out to be gorgeous!

Day 84 and 85 - More fender motorization

I spent a good chunk of time drilling various bits of metal and wood, and making sure everything was all lined up.  Finally, the wheel assemblies were ready to be bolted to the rest of the frame.

The problem with that much frame, however, is that there are not a lot of places to mount casters.  I got a set of small 2" casters at Lowe's and placed them temporarily onto the topmost and bottommost wooden struts using self-tapping screws.  I then eagerly took the fender outside for a spin.

After a few minutes of loud, rough trundling, one of the back casters snapped off.  As you can see from the photos, the screws were pretty close to the edges of the wood, so there wasn't a lot holding them into place.  A rough, pebbled cement driveway extends from my townhouse front door at an angle, and that also contributed.

The next day, I described some of my progress to some of my chums at work, and one of them (who builds robots) put in his thoughts on what I could also do.  He suggested reinforcing the third mounting point on the motor casings, which I hadn't yet done.  Since the wheels are mounted on parallel metal beams running the length of the fender frame, sufficient weight placed on them could splay them apart.

So I pondered a bit on how I could solidify this, and came up with adding a length of 5/8" solid threaded rod, bolted on either side with nuts and locking washers.  It's pretty rock solid.  In fact, I had to detach the wheels to even get the rod in place.  Once re-assembled, it wasn't going to splay at all.

Another chap had inadvertently eavesdropped on the conversation at the point when I was talking about the crappy urethane casters, and not knowing where to get ones that would really be able to handle a nice solid load.  He mentioned a store I hadn't even heard of that's still here in Seattle, called RH Brown.  I'm glad he told me about them!  I went there right after work and bought 3.5" and 4" rubber casters and took them home.  I didn't yet know what size I was going to use, and they said I could take back the set I didn't use for a refund.

There was no place on the frame to put them, initially, so I decided that I was going to trim some of the workings off of my monster assemblage.  I took my metal-cutting blade off of the miter saw, threw it onto my circular saw (same size blade), and cut off the upper and lower parts of the square steel tube on which the wheel motors are mounted.  I then unbolted that and the uppermost and lowermost wooden beams.

This cleared a large area for me to add the new casters.  In order for them to be just about level with the main tires, I needed to mount them on top of two 1/2" pieces of plywood.  I chopped up some offcuts, and secured everything into place, this time with 5/16" hex-bolts (and not self-tapping screws).

It looks a lot less complicated down there, now.  Still weighs in at a hefty amount, though.  We took some video of me test-driving it, but because it was so dark, it didn't turn out very well.  Also, I need to sand off a bit from the front plywood caster mounts, because at times the middle tires weren't in contact with the ground.  On a flat surface, this might not matter, but I know I'll hit angles from time to time.

Video of me trundling around likely to be posted soon!

Day 83 - Attaching the motor and wheels

After last night's Daleking, I pondered ways by which I wanted to attach the wheels to the fender.  I got to looking more closely at them, and it became obvious that there was only one way to attach them.  The two motors each have three mounting points arranged in a triangle, and a "freewheel" lever that disengages the wheels from the motors (if both are toggled).  I wanted that level accessible and I needed to attach two of the three mounting points to flat, steel tubing.

I drove out to Metal Supermarkets in Kent, Washington and picked up around 20 feet of hot-rolled square steel tubing, and 10 feet of flat steel (1" x 0.125").  The latter I did not use in today's adventures, but I will be using it on the top of the fender to reinforce what I did today.  I also swung by my neighborhood Lowe's (many, many times today, as it turned out) to get a new metal-cutting blade for the miter saw, and metal-drilling bits for the drill press.

After cutting off a portion of steel tubing based on the length of the fender interior, I drilled it to match the two mounting points I had selected.  I also cut a hole to accommodate a portion of the tire and motor.  It became glaringly obvious that my plan of bolting the square tubing directly to the fender wouldn't work—the wheels were much too small.  I stacked and stacked 1/2" offcuts of wood to get it to the height it needed to be for a good 2" of clearance from the fender base.  The stack was roughly 3.5 inches, bringing the length of tubing just about level to the fender base.

Back to Lowe's I went, this time for some (inaccurately named) 2x4s.  These beams of wood are actually about 1.5" by 3.5", but it was the same height as my stack.  I had the friendly store employee cut me up some three-foot lengths, and I also selected washers, nuts, and some hex-bolts of various lengths.

I got back home, and, since it was a beautiful day yet again, I took everything outside.  I placed the offcuts of the beams inside and placed the wheel assemblies on top to see if my madcap plan would work.  I was pretty happy with the result, but I still wanted to strengthen the fender with a framework of steel beams.

I cut, drilled, and attached three lengths of steel to the center, left, and right side of the fender.  Then, to get the best of both worlds, I made dado (housing) cuts in each of the wooden beams using the table saw to fit over the steel beams.  Next, I aligned my hand drill to the holes already cut in the steel beams, and continued drilling the rest of the way into the wood.  Then I took 5-inch long hex-bolts and secured them to the frame.  I make is all sound so simple; however, this part of the assembly took me awhile, from inception to execution.

This was all ad-hoc thinking on my part.  No plan.

I debated whether or not to trim the long lengths of steel tubing from the wheels since the two wooden beams I had attached weren't that far apart.  In the end, however, I decided to go overkill.  I repeated the above process and attached two more wooden beams: one closer to the front, and the other closer to the rear.  I figured that this way, the weight placed on the fender from the rest of the Dalek—including the batteries, skirt, shoulders, neck, head, extra bits, and, of course, me—would be more evenly distributed along the fender frame.

(The "L" brackets that can be seen in the pictures are right now just for show, but I plan on further securing the wooden beams to the fender with them next time.  I also plan on adding four more lengths of steel bar—one on either side of the two center wooden beams—then bolting them to the wood beams and steel beams attached to the wheels.  This will give added strength to, and further secure, the wheel assemblies.)

With all the gubbins that I attached underneath, I was very pleased at how clean everything was up on top.  When I took it back to the garage for the evening (man, that things weighs a lot more now), I placed it in its normal position flat on the floor and stood on it.  Then I walked all over it.  There wasn't a creak to be heard, and it felt very solid.  This was also with the wheel assemblies removed, so it will be another story altogether when I add those, along with appropriately-sized caster wheels in the front and back.

Now, I'm not an engineer by any stretch of the imagination.  This was a very ad-hoc approach to solving the problem of how to mount small wheels with bizarre mounting points.  I've tried to over-engineer my ideas as they came to me, but if anyone can see any problems that are glaringly obvious, I would be much obliged.

Day 82 - Fender and shoulder re-enforcement, and some wheelchair time

Today was an absolute gorgeous day, so I decided to cross a few of the unappealing yet necessary tasks off my to-do list.  Chief among these was laying fiberglass tape on the interior of the fender.  I carefully un-stacked Rainier and carried the fender outside.  I sealed off the exterior seams of the fender with painter's tape, flipped it over, and cut out sections of fiberglass for each panel.

I mixed up some resin, using much less catalyst than I had during the colder months (even so, one batch gelled and cooked sooner than I had wanted), and applied a strip of fiberglass each to the upper and lower seams.  I let that cure for a couple hours, then returned and flipped the fender over.  After taking off the painter's tape, I mixed up a couple batches of Bondo and filled the gaps on the exterior.

Since there was still plenty of sunshine left, I took a wee break and then decided to do the same thing with the shoulder section.  I carefully took off the slats and carried the shoulder section outside as well.  I positioned more fiberglass tape into place on each of the four interior beams, slathering resin onto each as I went.  I let that cure for while, and then added more Bondo to the underside of the shoulders for the heck of it.  People will likely never see that part, but if I attach the shoulders to the skirt with a hinge, it will be visible.  Overkill?  Probably.

By this time, the sunlight was fading, so I went into the garage and started tearing apart the wheelchair.  Before doing so, I downloaded the operators manual for the model (a Jazzy Select Elite) and read it thoroughly, seeing how it was all put together and whether or not I was going to blow myself up.  Eventually, I got the drive motors completely removed.  This was very encouraging to me, as I am eager to try Variable's non-welding method of attaching them to the fender.

At Lowe's, I saw perforated square steel tubing that I might be able to bolt the motors into.  I need to measure to be sure.  If not, I'll get non-perforated stock, and drill the bolt holes myself.  The only other question I have is whether or not I need to keep the wheels the same distance apart as they were when the wheelchair was assembled.  Specifically, would crazy things happen when I am trying to turn, as the fender top is much wider than the wheelchair (75cm vs 58cm).  Something tells me it will be fine, but I would like to make sure.

Day 81 - Cowl assembly

I decided to tackle the cowl assembly next.  I think it's the last great pain-in-the-neck part to build, so I might as well get it out of the way!  I'm heartened by reading that the actual prop cowls (when observed up close) look like they were made out of bread dough.  Mine will look better (one hopes).

So, first, I gave Rainier a haircut by trimming off the excess fiberglass from under the dome.  Now he's properly bald.  I also added the slats temporarily, just for kicks, as they make him look even more Dalek-y.

I removed the dome and took it upstairs to work in a dust-free area.  Taking my painter's tape, I masked off the approximate area on the dome where the cowl will be positioned.

Like ccain before me, I used my old MacBook Pro box (as well as a Wii U box) for the cowl parts.  It took me hours to extrapolate the dimensions from the NSD plans.  Two of the measurements had both straight line and arc values specified (very handy), but the rest didn't, so I wasn't sure what they were actually measuring.  I took my best guesses at these—looking at lots of reference photos while doing so—and figured I would just pad it with Bondo later on if the cowl wasn't aesthetically pleasing to the eye.

Why the role-playing dice?  Well, the small plastic box they came in proved convenient to make an exact 90° angle for the cowl front and cowl top.  Once I figured out where to position this part of the assembly on the dome, I wondered how I was going to make the side pieces conform to the curvature.  Then I remembered that I have the exact thing I needed: my old dome former.  I traced out that curve and cut out the pieces.

Then it was just a matter of assembling and securing everything to the dome with tape.  Like AdamSt, I attached duct tape face-up on the dome, taped it down with painter's tape, then added strips of cardboard along the sticky surface.  Because of the tension of the cardboard strips, some of the tape lifted up slightly from the underlying dome.  I will need to add extra painter's tape over the top of the cardboard to hold it down.

I had some trouble getting the nameplate section attached, which looks flat on all the cowls I've seen.  On mine, it needed to curve along the chamfer of the dome; otherwise, big gaps would exist on either side, which I haven't seen on any other cowls.  So that part was confusing.

Now that the major shape of the cowl is defined and attached, I can cover it with Bondo and see how it will all look after sanding.  Like the dome, this will be a three-part process of cowl plug, then cowl mold, then casting the eventual fiberglass cowl from the mold.