SR-71A Blackbird (Testors) Build #18 – Fuselage Tedium Continues…With a Much-appreciated Detour on the Engine Nacelles
After taking August off and away from the bench, I’m back at it. And since the fuselage isn’t finished, yet, I’m back at that, too.
I’ve done so much work on sections of the fuselage and, more importantly in terms of my ancient eyes, have used so many different materials that my ability to see the surface has diminished. To work around that, cue the primer! Normally I tend to not use primer as each coat of paint (of whatever type) fills in details, some of which I have labored to include. But this time, what the light does as it reflects off a surface that is mostly black, some white, and the green of putty, makes getting things correct has become a struggle.
Sod that…grab the rattlecan of primer (Tamiya Medium Gray):
Once under a uniform gray coat of primer, areas that still need work become evident (for me, the most important part of priming). These areas still need further sanding for filled areas to become invisible:
Some areas need just a little bit of filling (the holes will show you where they are):
Not everything needs more work, though:
And one spot needs just a little tweaking (note how a thin coat of primer, just enough to cover, has almost completely filled the two grills at the bottom-center of the photo):
After sanding and another touch of primer, one spot still needs more work:
Putty takes care of the small holes and surface imperfections:
With those small sections attended to, I wanted to check the…well…”fit” isn’t quite accurate, but it’s the least foul word I can think of…of how the engine nacelles and outer wings…well…yeah. Look closely. Where the nacelles attach to the inner wings has a LARGE GAP and those sections are supposed to meet:
Yeah…that’s going to need some work (and it’s going to take enough work that in contrast, I didn’t even mention the gap that runs the length of the attachment point). But before any fitting of these parts can happen, there are a number of details and modifications that have to be done to the nacelles/wings, first. It will be MUCH easier to do the work and make the modifications before these parts are attached.
About this time, the upgraded engine afterburner sections arrived, giving me a sincerely appreciated break from the ongoing fuselage diddling. The white conical parts (fuel spray assemblies) are 3D printed parts (something I expect I’ll be seeing more of as that technology becomes more affordable and commonly used) and the remainder of the parts are nicely cast resin:
I checked fitment of the provided parts and I like them much more than the modified kit parts I had done. It’s interesting in that I like the PE afterburner feathers much more than I do the resin parts that came with this set and they fit the kit parts more precisely. When it comes time to add these to the nacelles, the combination of both AM parts sets and kit parts will really dress up the business ends of the engines.
One of the things I wanted to see was how easily (or not at all) the engine intakes are going to fit. That AM set is very nicely cast resin and requires a bit of modification to the nose of the engine nacelles. For the resin intakes to fit, the molded-on lips had to be removed and the leading edge of the intakes cut back (the AM set provides a new, more accurate, part).
These are the intake parts:
The resin parts were cleaned up and everything fitted, then glued into one unit (twice):
With the resin parts assembled, it was time to cut, carve, and sand the nacelles to slide these things into place. The nacelle on the left is unmodified, the nacelle on the right has had its lip removed:
Once I had one side cut back and cleaned out, I slid the resin parts into place to see how they fit. There will be some work required (big surprise) to make them fit correctly but the overall effect is good:
I cut, carved, and sanded the other nacelle and the other intake “fit” equally “well”. Each side is specific to its location and I dry-fitted the shock cones to see how it all worked together. Again, some work required but the end result will be worth the effort:
There are replacement grills to add. Looking at references show that these panels fit flush with the surface on the Blackbird. That means I have to socket them into the nacelles. I started by taping the grills in place, tracing them with a needle, and then using a chisel blade to remove plastic.
This is what the kit parts look like:
I determined where the PE grills needed to go and taped them in position, then outlined the exposed grill with a needle:
Then I added tape to the exposed end:
And repeated the tracing process:
This is the result:
Now that I know where it goes, it’s time to cut plastic, leaving me with this:
Which enabled me to glue the grill into position:
Yeah…there’s a gap around the grill. I taped over the subtle surface detail and applied putty:
There are eight places on each nacelle where this had to be done. (Some of them came out better than others, requiring varied ways of filling gaps around them.) After seeing how easily the grills packed up with paint when I applied a light coat of primer under the nose, I wonder just how much of these details will be visible once everything has been painted. But having started this process, I saw it through until all the molded-in details had been replaced.
Scribing panel lines is an annoyance. I don’t like it. One little oops and things have to be fixed. (“One”…that’s funny!) In the process of socketing the grills and panels into place, I needed to scribe the panel lines of the nacelles. One little oops and this line isn’t quite straight:
Panel lines. ::heavy sigh:: If they’re correct, they’re mostly unnoticed. If they’re not correct, they’re as obvious as a hooker’s wink. To fill that one little oops with putty will result in the putty breaking out when the area is re-scribed. To avoid that annoyance, instead of using putty to fill the bobble(s), I use stretched sprue. It’s the same material as the surrounding area and the scribing tool cuts plastic, not putty and plastic. So a piece of stretched sprue gets glued to the bobble and let sit for a couple of days to be completely hardened:
Once that’s completely hardened, the sprue is trimmed and then sanded so that the surface is smooth:
A straight edge is laid down to connect the grooves and this time no bobble occurs:
The area is sanded through progressively finer grits until it looks like this:
Yes. Each time I bobble a scribe (something that happens MUCH MORE than I like) (hell, once is more than I like!) in a spot that will need to be re-scribed, I go through this process. (I also curse a lot.)
When I assembled the upper part of the nacelle/wing to the bottom part, the gaps were substantial. Also, note that the panel lines below the corrugated sections in the photos don’t match, so that had to be fixed as well:
MUCH FILING AND SANDING ENSUED. The white plastic I used to fill the gap below was .015 thick. The step from the trailing plane of the elevator to the body of the elevator was a LOT more severe than the above photo showed. I didn’t measure it but it was about 3/16″. “Was” is the operant word, here:
While I was making the two surfaces evenly meet, I kept looking at the trench between the strake (leading edge of the wing along the side of the engine nacelle) and the nacelle. The gap was huge and my initial intent was to stretch more sprue, fill the trenches, and spend many hours sanding, filling holes, and more sanding. I really wanted a structural putty, but making my own by partially dissolving styrene scraps in plastic cement resulted in something a lot more porous than I wanted. “Gee,” I thought, “I wish I had structural putty.” Miliput would work, but it doesn’t store well after opening the package, so that was out. And then I remembered I’d purchased some epoxy putty to do something with the Gemini build that I ended up doing differently. I put the epoxy putty in the drawer and promptly forgot about it. Well, if you need epoxy putty, allow me to mention Apoxie Sculpt.
The gaps and spaces in the two nacelle/wing parts have been filled with Apoxie Sculpt and it works VERY well:
Apoxie Sculpt saved me tens of hours of work to fill the trenches and I suspect it’s going to save me a metric (or SAE) buttload of work getting the wings to meet the nacelles properly!
I let this sit for a couple of days to be certain that the glue had completely cured before I finished it off:
I don’t know what they are, but I know what they look like and where they go. There’s a couple of blisters under the nose/cockpit area. They’re triangular in shape with a recess in the front. After flipping through the various reference photos, I put down some masking tape and outlined the places where they go:
Then it was a matter of finding the styrene that stood off from the surface far enough and transferring the dimensions; as you can see, I used .040:
Then two were cut and glued in place:
Adding tape, removing tape, working the surface, and so on, will certainly show the builder where something wasn’t quite glued on properly, so yeah…that got redone:
At this point, I needed a break from the tedium. I figured since I was just about done with the fuselage (sometimes I crack myself up, I’m so funny), I’d turn my efforts to the next tasks which will be the engine nacelles, the outer wings, and the varied details that need to be added and upgraded. The first step is to see how bad the fit of parts will be.
Well, the fit isn’t exactly the best, and adding a couple of decades of sitting around in a box, migrating between shelves, has caused just about every part IN that box to warp, which is what is keeping the two surfaces at the top of the next photo from meeting:
In addition to having warpage to deal with, well, there’s also the “fit” that’s been an ongoing feature of this kit, too:
The nacelles attach to the main wings. So that they would align later when it’s time to attach them, I used the main wings as my gluing jig (MANY other things aren’t going to fit, but at least where these parts attach to the model will):
While I was gluing the upper outer wings to the bottoms, I got a little bit too enthusiastic with a clamp. The curved line in the photo below is where the glue had softened the plastic sufficiently for the clamp’s pressure to flatten out the curve that’s supposed to be there:
I was far too thorough gluing these parts together. As I was trying to separate them, it became obvious that the amount of damage I’d do to this section would be significant. Having a second kit, though, provided me with the parts I needed to redo this section properly:
Even Dick Bong, Chuck Yeager, Erich Hartmann, Glenn Cunningham, Robin Olds, and Gordo Cooper wore parachutes…
With that oh-god-damn-it moment passed and dealt with, I decided to work a few PE parts and I started with the nosewheel landing gear bay doors. That started by cutting the parts away from the frets and folding them:
With both sides folded, alignment is checked (I love these flat-jawed clamps):
Satisfied, soldering flux is applied, and then the solder is cut (the lines of the cutting pad are in millimeters):
Then the parts are realigned, clamped, and thin slices of solder laid along where I want the parts joined:
A quick pass with the butane torch liquifies the flux, melts the solder (which follows the flux), and it’s attached (and yes…I had to file off a small bit of solder that wandered):
A couple of more VERY tiny parts are added and the doors are done:
While I was on a tear, I decided I’d do the “turkey feathers,” the movable vanes at the engine outlets, of the afterburners next.
Well, once again “confidence” rose and bit the body part I use to sit on. “Confidence” can sometimes diminish the caution and care that must be taken. While I was trying (unsuccessfully) to solder the exterior afterburner vanes into a truncated cone, I smelled burning plastic.
Unless intended, which this was not, burning plastic is never a good thing. I followed the line of the torch, since that was the only heat source around, and discovered this:
“This” is the edge of the fuselage chine. At least I didn’t smash this thing. I turned off the torch, apologized to the cat (wherever she’d run off to in panic) for screaming, and went off and did something else for the remainder of the day.
So. The next day, I put the soldering stuff away and decided that this time I’d use superglue to hold these [MANY DELETED EXPLETIVES] together. Getting the curve gradual and even was quite the chore. Twice. And then I had to do the INside. TWICE. As if that wasn’t enough fun, I had to fit the inside parts to the outside parts. But I got it done and I’m mostly satisfied with how it all fits.
These are the brass PE parts compared to the kit’s part(s):
And here are the tailfeathers in place against where they attach:
When I dry-fit all these things together, I noticed that the depth of the internals was off. If assembled as molded, these things will be too shallow. So I fiddled and figgered and realized that .75″ PVC extension collars from the plumbing supply department would work with a little bit of modification.
I chucked one into the lathe and started turning it to dimension where it needs to fit inside the bases that the turkey feathers mount to:
With the body of the afterburner section lengthened, I had to remove the fuel sprayers from where they were cast on the kit part so I could move them to the inner end of the PVC. I didn’t have a boring tool that would fit. And then I realized (again) that this is plastic, not any sort of metal, and that I could use the back of a #11 blade to cut the section out:
And then I did it all again for the other side. What I ended up with looked a lot better:
And…then Loki and Eris showed up. While I was online looking for something entirely unrelated to this build, I found that Lonestar Products has a resin set to bump up the accuracy of the engines:
So those parts are on order. ::sigh:: Once they arrive, I’ll cut/fit what I have between made and purchased parts to see which combination of bits gives me what I’m after.
With all that done and/or pending, it’s time to fix the melted plastic. (The cat came out of hiding a few hours after my scream. Food does that.)
The fix started by cutting out the melted area:
Then it was time to add plastic, which in this situation was .080 sheet, to the bottom:
Then the hole was filled with more .080 and clamped together:
I waited a few days before I went back at it to allow the glue to cure. The first step was to knock down the excess with a Dremel tool (yeah, I got sloppy and gouged the area above it…perfection still eludes me):
That was followed with a lot of scraping, filing, and sanding, ending with panel lines being scribed (and putty being added):
Having no (good) excuse to avoid working the fuselage again, I went back to it and discovered that one (VERY ANNOYING) section of the underside rear had snapped free, so I had to reattach it, fill it with plastic and putty, then sand, sand, and sand:
With all that done, I’ll be going back to those mystery triangular blisters under the nose. I’m hoping that the coming month does NOT have any more ugly surprises for me. But since I’m not perfect, I’m not betting on that…
I ended the previous post with “whew.” I was premature. Putting all the parts together was one (very small) step of a long walk. Now that the parts (sort of) fit, I have to make the parts fit. And I also have to get everything to look integrated, smooth, and have all the gaps filled.
One of the things I noticed when I was at the NAS Museum was that the triangular sections of the wings were actually raised, so .005 sheet was fitted and putty used to blend the ones that need to be blended:
Naively, I followed the raised lines on both sides of the wing. The problem with that is that the alignment of the lines on top did not match the lines underneath. Of course I didn’t notice this until I’d glued the plastic to the bottom, so I removed the panels on the underside and made sure to align them to the panels on the upperside:
When I separated the upper fuselage from the lower, a section of the elevator ripped out. That needed to be repaired and adding new plastic was the easiest path:
At this point I started scribing panel lines. Though I still don’t figure I’m good at scribing panel lines, I have gotten better at it (and this is good because I have SO much room for improvement!). One of the things I’ve learned with this build is that yes…adding sprue to fill large gaps can be good, and it can also be bad. Unless otherwise shaped, the sprue is round. This isn’t a problem as long as the removal process doesn’t remove more than half the diameter of the sprue. If it does remove more than half the diameter of the sprue, a gap is revealed (hopefully it’s obvious – there’s only supposed to be one line here):
I cut away the dodgy section and replaced it with scrap sheet styrene:
Something I didn’t realize at the time is something I will now draw your attention to. Look in the middle photo of the three previous. See that dark, short, line in the area I’d cut flat? That’s a void; there’s nothing there. As I later found out, leaving a void in an area that is going to be both thin and scribed won’t work well. The scribing breaks through the thin plastic and has to be filled. Again.
Sometimes scribing panel lines can be interesting. This is a raised panel line in an interesting place:
That line need to be recessed. To do that, I had to remove the line so that I could scribe the area:
That had to be done again on the other side.
I thought I had already addressed a fit problem but where things actually went after assembly required me to rework the fuselage between the main landing gear openings (the added plastic was filed/sanded to fit smoothly):
One thing I noticed when I got the ill-fitting fuselage section to fit was that there were gaps. The procedure for this build is fill with plastic, shave plastic down, fill smaller gaps with putty. But this time to get access and to rework the elevators and fuselage, removing the elevators (something that was on the to-do list since the elevators droop as #972 is displayed) was called for:
These photos show how far from meeting the surfaces that are supposed to meet are:
Scrap styrene acts as both wedges to keep surfaces aligned and fill for the gap (a file was used as a wedge to hold the surface in alignment):
I also added flat styrene to the elevators to close the ends since they’ll be visible once in place:
Lots of plastic needed to be added and then puttied over:
After these steps, days and days of sanding, adding putty, sanding, adding more putty, MORE sanding, ensued. I’m still not done yet and here is where things stand presently. All the white plastic areas are where I added plastic:
I haven’t even started on the engine nacelles and outer wingtips yet…
Before I do something as “big” as assembling the fuselage, “big” because once that’s done, there isn’t any “going back inside and fixing something” that can happen easily…if at all, I’ll sometimes sit and stew (or ruminate, for those who are adults) for days. But unless that “big” something isn’t done, the model will never be, either. In short (finally), I started at the nose and put the sodding fuselage parts together.
One (of many) thing that really does torque me out of true is when thin parts break off; it doesn’t matter if it’s during assembly or once it’s finished. I wanted something that would prevent that from happening with this one. What I came up with was to make the nose-probe (which on this bird was the pitot tube and a sensor) easily removable…as in, hit the thing hard enough to snap it and it’ll just fall off unbroken. I decided to hold the probe part on with magnets.
The first part of that involved getting the probe TO FIT tightly. Once that was taken care of, I wanted to socket a piece of steel sheet into the base of the probe. That started by cutting a piece from an old can, cutting the recess, then gluing the steel in place:
Next was to fill the socket where the (now removed) locating pin was to seat and then drill holes for the magnets to sit (kjmagnetics.com, part number ZD12, 1/16″ x 1/8″ rare earth magnets):
Works just fine:
Before I could start closing the fuselage, I needed to finish painting the landing gear bays and glue the nose bay into place. I misted Tamiya’s X-32 Titanium Silver over the flat black, and then touched a few connectors/caps on the spaghetti plumbing with Tamiya’s X-23 Clear Blue:
Okay, I liked how that came out, now to attach the nose gear bay. Since this model has some heft to it, I wanted to be certain I had enough surface area to support things. The first step was to get the bay in place. The vise on the right is supplying pressure to get a good bond in an area that wasn’t really fitting all that well (and there really wasn’t enough material left there to diddle around with):
I added some scrap .080″ stock to both sides of the box to increase the surface area the glue could act on:
And then I noticed that the box was too narrow. If I knew how that happened, it would not have happened. The bottom edge in this photo doesn’t quite come out to the edge of the opening:
My “fix” was to add a strip of plastic to move the edge of the opening inward…and with how far out of true the underside of this nose is, that little strip of plastic isn’t the worst of it:
Time to put these parts together:
Putting these parts together required a bit of adamant persuasion:
About the time I got this far:
I noticed this broken part sitting on my cutting mat:
That broken part came from here:
Not. Remotely. Pleased. The broken part was reassembled (almost completely…a very tiny part of it was never found) and glued back into place. NOT. FORNICATING. PLEASED.
To keep some moron (me) from blindly stuffing his finger into the bay again, I covered them all with excess plastic from a vacu-forming session:
I also noticed the numerous places where “fit” would need work to FIT, in addition to numerous places where plastic needed to be added to fill gaps. Flat .010″ fitted the underside of the nose:
And where the edges of the nose had gaps took some thicker scrap styrene:
Thicker stock filled gaps near the main landing gear bays:
And where fuselage sides met wing roots:
And where the fuselage met the fuselage:
Some places I filled with sprue:
At this point you get to see the “Right Proper Scare” mentioned in the header. I turned the fuselage onto its back and discovered that THIS part doesn’t come anywhere near close to fitting:
Well. That did fascinating things to my blood pressure.
Yeah, that’s going to require some sort of magick or some sort of trick or some sort of SOMETHING SODDING CLEVER on my part because if that ISN’T made to fit, I either end up with a 3/16″ step where there IS none:
OR I end up with a small hole like this:
I spent a few days considering how I could explain to the person that this is being built for that he wasn’t going to (ever) get it. I also spent a few days considering how I could fix it. I realized that fixing it was going to be easier.
If you look at the lower left corner of the photo above, you’ll see there’s a section missing from the edge of what is the elevator. That’s because I split the fuselage parts aft of the main landing gear bays. The fuselage part that doesn’t fit was added to the underside (mostly because that’s where it’s supposed to go), the glue allowed to set up for a couple of days (because there’s going to be SOME FORCE applied here, dammit), and once I was satisfied that the part was as bonded as I could make it, I started bending things a bit (as well as more than a bit) (and in one place a lot), until things actually lined up.
That required me to hold the upper and lower fuselage sections apart while the glue set up enough for me to release it:
But I got it to fit:
“Fit” is a relative thing, sometimes… (And can be the difference between someone who assembles a kit and someone who builds a model. It’s only when things head for the crapper does it become an indicator of the builders’ skills. If it all goes correctly, it’s all easy.)
Now I had to reattach the bottom of the fuselage to the top and get all that to fit as well. As things turned out, this problem, even though it scared me to borderline incontinence, actually solved a different problem I had been concerned about. Having to bend and force things to fit the underside piece properly actually straightened out the warped fuselage parts and that will end up making it much easier to attach the engine nacelles:
One of the things I noticed when I was at the NASM was that there were a number of fuselage panels that weren’t butt-fit but overlapped instead. The first place I noticed that was where these panels sat higher than the ones adjacent behind the leading edge of the wings:
I used .005″ sheet to raise them:
Once all the panels were added to the tops of the wing roots, I needed to blend one panel with putty:
And since I had the putty out, I added it underneath to make the part I’d forced to fit blend without any ridge (and I did more panel scribing while I was under there):
When doing a large area like this, it’s not uncommon to need to add putty here and there. Several thin layers to achieve the desired result is better than trying it in one, thick, pass:
Unsurprisingly, most of that got filed, scraped, and sanded away.
There was a lot of filing and sanding to smooth surfaces where plastic was added. Actually, there is a lot more filing and sanding to do yet, but much of what has been added has been smoothed:
And there is more to do yet, such as this repair when a chunk of the elevator tore loose when I split the fuselage:
There are more .005″ plastic panels to add, more fit problems to fix, panel lines to be scribed, and no shortage of work left. This is the underside with that gaping hole cleverly (and laboriously) filled and some of the panel lines scribed:
Did I mention “whew” yet?
For all the work that was done this month, I don’t have a lot to show. I have, however, gotten both the main landing gear bays AND the main landing gear completed! All pronouncements of “completed” come with the caveat, “for now.”
Having constructed the basic landing gear, it’s time to detail them. The first part of that was to make a bracket for Mystery Bits to attach to and I went to .005″ copper shim stock for that, cut out both pieces, and soldered them together into one bracket:
I don’t know why these lines are coiled, I just know that they are and they are visible, so, the coils get added to the bracket (I used solder for ease of manipulation) and the bracket as well as a junction block on the left side get added to the trunion wings:
There is another Mystery Bit on each strut that evidently serves as some sort of distribution block for what I assume are hydraulic lines (they also provide mounting points for the linkages that the landing gear door attaches to, which I will deal with later on). Those had to be made and are comprised of about 10-12 pieces each:
Setting those aside, I wanted to paint the compressible section of the struts before I populated the parts with more details. I used Humbrol’s Metal Kote Steel, #27003, which is my go-to paint whenever I need something to look like steel and I can’t put steel in (and yes…I thought about it). It’s a buffing paint; once cured, it buffs to a very nice representation of shiny steel. (And I didn’t take any photos of that; you can find how #27003 looks after being buffed in the Sherman M4A3 build as I used it frequently.) But what I really need is anodized aluminum (and note how well the landing lights on the nose strut turned out!):
The NASM has #972 on display and they have it up on stands that attach to the landing gear. The stands keep the weight off the tires. To keep the oleos from compressing as the seals dry and stop sealing, collars are attached to the compressible sections. To my eye, they look like anodized aluminum. To replicate that, once the steel paint had been buffed and cured, I coated that with Tamiya’s X-27 Clear Red. It’s not aluminum, but the effect is close enough:
While the red is still easy to access, that area was masked.
I started the pre-shading process by painting the inside of all the landing gear bays Tamiya’s XF-1 Flat Black:
There are circular blast shields inside the main landing gear bays. Evidently the tires got hot enough to sometimes explode and given how many hydraulic lines and how much wiring is in the area, Lockheed’s engineers decided to protect them. Those were also painted flat black and then glued in place:
Then I added all the details I could to the main landing gear (the yokes are spread so that I can put the center tire in place once the landing gear has been painted):
My next task is to take a mental-health break while I figure out what the next step will be. I’m thinking it’s time to start putting the fuselage parts together. This will require me to glue the nose landing gear bay in place, fill MANY GAPS where the fuselage goes (relatively) together, and scribe panel lines…
This was finished in ’91 and then boxed and stored shortly after it was finished…for about twenty-four years. I figured some bits would break off, which they did. I just thought more would have come off. For thirteen of those twenty-four years this was stored in an unheated and uncooled attic.
When it was built, I did a bit of detailing (not a lot). The canopies were vacu-formed (as were their inner frames), the pilot figures were modified from a Tamiya AM set, the oxygen and G-suit lines were made from guitar strings, some details were omitted from the cockpits (the Navy F-5s didn’t have on-board radar so I cut the radar screens off) and some were added (the hydraulic rams of the rear canopy hinge look like steel because they are – they’re straight pins), the formation lights were made from translucent toothbrush handles, hoses and lines were added to the landing gear (and the gear doors were scratch-built), and this was my first (somewhat poor) attempt at scribing panel lines.
Since I was taking it out of the box to display again, some fixing was called for:
This isn’t the first time the front landing gear has snapped here, so this time I added a pin to help keep it where it belongs:
This will do for now. The nose probe is still MIA; the paint that I used in this area is no longer available. (I’ll have to do something about that at some point.) For now, it’s ready to display again:
Photos taken shortly after it was completed in ’91:
Every so often I get to a point where in order to do this, I need to do that first. Sometimes I find myself where in order to do either, I have to do the other one first. Since either approach has problems with it, it turns out not mattering; cut the knot, Gordon, and proceed…and that’s where I’m at presently with this.
With the landing gear started, I decided to start adding things to the bays. I have no idea what this Mystery Bit does, but it’s visually prominent so I copied it, one for each bay:
The hydraulic cylinder that extends and retracts the landing gear mounts on a cross brace which rotates to maintain alignment:
I made both of them and discovered during the trimming process that I’d made them too thick. I made them again, just more appropriately sized:
With the cross brace done, I needed to make the hydraulic cylinders. However, in order to make them to the correct length, I found myself far too short of hands. I had to brace the landing gear strut in place, and I had to hold the cross brace in position, and I had to align the cylinder. Right… Since I couldn’t think of a way to do all that with only the usual quantity of hands, I decided to make the cylinders so that I could adjust their lengths later when the landing gear was permanently attached. That started by drilling out the plastic rod being used as the body of the cylinder to the diameter of the plastic rod being used as the ram:
This will allow the ram to slide and enable me to adjust length. Added a few details and here are the hydraulic cylinders next to the kit-supplied part:
Somehow, the trunion broke on one of the landing gear struts, so that will get fixed:
I started adding the various lines and as I was doing so, I realized that I was going to need to mount the cross brace about now because care would be needed so that I didn’t put things in that would prevent me from putting the cross brace where it should be. But I couldn’t do that because I only have two hands. What I needed was some way to mount the cross braces temporarily, but allow them to swivel so that they can be aligned relative to the angle (and length) the hydraulic cylinders need. My way around that particular problem was to hold the cross braces in position, drill through the side of the landing gear bay and the end of the cross brace, and that would allow me to put a pin (or wire…this isn’t that large) in there to hold the cross braces in place and allow them to swivel so that later on I can add the hydraulic cylinders with the alignment I want (and, hopefully, that’s correct). Once it was drilled and the wire pins in place, I used tape to keep the wires from falling out:
So yep…they swivel and by being in place, define where I can run lines and stuff:
And I ran lines and stuff:
With the bays done for now (yeah…there’s more to do, just not quite as much), I started making the extension limiters for the landing gear. I got to make them a few times since it seemed my Eyecrometer was out of whack:
Eventually, I got the parts sized correctly and started making the mounts to get them onto the struts:
During this part of things, I discovered that the epoxy I used to fasten the yokes to the struts didn’t really hold well. I used superglue to reattach the yokes and (so far) things seem to be attached.
Needing to take a break from this stuff for a bit (more like a week), I wanted to address something that’s been nagging me since I started.
Decals that could easily be forty years old. I looked for AM decal sets and the only one I found, though they look really good, aren’t what I need. I do NOT want to try to wet the kit’s decals, the kit’s forty-year-old decals, and have them come apart. There are no replacements so if these things don’t work, I’m [DELETED EXPLETIVE]. Proper [DELETED EXPLETIVE].
I read a suggestion online that seems to offer me a way out of this situation. Scan the decals into a BMP file, edit and clean them up, then print them myself onto decal paper.
Well. Let’s talk about pixel-by-pixel tedium. I started with this scan of the kit decals:
Note how IMPOSSIBLE it is to see the white ink. I made a copy of the file and diddled its contrast and brightness:
At least now I can see where the white ink is.
And a word about white ink. My printer (and most, excluding Alp) doesn’t print white ink, lazy git that it is thinks (because don’t all inanimate objects think?!) that white paper is enough when white is needed. Yeah, not this time. So when white ink is needed, I have to use white decal paper. I had to cut and paste the decals that need to be white into a separate file, and then surround the white part (after editing the hell out of them) with a contrasting color (black, in this case, since that’s going to be the color of the fuselage*) so I can see the sodding things:
Then I used the low-visibility markings that #972 sports and copied-pasted-edited them into another file that gets printed on clear decal paper:
Once I’d done all the markings #972 requires, I diddled around until I got the scaling correct so that when these things are printed out, they’ll be the correct size.
If this works as well as it’s looking it might, I think I have solved the “old decal” problem…and could end up with the capability of making my own decals!
*There will be some fiddling and color adjusting needed to make the decals’ black surrounds disappear. The black around the decals is BLACK; the black of the model will be color-corrected so it will actually be a dark gray. Should be “fun.”
At a certain point (and too often, an uncertain point) I get to the “chicken or the egg, and where do I start” point. I need this to do that, and I need that to do this. To start filling the bays with stuff, it would be handy to have the landing gear, or at least part of the landing gear, constructed. But, to build the landing gear, it would be equally handy to have the landing gear bays filled with stuff.
Hmm… I have a VERY worn 1900 Morgan silver dollar in my wallet that I use when I get to a decision that’s evenly (and/or oddly) balanced between two choices; heads I do, tails I don’t. At the “chicken or the egg, and where do I start” point, it’s time to bring out the Morgan. This time, heads meant I start on the landing gear.
I cut a piece of .025″ brass rod to an approximate length, leaving enough length to get the part as long as I want it and still enable the lathe’s chuck to firmly hold it without having to cut too closely to the chuck’s teeth to pose a hazard:
Lots of spinning and cutting as well as center-drilling the end for a pin I’ll need to install later and I ended up with this (which will be cut off at the shoulder on the left):
Okay, that’s what I want. Next trick is to do it again…and I did (sorry the photo is blurry…my vision was equally blurry and I didn’t notice at the time):
Originally I had purchased a set of metal landing gear from Scale Aircraft Conversions (#48067). All they do are landing gear sets from what seems to be a lead-based alloy. For a large and heavy model, it seems a good idea. Not faulting their process or business model, what I ended up with were copies of the kit part, only in metal. Great if the parts are accurate to being with…
One of the things that have been nagging me is just how am I going to do the yoke where the center tire mounts? Any idea I came up with was either impractical or far too complicated. The idea I went with was the most simple (a concept that I need to keep in the forefront of my mind); cut the yoke off the SAC parts and glue it to the brass struts (that’s why I drilled the struts for pins). The nice thing about a lead-based alloy is that it can be easily cut with a razor saw:
As with the nose gear, the top of the main struts have cast trunions. As with the nose gear, these have to be built. .080″ styrene is about half as thin as I needed. I laminated two sections together, rounded out the areas where they attach to the strut and glued them in place (if you look closely, you’ll see the pencil lines where I have to cut away unneeded material):
Once the wings were cut to their basic shape, the inside of them had to be carved out:
Some carving, some puttying, and I could add the pin. The size of this model called for the use of metal struts and I wanted to use a pin that was also strong. So I used a pin and then trimmed it:
Then there was carving and puttying on the next strut to do:
With the pin in place as the trunnions shaped, I center-drilled the yoke.
A word about that whole “center-drill” thing… It’s a genuine ass pain to do; ONE way to do it correctly, and an infinite amount of ways to get it wrong. Since my eyes (or pretty much any part of my decrepit body) aren’t what they once were, I’ve figured a way around my limitations. I drill the hole the pin will socket into slightly oversized. This way I have a built-in fudge factor in the likely event the hole isn’t PERFECTLY positioned. I countersank the hole because there’s usually a slight bubble of glue where the pin meets the surface. Countersinking the hole (done at this size by using a larger bit than I need for the hole) allows the two parts to fit FLAT against each other:
Dry-fitting the strut and yoke show that they do indeed fit snugly. Satisfied with the fit, after this photo was taken, I used 5-minute epoxy (for strength) to join the two parts:
Some putty is needed to create the illusion that the top of the strut is one casting, not a part with two other parts added. I got a little carried away when I carved the one trunnion, so that got puttied while I was at it:
I’m using a set of resin wheels and tires from Fisher Model and Pattern (part #A-4806) for this build. The details of the hubs are far superior to the kit’s “details.” Even as nicely done as they are, they still need some attention. All of my reference photos show that the contact surfaces of the tires are smooth and don’t have the treads Fisher has modeled into the tires. The contact surfaces are also supposed to be slightly convex, not slightly concave:
I roughed the surfaces of the tires hoping that this would offer more bite for the putty added to round the contact surfaces. If the putty wouldn’t work, the alternative would be to sand the corners of the tires away completely. Well…it worked, sorta. The putty wasn’t entirely interested in sticking to the resin (yes…I washed the parting agent off). I managed to get the putty to stick by almost sanding the putty down to where I wanted it and then coated the putty with superglue. Once the superglue cured, I finished sanding to shape and it all worked:
I encountered another problem with the nose wheels/tires. The profile of the tires is definitely rounded, not squared off. Files and sandpaper fixed that problem:
The last modification to the resin parts was to drill out the mounting holes so that they would fit onto the landing gear. The axle stubs of the yokes I’d added to the main struts also had to be trimmed down; initially, they were intended for hollow plastic parts.
With all the tires modified and fit, I wanted to get them under paint. The nose tires were painted with color-corrected Tamiya XF-85 Rubber Black. Then I LIGHTLY misted white onto the contact surface of the tires to replicate dirt and wear:
As they were curing, I mixed four parts Tamiya XF-16 Flat Aluminum with one part Tamiya X-18 Semi-Gloss Black. The tires of the Blackbird are impregnated with aluminum powder to facilitate heat dispersion and the flat aluminum alone looked too bright to my eyes so I added the semi-gloss black until it looked correct:
The hubs of all the tires were painted with a color-corrected coat of semi-gloss black. While I had the semi-gloss black in the airbrush, I had to check a couple of things and to do that I hit them with a coat of it. The first thing I wanted to check was how the trunnions turned out. Not quite perfect but certainly within 90-95%. I also have to spread the yokes to get them to accept the center tire. I didn’t know if I could bend them far enough without causing the paint to crack. Ideally, the acrylic paint would be flexible enough, I could get the tires in there, and I wouldn’t have to figure out how to paint the sodding yoke with the tires in place. Luck was with me and it worked:
For the rusted surfaces of the brake disks, I dry-brushed a mixture of two parts Heller Flat Rust (#9113) with Italeri Flat Rust (#4675AP). To my eye, the Heller flat rust was too brown and the Italeri flat rust was too red. The surfaces of the brake disks don’t appear to have an even layer of rust on the surfaces so I used a very small brush and dry-brushed the mixed paint onto the disks:
So…having decided which to start with, I’ve started with it. The next trick is to start making the stuff that goes into the landing gear bays and stuffing them with the stuff.
This is what the kit provided for the main landing gear bays:
Yeah…it’s pretty sparse and not very accurate. I keep reminding myself that when the dies for this model were cut, the Blackbird was TOP SECRET. So rather than beat up the designers over what isn’t accurate, they deserve credit first for making it at all, and then for making it accurate enough that some maniac (me, obviously) 40+ years later has enough to work with.
As with many kits in this scale, there is a major difference between the provided landing gear bays and how they should be. Primary inaccuracy for the openings is that the bay is not defined by the openings; the bay is recessed back from the openings. The first step is to remove the inaccurate bay bulkheads. Multiple passes with the hooked scriber enables me to get a slot started that I can insinuate the edge of a razor saw into:
Once those are cut away, my favorite chore of making a perpendicular surface fit the inside curve of a surface is next. I roughed them in using 3×5″ index cards for templates. There was MUCH fiddling and diddling to get them close (or at least I thought they were close at the time):
Large pieces of plastic stored snugly into a box and then left to sit for several decades doesn’t do good things for the dimensional integrity of the parts. Things are bent and because they stay bent, they stay bent. The curved surfaces aren’t supposed to be curved and since I wasn’t sure how the warped plastic would affect the build, I wanted to get the parts a bit straighter.:
I have some aluminum channel that I used as the straight edge and used clothespins to attach it. I’m hoping not to scald myself during the straightening process, getting my hands out of that process can only help with that:
The hot water here is HOT. It’s certainly hot enough to make me whine like a five-year-old. But it’s not hot enough to enable me to get the parts straighter (a situation not improved by the sink itself acting as a cooling fin):
I filled a glass pan with water and ran it through the microwave. A lot. (I wasn’t sure the glass would hold up to being placed directly on an electric stove.):
Though I wasn’t able to get the water to boil, I was able to get it to about 190 degrees. The parts were placed in the pan until the water temperature fell below 180, and then the process was repeated several times. And though not perfectly straight, they’re a lot better than they were when I started:
Having delayed and put off the tedium of fitting these bay bulkheads as long as I could, there was nothing to do but to fit the damned things. I had thought my cardstock templates were accurate, which wasn’t the case. So there was a lot of filing, sanding, cursing (never miss an opportunity for that) until things fit, then the first two bulkheads were glued on:
While the glue was curing, I decided to get another potentially fiddly task out of the way. Create the blast shields for the landing gear.
The tires on this aircraft GOT HOT. It was determined that taking off or landing with more than about half a load of fuel was too heavy for even aluminum impregnated tires to withstand and evidently they would blow up. These aren’t low-pressure tires and if they exploded in the bays, those large chunks of rubber moving at high speed did nothing to the hydraulic lines or wiring that anyone wanted to have done. The solution was to create circular blast containments that would surround the tires when the gear was retracted.
To make those, I staggered around the house, garage, and basement, looking for something the proper diameter that I could heat form cylinders around and use to make a buck to vacu-form the caps over. Turns out that a 3/4″ wooden dowel was just what I needed. To form the plastic, I needed to curve flat plastic (.010″) around the surface and hold it as snugly as possible. Rubber bands didn’t hold it tightly enough, so I went with cable ties:
I left the dowel/plastic in boiling water for about five minutes (might have been able to get away with less time, one of these days I’ll have to experiment to see) before taking it out to let it cool. While those parts were cooling, I chucked another piece of 3/4″ dowel into the lathe and turned the flattened dome of the top, then glued it onto a pedestal and attached it to my vacuum molder:
Done twice, I ended up with both the caps I needed:
When I snipped the cable ties, I found that they did indeed hold the plastic tight to the dowel…tight enough to impart cable tie impressions to the outside and wood grain to the inside. Not ideal but also not a deal-breaker, either. The caps were trimmed and glued onto the cylinders, then the ends of the cylinders glued closed (later the openings in the blast shields will be cut into the cylinders and take away most of the seams):
A quick test fit showed that the dimensions work:
Time to putty the impressions of the cable ties:
Sanding putty on these parts was sort of like doing body work on an eggshell.
The first two bulkheads went in with some fitting. Yes…I got the tops and bottoms to match the interior curves of the upper and lower fuselage halves well enough. Getting the distance between the upper and lower fuselage halves required some more fitting. And then I tried doing the next two bulkheads. As it turned out, I failed to notice that the front of the landing gear bays is narrower top to bottom than the rear of the landing gear bays are. Once again, I found myself with a couple of parts that I couldn’t use as they turned out (he says as if these things made themselves). I needed to add plastic back to make them fit properly.
So I did (you will see that I had to add plastic back more than once):
Since the joints are visible, they were puttied and sanded:
My initial plan was to use the top of the fuselage from the spare kit as the inner top of the landing gear bays to make use of the details there (the top of the fuselage over the landing gear bays is also the inner top of said bays). When it was time to make this clever plan a reality, I realized that there would be A LOT of sanding and filing to thin these fuselage sections to a usable thickness. The company I buy my plastic stock from (Evergreen Scale Models) also offers corrugated flat stock. I checked the measurements of the corrugations and though I couldn’t find an exact dimensional match, I bought a sheet that came very close. I cut sections to fit and glued them in place:
With the basic boxes made and installed, it was time to add some of the structural details:
When I was looking for the corrugated plastic, I noticed that Evergreen also has preformed stock. Making the c-channels took a long time, mostly spent waiting for glue to cure so I could work the parts. There are some stiffening ribs I wanted to add and instead of taking a couple of days on a small detail, I decided to buy T-section extrusions and use those instead:
As I was readying myself to start adding more of the cylinders, lines, and wiring that goes in next, I noticed that the c-channels don’t extend all the way to the outsides of the bulkheads. ::sigh:: Okay…those get trimmed to the correct length:
It’s not necessary to sand the areas where the c-channels were removed to absolute flatness; most of those areas will be populated with cylinders, lines, and wiring which will obscure the surface. One last check with the fuselage panels in place to make sure I’ve gotten the look I want:
Yep…that’s about right (he says hoping he’s correct this time). Time to start filling these boxes and the major reference point is the landing gear.
Time to make the landing gear.