Zylaxus: a dubious build thread

[neil_w]

Normally I have a design pretty much nailed down before I begin. Not so this time; there are many details here that either (a) I haven't figured out yet, or (b) I'm not sure if will work out, particularly regarding the paint and decals. And normally I will have gotten further into the build before starting the build thread; this time I've barely started. Nonetheless, here goes.

Zylaxus is an alien deep space voyager, powered by the Zylaxians' signature Plasmospheric™ drive.




Note the unusual (for me) lack of decals. I haven’t come up with anything I like yet. The final scheme is likely to be very light on decals. The fins and the ping pong ball will have to be the decor, for the most part.

ORK file is attached. This will actually be one of my larger builds at almost 31". It should come in around 4 oz but is quite draggy, so with its 24mm mount it'll be a D/E rocket for the most part.



This rocket is the final (?) evolution of the very first design I posted on my sprawling and ridiculous half-baked design thread, almost 7 years ago. Yikes. I guess it deserves to be built already. Other than the addition of the plasmospheric drive, this is remarkably close to the original version posted back then:

 

[BigMacDaddy]

Looks cool - what are you planning for the ball (and to allow ejection to go through the ball)?

 

[neil_w]

Looks cool - what are you planning for the ball (and to allow ejection to go through the ball)?

In the grand tradition of Shrox designs, it’s a ping pong ball with a tube (BT50h) running through it.

I also took considerable inspiration from @LW Bercini ’s awesome Apparition build (still one of my top favorite designs of all time).

 

[Azamiryou]

I love that the aliens went to the trouble of trademarking the name of their drive. Must be a bureaucratic race like the Vogons.

 

[neil_w]

Fins, part 1 of far too many

Even the most casual glance at the various fins in this rocket makes it obvious that laser cutting is the only sensible approach. That is why I will be hand-cutting everything. This will be more challenging than Alcubierre, second in sheer unbridled madness only to my upscale Quinstar.

I decided to start with the wings. I cut out the template and decided where to split it into pieces to optimize grain direction. I came up with a 2-piece cut. which became a 3-piece cut later on:


Here are my first two pieces for wing #1. With things like this, it is always critical to check fit and do the gluing with the roots against a straightedge, since it will be necessary for the finished assembly to sit perfectly flush against the body. You'll notice that the little curvy bit on the right inside was omitted from this, and will be added back with the fabled 3rd piece later. This is 1/8" balsa BTW.



Here are the two completed assemblies. They're not *exactly* the same but pretty close. At this point, if I find a significant discrepancy between the pieces I can fix (somewhat) with sanding and/or trimming. In any case, they look fine.


*Of course* I papered them, as per usual with Avery label paper. I will once again assert that while label paper does not add as much strength as glued paper, it *does* add quite a bit. These assemblies feel very solid. Also you can see from the 1" grid that these are pretty large pieces, at least for LPR.


When I finished with these I started to have misgivings about not having built them for TTW mounting. But I really don't want to have to build another set. We'll see if I change my mind later on.

 

[neil_w]

This is one design (of several) that I'm pondering for the plasma ball. I believe I could execute this successfully.


Looks decent (I think?) in the context of the rocket.

 

[Azamiryou]

I think it would be a good candidate for hydro dipping.

 

[neil_w]

Indeed it is. But there's no certainty of getting a good result with hydro-dipping, so I'm keeping my options open.

 

[NTP2]

Indeed it is. But there's no certainty of getting a good result with hydro-dipping, so I'm keeping my options open.

Do you have no confidence in me!

 

[modeltrains]

This is one design (of several) that I'm pondering for the plasma ball. I believe I could execute this successfully.

In a kind of sort of way, it looks like doing a painted marble effect & I have seen people use feathers as the tool for painting that effect.

 

[neil_w]

In a kind of sort of way, it looks like doing a painted marble effect & I have seen people use feathers as the tool for painting that effect.

Well, basically it's random splotches of fluorescent colors, with lightning decals applied on top. It's hard to guess how close to reality my render is, although I *think* it looks good enough to experiment with maybe.

You know what it *really* reminds me of (other than the lightning bolts)?

 

[NTP2]

Well, basically it's random splotches of fluorescent colors, with lightning decals applied on top. It's hard to guess how close to reality my render is, although I *think* it looks good enough to experiment with maybe.

You know what it *really* reminds me of (other than the lightning bolts)?
View attachment 624621

Well now I’m hungry, thanks for that…

 

[neil_w]

I know, right?

 

[neil_w]

Fins, part 2

Next up: the canards. I chose 3/32" balsa for these, thinking that I would also use it for the plasma cage and verticals. I simple with these and just make them with two equal pieces, front half and back half, joined at the top:


I quickly learned that (a) this was not very strong; needed to handle them very gently, and (b) I really need to let the TBII dry before handling. I would apply lesson (b) later; for these, I simply didn't handle them at all. I glued them, and then applied the top layer of label paper without ever lifting the off the mat. And once again I offer the reminder that label papering really *does* add a lot of strength. Once papered I could handle these normally, sanding all around as necessary.

I've always felt that a good test for whether the fin root is sanded correctly is to see if it will stand up on its own. That didn't work with the wings because they were just too big and top-heavy. But here, no problem. I will sand each fin slowly and gently on a block until it can do this:


Thus far I've been surprised at how well I've been able to handle the sharp fin points with balsa, as long as grain direction is correct. Haven't needed to go basswood yet.

I think this is about the time when it occurred to me that masking this rocket for painting the fins is going to be a nightmare. Oh well!

 

[NTP2]

I think this is about the time when it occurred to me that masking this rocket for painting the fins is going to be a nightmare. Oh well!

Why don’t you do it first?

 

[neil_w]

Why don’t you do it first?

Not practical. Need to have masked areas on the body tube and fins for glue joints and for fillets. Those fillets would need to be painted over in the end. A mess.

Maybe possible for a rocket being glued together with CA, but not something like this where everything (oy!) will need good fillets, *especially* the wings, which I continue to fret over.

I have done fillets with clear CA, which look fine, but I don't really trust them all the much.

 

[NTP2]

Not practical. Need to have masked areas on the body tube and fins for glue joints and for fillets. Those fillets would need to be painted over in the end. A mess.

Maybe possible for a rocket being glued together with CA, but not something like this where everything (oy!) will need good fillets, *especially* the wings, which I continue to fret over.

I have done fillets with clear CA, which look fine, but I don't really trust them all the much.

I know you are a LPR fan but maybe epoxy it’s strong you can sand the paint and get a good stick.

 

[neil_w]

I have very very cautiously pondered the possibility of doing epoxy fillets on the wings, to compensate for the lack of TTW mounts. I probably won't, but it's not completely out of the question.

I certainly wouldn't do *all* the fillets in epoxy. There are 22 fin roots on the rocket. It will be getting the wood glue treatment.

Besides, epoxy fillets don't solve the masking problem, since they still need to be painted.

Finally: one decision I made early on, which I forgot to document in my previous installments on fins, was not to round the fin edges. Instead, I'm just lightly knocking off the sharp corners. This has three benefits:
1) Less sanding
2) Easier fin papering
3) Easier fin root masking. Round fin edges are where most of the fin masking effort goes. I should have it much easier here than my usual.

So, 22 fin roots is a *lot*, but I'll get through it, especially if each edge only requires one cross piece of tape at front and back, and one along each fillet.

 

[stealth6]

You always do very cool designs.
This one however is WAY cool.

s6

 

[neil_w]

Fins, part 3

Next up is what I call the "plasma cage". In this case, there are four simple cage fins, and two that blend into the vertical stabilizers. I'm saving those latter two for the end, since they're going to be the hardest, so this will be just for the four "simple ones".

These are basically larger versions of the canards. I didn't like my butt-joints on the canards, so I did a different split this time that gave a larger joint. It does seem to have yielded stronger assemblies (once they're papered it doesn't really matter anymore, though).

Note a bit of wood filler at the lower right end of the seam; it's hard to get a smooth curve in there just from the cut balsa.

After I papered my second piece, it occurred to me to double-check how consistent I was being. Answer: not very. It's incredibly difficult to hand-cut fins like this and make them all exactly the same on the first try.

This particular error was solved with a knife... after this I decided I needed to check this before papering, where it's easier to just sand.

Here are the finished four pieces. They're still not *exactly* the same, but close enough. The most important part was the cutout in the middle that spans across the ping pong ball... those need to be as consistent as possible or it will be very noticeable.



Note in above pic how I have trimmed the tips of the fins square, to make masking as easy as possible.


I really do test all of my fins to make sure they'll stand on their own (provided they don't have TTW tabs).

 

[Azamiryou]

Would it work to print the fin pattern on labels, then stick them to the fin material for cutting? Might make it easier to cut them to match, and they'd already be papered on one side.

 

[neil_w]

Would it work to print the fin pattern on labels, then stick them to the fin material for cutting? Might make it easier to cut them to match, and they'd already be papered on one side.

Maybe! I’ll have to try that sometime.

That said: for multi-piece fins like this, I don’t actually have a design for the different parts… I just have the whole fins then I cut the template into parts. I’d need to do some additional drawing work on the computer (not exactly my wheelhouse) to create printable patterns.

 

[BABAR]

Maybe! I’ll have to try that sometime.

That said: for multi-piece fins like this, I don’t actually have a design for the different parts… I just have the whole fins then I cut the template into parts. I’d need to do some additional drawing work on the computer (not exactly my wheelhouse) to create printable patterns.

Make a square or rectangle with your two pieces of wood big enough to fit four fins in shape given with the joint matching where you want it. Allow joint to dry completely.

Cut out a piece of adhesive paper and attach to wood. Draw a line in pencil (Tim VanM says ink will show through paint) that shows joint location

You might as welll paper the other side while you’re at it.

Take your fin template and mark where you want joint to be.

Trace four fins on your wood/paper, matching the fin joint line on template to line on the wood/paper.

Cut out the fins, if you papered both sides pre-cut, you now have four papered matching fins.

I’m guessing all you need to do is some sanding and maybe CA the edges.

 

[neil_w]

Did a quick experiment today. I noticed that Michael’s had holographic glitter paint, though that might be an interesting look for the ball.

It seems to be holo glitter in a mostly clear base, so multiple coats would be necessary to get good coverage.

It looks decent in the light…


… but utterly dead when not:


Verdict: nope.

 

[Azamiryou]

How's it look painted over a dayglow base?

 

[neil_w]

How's it look painted over a dayglow base?

I’ll have to try it. They say either over a like color or black. I do have some neon orange do I can try that next.

 

[neil_w]

Filling Spirals, part 1 of 37

I filled my two body tubes, using an improved technique that made it go so quickly I couldn't believe it. I was not looking forward to filling the long tube, but it ended up being easy peasy (and yes, lemon squeezy).

 

[neil_w]

Ping Pong Prep

I purchased a pack of 6 ping pong balls, figuring that would be enough to accommodate some trial and error. I bought the cheapest 3 balls I could find on Amazon, with small logos that I could be sure I would cut out completely. 3 are thicker-walled and more rugged than the super cheapy no-name balls you can find, and I wanted it to withstand some handling, especially after cutting. Here's one:


First I jammed a piece of BT50 against the ball, covering the logo, and traced it with a pencil:


For my first attempt, I intentionally cut inside the line, not wanting to accidently make the hole oversized. I soon learned that this was a bad strategy, because enlarging the whole by whatever means is really a pain in the neck. So for later cuts I tried harder to make the initial cut much closer to the final needed size.


To cut the hole on the other side, I took inspiration from @LW Bercini 's fantastic Apparition build (still probably my favorite scratch build of all time). He credited Gary Byrum for the technique. I jammed the tube in the hole, and then shined a flashlight into the other end of the tube:


This gives a pretty good visual marker for drawing the cut line for the hole. Later on I realized that this would yield an outline of the *inside* of the tube, so once again I ended up with a hole that was too small and needed to be enlarged. Let's just say the first ball was not my best work, but I eventually got it done.


It was done when I could slide it snugly over the tube.



I made two more, definitely doing better than the first.


Today those three balls are in the mail to @NTP2, who has gamely volunteered to try hydro-dipping them. Let us all wish him luck. When the time comes, he'll jump in and document what he did as part of this thread.

I still have 3 more balls in reserve, to do my own paint experiments on.

 

[neil_w]

Fins, part.... I don't know, I've lost count

Time for the fins I was most apprehensive about, the verticals which are blended with the cage pieces. These are by far the most fiddly fins I've ever been stupid enough to try to construct.

Here's the template, and here are my cut lines for the four-piece assembly. I was particularly nervous about the skinny joint between pieces 6 and 7.


After cutting piece 7, I cut piece 8 and went to check fit...

Well that is not good. My first thought was that I had cut a bad #8, but then I checked the template...


It turns out that my piece 8 matches the template quite closely... so it's my piece 7 that is apparently *way* off. But I had already invested some time into that piece, so I just cut another 8 specifically to fit that particular 7.

That's better.

I started by gluing 5 and 6 together, and 7 and 8. Double checked fit between 6 and 7...


Looked good, so I went and glued it all together., held against the straightedge and held down to ensure absolute flatness.


Sharp-eyed readers will notice that I actually swapped my 5 and 6 pieces... It actually fit better this way so that's what I did. Also not shown is that I did some shaping of the front half of the assembly to ensure consistency with the other cage pieces.

After the glue dried I decided I was afraid to even try to lift it off the wax paper. So I sanded the facing surface and applied my first layer of label paper without taking it off at all. Once the top label was on, it was strong *enough* to handle, although there was still some flex at the middle joint. Nonetheless, I was able to get the whole thing papered and trimmed and looking pretty good.


Note I applied a bit of wood filler in the middle joint area to create a smooth curve.

Final photo is apparently obligatory for this build:

Let me tell you it was not easy to get that fin to stand, but I didn't want to disappoint my loyal readers.

So that's the first vertical. Still one more to go.

 

[neil_w]

Another ping pong ball experiment… although tested on a little 2x2” canvas that i thought would be easier to work with. To some extent it is, although the bumpy canvas surface is a pain and makes brush-painting it somewhat different (I think) than a ping pong ball will be. So I might need to sacrifice one of my remaining ping pong balls for further experimenting.

These are neon UV-glowing acrylics, other than the black lines which are a black paint pen. The green is pretty bright (not showing so well in the photo, color is not accurate), the purple less so, at least under normal light. As expected this took many coats and I still couldn’t get even coverage. Maybe better on a smooth surface? I don’t know. I need to decide if this is a good enough look to even continue experimenting. Right now I'm torn between "hmm, maybe promising" and "awful, abandon ship".



What do you all think, is this worth trying on a ping pong ball? I also have some neon orange (from the Angled Invader build) that I could mix in as well.

Rough preview: