Lakeroadster's X-Wing Alpha Build Thread

[lakeroadster]

Fin Alignment Tool.. I stumbled on the" Fin Alignment Jig" thread here earlier today https://www.rocketryforum.com/threads/guillotine-fin-jig-plans.123088/ and took a stab at designing one for the size rockets I anticipate building.. BT-50 through 4-1/2" o.d..

Putting this on the build bucket list... before the next scratch build. Neat because the only thing I need to build it is some angle pieces. Everything else is sitting in the woodshed and the barn.

Hats off to member tmacklin for the concept.. well done sir. https://www.macklinmissileworks.com/shop/mid-size-guillotine-fin-jig-1

 

[Brainlord Mesomorph]

Great build and great thread, Lake. I haven't felt worthy to chime in. (This thread actually predates me on this site.)

But I have to ask; What apps are you using? (full plans, stress analysis??)

/I'm muddling by w/ OR and CorelDraw.
//was a CADD user in 1986

 

[lakeroadster]

Great build and great thread, Lake. I haven't felt worthy to chime in. (This thread actually predates me on this site.)

But I have to ask; What apps are you using? (full plans, stress analysis??)

/I'm muddling by w/ OR and CorelDraw.
//was a CADD user in 1986

Thanks... AutoCAD Inventor Professional.. I've been a CAD Monkey since the early 1980's.

"Live to Desgin, Design to Live"

 

[Brainlord Mesomorph]

We sound like the same age.

I used MARS CAD and CEADS (?) CAD on HP1000 mainframes back in the day.

 

[lakeroadster]

I'm 57.

I've always been a PC based guy, having worked for small manufacturing / fabrication companies that didn't want to invest in mainframe based systems.

I started on a drafting board for the first couple years, then 2D AutoCAD. Didn't get the opportunity to do true solid modeling until 2004, since then CAD has been truly rewarding.

 

[lakeroadster]

I did some testing today on the mylar chute and found a problem. The shroud lines easily cut through the mylar / shipping tape..... just a slight tug zippered right through.

After revising the design to utilize Scotch #8959 Bi-Directional Filament Packaging Tape I tested the arrangement by adding weight, about 1 lb each test, until the test chute failed.

Maximum load was 21.7 lbs, using 4 shroud lines.

Assuming a Safety Factor of 1.5 that means the Hexagnal Chute, using 6 shroud lines, should be good for a drag load of about 20 lbs, with the upgraded reinforcement to the Scotch #8959 Bi-Directional Filament Packaging Tape.

The other option would be to run the lines all the way over the chute... as shown in the Apogee video here:

Still on the fence as to which way I'll go. The more I think about the continuous lines, the more it makes sense. Only thing holding me back is all those loose lines... seems like a golden opportunity to get snagged or tangled.

What say ye folks?

 

[Brainlord Mesomorph]

I'm 57.

I've always been a PC based guy, having worked for small manufacturing / fabrication companies that didn't want to invest in mainframe based systems.

I started on a drafting board for the first couple years, then 2D AutoCAD. Didn't get the opportunity to do true solid modeling until 2004, since then CAD has been truly rewarding.

52. But I was doing CAD before I was out of high school. It was all 2D then. I didn't stick with it, I took those skills to a career in computer graphics, illustration, and finally computer programming. CAD experience helped CG animation though. Currently I use a 3D app called Blender, for 3d printing and Zbrush which is like playing with CGI clay.

 

[BABAR]

I use paper reinforcement discs ( edit they are actually “Self-adhesive, super thin poly-vinyl rings ”)

https://www.amazon.com/dp/B00006IBUZ/?tag=skimlinks_replacement-20

I put one on each side of the hole.
I also go with an 8 sided chute (easier to cut out. Fold square in 1/2. Fold resulting rectangle in 1/2. Fold resulting squared diagonally in 1/2 (sort of like how you folded to cut out snowflakes when you were a kid!). Cut across at shortest edge to center. Unfold one level, use a hole punch backed by cardboard to punch your shroud line holes across the middle edge line (the line from the last fold you just opened.). Open chute all the way and put your hole reinforcement discs on each side of each hole. Attach your lines and snap swivel and you are good to go.

8 lines also makes the parachute more efficient than 6, although the gain is VERY minimal. Two extra lines DOES definitely buy you lower stress per attachment point (force divided by 8 instead of 6) and more redundancy (failure of 2 lines has more consequences if you have only 4 remaining lines vs 6.). But as I said, main reason for me is easier to measure and cut.

 

[lakeroadster]

Build Day 12

At this point I'm pretty much done with wood filling and sanding. Engine pod components are done and it's time for final assembly.

But.. I have a question.

• Glue the engine pods to the body tube and then paint... or pre-paint and then glue?

The rocket is so small I'm afraid I won't have access to allow spray paint coverage of all the parts.

Maybe glue the larger front section of the engine pod to the body tube, then paint, then attach the smaller rear section after paint?

What say ye folks? As always, thanks in advance for your thoughts. One fear I have is the strength of the wood glue bonds to paint.

Photo's below show the engine pods mocked up... engine pods aren't glued together, or glued to the rocket.

 

[kuririn]

Your choice. You can mask off a strip on the pods where the glue will contact it. Same thing with the wings/body. Then spray paint. Unmask when dry and glue the sub assemblies. You are right that a glue to paint joint will be weak. Touch up with a brush.

Or you can glue everything, then mask and spray. Your design does not have nearly as much inaccessible areas as some. The hard to reach areas can be touched up with a brush. Good tips for touch up here:https://modelrocketbuilding.blogspot.com/search?q=paint+brush+touch+up

Don't forget to cover or mask off the inside of the pods if they are pre-painted. No clearly right or wrong answer here, whatever you feel most comfortable with. (Though if it was me I would pre-paint).

 

[BABAR]

Tube fins work well with masking the attachment points with tape strips then painting THEN gluing.

The curvature of the painted tube often completely hides the joint.

BEFORE you put the glue after you pull off the tapeon you can use a colored marker of appropriate color to pre color the joint. This will further hide the joint

 

[neil_w]

For what it's worth, I struggle with this question all the time.

 

[GlenP]

launch report: sorry no picture, but it DID happen. I was able to launch my X-wing today, also based on the Centuri Design Contest plans with an 18mm mount, on a C6-3. It had a nice arc to its flight path, I would guess less than 600'. I packed a too-large chute that only partially opened, but it slowed it down enough for a soft landing with no damage. Was an nice, low & slow flight. I would not launch this on an A engine, maybe not even a B.

 

[kuririn]

P.S. Forgot to mention, some people prefer to paint everything without masking, and then sand off the paint where the glue joints will be, then glue and assemble.

 

[lakeroadster]

launch report: sorry no picture, but it DID happen. I was able to launch my X-wing today, also based on the Centuri Design Contest plans with an 18mm mount, on a C6-3. It had a nice arc to its flight path, I would guess less than 600'. I packed a too-large chute that only partially opened, but it slowed it down enough for a soft landing with no damage. Was an nice, low & slow flight. I would not launch this on an A engine, maybe not even a B.

Got any photo's of your X-Wing you could share with us Glen?

 

[BABAR]

One masking trick for body tubes (try this on 2 spare pieces of tube before you use it on the real model.)

Use scotch tape to mask. Press it on really hard.

Paint the tubes

Go very lightly around the edge of the tape with a blade, just enough to scratch the outer paper layer.

Pull the tape off carefully.

The tape will come off with the outer layer of the paper tube, leaving a fuzzy glue adherent surface perfect for the next step.

Do a double glue joint, where you put a VERY thin layer of glue on the opposing parts, let it partially dry (just barely sticky) add just a touch more fresh glue and stick the parts together.

 

[lakeroadster]

Build Day 13

After reviewing your folks advice I prepped and then glued the larger front section of the engine pod to the body tube / wings.

I'm pretty sure I'm going to make the smaller rear section removable for flight. They are really "draggy" and they pull out easily.

I still need one more round of glue filleting before primer.

 

[GlenP]

Got any photo's of your X-Wing you could share with us Glen?

Main body tubes are paper towel rolls, other tubes were hand rolled with cardstock and a glue stick. I found a paper template for an X-wing that I used for the nose cone. These are just under 4 oz on the pad. I modified the X-wings on the blue one to look like the New Resistance.

https://www.rocketryforum.com/threads/centuri-design-contest-x-wing-fighter.33071/page-2

 

[lakeroadster]

Main body tubes are paper towel rolls, other tubes were hand rolled with cardstock and a glue stick. I found a paper template for an X-wing that I used for the nose cone. These are just under 4 oz on the pad. I modified the X-wings on the blue one to look like the New Resistance.

Nicely done... thanks for the photo and link.

 

[lakeroadster]

Build Day 14

It ain't easy being green... first coat of flat green.

 

[BABAR]

Definitely looks more sinister in green than original

 

[GlenP]

that 24mm engine in there looks sinister

 

[lakeroadster]

Seeing red.. added the red paint to the nose, body tube and rudder.

Pretty tough to mask.. should have made the rocket 4 times bigger.


____________________________________________________________________________

A little over spray in a couple places.. nothing that can't be easily touched up. All in all, I'm happy with the results thus far.

 

[kuririn]

Nice masking job. BTW did you see this finished X-Wing on Chris' blog?

https://modelrocketbuilding.blogspot.com/2018/09/office-supply-x-wing.html

Thought you might get a kick out of this.

 

[neil_w]

Nice!

 

[Nytrunner]

Lol, larger rockets are $$'er and harder to store, but boy are they easier to mask.

Keep up the good work!

 

[lakeroadster]

Anti Glare Flat Black Applied... Afterall, the pilot's gotta be able to see, right?

 

[BABAR]

Continuing to look good.

I keep thinking the wing tip pods need a contrasting color from the flat olive background.

 

[lakeroadster]

Continuing to look good.

I keep thinking the wing tip pods need a contrasting color from the flat olive background.

Good Point, thanks.

I'll look at adding some detail, maybe some black accents slots that look like vents. That's what was done on the movie models.

 

[lakeroadster]

Found a bit of time today to break out the brushes and do some more painting....