Estes Titan III E clear fin modification

[burkefj]

Nothing earth shattering here, but I ran accross an unopened Titan III E kit at a good price and had always wanted to build another. I built one in the 90's and flew it at the boeing Kent space center field on E-11 motors a lot. I always hated the duck fins though. So I decided to upsize the fins and make them from 1/32" polycarbonate and mount them through the booster motors permanently. One fin slots through the side booster tube, through the 24mm inner tube completely to the other side of the booster tube. The other fin goes through the booster tube and 24mm tube and will butt glue to the other fin. I decided to glue the transition in place after opening up the lower portion, and keep the upper portion of transition which has a reduced opening as is. This will allow me to keep the nylon chute up forward to help CG and will keep the wadding and chute from sliding down under thrust. Just the nose cone will eject. I glued a 1/8" kevlar strip down inside the main body tube and routes forward about 3" from the end, I'll attach 3/8" elastic which will help prevent zippering. I added rail buttons on one of the booster tubes in a similar location to the recommended launch lugs.

I decided on this kit I would wrap the tubes with self adhesive vinyl and then use Stickershocks cut vinyl set. I was never happy with the Estes decals over the silver paint so this should be much better. Only painting required are the cones and the engine bell details. I've got it framed up with vinyl removed at the gluing locations, waiting for decals then assembly. The polycarbonate fins were around 5 grams more per side than the original plug in units, but aren't as far back so not very significant.

I worked up two rocksim sims just for CP calculation only(ignore weight and CG location) by modifying one that Charles Mcg posted recently updating it for the correct estes tube lengths and motor mount location and my fins. I did one with the original fin placement and size and one with my fins just to see how much the CP changed, around 1.7 inches, I think I'll still get away with very little added nose weight on this one. For the rear booster bells I just used a transition that was the right length and rear diameter but not the complex shape of the real units since it doesn't matter.

I may also make the upper transition detachable via a couple of screws so that I can put a Dynasoar upper as well, even though it wouldn't be 100% right, it would still look neat.


My original flying at the Kent Space center...The black duck feet in front of the Trees hid them pretty well.

 

[mbeels]

Nice, those look like good improvements. I also like this kit and got one back in the 90s. How did you finish the balsa on those side pod nose cones? They look clear and glossy, is that sanding sealer, or CA? Or something else?

 

[burkefj]

It's three coats of thin CA sanded inbetween, I think it will look ok when painted.

Nice, those look like good improvements. I also like this kit and got one back in the 90s. How did you finish the balsa on those side pod nose cones? They look clear and glossy, is that sanding sealer, or CA? Or something else?

 

[mbeels]

It's three coats of thin CA sanded inbetween, I think it will look ok when painted.

Yeah, it looks really good!

 

[burkefj]

Roy Houchin was nice enough to share this with me from his stack of data....I believe I'd need a short 4.5" BT-60 extension to stretch the 1/72 scale estes kit length for the main tube. Approx since the blueprint shows 1/72 booster length to be 10.95 and not 10.375 as in the kit.

I did contact boyce and he is getting back to me with a quote for a 1/72 dynasoar with transition and shoulder tomorrow to fit this kit. It turns out my little dynasoar model I had was about 1/144 scale....all rights/credit to Roy Houchin and Boyce for these...

 

[aerostadt]

Some others have tried this including myself. I used an X-20 crafted by Sandman.

https://www.rocketryforum.com/threa...-booster-i-e-x-20-dyna-soar.5404/#post-232010

 

[burkefj]

Got the little painting bits done , decals will be here tomorrow and then gluing it together.

 

[burkefj]

Here she is with markings applied and assembled. I also made an extension which will allow me to swap the dynasoar upper or fly the centaur. Just goes to show though, that even though you can be super careful during every stage, and plan and look, you can still screw up. As modelers know, it's not whether you will make a mistake, but how you hide them that makes the difference....

I got one upper centaur decal upside down, but Mark at stickershock had cut them out of silver and they should have been gray, I didn't catch this due to the backing paper covering, till it was applied and too late to peel it all off. Up close you can see them because they have some thickness, but a foot away they dissappear. If they were gray, they should contrast with the silver upper enough to see them.

Some of the 5/8" wide black and gold wide vertical stripes that line up with the horizontal bands with little extensions on them for locating the strips were not the same width as the strips, so I had to hand trim a few of them so that there would not be a mismatch at the joint between them. Everything else seemed to work very well as expected.

I did the rest and got everything ready to assemble, sanded the glue areas and started attaching the first side booster with thick flexible CA. I accidentally touched the glue with the side of my hand and it brushed on the booster as I was putting it in place. I scraped it off mosly from the black and white areas on the side with an exacto but thought, hey I've got some Ca debonder, I'll use that to get it all off. Unfortunately this melted the black vinyl and made a nice black smear on the white... Much swearing and gnashing of teeth later, I peeled it off, salvaged the white and cut a new strip and applied it. ugh.

Next side goes fine and I install the clear fins, I'm gluing from the inside just on the inside fin joints to avoid any glue on the outside of the fins so that they will dissapear, it's perfect. I get all done and only then see a thin glue hair
on one of the front fins, apparently there was a little hair like dribble in the bottle as I pulled it away and it flung itself on the fin. I tried the CA debonder on a test piece of polycarbonate(see I learned my lesson) and it crazed the finish, so I decided I'd just have to live with that....As you can see it doesn't look bad, but it was not my best day....sigh.

Frank

 

[mikec]

As you can see it doesn't look bad...

Looks great to me, Frank!

 

[Bruiser]

Looks fantastic to me. I'd be very happy to say it came off my workbench.

-Bob

 

[Charles_McG]

So much prettier than mine

 

[burkefj]

So much prettier than mine

You are too kind!

 

[mbeels]

That's fantastic!

 

[Crawf56]

Nice work.

 

[burkefj]

I got the parts from Boyce today and put together the Titan 2 stack, I've already built the Titan three core and boosters and finished them I just need to sand and finish the boyce parts and install them on the stack tomorrow. The hand is for scale, the Dynasoar and transition piece are about 6" long. The glider has a hollow core to put nose weight in before gluing the transition in place, the transition has an extention that goes up into the glider...(no it doesn't actually glide). Also attaching a blueprint I got from Roy Houchin...

 

[Charles_McG]

What? No MOL? Or even better, an MOL with a Dynasoar on top.

Those parts look great. Did you develop the CAD models (as in 'do you have shareable STLs?') or did Boyce do it for you?

I've looked long and hard at the Dynasoar on a Titan III. And also at a Dreamchaser on a Delta IV Heavy. Mostly because I like playing with booster separation. The Dreamchaser/Delta IV Heavy would be an unlikely IRL combo - it's enough delta V for trans Martian injection, but what the heck would you do with a Dreamchaser at Mars? Aerobraking might get you into orbit, but Mars only has enough atmosphere to be annoying - not enough for that lifting body to be effective.

I was going to ask you if the Dynasoar/Titan III would have a similar problem - but I just went and did some digging, and the answer is 'maybe'. The Titan III probably couldn't boost a Dynasoar to escape velocity - but it could come close. It looks like my silly Dynasoar/MOL/Titan III combo would be about 10% too heavy to reach LEO.

 

[burkefj]

Boyce already had some cad drawn up, I think he worked with Roy Houchin a bit, thinking about a kit that never got implemented yet, maybe I pushed him over the edge. For purists, the glider transition was different on the Titan II versus Titan III but that's a fine point, I'm ok as is.
I sent him a pic of George Gassaway's two view of his competition Titan II stack for the fin shapes and he worked that up as well, he already had something ready for the Titan III parts.

Not sure on the whether you could reach escape velocity or not, not sure if the dynasoar would survive a re-entry anyway with a speed and trajectory from outside earth orbit...maybe same for the dreamchaser...

Frank

What? No MOL? Or even better, an MOL with a Dynasoar on top.

Those parts look great. Did you develop the CAD models (as in 'do you have shareable STLs?') or did Boyce do it for you?

I've looked long and hard at the Dynasoar on a Titan III. And also at a Dreamchaser on a Delta IV Heavy. Mostly because I like playing with booster separation. The Dreamchaser/Delta IV Heavy would be an unlikely IRL combo - it's enough delta V for trans Martian injection, but what the heck would you do with a Dreamchaser at Mars? Aerobraking might get you into orbit, but Mars only has enough atmosphere to be annoying - not enough for that lifting body to be effective.

I was going to ask you if the Dynasoar/Titan III would have a similar problem - but I just went and did some digging, and the answer is 'maybe'. The Titan III probably couldn't boost a Dynasoar to escape velocity - but it could come close. It looks like my silly Dynasoar/MOL/Titan III combo would be about 10% too heavy to reach LEO.

 

[Charles_McG]

Well, dreaming up flight profiles for canceled vehicles is good, clean fun any day.

Your builds are inspiring. I've been pondering a 1/72 Dynasoar to go with my Titan III. I've print half a Dynasoar. Haven't circled back around to the nose and the interstage.
Or a 1/35 DynaSoar and build a Titan II or III to go under it. Big and complicated! But lots of tubing to make.
Or a 1/72 Dream Chaser - I've already printed a spiralized outer contour model of that one - I'm struggling with designing the interstage. The Atlas V to go with it would be BT70. Or maybe a 3" Vulcan Centaur - without the fairing.

 

[burkefj]

Here she is with sibling and family photos

 

[mbeels]

Wow, those really came out sharp! Awesome!

 

[Ez2cDave]

 

[burkefj]

Had three great flights of the Titan IIIE Centaur on a D-12-3 today, Titan III Dyna-Soar on an E-20-4, and the Titan II Dyna-Soar using the boyce parts and clear fins on a D-12-3, dead straight on all three.