Gemini Titan build

[MaxQ]

I was able to get a Sheri's Gemini Titan kit recently and I thought I'd build this when I had (or needed) down time from scratchbuilding...

I'd like to hear from other people who have built and especially from people that have flown this rocket.


The kit Sheri offers has a resin capsule, pulled (I suspect) from the Revell kit.
I had the Revell Gemini kit which I built when I was in 7th grade.
Back then I didn't realize there were a few inaccuracies in the Revell capsule.
This kit from Sheri has none of the Revell detailed parts so you won't need to deal with those inaccurate parts. You will have to do something if you crave more detail.

There are no equipment bay/fairing details such as orbital manuvering motors and other stuff, she does however provide good references for aftermarket stuff.

A few searches online got me enough close up photos of the Gemini 7/6 mission to make a few detailed parts for the fairings behind the capsule.

I added the fairing ribs to give a little more realism and help stiffen the styrene plastic fairings since I felt that part was too weak for a lot of handling and for flight.
I had dropped the capsule during assembly, and that resin capsule is one heavy part (which should help as nose weight for stability). The plastic sheet fairing got a couple of dents and creases as a result, this additional detailing allowed me an opportunity to cover it up.

Besides, they add something to the overall appearance - even though the balsa strips I used are a little oversized.

[MaxQ]

Depending on how much realism you want, the capsule will benefit with some extra work and attention.
I had to rescribe some detailing in the way of panel lines and texture as it apears the RTV molds have seen a lot of use, and some fidelity of detail was not present.

The obvious dimensional mismatch between the conical forward section of the capsule to the capsule body could use a trim ring to cover that up.

[MaxQ]

The really fine part of this kit is the engine bell assembly which is also designed to serve as the motor retention.

This is really nice as you can fly this thing with the beautifully machined aluminum nozzles in place.

If you carefully drill and trial fit the clear plastic fin hardware mounting brackets you should have little trouble workng around them and the kit provides lots of engine plumbing detail which I'm anticipating doing next.

[MaxQ]

The biggest challenge that I had with this build was dealing with the airframe body tube provided in the kit.
This is a hefty tube, thick walled. Industrial strength. It is not a smooth glassine finished tube.

You will need to do the usual "drill" when finishing a body tube - filling the spiral seams.

What vexed me was the degree of fiber and fuzzies that repeated sanding appeared to lift after every treatment.

Repeated applications of primer were needed to get this problem under control.

I used two full cans of Krylon primer (the new stuff) - four coats and four sandings to get the level of finish I felt satisfactory (and this isn't a competition bird.......just a fun fly/sport scale model).

[MaxQ]

The overall size of this rocket is still pretty impressive for those who may be more accustomed to mid sized high power rockets ...I had some trouble getting it in frame for the picture.

Looking forward to the painting and finishing...

[ben_ullman]

looking good Jim! Can't wait to see it fly!

Ben

[MaxQ]

Thanks Ben.
Due to the engine bells, I'm limited to two 29mm's.

I'll be pondering the best way to get two lit - together, as this isn't a "deuce"
with vectored MMTs..

I guess two Cessaronis would work.

[BsSmith]

Looks great!

I built one last year completely stock, with no aftermarket details. Here is a photo gallery of it's first launch. http://cia-rocketry.smugmug.com/Local-Launches/CIA-Launch-at-Dodds-Park-1/6682220_uofsN#426564306_jtDB6

Unless you have flush aft closures, the Titan can only be launched on G77-4s because they are the only motors with a 4 second delay that will fit in the nozzles. I tried putting the new G80-7s in it, but it zippered. Will the Pro-29s fit?

To light it, if you have a club with multiple launch systems hook up each igniter to a different pads clips. I use magnalite for mine, and it hasn't had a problem.

[MaxQ]

Looks great!

I built one last year completely stock, with no aftermarket details. Here is a photo gallery of it's first launch. http://cia-rocketry.smugmug.com/Local-Launches/CIA-Launch-at-Dodds-Park-1/6682220_uofsN#426564306_jtDB6

Unless you have flush aft closures, the Titan can only be launched on G77-4s because they are the only motors with a 4 second delay that will fit in the nozzles. I tried putting the new G80-7s in it, but it zippered. Will the Pro-29s fit?

To light it, if you have a club with multiple launch systems hook up each igniter to a different pads clips. I use magnalite for mine, and it hasn't had a problem.

Well, that certainly gives me something to think about.
I want to make sure I have motor options...like flying with two H's to avoid early ground contact.

Flush aft closures?
I can understand the retention during ejection charge, but there also needs to be a thrust ring for the forward motion on ignition doesn't there? The G77 - 10 in the picture has one...did this motor fit? Doesn't look exactly flush on the aft end to me...
Maybe I'm not getting what you're explaining...
(Thanks for the launch pictures, it looks great)

http://www.apogeerockets.com/images/Aerotech/Composite_motors_sizes.jpg

[BsSmith]

The G77 comes with a paper ring that you can glue onto the end, I don't glue it on. Instead, I have thrust rings glued inside the motor tubes. They're just pieces of spent single use motors glued inside the tubes.

[MaxQ]

Just pulled the two aluminum engine bells off of the plywood motor flange and checked the fit of an Aerotech 29mm reload (29/240).

The cavity in each engine bell is machined to take a 29mm case, but not the aft closure/thrust ring that comes with the reload hardware.
It is darn close...but it just won't go in.

This is a big problem if you want to use standard reloads...I'm not even sure an aerotech G reload would fit.

Guess the single use G's would work...as Brian has the picture to prove it.
Wow...I need to rework this one.

I'm concerned about ultimate flight weight as this thing is going to be heavy, with the airframe tube, paint, resin capsule etc.
I'd like to have flexibilty of motor choices.

[MaxQ]

The G77 comes with a paper ring that you can glue onto the end, I don't glue it on. Instead, I have thrust rings glued inside the motor tubes. They're just pieces of spent single use motors glued inside the tubes.

Thanks...you answered my question and I understand how you accomodated it.
I guess putting the thrust ring on the inside of the motor tube kinda limits your motor choices now...given motor length varies ....

[Stymye]

I have always put thrust rings inside my rockets to accomidate the longest motor I plan to use .. than I simply drop in spacers for the shorter ones.I've done this for years. I keep a number of reuseable spacers in my range box, it doesn't take that many to cover all the bases

It's fast to load, keeps the aft of the rocket clean looking and makes the spent motors simple to remove as well.I much preferr it to masking tape or glueing on rings.
I'm already at the pad loading up by that point
( ofcourse I can still install motors with built in thrust rings as well)

it's one way to go and in most of my midpower birds I could install every motor in that photo with very little effort and in very little time.

(I keep diameter adapters for the smaller motors in my box also)

[blackjack2564]

Take the largest motor you intend to use. Mount your thrust ring for that. Use spacers of various lengths for shorter motors to fit.

AND CTI DOES have a new flush mount closure for 29mm . AND with their new grain spacers, you could fit your tube for the largest case you want to fly and then use the internal grain spacers for different size loads. I.E fit for a 4grain case and use spacers in the same case to fly 2, 3. grain reloads!

Here is the thread discussing these new spacers in case you have not heard of them. Yes they work, I've seen them.

http://www.rocketryforum.com/showthread.php?t=5729

[MaxQ]

Take the largest motor you intend to use. Mount your thrust ring for that. Use spacers of various lengths for shorter motors to fit.

AND CTI DOES have a new flush mount closure for 29mm . AND with their new grain spacers, you could fit your tube for the largest case you want to fly and then use the internal grain spacers for different size loads. I.E fit for a 4grain case and use spacers in the same case to fly 2, 3. grain reloads!

Here is the thread discussing these new spacers in case you have not heard of them. Yes they work, I've seen them.

http://www.rocketryforum.com/showthread.php?t=5729
Well...I could deal with motor spacers all the way up the inside of the motor tube if I have to...they probably get a little crusty after awhile , but I can deal with that. It does all depend on a flush aft closure motor to pull it off (that means all new hardware in the 29mm line, ......unless Aerotech has a flush aft closure.


I sure hope they (Cessaroni) do have a flush mount...this is the part (see the picture) that won't fit inside the engine bell cavity....the cavity will take the 29mm case width, nothing more.
http://www.pro38.com/products/pro29/images/3.jpg


http://www.pro38.com/products/pro29/pro29.php#

[BsSmith]

I'm concerned about ultimate flight weight as this thing is going to be heavy, with the airframe tube, paint, resin capsule etc.
I'd like to have flexibilty of motor choices.

Mine is 6.6 pounds at take-off, and it flies perfectly on the G77s. It even deploys the chutes exactly at apogee.

The fins might have problems holding up to an H flight also, the root for them is very small.

[MaxQ]

Mine is 6.6 pounds at take-off, and it flies perfectly on the G77s. It even deploys the chutes exactly at apogee.

The fins might have problems holding up to an H flight also, the root for them is very small.

I heard from another builder that pranged his on two G's.

Any idea what altitude you got on the G77's?

[blackjack2564]

Here's a shot of both the closure and the spacers. AT hardware can also use a flush closure. I think Wildman has them. Little heard about but they are out there I have seen them.

[BsSmith]

Any idea what altitude you got on the G77's?

About 600'.

There's a video on the NSL website that shows it on 2 G80s, it got to about the same altitude.

[bsexton]

Other than the engine bells this kit looks painfully simple for the money. I have to say the "extra" work you've done on the capsule will make a nice difference.

[BRC]

Not a Hot Rocket but a Neubauer with a G80-7 from this past weekend..

[BsSmith]

Another thing you might want to do is ditch the 1/4" lugs and put rail buttons on it. I always launch mine off an 8' rail.

[MaxQ]

Another thing you might want to do is ditch the 1/4" lugs and put rail buttons on it. I always launch mine off an 8' rail.

I agree...I'll be looking for some rail buttons.

[dwmzmm]

Here's a few pics of Lannie Phillips (of the NHRC # 365 Section) Sheri's Hot Rockets Gemini Titan model; took these pics at a recent modroc contest down at JSC earlier this year.....I don't think he's flown his yet (wants to get some experience on HPR clustering first)....

[bsexton]

Are all of the body details wraps or is it a combination of painting and wraps? This model looks very nice.

[MaxQ]

<took these pics at a recent modroc contest down at JSC earlier this year>

Nice line up ..

What Apollo Little Joe II kit is that?

[BsSmith]

Are all of the body details wraps or is it a combination of painting and wraps? This model looks very nice.

It's a combination of both.

The white and silver are painted on, and the black is wraps.

[MaxQ]

It's a combination of both.

The white and silver are painted on, and the black is wraps.

I'll bet that chrome isn't paint.....

[MaxQ]

Here's a shot of both the closure and the spacers. AT hardware can also use a flush closure. I think Wildman has them. Little heard about but they are out there I have seen them.

I have a call into him and some other vendors...we'll see what shakes out.
if nothing...I may have to see about remachining these cavities at the back of the engine bells to get a standard Aerotech 29mm to fit.

[dwmzmm]

<took these pics at a recent modroc contest down at JSC earlier this year>

Nice line up ..

What Apollo Little Joe II kit is that?

That's the Sheri's Hot Rockets Apollo Little Joe, only that Lannie made it a later round....looks great, doesn't it?

[MaxQ]

That's the Sheri's Hot Rockets Apollo Little Joe, only that Lannie made it a later round....looks great, doesn't it?

I like it...it does look really good.

....almost as good as my scratch built. (that's a joke fellas...me trying to be funny)

[BsSmith]

I'll bet that chrome isn't paint.....

The chrome on Sheri's is stick on chrome Monocoat. When I looked at the pictures of the real Titan I thought the Monocoat was too shiny so I used Testors Chrome paint for mine. I think it fits in much better.

[MaxQ]

The chrome on Sheri's is stick on chrome Monocoat. When I looked at the pictures of the real Titan I thought the Monocoat was too shiny so I used Testors Chrome paint for mine. I think it fits in much better.
<I thought the Monocoat was too shiny>

Yeah...it is...but it sure is pretty.

I'm building a Mercury Little Joe on another thread..it has a very shiny chrome finish, a bit non scale , but I thought I'd try it out. I saw this chrome posterboard at a Ben Franklin and couldn't resist the thought of rolling a rocket body tube with it...

It is all a matter of personal preference I guess, unless you are going FAI scale.
http://www.rocketryforum.com/showthread.php?t=3465&page=3

I may try various shades of silver and aluminum paints on this Gemini...like the plastic scale model plane guys with their "metalizers".

[BsSmith]

The "metalizers" are very nice.

I used the Testors air brush on buffing metalizers for the top silver section (Brushed Aluminium) and the capsule (Gun Metal-Exaust). They are some of the best metallic paints I've used.

[Bravo52]

Everybody can jump in here with their favorite metal paint suggestion, however, if you are going to cover a large area, be prepared to spray and spray and spray... You can get the metalizers in a can, however, it is not the buffing type and you will end up with a basic flat coat. I've used Testor's Metalizers for years and have found that the buffing metalizers tend to not be a good finish if you are going to handle the object because they easily wipe off. To combat that, Testors has a top coat that when applied, dulls the finish and you are no better off than any other metal paint.
A better option in my mind is the Alclad lacquers. They are rock-hard and very durable. Perfect for a rocket. They retain their luster even when top-coated. Finger prints are not an issue! The one drawback is they are a lacquer so handeling is a little different. You also have to be careful when spraying over plastic as the lacquer can craze the finish...... :2:

[rockets2000]

I've used Testor's One Coat Lacquer rattle cans in both blue and silver metallic and had good results. I sand the primer with 600 grit to get it reallly smooth, and the paint flows on very nicely. It takes pretty well to clear coat if you're patient, which I'm not, but it can be done.

Has anyone used Future on metallic paint?

[MaxQ]

Here's a shot of both the closure and the spacers. AT hardware can also use a flush closure. I think Wildman has them. Little heard about but they are out there I have seen them.

Well, the Wildman says he doesn't know what we are talking about, this "flush aft closure" thing

Maybe what was seen was custom made?

I have yet to hear from the other vendors, so...

I'm thinking it's time to get someone to reem the motor retention portions of these aluminum engine bells so that I can use something other than G77s....

[tonypv]

I've used Testor's One Coat Lacquer rattle cans in both blue and silver metallic and had good results. I sand the primer with 600 grit to get it reallly smooth, and the paint flows on very nicely. It takes pretty well to clear coat if you're patient, which I'm not, but it can be done.

Has anyone used Future on metallic paint?

Future works really well with Testors metallic paints.
I think it really makes them pop.

[rocketguy101]

The chrome on Sheri's is stick on chrome Monocoat. When I looked at the pictures of the real Titan I thought the Monocoat was too shiny so I used Testors Chrome paint for mine. I think it fits in much better.
If the GT finish is the same as the Titan II the USAF stuck in silos, then the Monocoat is definitely too shiny. Here are some pics I took at the Titan Missle Museum in Tucson.

[rocketguy101]

Here are some shots of the main engines...

[MaxQ]

Here are some shots of the main engines...
That's a lot of little pipes.
Guess I better get started on the detailing...............

[bguffer]

Well, the Wildman says he doesn't know what we are talking about, this "flush aft closure" thing


The below suggests flush aft closure does exist in the 98mm Aerotech line:
http://www.rocketryforumarchive.com/showpost.php?p=526862&postcount=17
http://www.rocketryforumarchive.com/showpost.php?p=528003&postcount=21

Wildman would not be the only vendor unaware. I spoke to another well known west coast vendor a year ago, who was also unaware.

[MaxQ]

The below suggests flush aft closure does exist in the 98mm Aerotech line:
http://www.rocketryforumarchive.com/showpost.php?p=526862&postcount=17
http://www.rocketryforumarchive.com/showpost.php?p=528003&postcount=21

Wildman would not be the only vendor unaware. I spoke to another well known west coast vendor a year ago, who was also unaware.

Maybe they do......in 98mm.

I was thinking ..I'll just get two 29mm standard aft closures and have someone grind off the thrustring...(might look as cool as a sparky motor while they're doing it...)

[MaxQ]

I heard back from Gary at Aerotech...

No flush aft closures as yet...so it looks like I'll need to either remachine the thrust rings on two
std. 29mm aft closures down to fit into the engine bells "as is" ...or remachine the nozzle cavities a bit wider on the engine bells...to let a std. Aerotech reload fit.

[bsexton]

I'm sure I'm missing something here. If you have a flush aft closure what do you do for forward motor retention? Are you going to use a thrust ring/engine block inside the motor tube? I probably need to read the thread more closely...

[ben_ullman]

I'm sure I'm missing something here. If you have a flush aft closure what do you do for forward motor retention? Are you going to use a thrust ring/engine block inside the motor tube? I probably need to read the thread more closely...

you are correct Bruce. If he was to go with flush closures he would implement a motor block setup

Ben

[MaxQ]

I'm sure I'm missing something here. If you have a flush aft closure what do you do for forward motor retention? Are you going to use a thrust ring/engine block inside the motor tube? I probably need to read the thread more closely...

For flush aft closures w/o a thrust ring...several guys here have posted that they used various lengths of spacer tubes to but up against an "internal thrust ring"...glued to the inside of the motor tube the farthest dimension for the biggest motor (read : the longest)you plan on using.

Kinda like the Estes E to D conversion spacer.....but bigger

See post #9 for the discussion...

[MaxQ]

As you know, I was concerned with the diameter of these engine bells not being wide enough to take a standard 29mm reload case with the aft closure thrust ring on the end of the motor.

Well, yesterday after making a few calls, I was able to locate a machine shop that would do the work w/o an excessively high minimum fee for a small job.

After striking out first with an automotive machine shop (their tooling wouldn't fit inside the engine cavity...it was too small) I got hooked up with an industrial machining company, that luckily was only five minutes from work.

The price was $20 each nozzle, which I had no problem with paying as they practically did the job while I waited.
They were nice guys and while we went over the specs... they asked a lot of questions about the hobby and were fascinated with the engine bells and all manner of rocketry stuff.

The first picture shows the aft closure on my 29/240 Dr. Rocket reload set against the engine bell cavity - which was too small in width to admit the aft closure thrust ring.
The second picture shows the remilled engine bell which comfortably allows the thrust ring to be set inside the engine bell.


This small modification will allow me to use every 29mm motor I can think of, rather than just the G-80 or G-77 single use motor, and not rely on internal spacers stacked against an internal thrust ring mounted in the motor tube.
Now .............................On with the build.

[bsexton]

Excellent!

[MaxQ]

Excellent!

I was relieved to get this resolved.

I didn't want to fly it on two "single use" G's ..especially if the built up weight got heavy.

I don't know if I can fit two Cessaronis 29mm in there, but accomodating my existing hardware was good enough for me.
All I need to do is concentrate on getting two aerotech motors lit together...ontime.

[BsSmith]

That's great that you got them machined! I should look into doing that with mine sometime, the G77 flights are getting boring.


All I need to do is concentrate on getting two aerotech motors lit together...ontime.

Magnalite works great for me, the motors light instantly with it.

[MaxQ]

Proceeding with the two motor mounts and faux plumbing.
Yep...those are drinking straws...with elbow bends.

They are effective.
This is a merely representation of the fuel lines and structural components...if you tried to do the thing accurately (to scale) it would probably take a lot of different tubing and a year to do it.
(as evidenced by the pictured from Rocketguy101)
http://www.rocketryforum.com/attachment.php?attachmentid=11466&d=1253672362)

Once I figure out how to mask off the black motor tubes I'll paint them silver ...
I added some surface detail to the airframe to give it a more realistic look.

[MaxQ]

I'm using new formula Krylon on this one...
The matte aluminum isn't too bad...

[rocketguy101]

Niiiiiiiiiiiiiiiice! Love the flex elbows! You do beautiful work!

[MaxQ]

Niiiiiiiiiiiiiiiice! Love the flex elbows! You do beautiful work!

Thanks...we'll have to give Sheri credit for those...(her idea).

[MaxQ]

More paint.
I decided to forgo the vinyl wrap decals and mask and paint the black roll patterns...

[MaxQ]

After masking the aft end, engine details were painted with old formula Krylon Chrome...a very nice paint. (Wish I could find some more).

There is some clean up of overspray on the airfame to do here..then on to the capsule....

[MaxQ]

Paint and decals on...finished masking off roll pattern trim areas

Some overspray needs a fix here and there ...

[MaxQ]

The scratch built details on the capsule transition/fairing were time consuming, but I think they add to the overall appearance...

I used Krylon black on the resin capsule, there were some problem with paint adhering to the surface, I think it will need a touch up before decals and trim tape go on.

Parachutes, shock line and rail butons arrived from Ken(Performance Hobbies) this week, so this is almost ready to go...

[bsexton]

Nice job -- looks like you will have plenty of new rockets to fly at Battle Park!

[MaxQ]

Nice job -- looks like you will have plenty of new rockets to fly at Battle Park!

Yeah.........when I finish up the Mercury LJ -I , I'll clean off my table and realize that I might need a "new project" for winter '09/10......

But there are no more Joes to do.

[rockets2000]

Beautiful!

[Handeman]

Nice job -- looks like you will have plenty of new rockets to fly at Battle Park!

Bruce and Max, are you both going to be at BattlePark? Chuck and the VAST crew are hosting a night launch on the 31st. I got the new website up, it's still a work in progress, but the homepage is coming along pretty well. It's http://BattlePark.org

Max, you better vistit quick, I'm not sure how long your pic will be on the homepage.

[MaxQ]

Bruce and Max, are you both going to be at BattlePark? Chuck and the VAST crew are hosting a night launch on the 31st. I got the new website up, it's still a work in progress, but the homepage is coming along pretty well. It's http://BattlePark.org

Max, you better vistit quick, I'm not sure how long your pic will be on the homepage.

Wow.......cool.

I guess my "fifteen minutes of fame" is over now!

(I'm planning on doing Culpeper ....and I'd love to do the night launch,....but the spousal unit wants me helping with trick or treaters and various halloween stuff Saturday evening...gotta do what ya gotta do).

[MaxQ]

Bruce and Max, are you both going to be at BattlePark? Chuck and the VAST crew are hosting a night launch on the 31st. I got the new website up, it's still a work in progress, but the homepage is coming along pretty well. It's http://BattlePark.org

Max, you better vistit quick, I'm not sure how long your pic will be on the homepage.

Soooo........................how did it go?
Those of us that planned on going on day got rained out.

[RoboRocketry]

Do you have an electronic copy of the Sheri's Hot Rockets' Titan plans? One of the students took the plans home to go over them and can't find them. We didn't get the CD when we ordereed from Red Arrow Hobbies.
It would be greatly appreciated.
Thanks,
Duane