7.5" Titan II Missile 2 Versions

[burkefj]

For the tubing around the nozzles, I drilled some tiny holes in the base plate, ran some weed whacker line and CA'd it at one end, then did some bendy straws over the line and glued the other end down...painted titanium and flat black for the base plate, I'll finish painting once the motor tube is in place and filleted...I didn't want to glue the straws since those will probably snap when it hits the ground, like this, it's really light and can flex a lot so if it hits anything hard hopefully it will just move out of the way and not break.

Frank

 

[burkefj]

Here is the openrocket file I'm using. Shows the internal structure.

View attachment titanII.ork

 

[burkefj]

Here is the nose cone internal structure. I used some spare centering rings to center the 29mm tube which goes over the carbon rod that ties the whole thing together. The 29mm tube is just there to give me something to glue the foam stringers to before sheeting.
I'll glue the coupler to the base plate(actually will split the coupler and double it) to make the shoulder for the nose cone.

 

[burkefj]

I spent a little time making the foam stringers for the nose cone and the lower transition that will stay attached to the parachute bay.

Nothing is permanently glued because I have to wait for the tubing, but you can see how it is starting to look like a cone.

Frank

 

[burkefj]

I stacked some foam disks I made over the parachute bay, and then used my belt sander to create the short transition from the body to the start of the cone, then I sheeted it with smooth 2mm depron, came out ok.

 

[burkefj]

Here is the airframe stack, just waiting for tubes to come on thurs for assembly, and showing the fins in their guides in the top and bottom plates, the lightening holes in the root.

Frank

 

[rharshberger]

You are a building machine Frank. The new model looks good, I wonder if it will tail slide at apogee like the other foamies do.

 

[burkefj]

I don't know the secret to the backslide, but 4/5 of these foamies do it every time, the hellfire has done it once, out of four flights....it tends to weather cock more easily than the others....

Frank

You are a building machine Frank. The new model looks good, I wonder if it will tail slide at apogee like the other foamies do.

 

[rstaff3]

I don't know the secret to the backslide, but 4/5 of these foamies do it every time, the hellfire has done it once, out of four flights....it tends to weather cock more easily than the others....

Frank

They are very draggy and relatively light so they slow fast and don't have a chance to pitch over. They are underpowered (not necessarily from a thrust/weight) when compared to most rockets of their girth.

 

[burkefj]

I assumed it was low "sectional density" that caused it to bleed off speed and lose momentum quickly..basically what you said...I like it actually, things don't slam into each other that way....

They are very draggy and relatively light so they slow fast and don't have a chance to pitch over. They are underpowered (not necessarily from a thrust/weight) when compared to most rockets of their girth.

 

[burkefj]

Looks like I may not need any balast, the fin unit and nozzles/retainer are at 26-27 oz, the front end with kevlar, chute, nomex, altimeter and nose/parachute bay is at 30-31.. so that would put my dry CG ahead of midpoint. With the motor of 13 oz the CG should be about right.

 

[burkefj]

Got the stuffer tube in the mail and installed it and glued the entire outer structure together. Sometimes things just work as they should and go smoothly. This was not one of those times..... I thought I was making it easier and simpler not doing notches in the stringers, while it did make it easier to assemble things it was very hard to keep the centering rings at 90 degrees to the stuffer tube and some got a little crooked. I hate when I learn something, then forget why I did it, and wonder why I make it so complicated, then learn why I had done it in the first place? But, it is together, straight and ready for sheeting.

I'll sheet the upper section, then add the fins to the lower portion with the rear thrust plate, then sheet between the fins when done. For the nose I'll sheet the transition then slide the parachute bay and transition down onto the centering rings and glue it after. That way it will allow me some margin for error at the ends when I do the sheeting and avoid any unsightly gaps.

 

[mikec]

Got the vinyl from stickershock, Mark was very nice and he went out of his way to work with me on these.

Could you go into a little detail about what you gave Mark in terms of design guidance and image files and what you got back? Were they full printed multicolor one-piece wraps or multilayer one-colored vinyl assemblages?

 

[burkefj]

Hi, I sent him the drawing I have in one of the first postings from Peter Alway, along with a color photo of a liftoff shot. These were not printed, the only one that is multi color is the star/bar which is layered as delivered.

I first did a vinyl silver or white wrap on the body tubes, and did the nose and transition as smaller pieces I cut myself. Then I applied the roll markings/usaf/and other details one at a time over the vinyl.

I'm sure at a smaller scale he could do a wrap or something similar. he's already got these in his db so he could scale up or down...

Here is what Mark Sent me as a reference to give you an idea...I did not add 3-d conduits, but used gray vinyl to represent them.

Could you go into a little detail about what you gave Mark in terms of design guidance and image files and what you got back? Were they full printed multicolor one-piece wraps or multilayer one-colored vinyl assemblages?

 

[mikec]

Thanks, Frank. I'm designing an Atlas V which has somewhat more complex markings and just wanted some insight into how the vinyl might work.

 

[burkefj]

Got the pml tubing in today, created the parachute bay, sheeted the fuse and transition. Next up is to do most of the upper covering, then do the fin assembly, sheet it and then see about nose weight if any before sheeting the tip of the nose cone.

Frank

 

[dixontj93060]

Although more modeling work than I'd go through, I sure admire your finished products!!

 

[burkefj]

I appreciate that. It really isn't more time/work. If I was using epoxy and cr/tubes I'd have to wait for things to cure, do a lot more/longer sanding, etc. Then painting. If the rocket is mostly white as soon as it's assembled it is done, I don't have to do much if any painting etc, and I can work at the speed of contact cement and CA glues, and the foam cuts way easier just one or two passes with an exacto, sanding is quick, not as much scroll saw/belt sanding etc.

Although more modeling work than I'd go through, I sure admire your finished products!!

 

[burkefj]

Ok, spent the evening putting on aluminum trim monokote on the upper portion, then adding the excellent vinyl from Mark at stickershock. I did this before adding the fin unit because it was lighter/easier to handle with just the round tube. Tomorrow I'll add a second layer to the top 3" of the transition to mimick the thick ablative layer and make it black, then do the fin unit, and check my CG before I finish sheeting the nose. It's starting to looking like a titan. For the conduits I used chrome mylar monokote that I scuffed with some scotchbrite pad and it makes it look more like bare aluminum...

Frank

 

[burkefj]

ok, got a lot done this morning, in fact all of it

Cut the altimeter bay, created a door using .015 styrene sheet, a piece of 6mm foam and some magnets, and covered and hinged it with the aluminum trim monokote. It's much thinner and easier to make this way than my old way of making a foam structure that is inset into the opening..I added the wiring to the deployment charge cap, you can see the cap inside where it plugs into the stuffer tube, the wiriing is below this, the ejection charge will sit on top of it.

Epoxied the fins in place then skinned the structure after putting some longerons between the fins and also putting some foam ledges on each side of the fin for the skin to glue to. Covered it with the monokote.

Weight is right at 5 pounds with everything but altimeter and motor, 6# rtf. No nose weight was needed, in fact I probably have used a styrofoam nose instead of the hardwood nose since I have some margin.

Hope you enjoyed it, I think it came out looking pretty good.

Frank

 

[rharshberger]

Another great project Frank, some excellent techniques to be learned from your methods.

 

[burkefj]

Some closing thoughts

Using this building technique and materials in something approximately 7-8" in diameter and 6' tall, you have a practical minimum weight limit, assuming a 48" chute, altimeter, kevlar, nomex, 29mm stuffer tube, glue, motor retainer, eye bolts, pml upper tube, and some ply upper and lower centering rings that would be common to any design of around 32-40 ounces for the core components. Add to that your foam outer skin and structure, and lightweight carbon re-inforced fins and you have a practical minimum dry weight of 50-55 ounces. Motor weight can run from 4.5-13 ounces for G-80 to I-200 motors and assuming you need no additional nose weight. You may be able to cut an ounce here and there by using cardboard upper tubing, instead of PML phenolic, but the phenolic helps in giving a naturally nose heavy design.

This is nice for rockets that do not have large fins and normally need lots of nose weight(aka hellfire missile), or for something that is in impressive scale, but does not require an expensive motor, or a large field to fly in.

Of course you can scale this down as well, I've done a 5.5" by 48" tall Pershing 1A that is 20 ounces ready to fly using motor ejection and a very thin 36"chute and can use 24mm motors.

You could also consider using foam board(from dollar tree) as a cheaper but slightly heavier structural component and some sort of cardboard/cardstock material for the skin, but which would require some waterproofing/paint or covering material.

 

[burkefj]

Perfect Maiden today in the tri-cities on an I-200W motor to around 1000'.

[video=youtube_share;fAIObSIuIgs]https://youtu.be/fAIObSIuIgs[/video]

 

[burkefj]

Here is another flight at tri-cities this weekend on an I-200W, great flight and recovery.

[video=youtube_share;bLBXyM-t4Y8]https://youtu.be/bLBXyM-t4Y8[/video]

 

[gerbs4me]

Wow great flight!!!
Great work!

 

[rstaff3]

I love seeing your flights, thanks for posting the video!

 

[aerostadt]

This is really a nice looking Titan II. I like the photo of it on the TRF calendar for the month of April.

 

[BMAT]

As a former Titan II crew member, I approve of this thread! :headbang:

 

[burkefj]

Thank you! Here is a photo of the two side by side, heavy 20# version for 38mm J-510's on the left, 5# foam version for I-200's on the right, the length difference is simply the simpler/shorter dummy nozzle setup for the foam version to save weight.

Frank

 

[DocBrown]

I have always lovedthe look of the Titan series rockets and what you are doing is puremagic. Fantastic work.