MIM-104 Patriot Bash

[Bruiser]

I haven't been doing any building lately. Just haven't been feeling to well. Crohn's can be fatiguing at times but I am feeling up to a small build. I've written about this a little now and then so here we go

I am using an Olympus kit to build a sport scale Patriot. The nose cone is pretty close to the correct length for the diameter and the body tube size will better allow some detailing such as the boat tail and side conduits. I'm still having to cheat some on the size of the fins but I have tried to keep it not too noticeable by adding weight to the nose cone.. My plan is for it to be a "cheap" flyer ; i.e. able to use 24mm D and E Estes motors from Hobby Lobby.

I've made my OR file and sorted out everything that came up during the design stage but of course things always arise while building the rocket. The first thing was how the body tube fit over the nose cone shoulder and the shoulder of the plastic coupler. For those who aren't familiar with the Olympus it is a payload rocket that has a clear payload tube.



It was my idea to replace the clear payload tube with a section of body tube of the correct length to simulate the nose cone and warhead section of the Patriot. This section will separate from the main body tube during chute deployment.



That is when I ran into the first small problem. The body tube fit very loosely over the plastic coupler and the shoulder of the nose cone. At first I thought it was because they were designed for the plastic payload tube and that maybe it is thicker than the body tube. I measured with my calipers and discovered that it is the same size of the body tube at .021 inches. I can't explain the looseness but I decided to glue two "wraps' of printer paper inside of the body tube to get rid of the slop and that did work.

Now I need to decide if I should just glue all three pieces together or leave them as a friction fit. Maybe glue the nose cone to the tube and leave the coupler as a friction... I just don't know and would welcome your thoughts.



Well, that is it for now. I need to go buy some epoxy for the next steps. Can't believe I ran out but I couldn't find any in my stash.

-Bob

 

[Ez2cDave]

https://www.rocketryforum.com/threads/patriot-missile-paint-scheme.52347

Dave F.

 

[Bruiser]

Hello Dave,

I've seen that thread. Nothing to good there really. The "Estes" scheme seems to be the most commonly seen. The scheme for the museum missile is a little different. It is slightly different than the missile on display at WSMR. I'm having trouble finding a color (in a spray can) close to the reddish-brown used on the front and the fin/can areas. The "Estes" scheme is certainly easier to see and requires more work because I'd have to make decals or paint masks. Don't know which way I am going yet.



I designed in a laundry shelf with a block added for the upper rail button. I also made a mount for the lower rail button and epoxied them in place.


I glued in the motor mount using two of the supplied centering rings and started on the boat tail. I used PayloadBay.com for the template. I made an extra centering ring from some 1/16th balsa for the upper end of the boat tail and I trimmed the circumference of the (3rd) supplied centering ring to support the boat tail mid-way. I used two layers of paper plate cardboard for the boat tail. I find the thinner material easier to bend and it's easy to laminate putting the seams 180 degrees apart.


Once glued up, I slid the boat tail over the aft of the motor tube and glued it in place. I needed to keep the bottom of the rocket lite so I left the retainer in the bag and bent up an engine hook out of wiper blade metal.


All caught up. Today will either be fin day or CWF day.

More to come,
-Bob

 

[KenECoyote]

The "Estes" scheme seems to be the most commonly seen. The scheme for the museum missile is a little different. It is slightly different than the missile on display at WSMR. I'm having trouble finding a color (in a spray can) close to the reddish-brown used on the front and the fin/can areas. The "Estes" scheme is certainly easier to see and requires more work because I'd have to make decals or paint masks. Don't know which way I am going yet.

What timing!

Madcow 4" Patriot finishing ("Paintriot")

Hi Everyone! I did a rush build of a Madcow 4" Patriot recently (just in time for club's pre-July 4th launch) and thought I'd document it in case anyone else finds this helpful. I've done some complex (insane?) paints and felt rushing this on the fly was right up there for me. On the flight...

www.rocketryforum.com

I'm still writing this, but had finished the rocket already. I LOVE it! Coming up, I'll detail how I researched and painted the roll pattern, created my own "U.S. ARMY" lettering and also made those rectangular boxes from vinyl.


I'll likely later add the black dots (bolt heads?).

 

[Bruiser]

I'll have to look at that tonight. This computer doesn't let me see pictures on TRF. Very weird...

So it has turned out to be a CWY and fin day.

I have the initial taper sanded into the fins. BTW they are laminated from 3/32nd balsa, then 1/32nd ply, and 3/32nd balsa. They are just temp installed into the body tube right now for motivational purposes


The spirals on the body tube have been filled and sanded. The boat tail has also received a coat of CWF and has been sanded. I think I have a little more work to do on it after it hardens a bit more.


Now I need to find my measurements for the leading and trailing edge tapers. They are in the OR file which is on my laptop at home. Thankfully it is lunchtime

-Bob

 

[Bruiser]

I've been working away on the Patriot. I'm in the process of doing fins right now. They remind me of Honest John fins with the diamond shape and taper from the root to the tip. I understand why there are so many Patriot models out there that have flat fins with simple, rounded leading edges. Sanding the taper in just right is a huge project!

I already explained how my fins have a plywood core. That comes in handy when doing the sanding. Because the balsa sands so much easier than the ply you will know when you meet the mid point. First I sanded the outboard taper, then the leading edge taper and lastly the trailing edge taper. After the first one was done I stopped to ask myself why I need to make things hard. The answer was that a flat fin is just too easy

After I finished all four fins I prepped them for papering by double checking the tapers and cleaning the dust off


Next step was to skin them with Avery label paper. Before I put the paper on I folded it and made a sharp crease. Then I aligned the paper to the fin and pressed it firmly in place. The crease will help accent the "peak" of the diamond airfoil. You just have to be careful about sanding after the primer...


Next step was to use a razor blade and sand paper to trim the edges of the paper. Then I ran some thin CA over the edges to seal them in place. Walla, a fin ready to be glued to the body tube.


I also built the conduits. They are made of 1/32 bass and are 13/32nds wide. To help them fit the contour to the body tube I glued a slender strip of the 1/32 bass to each side which turned out to be quite tricky. My CA must be getting old as it did not want to join the two pieces together even though it was working well on my fingers... Finally I glued the conduits to the body tube with some Titebond. After the glue set up I gave it all a coat of CWF, most of which got sanded back off once it had dried.


That's it for today. Thanks for following along.

-Bob

 

[Bruiser]

I was hoping to get some primer on today but it's super windy. I think it's starting to look like something. I still need to add the rotary actuators for the fins before prime so I do have something to do.


-Bob

 

[SolarYellow]

Cool build. Any updates?

 

[Bruiser]

There were some before I left on vacation to visit the in-laws in Connecticut. We go back home tomorrow so I'll be back at it next week.

The rotary actuators are on and it has had a coat of primer. Pics next week.

Bob

 

[Bruiser]

So I did get the rotary actuators done. They were a little tricky to make look round when looking directly at them sideways but I get better each time


I also have everything sprayed in primer. Still need to do some sanding.


One thing that I am getting hung up on is the payload bay area. I was thinking of possibly carrying an altimeter in there But after losing a brand new Altimeter One on our last launch day I am wondering about how to secure it. I was thinking I would do the "tri-fold" paper inside the body tube with the elastic going to the nose cone and attach the altimeter to the nose cone. Then when I was taking this picture today I realized the nose cone does not have an attachment point.


The lip on the nose cone is barely over 1/8" wide so I can't jut drill a hole in it. It seems I am either going to have to put some sort of bulkhead in there for an attachment point. Any idea's?



Thanks,
-Bob

 

[waltr]

Screws or plastic rivet through the payload tube into the nose shoulder.

 

[SolarYellow]

Make the bulkhead match the ID of the shoulder. If you can't ovalize the opening enough to slip it in sideways, you can notch the 45 chamfer so it goes in. Then turn it so the plane of the bulkhead is the way it will go and glue it in. The lip will hold it very securely in addition to the glue.

 

[Bruiser]

I started this build on July 6th as I was feeling better but then I ran into a few technical decisions to be made which my brain just couldn't process at the time.
Anyway I've been feeling a little better again so I got out some sandpaper and paint and got busy. This is where she is at now.




I think I am going to use a short piece of 1/4 inch elastic secured to the payload tube with the old tri-fold method. I've made a bulkhead up that I will glue in to the shoulder of the nose cone. I'll put a screw eye in that to connect tie the 1/4 inch elastic to. I just need to figure out how much weight I need to add to the nose cone before I glue in the bulkhead. That's for another day though.

Thanks for checking out the update,
-Bob