Nike Ajax Build Thread!

[Howitzer]

Hey everyone! Don't post often but I thought this special project would be a good build thread!

I'm obsessed with the Nike Ajax and the Herc. There are a handful of old Nike missile sites within a few miles of my home and the history of the whole program is very interesting. Most of you probably know how difficult this missile is to build and fly, but I am going to try.

I still don't know If I want to stage it, leaning towards not for simplicity. Not like I haven't staged HP before .

Anyways onto the program. I hope the pics upload!

Now, I 3D modeled the whole missile in full scale using drawings and docs found on this site. I cant remember where I got them exactly but thanks to those who posted them!

I scaled the entire build based on a LOC 4" booster, which thankfully mean that 3" LOC Tubing was just about correct for the sustainer, so score.

Note: I had already printed the interstage months ago, but it came out like crap, so that needs a redo but its a great placeholder for now.


This picture shows a fin halfway through the machining process. You can see here the doweling fixture I made so that could flip the stock and essentially carve the fin from the 1/2" ply


This photos shows the machined fin after being cut out of the stock and tabs sanded off.


And heres the magic of the CNC, a perfect tapered diamond airfoil with no sanding! (Okay perfectish but good enough)



Next up. BEEFY centering rings!

 

[Howitzer]

BEEFY RINGS and motor mount.

54mm MMT for some J's and K's!

So All I had was 1/2" ply and I had forgot to add some reliefs in the fin tabs for them to lock together so I improvised. This is a short one because everyone knows about making and tacking on centering rings etc. So just a couple pics will do.


I didn't take any pics of the complete machine operation but here's an action shot of my little 1/8" downcut bit making my alignment slots.


And motor mount tacked together. Slotted rings made it all a breeze. I will build the fin can outside of the air frame as I usually do and slide it in. This method is the easiest way IMO.

 

[Howitzer]

Booster Mock up!

Self explanatory. I'm sure most of you have slotted an airframe with an exacto and a straight edge, so I'll leave that out. I didn't get pics anyways ha.



Yay it all fit! Love when a plan comes together. You can see my PETG printed interstage and how gnarly it looks underneath. Im probably going to do a better one in 3 pieces, an upper and lower part with 3 separate struts. I may machine the struts from aluminum other wise I will have to put a tube up thru the middle, but I really want to try to stay to the original design of the interstage and leave it open like in real life. My plan for the single stage version is to just let the sustainer act as a nose cone and do a single large chute with a MARSA33 and a Jolly Logic Release for sort of a singe break dual deploy. I just dont see how I will fit a 60"+ chute in the 3" sustainer section.

I will update this as I make progress, but I also post a bunch on the NAR FB page. The booster is the easy part, but I have already built a BT-60 based sustainer using my 3D models and it all worked. But the nose cone on this will need to be done in multiple parts and possibly contracted out.

 

[Hobie1dog]

Wow I'm highly envious of your machinery and talent, keep the pictures coming.

 

[Howitzer]

More progress! Pics are in no particular order.

Cutting G10 on my CNC!


Canards test fit into PETG nose cone assembly


Dry fit of sustainer components. Sustainer fins are DADO style with a coupler inside, this type of attachment is used on my PML AMRAAM-4, I'm confident it will be fine!


Full up test fit and stack up. The interstage here is just a filler. I changed the design and made some comprises in that area for functionality and strength. Will be shown below.



new interstage design. Using it as my avbay with a central 54mm airframe thru it. the printed part will not really be structural now. Plenty of room for my MARSA33 and related parts.



Kind of self explanatory here


Ill post more as I get further along. Looking to fly this thing at NYPower over Memorial day weekend.

 

[Theory]

DANG!!!!!!!!!!!!

this is legit. very well done

 

[FlyBy01]

That’s above and beyond

 

[Howitzer]

CNC'd all my centering rings and Avbav covers. My avbay interstage is coming along very nicely. Epoxied in fin can the night before as well and printed 4 more conduits. 9 conduits down, 13 to go.

 

[Howitzer]

Weekend Update!

Finished the Avbay interstage and Nose cone assembly. The nose cone is around 24oz without nose weight, and according to rocksim it alone will give me 2 cals of stability with a K535. I'll call that a win.


Booster and sustainer next to a dry fit up of a loc 5.5 phoneix thats 60" tall. Conduits are still printing, and other than that I just need to do fillets, epoxy on my printed rail button stand offs, and make a sled for a MARSA33.

 

[Getmore]

Very nice project.

 

[vcp]

Very neet model. Just one suggestion; a picky detail point, and something almost everyone misreads. On the legs of the interstage, you have a midway 'rib'. Logically you'd think there could be a rib there and it looks that way on most drawings. But it's actually a thickness change in the web of the leg, where it transitions in a slope from a thin to a thicker web. Readily seen here:

 

[Howitzer]

Very neet model. Just one suggestion; a picky detail point, and something almost everyone misreads. On the legs of the interstage, you have a midway 'rib'. Logically you'd think there could be a rib there and it looks that way on most drawings. But it's actually a thickness change in the web of the leg, where it transitions in a slope from a thin to a thicker web. Readily seen here: View attachment 563212

Dangit. That would have been easier to print. Thanks for the pic! Gonna fix my model!

 

[Howitzer]

More progress last night!

One complete conduit attached to the sustainer. I had to print (5) 7" sections per quadrant plus a last 4.25" section at the end. I got them all on pretty straight. I used the same technique on an Estes Pro Series Patriot build. This was the least painful way of doing it. 3 more to go!

Rail button stand offs installed onto the booster.



Saving the worst job for last..... Fillets. Since rocketpoxy seems to be unavailable everywhere, I will be forced to use the Proline 4500, so I hope it works as nicely as rocketpoxy does.

Off topic addition: I assembled and epoxied the RNWS into the 5.5 Phoenix nose cone.

 

[Howitzer]

Yay conduit #2 done! Does anyone know what type of filler works best with PLA and PETG printed parts?

 

[Howitzer]

I'm terrible at updating these things!

The build is pretty much done with this one. Just have to fill, blend, sand, and finish the AV bav sled.

First complete stack up, interstage detail, and conduit shots where they need to be blended.

It will be going up on a J450DM at NYPower over memorial day weekend.

 

[Howitzer]

I totally dropped the ball on updating this thread!

I was able to launch and recover it this past weekend at NYPower. It went to 2561' on a J450DM!

 

[Ez2cDave]

Come over and visit the Scale forum !

https://www.rocketryforum.com/forums/scale.45/