LOC 4" Nike Zeus build thread (With mods)...

[Mugs914]

Got started on the middle set of fins last night. Even though the kit parts are very nice (I've got plans for them on another project), I'm building these up because I want to make them wedge-shaped like the ones on the Spartan.

I've got the cores done and I'm starting on the ribs. This set is built exactly like the canards but different...

The core is made of 1/8" balsa laminated with 1/64" ply. The mid-fins are a bit thicker than the canards so an all ply core would be pretty heavy.

Here are some pics:

1/64" ply skins cut:


Skins glued to balsa. A small piece was added to the tip area:


Once the skins were glued and cut from the balsa sheet, they were glued to the ply sheet to make the other skin:


All four were glued to the sheet then cut out and sanded:


I need to stack sand the cores then start on the ribs...

 

[Theory]

Looking good my friend!

 

[Mugs914]

Thanks Sean!

I took some time away from the build last week to concentrate on making my first dual deploy flight. The flight and recovery went perfectly, but it managed to come down on a power line. The power company came and made the terminal recovery at no charge so all ended well. That is one big step closer to my Level 2 flight!

So now, back to work on the Spartan!

I got the center set of fins finished up today. Like I said before, they were built up like the canards but were much simpler to make due to the wedge airfoil. Here are the cores with the ribs added and sanded:


And here with the skins and bass wood leading edges added and sanded:


Here is a comparison with the kit parts. The new fins are a tiny bit bigger, extremely strong and stiff and quite a bit lighter than the solid ply fins (13.6 gms. vs. 20 gms for stock):


I feel like I should say at this point that the mods I am making to this kit are purely for my personal preference and are not intended to correct any perceived flaws in the kit itself (There aren't any as far as I can tell!). I'm a big fan of LOC's stuff and this kit is no exception. The parts and materials are top notch and I can't recommend it highly enough. The stuff I'm doing to it stems solely from my inability to build anything without trying to make it look like a "scale" model of a real something!

I should have some time tonight to start getting the canards and middle fins glued up to their respective tubes. The main fins will be made from the stock kit parts but will be pretty heavily modified. Gonna get started on those tomorrow at work!

 

[Mugs914]

Okay, I actually glued some components together (Finally...)!

I got the canards glued into place on the 3" tube that goes up front.

Being so far up front, I was concerned that the alignment be just right, so I decided to glue one at a time. I made this single fin alignment tool so I could baby sit the longitudinal alignment until the epoxy set up.




After three more I had a complete "missile control unit"! (As it is labeled in one of the cutaway drawings)




Looks pretty neat with the nose on it. Maybe I should put a G-64 in it and let 'er rip!

 

[Mugs914]

Got the middle set of fins glued to the booster tube last night, so it's starting to look like a rocket (pics coming). I guess I'm sort of working from the outside in on this one. Probably start on the motor tube in the next couple of days.

In the meantime I got started on the main fins today at work. I will be building these up too, but I'm using the kit parts for the fin cores. I don't want things to get too heavy on the aft end, so I added a bit of lightness with a hole saw... (The little Skybolt was on the bench and asked to be included)



All in all, 40 gm (~1.4 oz) removed from each fin.

 

[Mugs914]

Been a while since I've had much time to work on this bird, but I did get a bit done this weekend. I'm still scheming on how I want to go about building up the main fins (ribs with ply skin, foam, other ) so I got after the motor mount tube, recovery harness and centering rings. I made a few mods to the kit assembly, mainly to do with the recovery harness attachment and motor retention.

This kit uses LOC's "LOCin ring/fin system" in which the fins are not only through the wall, but are slotted in to the forward and aft centering rings as well. I gotta say that I REALLY like the way this system goes together. The instructions describe two methods of construction; conventional through the wall (centering rings and motor tube assembled, glued into airframe, fins glued through slots) and building the fin can first and then gluing it into the airframe. I didn't do either...

I built the motor tube leaving the aft centering ring off so I can triple fillet the fins. This didn't cause any particular difficulty, but I did have to be careful with my measurements to ensure that the aft centering ring would be flush with the end of the motor tube to accommodate an Aero Pack flanged retainer.

The bigger mod was to the recovery harness attachment. The kit uses an eyebolt through the forward centering ring, but I opted to make a kevlar bridle and epoxy that to the motor tube.

Pics tell a better story, so here they are!

First, a few shots of the center fins glued to the airframe:
Notice they are glued one inch north of the original middle fin slots. This was just for appearance purposes and was part of the original OR sim.

(Please pardon the messy bench...)

This is the recovery harness and it's installation. The knots serve two puposes:






Suitably gooped...


Kind of a lousey shot, but the whole thing did get installed in the airframe. It isn't quite as recessed as it looks...


There is a section of coupler tube that gets glued into the airframe where the middle fin slots are. May get that done tonight. The slots will be filled or turned into scale-ish details, of which there will be plenty on this thing!

Thanks for looking!

 

[Theory]

really dig your choice for the harness. no doubt that will hold up for a good long time!

 

[Bruiser]

Umm, been waiting for an update. Did you finish this one? It's an interesting build.

-Bob

 

[Hooked On Rockets]

WOW!
This is coming out AWESOME!!!
The time and detail and workmanship!!!

Kudos!!!!

 

[Mugs914]

Sorry guys, it has been a while! Funny you posted when you did though Bob; I had just gotten back to work on the Spartan and actually have a bit of progress to report.

One of the reasons for the delay (there were many...) was that I was trying to decide what method I was going to use to build up the main fins. I considered using 1/4" foam laminated to the cores, sanded to profile and either glassed or skinned with 1/64" ply, but decided that would be more trouble than just building them up like I did the other fins. It would also be a bit heavier and would create a titanic mess. On the other hand, the original method would involve cutting and shaping over 20 pieces of wood for each fin not including the skins.

In the end I just sucked it up, put in a movie and started cutting...

This is where I am so far. There are a few more stiffening ribs to add, but all four are up to this point.






I also got a piece of coupler tube epoxied into the main booster tube where the original slots for the middle fins were. I'm going to either fill the slots or use them as the basis for some kind of scale-ish detail. Haven't decided on that bit yet...



Thanks for looking and following along! More later...

Mike

 

[Bruiser]

Looks good! I like what you are doing with it. I keep eye-balling the 2" version. Following your thread is almost as good as building one myself!

-Bob

 

[Mugs914]

That's mighty kind of you Bob, thanks!

There have been a couple of glitches along the way, but nothing too major:

Two of the main fin cores developed a slight warp after I drilled 'em fulla holes. They were steamed and straightened before the skins went on.

I tried to do a card stock wrap around the fin can area using thinned white glue as an adhesive, but it puckered and wrinkled up so bad it looked like an elephant leg. I managed to get most of it off before it set up too bad, but there is still a bit of sanding to do to get back to zero.

I'm going to redo the wrap, but I think i'll use finish epoxy this time and work in smaller sections.

I did manage to get the stiffening ribs all cut and installed today. These mainly support the skins, they add little strength to the fin themselves. I also got the aft part of the ply skins on (pics coming). Leading edge sheeting will go on tomorrow, then leading edge caps.


With any luck at all I might have the fins on this bird by tomorrow night!

 

[Mugs914]

Oh, and I was mocking up the fins today when I saw this nose cone just sitting there with nothing to do.

Looks kinda cool, I though to myself... Lessee, where'd that Open Rocket icon get to?





G'night all...

 

[Mugs914]

This is where I left off last night:



This is where I am now. All four skinned, sanded and ready for basswood leading edges.



Counted it up (shouldn't have) and there are 30 pieces of wood in each fin...



My next build is gunna be a Mosquito...

With no paint...

Have to say though that they are looking pretty good so far, and are still a little lighter than the solid ply core before drilling, believe it or not.

More later...

Thanks fer lookin'!

Mike

 

[Bruiser]

Is that 1/64th you are using for skins and are you using CA for the adhesive?

-Bob

 

[Mugs914]

Yup, skins are 1/64" ply and i'm using both thin and medium CA, depending on the joint (some get both).

Progrep: Leading edges have been installed and I'm getting them planed and sanded to profile (tedious). Two down, two to go...

Basswood LE.


Tape to protect skins.


Master Airscrew razor plane. Carve away...


After initial sanding.


Finished fin.

 

[kuririn]

I need to get me one of them planers. Sure would save me a lot of sanding.

 

[Theory]

WOW!!!

truly an amazing job

 

[Forever_Metal]

where'd you source the 1/64" sheets? I had one that still had stock available but the quality was far south of being good for anything other than internal use...

thanks in advance

fm

 

[Bruiser]

I've run out of 1/64th also and the hobby shop in El Paso doesn't stock it.

-Bob

 

[Mugs914]

where'd you source the 1/64" sheets? I had one that still had stock available but the quality was far south of being good for anything other than internal use...

thanks in advance

fm

I used to be able to get it at Michael's, but the one here doesn't seem to carry it (May want to check there if you have one close by). Now I order it from Sig Mfg.

https://sigmfg.com/collections/plywood-wingskins
I'm sure that other model airplane suppliers have it too, but I was already ordering some other stuff from Sig so I just added a couple of sheets.

 

[Forever_Metal]

Thanks Mike!

fm

 

[Bruiser]

Those fins are coming out great

-Bob

 

[Mugs914]

Thanks guys!

I feel like I owe those of you who are still following along an apology for promising a build thread but delivering a five month long fin building odyssey. The good news is that the all fins are finally done!



There will be a little filler to apply in a couple of spots, then sanding sealer. I'm thinking I'm going to paper the big fins (maybe all fins) with silkspan model tissue and dope. Adds a bit of strength and kills the wood grain, and is really light.

Gotta get the fin can wrap re-done, then the fins can be glued in place.

So thanks for hanging in there with me this far. I promise things will be decidedly more rocket (missile?) shaped from here on out!

Mike

 

[mbeels]

I'm thinking I'm going to paper the big fins (maybe all fins) with silkspan model tissue and dope.

ooh, nice touch. Those fins came out fantastic, very realistic looking shape.

 

[Bruiser]

Can't speak for anyone else, but I've been enjoying the fin building

-Bob

 

[Mugs914]

You guys are too kind, thanks...

Did make a bit of progress this weekend, starting with a bit of repair.

Don't you just hate it when you get a bit of hangar rash before the thing is even finished? One of the issues that comes along with the built up fins is that the skins are very thin and somewhat susceptible to damage (Kind of realistic, in an unfortunate sorta way...). Once the thing is built the surfaces are a bit more protected, but at some point something got dropped on one of the fins and punched a hole in the forward skin.



Nothing that couldn't be fixed with a bit of thick CA and a bit of CWF. Kind of ugly looking at this point, but it's smooth, and it'll be painted over...


At this point all four fins have three coats of dope each and are ready to be covered in silkspan tissue. I'll get started on that tonight.


While the fins were drying up I got started on the fin can details. I did a couple of 1/64" ply wraps to look like the attachment flanges between what would be the motor section and the fin can on an actual missile. Then pieces were cut from 1/64" ply and glued on either side of the fin slots to simulate reinforcement panels. The wider places are where there will be fin mounting brackets.

Here are a few pics in progress and the mocked up fin can.


As always, thanks for following along! Just for fun here's a link to an actual Nike Zeus firing. Check out the paint burning off just before staging!



Thanks again!

Mike

 

[Glasspack]

Mike, Your modeling skills are quite impressive...…….. That looks Nice as hell !!

 

[Mugs914]

Thanks Glass! You are very kind.

I got the fins all covered with silkspan tissue and three coats of dope applied. For those not familiar with old model airplane techniques, a dope/tissue finish is a lot like fiberglass in that you have a flexible matrix embedded in a rather brittle material that when combined make a tough, resilient finish that can add quite a bit of strength to a structure. In this case the structure itself is more than strong enough, but I wanted to toughen up the thin, 1/64" ply skins a bit. It also kills the wood grain and adds very little weight.

I already had three coats of dope on the fins. When more is applied through the tissue, the solvent in the new coat softens the previous coat so they bond together, trapping the tissue in between. A few more coats seals everything up and gives you room to sand everything out without getting into the tissue.

Pics:
Lay on some dope...


Lay on the tissue...


Apply dope through the tissue...


The tissue is cut a bit oversize so the tip and trailing edges get covered too.


The leading edge gets wrapped over as well. When both sides are done the leading edge, tip and trailing edge all have two layers of tissue since they take most of the abuse.


As I said, all four are covered and drying. It is pretty humid here so I'll leave them to cure up a for a little while before sanding. Once sanded they will be ready for primer and a few surface details before being glued on (Finally!!)

I also got started on some details up on the nosecone. The Spartan has small ramps on the nosecone that deflect the hypersonic shock wave away from the base of the movable canard fins. You can sorta see 'em in this pic, and a bit better in the drawing below.


Of course, gluing anything to a LOC nosecone is pretty tough, so I had to do a bit of research to find something that would work. Thread here:

https://www.rocketryforum.com/threads/glue-that-works-on-loc-nosecones.159559/
Turns out DAP has a product for gluing these types of plastics that seems to work pretty well.

Got these parts made and ready to be glued. They will go in front of each canard and will be the base for building up the ramps.


As always, thanks for playing along! More in a bit...

Mike

 

[Mugs914]

I reckon anyone still following along will certainly appreciate any update that doesn't involve fins...

I did manage to finish up the ramps on the nose cone. I have to say that I am pretty impressed with the DAP plastic glue system. I'm still experimenting with it a bit and I'll post up results here: https://www.rocketryforum.com/threads/glue-that-works-on-loc-nosecones.159559/

Because these things were being fitted to a compound curve, it took a bit of figuring to get the shape right. The good news was that the shape is a little bit simpler than an Honest John spin motor.

Here are a few pics. I have been assured that they are each worth 1000 words...



Once the proper curve was determined, eight of these were cut out.


Then glued and sanded with this result...


More soon...

Mike