Nike Hercules Two-Stage by rharshberger

June 25, 2017

Tonights progress was glassing the sustainer transition.


Left: Two layers of 6oz Fiberglass applied to the transition.

Right: While digging through the box of FG rems, I happened across a lonely little piece of 6oz Carbon Fiber......I think that with a bit of work it would make awesome covers for the timer and batteries, too bad they would have to be painted to match the sustainer.

After the FG cures I will wrap the transition with mylar and then form the covers over the top in one solid piece.

The former for the transition is nothing more than three 1/4" centering rings to keep the transition round, the rings are edged with packing tape so the epoxy will not stick to the rings.



Edit: Just realize that the 6oz FG is actually 10oz (the Bondo Branded stuff from Home Depot/Lowes).

June 26, 2017

Not much to show here but the transition was wrapped with a layer of clear drafting mylar (Drafting Film from Hobby Lobby, 4' long roll iirc). The mylar is thick and epoxy will not stick to it for the first couple of uses. After the application of the mylar the transition is ready to be the mould for the covers for the timer and battery bays. After the application of the mylar, I cut 2 pieces of 6oz FG to go with the single layer of CF, mixed my epoxy ( 16 grams, was about perfect), and applied the 3 layers to the mould, wrapped them with peel ply after using a squeegee to make sure everything is wetted out fully. Carbon Fiber can be hard to tell when its wetted out but a good light source will allow you to see the wet reflection off the surface of the carbon and tell where the dry spots are, my light source was the open door of my garage and the sun. After application of the peel ply I applied a layer of breather fabric ( its actually a cotton quilt batting my wife gets at JoAnn's Fabric, that is about a 1/4" thick, she gives me her scraps which are usually plenty large enough to do the job). Once the breather was applied I used some green masking tape (it was on hand) to secure it around the peel ply. After the breather was on the next step was wrapping the whole thing with several layers of Saran Cling Wrap (yep back into the wife's stuff again ), once it was nice and snug a heat gun was used to shrink it onto the mould (technically its a mandrel I guess), not much heat is needed but it makes the Saran wrap nice and tight.

Edit: the black dots visible in the left photo is the epoxy wicking through the perforated peel-ply and into the breather fabric. If I can remember too this afternoon I will take a photo of the process again to show how much wicking action has taken place.



Edit part deux: Picture below is of the completed hatch cover blank, notice the line that looks dry, it isn't but the weave did not get covered with enough epoxy to fully fill it. The dry looking area was caused by a wrinkle in my peel ply from the long term storage, its 60" wide and was rolled then folded in thirds, one of these days I need to re-roll it and flatten it.



Hint to anyone new to peel ply make sure and order it ROLLED NOT FOLDED, its caused way to many problems as the darn creases are near impossible to get out of it even with a laundry iron (my wifes craft one not her good one).

July 8, 2017

Got a bit of work done on the Airstart Avionics Bay for the Nike Hercules, its all wired up now.



Left: Left side showing timer bay and computer battery compartment

Center: Timer and arming switches (screw switches at bottom, currently hidden by wires, one switch for computer power and one for pyro power).

Right: Right side showing compartment for Pyro battery.



Pre-Installation of sustainer FG shroud is below.

July 14, 2017

Got some more work done yesterday (forum wouldn't allow uploads of pics yesterday or today due to the forums photo limit is reached I guess). So I went through this build and deleted unnecessary photos (I hope) in the hopes that I can upload some new ones.

July 30,2017

I have taken a temporary break on the Nike Herc, but it is getting closer to completion. The steering flaps are completed as are the nose fins. Nose cone threaded inserts are installed to mount the NC bulkhead plate to, I still need to get a piece of 1/8" aluminum for the bulkplate.

September 3, 2017

Got the sustainer steer fins/flaps on the Nike Hercules Sustainer, for some reason this build has slowed considerably, only 8 fins left to go and they are on the nose cone, still need to make the covers for the staging timer and battery bays (the piece is already laid up I just need to trace the patterns onto the CF part and cut the covers, install the pem nuts and the sustainer will be mostly done).

rharshberger said:

Post #36

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Post #37, looks like a good build incoming.

I have to go take a few more pictures but basically the only thing done since the last post is the cover for the AAB (airstart avionics bay).

Far Left and left of center: outer and inner sides of AAB cover.

Center and Right of Center: cover in place but not fastened, I do have PEM nuts for this purpose but the cover fits so good I may just use tape to secure it.

Right: Nose cone with threaded inserts installed and hollowed out, regrettably it was hollowed the hard way, as I didn't acquire my newest to me lathe until well after the exterior was finished so the hollowing deep in the NC isn't as neat as it could be using forstner bits and stepping the hole using the chuck in my tailstock.



I have gone through the earlier posts and added a few comments here and there to improve the continuity or to correct vague references. Now I just have to finish installing fins on the NC, make the Nose cone bulkplate and shock cord mount, make the sleds for the two altimeter bays, and acquire 5 sets of CTI 4 grain 29mm casings and some spacers. The rocket has MMTs long enough for the 4 booster motors to use 4 grainers, and I will use CTI just for reliability reasons.

The sustainer is designed to use a separation charge prior to motor ignition however it if happens to drag separate so much the better and I will adjust the second stage ignition profile post shakedown flight. The worst part of this rocket is that OR will only be able to do a very rough sim (mostly garbage, due to the fins on nose cones, and the inabilitly to properly sim the booster section).

Very impressive build, thanks so much for sharing it with us! The Nike Hercules is my all-time favorite rocket.

Rich are you using a Lipo with the PET2 ?

timbucktoo said:

Rich are you using a Lipo with the PET2 ?

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I plan too, a smallish one for pyro side and a larger higher capacity for the computer side. Since I am planning to use CTI motors ematches will be easy to light and not real high draw.

Very impressive. Will be watching...

I'm sure everyone will be excited to see this fly.

Back in your first post you mentioned: "Thanks to a very generous member of the rocketry community I was able to get my hands on a set of very detailed drawings of the Nike Herc." And I was wondering what those drawings might be. I've got these:
Briedon - Nike M5 Motor
Stephen Maire - 14 coarse GIF's (so I may have the name spelling wrong) (I'd be interested in a clearer copy of anyone has something)
R.S. Barker - 4 DXF/DWG pages whose original source data was Russian drawings on a Mike Dorffler CD
R.S. Barker - 2 .png images, which cite an American Space Modeling Scale Plan, Ron Goforth, and Peter Always, as well as the Dorffler CD.

Do you have something else? In particular I'm interested in the profile of the nose cone. It's definitely not a tangent ogive, and doesn't seem to match a Haack either. The data I've listed only provide a couple of diameters. Did you have more, or just scale intermediate diameters off of one of those drawings?

For those interested, I've placed all of that data I have in the Rocketry CAD Repository at https://drive.google.com/drive/folders/0B61IjVuE29dEQ2V5SVlIc21NcEU?usp=sharing
(which continues to have disappointingly few contributions).

I can recreate the nosecone profile easily in OR and share that file.

If you have the RS Barker DXF/DWG drawings you have the same ones. I used a graphics editing program to convert to pdf and then rescaled it like 500% to get a sustainer diameter of 3" ( sustainer diameter for Estes 3" tubing aka BMS T300-34). The booster motor tubes are almost exactly the same diameter as BMS T204-34 and the rocket stands like 58" tall iirc.

After the rescaling of the drawing I took the file to a local office printing place and they printed it out at 1:1 scale for me ( a 36"-ish x 60"-ish in color). No need to do scale conversions I just walk over to the drawing and take a measurement, it cost me like $20 for a color and two B&W prints.

I would love to get my hands on a set of the Nike Ajax drawings of the same quality.

Wow, beautiful workmanship! I'll be watching this one .I'll be starting my scratch Nike Herc soon. Looks like you and I had different ideas about how to approach the build. I like that. ---H

rharshberger said:

I would love to get my hands on a set of the Nike Ajax drawings of the same quality.

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Mee too.

I'm looking at a much smaller scale, and I can scale from the Barker drawings - it looks like they match NH photographs pretty well.

Thanks, Gary

This is an amazing build, one of my favorite ever. You made the interstage coupler look so simple.

Because it really is, it just looks complicated.

Impressive, to say the least.

Rich it looks great one of my favorites as well. How is it coming haven't seen anything in a while.

Larry W said:

Rich it looks great one of my favorites as well. How is it coming haven't seen anything in a while.

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Larry, I am hoping to find time to put the remaining nose cone fins on sometime in the next two weeks. The small canards and the forward parts of the long fins are the only fins not currently on the NC. I still need to make the aluminum NC bulkplate/recovery mounting point and nose cone electronics sled. The booster avbay sled is made and needs the Quark mounted. Nose bay will use a Quantum, and the airstart/staging will be haandled by the Missleworks PET2+ in the sustainer tailcone. It should only take about 5-6 hours to finish the build portion and get a coat of primer on it.

Man, this is great work! I'd love to just hang out in your workshop and watch you build.

lcorinth said:

Man, this is great work! I'd love to just hang out in your workshop and watch you build.

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Might be boring because some of the nicest work takes time and folks sometimes have to walk away from a project for awhile to chill and come back to it later. Kurt

ksaves2 said:

Might be boring because some of the nicest work takes time and folks sometimes have to walk away from a project for awhile to chill and come back to it later. Kurt

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This has been one of those projects for sure, not much has been done lately due to increased work OT and the Honey-Do list getting longer because I am generally working 50-60 hrs/week. Normally I work 4 Ten hour shifts and have 3 day weekends but the last several months have averaged over 60 hrs per week.

I was planning to get all the fins on it yesterday and today, and then came down yesterday with Flu A and we currently have 3 out of 5 family members fighting it, so far the wife and son are clear of it but myself and my girls are both stuck in bed.

ksaves2 said:

Might be boring because some of the nicest work takes time and folks sometimes have to walk away from a project for awhile to chill and come back to it later. Kurt

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My best ideas come to me at night, asleep or not. BTW Rich, the Herc is my favorite scale/military rocket. Awesome job so far!

captbk said:

My best ideas come to me at night, asleep or not. BTW Rich, the Herc is my favorite scale/military rocket. Awesome job so far!

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Thanks Kurt, this is sort of a scale project, lots of scale features and a couple of not so scale features, it could be called sport scale. Main reason its not true scale is that I used OTS components for tubes and couplers. The sustainer is actual scale, the booster is a tiny bit off in diameter of each M5E1 motor tube (and I mean just a tiny bit) and and the booster motors are slightly longer (a 2-3" iirc) to accomodate both the Av-Bay and the possible need for a 4gr motor. The plans for this were the aforementioned ones from the Mike Dorffler CD and the Launch Pad Plan Pack (mainly for brainstorming).

gdjsky01 said:

Awesome job so far! Great build thread! Thanks for taking the time to share it!

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Thanks Jeff!

And...all fins are on the rocket. Tasks left to complete are mostly internal stuff now as well as the booster motor retainers. I will be filleting the nose cone fins with very minor fillets, mainly to fill small gaps here and there along the fin root edges. The rocket stands just a hair under 50" tall, and once the fin glue finishes curing/drying I will get a weight on the rocket (its actually pretty lightweight at this point somewhere around 4-5 pounds).

Is there definitive data on the longitudinal weld line orientation on the Hercules Nike motors? I've not seen that on any data, and the photographs I have are inconclusive or perhaps contradictory. Does it vary with the round/model? I guess I'm also wondering what physically distinguishes the MIM-14, 14A, and 14B? I seldom know which one I'm looking at in photos.