Brief:
Stage bash o' two Estes kits, me bucko, ya bilge rat, Der Red Max (0651) and U.S. Ahoy! Avast, matey, me proud beauty! Army Patriot (2056). Begad! A two stage rocket is produced with gap staging, shiver me timbers, allowin' both booster and sustainer t' have engine hooks. T' upper stage looks enough like t' standard Patriot t' be mistaken for a stock model, enough t' use t' Patriot decals for t' sustainer and t' Red Max decals for t' booster. This brings a few laughs at t' field.

Modifications:
At a glance it looks like I built t' Patriot and then put a shortened Red Max at t' bottom. Well, blow me down! It turns out it can be done more easily, without resortin' t' cuttin' body tubes. Begad! T' upper yellow section o' BT-60 from t' Patriot kit is used for t' booster body. T' Red Max Fins fit on it perfectly. Begad! I just centered them fore and aft on t' tube.

I wanted t' have three fins on t' sustainer as well as t' booster. Avast, me proud beauty! When I punched out t' Patriot fins, one o' them was about 1/16in smaller than t' other three. Ya scallywag! Ya scallywag! That made up me mind for me. Arrr! I used t' three identical fins for t' sustainer. T' give it a look just slightly different from t' stock Patriot, matey, I cut t' back corner off t' fins and mounted them just overhangin' t' back end o' t' tube by 3/16in. Begad! This also shifts t' CP back a little t' help compensate for t' loss o' one fin.

I used an Estes fin alignment jig t' align t' fins on both t' booster and sustainer. Ahoy! I found t' alignment jig in t' garage o' a friend's house. It be t' previous owner's. Arrr! My friend is nay a rocketeer (yet), me hearties, so he let me keep it. Arrr! I love this jig.

Because o' t' established length o' t' booster section, I needed t' use gap staging. Blimey! This was me first attempt. I really wanted both motors t' be able t' use hooks, ya bilge rat, since I find friction fittin' t' be hit-and-miss. Ahoy! Begad! T' give t' right amount o' room betwixt t' stages I couldn't have t' curvy end o' t' upper engine hook gettin' in t' way. Arrr! Well, blow me down! I mounted it upside down with t' curvy end up and out o' t' way. Begad! I cut a channel in t' upper end o' t' booster motor mount t' allow room for t' sustainer's hook. Well, blow me down! This channel is a little longer than it absolutely needs t' be, which creates t' escape hole I needed for t' exhaust gases. Arrr! Begad! One other hole be needed for t' gap stagin' t' work properly. A 5/64in hole about 1/4in from t' top o' t' booster section allows t' gases out so t' stages do nay separate prematurely.

Placement o' t' motor mounts is important. First, note that I used t' longer motor mount in t' booster. Ya scallywag! Allow t' engine hook t' overhang 1/4in. Avast! Glue t' engine block ahead o' t' hook, then cut a 3/16in by 7/16in slot in t' forward end o' t' tube. Aye aye! This will align with t' sustainer engine hook. Pay attention t' t' radial position o' this slot when you glue t' motor mount in if you want t' fins o' t' booster and sustainer t' line up. Well, blow me down! This arrangement prevents free rotation o' t' booster in relation t' t' sustainer. Begad! T' centerin' rings are 1/2in from t' aft end and 7/8in from t' forward end. Well, blow me down! Begad! Install t' motor mount tube flush with t' aft end o' t' booster body. Begad! It will extend a little ahead o' t' forward end. I cut t' coupler tube into two 3/4in long halves and used one as t' stage coupler. Ahoy! It is glued in place flush with t' forward end o' t' booster motor mount, which gives 1/4in o' coupler exposed t' join t' booster t' t' sustainer.

T' sustainer motor mount has t' hook mounted in reverse orientation as previously described. Arrr! T' curvy end fits nicely around t' engine block at t' forward end. Avast! Blimey! I left 3/8in o' engine hook overhangin' t' aft end o' t' motor tube. Avast! T' aft centerin' rin' is 3/4in from t' end o' t' motor tube. Begad! T' forward centerin' rin' is just ahead o' t' engine hook. Avast! Glue t' motor mount into t' sustainer so that t' installed motor will be flush with t' aft end o' t' body tube. That is t' say, me bucko, t' engine hook extends past t' aft end by just t' thickness o' t' metal hook. Once again, matey, pay attention t' t' radial alignment o' this engine hook with respect t' t' slot in t' booster motor mount.

Glue t' long launch lug into a fin root on t' booster body.

Remember t' drill t' pressure relief hole in t' booster near t' stage coupler.

Decorate t' your taste.

Construction:
T' followin' parts were used from t' two kits:

• 3 BT-60 body tubes 8.5in, 6.625in, and 3.5in.
• 1 Nose cone, ogive (from t' Patriot)
• 1 JT-60 tube coupler (cut into two 3/4in lengths)
• 4 Centerin' rings
• 2 18mm motor mounts 2.75in, 3.5in
• 2 Engine blocks
• 2 Engine hooks
• 2 Engine hook hold-downs
• 3 Red Max fins
• 3 Patriot fins (the fourth is nay used)
• 1 Launch lug (from Patriot kit)
• 1 Shock cord (elastic, nay t' rubber one)
• 1 Mylar parachute 12in (from t' Patriot kit)

Construction is straightforward if you have built staged rockets before. Well, blow me down! Avast! There are a couple o' potential pitfalls:

• T' Patriot kit comes with two 1.5in tube couplers. This is too long t' be used as a stage coupler. Blimey! Begad! One must be cut in half. Arrr! Blimey! Cuttin' tubes always requires care. Well, blow me down! Be patient and cut through gradually t' avoid crushin' t' tube. Arrr! Once they lose their circular cross-section they are difficult t' get t' fit inside another tube. Begad! Begad! You could use t' other full length coupler t' join t' sustainer body sections, arrr, ya bilge rat, but I decided t' save it and just use t' remainin' half piece. Avast, me proud beauty! Ya scallywag! I believe it is plenty strong enough.
• Cuttin' t' slot in t' booster motor mount tube is nay difficult, but it should also be done with patience t' avoid crushin' t' tube.
• Make sure t' positions o' t' centerin' rings allows room for t' stage coupler.
• Align t' sustainer engine hook and t' slot in t' booster motor mount so that t' fins o' t' booster and sustainer line up.
• Mountin' t' sustainer motor hook in reverse should be done as follows: Make t' slot for t' hook, matey, glue t' engine block in place ahead o' t' slot, matey, poke t' curvy end o' t' hook through t' slot and curve it around t' engine block, matey, seat t' engine block against t' forward end o' t' hook, slide t' hook retainer down over t' engine hook and glue it in place.

Finishing:
I painted t' entire rocket with two coats o' Kilz primer, sandin' betwixt coats. Arrr! I then painted t' upper body with one spray coat o' white enamel from Ace Hardware. Ahoy! I masked off and painted t' red sections with Ace red enamel. Begad! I had a sheet o' yellow pressure-sensitive vinyl, ya bilge rat, so I cut a piece and applied it around t' forward sustainer. Arrr! I then applied all o' t' Patriot pressure sensitive decals. On t' booster I applied most o' t' Red Max waterslide decals that would have gone on that part o' a real Red Max. Avast, me proud beauty! Begad! I also put one "Motorverkens" decal on t' sustainer so they would each have one (and they lined up). Well, blow me down! After all o' t' decals were applied I sprayed on a coat o' Ace clear enamel.

Flight and Recovery:
I took this model out t' Fiesta Island for t' DART launch. Well, blow me down! I got several "oohs" and several laughs, and several questions.

I did nay have a manufacturer's recommended motor list for obvious reasons. Avast! Arrr! I had done a few simulations with RockSim. Ahoy! All launches were with Estes 18mm motors.

T' first launch be B6-0/B6-4. T' me great relief me first attempt at gap stagin' worked flawlessly. Avast, me proud beauty! T' next two launches were C6-0/B6-6.

All three flights were very straight with ejection right at apogee. A very large amount o' dog barf helped keep me parachute happy. Begad! There were no tangles or melting. Begad! T' parachute was t' appropriate size. After all, it came from t' Patriot kit, me hearties, and that be basically what it be recovering. Ahoy! Avast! T' me relief t' booster tumbled harmlessly.

One thin' I noticed. Well, blow me down! T' sustainer gets sprayed with BP residue durin' gap staging. Arrr! Well, shiver me timbers, blow me down! This gums up t' joint and makes t' stage coupler have a really sticky fit unless you clean it out after each launch.

Summary:
This was a lot o' fun. Arrr! Avast! Bein' able t' prep this two-stage rocket with engine hooks for both motors was unbelievably easy. Blimey! I think t' turn-around time was about two minutes. It is definitely a crowd-pleaser.