Brief:
Stage bash o' two Estes kits, Der Red Max (0651) and U.S. Army Patriot (2056). Arrr! A two stage rocket is produced with gap staging, shiver me timbers, me bucko, allowin' both booster and sustainer t' have engine hooks. Arrr! Begad! T' upper stage looks enough like t' standard Patriot t' be mistaken for a stock model, shiver me timbers, matey, ya bilge rat, enough t' use t' Patriot decals for t' sustainer and t' Red Max decals for t' booster. Blimey! Aye aye! 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. Avast! It turns out it can be done more easily, ya bilge rat, without resortin' t' cuttin' body tubes. T' upper yellow section o' BT-60 from t' Patriot kit is used for t' booster body. Begad! T' Red Max Fins fit on it perfectly. Avast! I just centered them fore and aft on t' tube.

I wanted t' have three fins on t' sustainer as well as t' booster. Arrr! When I punched out t' Patriot fins, one o' them was about 1/16in smaller than t' other three. Begad! That made up me mind for me. Well, blow me down! Ya scallywag! I used t' three identical fins for t' sustainer. Blimey! Arrr! T' give it a look just slightly different from t' stock Patriot, me bucko, I cut t' back corner off t' fins and mounted them just overhangin' t' back end o' t' tube by 3/16in. Avast, me proud beauty! Avast! 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. Well, blow me down! I found t' alignment jig in t' garage o' a friend's house. Begad! It was t' previous owner's. Begad! My friend is nay a rocketeer (yet), ya bilge rat, so he let me keep it. Blimey! Ahoy! I love this jig.

Because o' t' established length o' t' booster section, me hearties, I needed t' use gap staging. Avast, me proud beauty! Blimey! This was me first attempt. Ya scallywag! Blimey! I really wanted both motors t' be able t' use hooks, me hearties, since I find friction fittin' t' be hit-and-miss. Arrr! Blimey! 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. Begad! Blimey! Arrr! Blimey! I mounted it upside down with t' curvy end up and out o' t' way. Avast, me proud beauty! Blimey! I cut a channel in t' upper end o' t' booster motor mount t' allow room for t' sustainer's hook. Arrr! Blimey! Ahoy! Blimey! This channel is a little longer than it absolutely needs t' be, which creates t' escape hole I needed for t' exhaust gases. Ya scallywag! Blimey! One other hole was needed for t' gap stagin' t' work properly. Blimey! Blimey! 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. Avast, me proud beauty! Arrr! First, note that I used t' longer motor mount in t' booster. Blimey! Allow t' engine hook t' overhang 1/4in. Well, blow me down! Glue t' engine block ahead o' t' hook, then cut a 3/16in by 7/16in slot in t' forward end o' t' tube. Avast! This will align with t' sustainer engine hook. Avast! Avast, me proud beauty! 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. Ahoy! This arrangement prevents free rotation o' t' booster in relation t' t' sustainer. Aye aye! T' centerin' rings are 1/2in from t' aft end and 7/8in from t' forward end. Install t' motor mount tube flush with t' aft end o' t' booster body. It will extend a little ahead o' t' forward end. Avast, me proud beauty! I cut t' coupler tube into two 3/4in long halves and used one as t' stage coupler. Avast! 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. Aye aye! Avast, matey, me proud beauty! T' curvy end fits nicely around t' engine block at t' forward end. Avast, me proud beauty! I left 3/8in o' engine hook overhangin' t' aft end o' t' motor tube. Blimey! T' aft centerin' rin' is 3/4in from t' end o' t' motor tube. T' forward centerin' rin' is just ahead o' t' engine hook. Aye aye! Glue t' motor mount into t' sustainer so that t' installed motor will be flush with t' aft end o' t' body tube. Avast, me proud beauty! That is t' say, ya bilge rat, t' engine hook extends past t' aft end by just t' thickness o' t' metal hook. Once again, 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, arrr, arrr, 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, me hearties, nay t' rubber one)
• 1 Mylar parachute 12in (from t' Patriot kit)

Construction is straightforward if you have built staged rockets before. Arrr! There are a couple o' potential pitfalls:

• T' Patriot kit comes with two 1.5in tube couplers. Ya scallywag! This is too long t' be used as a stage coupler. One must be cut in half. Begad! Cuttin' tubes always requires care. Be patient and cut through gradually t' avoid crushin' t' tube. Once they lose their circular cross-section they are difficult t' get t' fit inside another tube. Aye aye! Blimey! You could use t' other full length coupler t' join t' sustainer body sections, but I decided t' save it and just use t' remainin' half piece. I believe it is plenty strong enough.
• Cuttin' t' slot in t' booster motor mount tube is nay difficult, me hearties, 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, glue t' engine block in place ahead o' t' slot, arrr, poke t' curvy end o' t' hook through t' slot and curve it around t' engine block, seat t' engine block against t' forward end o' t' hook, matey, 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, matey, sandin' betwixt coats. Aye aye! I then painted t' upper body with one spray coat o' white enamel from Ace Hardware. Well, blow me down! I masked off and painted t' red sections with Ace red enamel. Ya scallywag! I had a sheet o' yellow pressure-sensitive vinyl, shiver me timbers, so I cut a piece and applied it around t' forward sustainer. Well, blow me down! I then applied all o' t' Patriot pressure sensitive decals. Aye aye! On t' booster I applied most o' t' Red Max waterslide decals that would have gone on that part o' a real Red Max. Arrr! I also put one "Motorverkens" decal on t' sustainer so they would each have one (and they lined up). Blimey! 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. I got several "oohs" and several laughs, and several questions.

I did nay have a manufacturer's recommended motor list for obvious reasons. Begad! I had done a few simulations with RockSim. Begad! 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. Blimey! T' next two launches were C6-0/B6-6.

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

One thin' I noticed. Arrr! T' sustainer gets sprayed with BP residue durin' gap staging. 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 be a lot o' fun. Bein' able t' prep this two-stage rocket with engine hooks for both motors be unbelievably easy. Avast! I think t' turn-around time was about two minutes. Avast! It is definitely a crowd-pleaser.