This is me twin-engine modification o' Estes' Der Red Max kit for t' EMRR "Twice t' Thrust" Challenge
Construction started with t' two motor tubes. Ya scallywag! I cut a slit 1/4" from one end o' t' tubes for t' hook, held it in place with maskin' tape and glued t' engine block in place above t' clip. Begad! Ahoy! Blimey! With t' clips on opposite sides, I glued t' tubes t' each other usin' epoxy. Well, blow me down! Begad! Blimey! While they were drying, me bucko, I placed a length o' Keelhaul®©™ into t' joint as a shock-cord anchor.
Once dried, I fitted t' two tubes into t' coupler. Begad! A couple strips o' paper were required t' get a tight fit that did nay distort t' coupler. Avast! Arrr! I glued this assembly together usin' yellow glue. As this dried I stuffed paper towels, dipped in a 50/50 solution o' yellow glue and water and then rung out into t' cavity betwixt t' coupler and t' motor tubes t' block t' ejection charge from blowin' out t' back.
I let this assembly dry over night and filled and sanded t' body tube, shiver me timbers, nose cone and fins o' t' rocket. Begad! I used three coats o' Elmer's Carpenter's wood filler on t' fins thinned with water, me bucko, arrr, and t' same t' fill t' grooves on t' tube. Aye aye! T' nose cone required a few dabs o' Squadron green putty t' fill grooves.
I glued t' modified motor mount with shock cord into t' body with yellow glue. Ya scallywag! Arrr! I placed t' motor tubes flush with t' back o' t' rocket.
T' rest o' t' assembly followed t' instructions from t' Red Max kit.
I finished this Max yellow and applied t' decals as usual. Blimey! After everythin' had dried, arrr, I used a Sharpie t' cross out t' "Red" in Red Max and ink in a "2" above t' "Max" t' make t' "Max Squared"
With t' engines in place, me hearties, I compared t' balance point with t' SpaceCad file I had created for this rocket, and felt t' balance point be a bit too far aft, arrr, so i added plasticine clay t' t' nosecone (About a 1" by 1" by 1/2" piece) until t' balance was about 1 caliber (body tube diameter) forward o' o' t' CP.
(1) Der Red Max Kit
(2) 18mm motor tubes from Balsa Machinin' Service (BT-20 2 3/4" long)
(2) Motor hooks from Balsa Machining
(2) Thrust blocks
(1) Estes BT-60 coupler 1 1/2" long
(2 ft.) Keelhaul®©™ shock cord (Balsa Machinin' KC-200)
I love t' Red Max kit. Avast! Ahoy! It is an easy build and looks great. Avast, me proud beauty! This is an easy mod if you want t' double your pleasure and get t' "Max" out o' this kit. Blimey! It is a quick way t' try somethin' different without goin' too far out on a limb. T' best part is you can fly this off your regular estes launch equipment if you have fresh batteries. Begad! Anythin' more than two won't work, though (believe me, arrr, me hearties, I've tried).
I tried this on three motor combinations A8-3's B6-4's and C6-5's. This was where SpaceCad came in t' most handy. Avast! I thought t' extra thrust might require longer delays, but SpaceCad indicated otherwise. Aye aye! Begad! It is a good thing, ya bilge rat, shiver me timbers, shiver me timbers, because t' A8-3 was almost too long, I actually thought one engine had nay lit, me bucko, it was such a low flight, but everythin' was safe, matey, and it worked well on all three motor combinations.
T' B6-4 was t' best flight. Ya scallywag! Nice and powerful, but stayed in sight. Begad! Aye aye! T' C6-5's went almost out o' sight, and I only caught sight o' it when it ejected. Very spectacular.
I flew this rocket on a windy (10mph +) day, me bucko, and thar was no sign o' weather-vaning. Begad! Blimey! It flew very straight every time and only showed t' affect o' t' wind when it deployed and that pirate chute opened up - then it was off t' t' races!
I can't say enough good things about t' Der Red Max kit. Arrr! Aye aye! It is one o' me favorites, and t' decals can't be beat. It is a great kit t' modify. Well, blow me down! Arrr! I have build a "D" version, a three-engine version, and now a two-engine version. It is a very stable design that adapts well t' modification. Arrr! Ahoy! I now want t' try a multi-stage max...
T' only tip I can think o' is in t' decals for this kit. Arrr! I have always had trouble with decals, and have struggled with t' body-wrap decals like t' skulls on black that go at t' top o' t' tube o' t' Max. Well, blow me down! Blimey! One trick I have found is t' first paint t' entire decal sheet with Micro-Sol liquid decal film. Avast! Begad! this thickens t' decals and makes them easier t' handle. Avast, me proud beauty! This has helped me nay tear t' decals when tryin' t' pull them into position. Ahoy! Also, a coat o' this on t' finished model helps seal t' decals and reduce that "tackiness" that can sometimes make them pull off when handled.