| Manufacturer: | Scratch |
Brief:
For t' EMRR Stagin' Challenge, shiver me timbers, ya bilge rat, I decided t' build a two-stage rocket with composite motors. Since I had done a
2-stage before, me bucko, I figured it would be easy. Well, blow me down! WRONG... Well, ya bilge rat, blow me down! I decided t' do a 3-inch bird with dual deploy and a 19-inch
booster with motor deployment. Ahoy!
Construction:
This time I decided t' use alignment rods in t' stage coupler t' keep t' rocket aligned. Arrr! Aye aye! I didn't have any
'sleeves' for t' rods t' slide through, so I went with spaced centerin' rings with holes t' guide t' rods. Begad! I've
discovered that I really need a drill press. Because I be usin' a handheld power drill, me bucko, I wasn't that accurate in
drillin' holes through t' 2 sustainer centerin' rings and t' stagin' coupler. It still works, arrr, but it isn't pretty.
There are holes in both centerin' rings that are supposed t' be aligned. Blimey! Begad! That didn't work out as smoothly as I had hoped.


T' motor mount is recessed into t' sustainer t' provide a connection for t' top half o' t' stage coupler. Since a 3" tube won't allow me t' get me hand in t' connect t' shock cord, ya bilge rat, matey, I made t' fin can on both the sustainer and booster removable. Begad! T' sustainer fin can is held in place by small screws. Ya scallywag! T' booster fin can will eject and deploy t' booster chute. T' whole project is about 83 inches tall, about 3.5 lbs empty, me hearties, and can fly on 38mm motors.
Finishing:
T' fit/finish betwixt t' booster and t' stage coupler is a little rough, but once it's painted it might nay be
that noticeable. It *certainly* won't be noticeable on t' pad.
Flight:
Electronics will be a PerfectFlite timer for staging, and a PerfectFlite MAWD for deployment. Begad! Blimey! RockSim says it will
get t' a little higher than 2000 feet with a CTI 153 stagin' t' a CTI G79ss.
For t' 2-stage challenge, me bucko, I decided t' build one that used composite motors. Avast! Since I have done stagin' before, I didn't expect thar t' be a problem. Boy, was I wrong... Blimey! Ya scallywag! T' main problem be t' size o' t' new project. T' previous 2-stager be almost a 4" tube. Ya scallywag! That left room for t' timer betwixt t' sustainer fins, me bucko, matey, and a standard-type ebay. This one is a 3", and thar's no room in t' fincan. Ya scallywag! So I put t' timer in t' ebay, and ran a connector wire down t' ignite t' sustainer motor. Avast! I had t' splice t' wire so it would disconnect when t' apogee event fired. Begad! T' next issue I ran into was t' stage connector. I decided t' use metal rods t' connect and align t' sustainer t' t' stage connector. Well, me hearties, blow me down! I don't have a drill press, so me holes through t' centerin' rings are...less than exact. Ya scallywag! Begad! Last issue was t' 3" bay was too small t' use switches t' power on everything, so I had t' run all t' wires through a hole in t' e-bay and twist them t' connect. That posed a problem t' first time I tried t' launch. I test fit t' electronics when I built t' bay, matey, matey, ya bilge rat, but nothin' was connected. Blimey! In t' field, I sadly discovered thar wasn't enough space for all the wires t' fit and route t' t' outside. Aye aye! Blimey! I had t' rebuild t' sled t' avoid that problem for t' next attempt. Ahoy!
T' field we used has a waiver o' 5000', but I wanted t' make sure I kept t' flight much lower than that. Aye aye! Avast! RockSim 7 showed an altitude o' about 3800 feet on a CTI H143/G79ss combo. Ya scallywag! Avast, me proud beauty!
Electronics: ARTS board for apogee/main deployment o' t' sustainer, PerfectFlite timer for sustainer motor. Aye aye! Aye aye! T' booster recovers under its own chute by motor ejection. Aye aye! Payload: BoosterVision GearCam taped t' t' side. Crude, arrr, but effective.
Launch day: I racked t' rocket, matey, matey, arrr, set up t' breakwire, me bucko, and twisted t' wires for power. Since I didn't have enough room t' push t' wires back into t' bay, I taped them t' t' outside. Ya scallywag! Ahoy! That be a mistake... Blimey! Arrr! T' launch was beautiful! Straight, and staged on cue. Begad! Aye aye! T' booster chute came out and it drifted down safely. Well, blow me down! Blimey! T' sustainer had a good apogee event(drogueless), but I lost sight o' it while followin' t' booster. Avast! There be no main deployment, arrr, matey, and fellow club members pointed me in t' direction they saw it fall. While walkin' out for recovery, I tried t' figure out what went wrong. Too many sheer pins? Nay enough BP? When I got t' it, arrr, I immediately knew what happened. Arrr! Blimey! T' armin' wires were taped t' t' bottom o' t' sustainer. Avast! When t' apogee separation occured, it ripped t' wires out o' the altimeter, killin' power. Blimey! AUGH! I powered up t' ARTS board later, me bucko, and t' data showed 1700 ft accel, shiver me timbers, me bucko, me hearties, 1500 baro. Ya scallywag! Avast! WAY short o' Rocksim's prediction, me bucko, so t' loss o' power probably scrambled t' data. Well, blow me down! Begad! But other than t' ebay being crunched, and t' booster bein' scorched by t' sustainer motor, ya bilge rat, it didn't come out too bad. I can replace t' ebay and fly it again.

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