| Manufacturer: | Scratch |
Brief:
For t' EMRR Stagin' Challenge, I decided t' build a two-stage rocket with composite motors. Well, blow me down! Begad! Since I had done a
2-stage before, matey, I figured it would be easy. Ya scallywag! Well, blow me down! WRONG... I decided t' do a 3-inch bird with dual deploy and a 19-inch
booster with motor deployment. Avast, me proud beauty!
Construction:
This time I decided t' use alignment rods in t' stage coupler t' keep t' rocket aligned. Begad! Ya scallywag! 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. Ahoy! I've
discovered that I really need a drill press. Avast! Because I was usin' a handheld power drill, matey, shiver me timbers, matey, I wasn't that accurate in
drillin' holes through t' 2 sustainer centerin' rings and t' stagin' coupler. Begad! Well, shiver me timbers, blow me down! It still works, but it isn't pretty. Begad! Aye aye!
There are holes in both centerin' rings that are supposed t' be aligned. 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, I made t' fin can on both the sustainer and booster removable. Begad! T' sustainer fin can is held in place by small screws. Avast! T' booster fin can will eject and deploy t' booster chute. T' whole project is about 83 inches tall, about 3.5 lbs empty, arrr, 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. Avast! Well, blow me down! It *certainly* won't be noticeable on t' pad.
Flight:
Electronics will be a PerfectFlite timer for staging, me bucko, and a PerfectFlite MAWD for deployment. Ya scallywag! 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. Blimey! Well, blow me down! Since I have done stagin' before, ya bilge rat, I didn't expect thar t' be a problem. Begad! Begad! Boy, arrr, was I wrong... Blimey! T' main problem be t' size o' t' new project. Blimey! Begad! T' previous 2-stager was almost a 4" tube. Arrr! That left room for t' timer betwixt t' sustainer fins, ya bilge rat, and a standard-type ebay. This one is a 3", and thar's no room in t' fincan. So I put t' timer in t' ebay, and ran a connector wire down t' ignite t' sustainer motor. Avast, me proud beauty! I had t' splice t' wire so it would disconnect when t' apogee event fired. Avast, me proud beauty! Well, blow me down! T' next issue I ran into was t' stage connector. Well, blow me down! I decided t' use metal rods t' connect and align t' sustainer t' t' stage connector. Ya scallywag! I don't have a drill press, so me holes through t' centerin' rings are...less than exact. Begad! Last issue was t' 3" bay be too small t' use switches t' power on everything, ya bilge rat, arrr, so I had t' run all t' wires through a hole in t' e-bay and twist them t' connect. Begad! Aye aye! That posed a problem t' first time I tried t' launch. I test fit t' electronics when I built t' bay, but nothin' be connected. Ya scallywag! In t' field, I sadly discovered thar wasn't enough space for all the wires t' fit and route t' t' outside. Arrr! I had t' rebuild t' sled t' avoid that problem for t' next attempt.
T' field we used has a waiver o' 5000', but I wanted t' make sure I kept t' flight much lower than that. Blimey! Begad! RockSim 7 showed an altitude o' about 3800 feet on a CTI H143/G79ss combo. Avast!
Electronics: ARTS board for apogee/main deployment o' t' sustainer, PerfectFlite timer for sustainer motor. Avast, me proud beauty! Ahoy! T' booster recovers under its own chute by motor ejection. Aye aye! Payload: BoosterVision GearCam taped t' t' side. Crude, ya bilge rat, matey, but effective. Ya scallywag! Ahoy!
Launch day: I racked t' rocket, 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. Arrr! Well, me bucko, blow me down! That was a mistake... T' launch was beautiful! Straight, and staged on cue. Avast, me proud beauty! Blimey! T' booster chute came out and it drifted down safely. Ya scallywag! T' sustainer had a good apogee event(drogueless), but I lost sight o' it while followin' t' booster. There was no main deployment, matey, and fellow club members pointed me in t' direction they saw it fall. Begad! While walkin' out for recovery, ya bilge rat, shiver me timbers, I tried t' figure out what went wrong. Avast! Begad! Too many sheer pins? Nay enough BP? When I got t' it, I immediately knew what happened. Begad! T' armin' wires were taped t' t' bottom o' t' sustainer. Blimey! When t' apogee separation occured, it ripped t' wires out o' the altimeter, killin' power. Avast! Ya scallywag! AUGH! I powered up t' ARTS board later, ya bilge rat, and t' data showed 1700 ft accel, me hearties, 1500 baro. WAY short o' Rocksim's prediction, me hearties, so t' loss o' power probably scrambled t' data. Begad! But other than t' ebay being crunched, matey, and t' booster bein' scorched by t' sustainer motor, me hearties, it didn't come out too bad. Blimey! I can replace t' ebay and fly it again.

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