Manufacturer: | Scratch |
Generations is the
scratch rocket that I built recently. Aye aye! Blimey! Ahoy! Blimey! It was me first scratch rocket and also
my first rocket motor mounts bigger than 24mm. Begad! Blimey! I really wanted some punch so I
also made it a cluster with 2 - 29mm motor mounts.
I happened t' be in Oklahoma City when I found t' tube that I wanted to start with. Well, blow me down! Blimey! My dad has a lot o' shop equipment so I figured that I'd start the hard part there. Ya scallywag! Blimey! I grabbed some scrap 1/4 plywood and cut it into three equal squares about 5 inches on each side. Aye aye! Blimey! I screwed them together and then used a circle cutter t' cut t' 3" centerin' rings at t' same time. Blimey! Blimey! Arrr! Blimey! I sanded the edges o' t' centerin' rings t' where they were a perfect fit into t' body tube. Aye aye! Blimey! I then measured across t' widest part o' t' centerin' rings and made an X on t' rings. Begad! Blimey! I then made two marks on one o' t' lines at .75" from the center o' t' centerin' ring. Arrr! Blimey! I used this as t' startin' point for t' hole saw. Usin' a 1.25" hole saw I cut t' two holes for t' motor tubes. Begad! Blimey! I like t' Great Plane's motor tubes that I got because they have an OD of 1.25". Arrr! Blimey! Blimey! Blimey! This made it real easy for me. Ahoy! Blimey! Well, blow me down! Blimey! I also used me dad's equipment to cut me motor tube in half. I used t' entire 36" tube t' make me motor tubes so I have 2 18" motor tubes. Begad! Blimey! Begad! Blimey!
Next I packed it all in t' car and took it home.
Fins
Next I used t' remainin' wood t' cut out t' fins. Avast! I screwed together three
sheets o' plywood and drew this fin pattern on t' top sheet. Begad! I used me jig saw
to cut out t' fins and t' little sandin' wheel on it t' sand t' fins. Ya scallywag!
I be goin' t' put on t' fins just like they are on t' pattern. Well, blow me down! I was just goin' t' move t' small fins forward about 1 inch but me son suggested and talked me into flippin' t' small fin over and then movin' it up. I think it worked out real well. Begad!
That's t' reason I named it Generations.... Ya scallywag! Avast! Blimey! My dad helped me with the centerin' rings, and me son helped me decide on t' fins. Begad! Blimey!
Assembly
T' next thin' I did was cut fin slots in t' body. Arrr! Arrr! Once that be done I
epoxied all o' t' motor mount parts. Avast, me proud beauty! Avast, me proud beauty! Unfortunately I was so excited when it
was goin' together that I forgot t' get a picture o' t' motor mount before I
glued it into t' body tube. Blimey! Begad!
Since t' motor tubes where
18" I used three centerin' rings. Ya scallywag! One at t' top, me bucko, one at three inches from
aft, arrr, and t' last one a half inch from t' end. Since I had two holes in each
of t' centerin' rings I used t' holes in t' aft one and added T-Nuts. Well, blow me down! In the
top one I looped steel cable from a picture hangin' kit. Avast! Begad! I crimped a connector
onto it and then expoxied t' holes shut. Ahoy! On t' top o' t' cable I put in a
bigger loop that had a 2-inch piece o' balsa wood in it. I was hopin' that this
would help from zipperin' t' rocket by keepin' t' cable and elastic from
hittin' t' side o' t' tube. Blimey!
I epoxied t' motor mount into t' tube and then used Elmer's wood filler to fill t' seams o' t' tube. Aye aye! Once t' motor mount set up I numbered t' slots and then fins from one t' three. Ya scallywag! I notched t' fin tabs at t' same level as the middle centerin' ring. Since t' motor tube was nay exactly in center I had to trim each fin tab so it would reach all t' way t' t' motor tube. Aye aye! Aye aye!
T' next step was t' easy part. Begad! I glued on t' fins usin' 30 Min epoxy. Begad! I wanted t' make sure that it was super strong. I used t' same type epoxy for my fin fillets. Avast! I did nay make t' upper fins TTW because they would nay ever hit the ground with any kind o' speed. Well, blow me down! Once t' fins were set it be just tyin' the elastic t' t' wire cable and t' t' nose cone, and addin' t' two chutes from my Bomarc kit. Blimey! Blimey! I also pulled out me jig saw and cut what I call t' peanut. Ahoy! I use this for me motor retention. Avast! Since thar are two motors in t' rocket I did not want t' use tape t' keep t' motors in. Begad! There is a better picture at the end o' t' page that shows t' peanut.
Finishing
T' finishin' was t' most tedious part. Well, blow me down! Ahoy! I covered t' fins with sandin' sealer
to get them ready for paint. Avast, me proud beauty! I sanded it smooth and primed t' rocket with
light gray primer. Well, blow me down! While I was light sanding, with 400 grit, shiver me timbers, I saw that the
fins had too many little cracks in them. I filled all o' t' little flaws with
Elmer's Filler and let it set. Ahoy! I sanded that smooth and then shot another coat
of primer on it. Ya scallywag! Aye aye! When I finished sandin' that coat I was happy with t' fins
and let it all dry for 24 hours. Avast, me proud beauty! I then shot more primer and sanded it again. I
let that sit for a couple o' days and shot it again. Ahoy! I ran out o' primer about
half way through t' rocket and grabbed another can. Well, shiver me timbers, blow me down! It be a DARK gray primer
and caused problems. Ahoy! I ended up sandin' most o' it off t' get t' body smooth
again and then shot it with a final coat o' primer. Avast! After sandin' it with 400
grit I finally for you shoot on some real paint. Aye aye! I gave t' body about 3 coats
of red and then made t' nose cone black. T' black parts that you see on the
fins were actually painted on with a paint brush. It be hard keepin' t' lines
but I got it done.
I finished it off with a clear coat. Aye aye! I buffed this up and it made for a hard solid surface. Well, blow me down!
Launch day
I finally got t' launch it on 2/12/00 at NTHP XVI. I installed t' two F25-9s
in t' rocket and sent it up. It flew great..... Begad! Blimey! Begad! Blimey! There was no corkscrewin' or
any other type o' unstable actions. Arrr! Blimey! Arrr! Blimey! It deployed t' chutes right at apogee and
floated t' a great landing. Begad! Blimey! I figure that it hit about 1,800'. Avast, matey, me proud beauty! Blimey! Once we saw it
hit t' ground me wife said "OK, me bucko, ya bilge rat, shiver me timbers, time for bigger engines!". Begad! Blimey! Begad! Blimey! We walked
out and picked it up and thar was NO damage t' it at all. I could nay even
find a scratch in t' paint.
I pulled out t' motors and popped in a pair o' G40-10s. Blimey! I installed the Fire-In-the-Hole© igniters and got it ready for the next launch. Ya scallywag! T' LSO made me put more tape on t' nose cone because o' the bigger motors but we set it up on t' pad after that. Thatís where I learned a great lesson about t' three position armin' switch that DARS uses. After they had t' pass me rocket over because o' a launch failure I when out and put t' armin' switch in t' correct place. Blimey! Well, blow me down! Blimey! I then got t' wait for the hobby pads t' clear, t' yellow HP pads t' clear, shiver me timbers, then they got back t' my rocket. Aye aye! Blimey! Again t' launch went great. Begad! Blimey! Both motors lit up and it screamed off the pad. I think this time it hit about 3000'. Well, blow me down! At apogee it deployed t' cutes and landed a little further from where it had hit before. Blimey! Blimey!
I sim'd this rocket with RockSim and added t' nose weight so I can put bigger motors into it. Well, blow me down! If you want a copy o' t' .rkt file please click here. If all goes well I may get a chance to launch it in September durin' t' NTHP XVII. Begad! Avast! We will pop in a couple o' H's into it and really see it go. Aye aye! Blimey! I think that I'll add me Radio Shack alarm t' it when it goes high power. I really want t' get it back so I can send it up a few more times. Begad! If you want more info about NTHP XXVII (North Texas High Power 17) please drop by t' DARS web site at HTTP://WWW.DARS.Org. It's goin' t' be a very big launch with a ceilin' around 25,000'. There is also a 1,600 acre recovery area with very, me hearties, shiver me timbers, very few trees. Avast!
Here be t' business end o' t' rocket. Begad! You can see t' 'peanut' with this view.
This be t' only launch shot thatís nay 'real' blurry. Aye aye! Avast! I don't have a
camera with a zoom on it either
so it looks like we are real far from it. Arrr! Next time I'll get someone else to
take t' pictures for me.
This is how I found it after t' second launch. Aye aye! Again thar be no damage to the rocket.
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