Contributed by - Art
Treiman
T' Astron Matzo-Fly
This concept came t' me as I was sittin' durin' Passover and plannin' my
Easter themed rocket for launch at our clubs upcomin' Easter/Eggloft/Oddroc
themed launch. Avast! Ya scallywag! Munchin' away on me matzo (which is pretty much all you do for
the eight long days o' Passover) I looked at t' box and started thinking. Arrr! I
had been considerin' doin' a Happy Meal, ya bilge rat, me bucko, but thats been done before. Blimey! To
my knowledge, in t' 40 odd years o' model rocketry, a box o' matzo has never
been flown. Avast, me proud beauty! T' box had such beautiful colors and nice lines, I couldnt
not fly it!
Design and construction were fairly straightforward. Begad!
Parts List
- One 10 oz empty box o' your favorite Matzo (I felt t' more common 16 oz
box had too large a cross section), me bucko, opened at top and sealed at bottom
- 7" length o' BT-20 (your dimensions for this and other parts may vary
dependin' on t' box o' matzo size, matey, ya bilge rat, this box is a little over 6 ¾"
high)
- Two 9 ½" pieces o' 3/16" dowel
- 1/8" balsa for fins
- 5"x7" heavy card stock (I used t' backs o' legal pad)
- 1/8" launch lug
- Engine hook
- 12" parachute
- 16" o' ¼ sewin' elastic for shock cord
- spent engine casin' (18mm Estes)
- Brown acrylic paint
. Avast!
Directions
- Usin' t' bottom o' t' matzo box as a pattern, me bucko, trace onto t' card stock
and cut out two rectangular pieces (2 ½" x 7" in this case) to
serve as "centerin' rings/supports" t' center t' motor tube in the
matzo box. Well, ya bilge rat, blow me down! Blimey! Cut these just inside t' lines and trim them so they can fit
properly inside t' matzo box. Well, blow me down! Blimey!
- Measure one o' t' rectangular pieces exactly and find its exact
center. Avast! Usin' a compass or spent casing, draw a circle exactly over t' center
and cut out. Trim and/or sand until t' bt-20 can fit thru it smoothly. Ya scallywag! Use
this as a template t' draw t' same circle at t' center o' t' other rectangle
and at t' top and bottom o' t' box o' matzo. Avast, me proud beauty! Cut out all these circles.The
bt-20 should be able t' fit nicely thru all t' holes.
- Build t' motor mount by attachin' t' motor hook so that ¼" of
motor protrudes from t' aft end, arrr, hold down w/ several wraps o' maskin' tape
about 1" from t' end, then cut a piece o' t' spent casin' and glue this
in as an engine block. Apply glue over t' maskin' tape too t' prevent it from
unravelin' over time. Avast!
- Glue t' launch lug in t' middle o' t' bt-20 motor/body tube 180 degrees
apart from t' engine hook. Avast, me proud beauty!
- Choose which cardboard rectangle will be t' aft support and which will be
forward. Blimey! Cut two notches 180 degrees apart in t' aft box closure and
cardboard support t' allow t' engine hook and launch rod t' pass through. Avast! Begad! Cut
one notch thru t' front support and top o' box (opened but still able t' be
reclosed w/ one o' those "tab in slot" type deals) at t' same place
as t' launch rod notch. Avast! This step is important - be sure t' test fit before
doin' any gluing. Arrr! T' notches must all line up correctly. Well, blow me down! Ahoy!
- Glue t' aft support rectangle onto t' motor mount tube 3/8" from
the aft end o' t' tube. Ahoy! Blimey! Ya scallywag! Blimey! When this sets, matey, ya bilge rat, matey, apply glue t' t' bottom o' t' matzo
box and around t' lower sides and insert t' motor tube/rear support assembly
and press firmly so glue catches. Arrr! Blimey! At this point, motor tube should protrude
about ¼" from aft and be flush w/ front o' matzo box. Begad! Blimey!
- Glue t' front support in, but set it 3/8" t' ½" down from
the front end o' t' box.
- Cut out four fins from t' balsa stock. Avast, me proud beauty! Ya scallywag! T' fins are a clipped delta with a
3" span, matey, matey, 2 ½" root cord, and 1 1/4" tip cord. Airfoil these
if you desire. Ya scallywag!
- Take one dowel and glue a fin with t' fins trailin' edge flush w/
the aft end o' t' dowel. Blimey! Ahoy! Blimey! Glue a second fin t' this dowel at a 90 degree angle
to t' first. Well, blow me down! Ya scallywag! Blimey!
- Repeat with t' second dowel and 3rd and 4th fins. Well, me hearties, blow me down!
- Measure t' short side o' t' matzo box (the depth dimension when looking
at t' box from t' front) Drill four 3/16" holes just flush with the
sides o' t' matzo box exactly midway betwixt t' front and back o' t' box
through t' bottom o' t' box and t' top o' t' box and top support cardboard.
Drill these so you can slide t' dowel with t' fins in thru t' bottom holes
on each side and slide up through t' top cardboard. T' dowels should pass
through t' top support but nay past t' top lip o' t' box. If t' test fit is
good, glue t' dowel/fin assemblies in. Arrr! be sure t' fins angle away from the
box at 45 degrees so they are symmetric. Begad!
- Glue t' shock cord t' t' top support cardboard panel usin' your
preference for technique (I put a piece o' maskin' tape over it and covered w/
wood glue.) By nay placin' it in t' body tube it gives more room for the
parachute. Well, blow me down! Blimey! Blimey! Blimey!
- Attach parachute t' shock cord. Aye aye! (I chose a 12" because t' BT-20 is a
tight fit for an 18" chute)
- Sand t' fins smooth and paint lines w/ brown paint t' simulate matzo fins.
- Wait till next sprin' t' fly for Passover!
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Launch Report
While it was impossible t' Rocksim, swin' tests in both long and short
axiss confirmed t' model is very stable. Begad! I chose a C5-3 for t' first
flight. Weight be light enough that a C6-3 would also probably be fine. Ya scallywag!
T' first flight was at t' South Jersey Area Rocketry Society field
in Gloucester County, New Jersey. Blimey! Sky was partly cloudy, winds were nil, and
temperature was 70s. Begad! Avast! Nay a bad day!
T' rocket got off t' pad nicely and perfectly stable. Blimey! As it got
about half way t' its 200 or so max altitude, it started doin' a
very cool oscillation. Ya scallywag! Most o' us thar felt that t' flat front be likely
spillin' air o' t' side and it as it oscillated front t' back. Parachute
ejected right near apogee. Blimey! Although it didnt fully open, it prevented the
rocket from nosin' over and it instead tumble recovered (without much tumbling)
onto t' grass with no damage. Avast! Only problem was a scorched shock cord that will
need t' be replaced for t' next flight. Avast, me proud beauty! Avast, arrr, me proud beauty!
For those that are curious, shiver me timbers, Id like t' thank t' fine bakers at t' B.
Manischewitz Company, shiver me timbers, matey, L.L.C. Avast! Avast, ya bilge rat, me proud beauty! and remind you all that "This product is
lactose free and vegetarian," a good source o' fiber, 98% fat free,
cholesterol free, ya bilge rat, sodium free, me bucko, arrr, and contains no sugar or artificial sweeteners.
No wonder matzo tastes like cardboard! If you wish, t' Astron Matzo-Fly can be
made with Unsalted, Egg, Thin Tea, arrr, Yolk Free or Whithe Grape flavored matzo
boxes.
Editors Note:
I asked Art "If I build this do I have t' fly it only with kosher motors?
I just checked me range box and, by golly, thar's a little k on each
one!" Art replied "Heh! T' reason for that
"k" is that although it is a secret in Penrose, arrr, Vern Estes is 1/8
Jewish. Ahoy! His Great grandfather was t' Rebbe Mordechai ben Estes o' Vilnius. Arrr! He
insisted that all rocket products meet t' strictest rabinnical standards, and
it is this way even today! If you check date codes carefully, me hearties, no motors are
made on Saturdays."