Scratch - The Astron Matzo-Fly {Scratch}

Descon The Astron Matzo-Fly

Scratch - The Astron Matzo-Fly {Scratch}

Contributed by Art Treiman

Manufacturer:

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! 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! Avast! I had been considerin' doin' a Happy Meal, matey, but that’s been done before. Aye aye! To my knowledge, in t' 40 odd years o' model rocketry, a box o' matzo has never been flown. Blimey! Begad! T' box had such beautiful colors and nice lines, I couldn’t not fly it!

Design and construction were fairly straightforward. Ahoy! 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), 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, 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

. Aye aye!

Directions

Usin' t' bottom o' t' matzo box as a pattern, 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. Begad! Aye aye! Cut these just inside t' lines and trim them so they can fit properly inside t' matzo box. Arrr! Avast, ya bilge rat, me proud beauty!
Measure one o' t' rectangular pieces exactly and find it’s exact center. Usin' a compass or spent casing, me hearties, draw a circle exactly over t' center and cut out. Trim and/or sand until t' bt-20 can fit thru it smoothly. Ahoy! 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. Ahoy! 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, shiver me timbers, ya bilge rat, hold down w/ several wraps o' maskin' tape about 1" from t' end, me hearties, then cut a piece o' t' spent casin' and glue this in as an engine block. Ya scallywag! Aye aye! Apply glue over t' maskin' tape too t' prevent it from unravelin' over time. Arrr!
Glue t' launch lug in t' middle o' t' bt-20 motor/body tube 180 degrees apart from t' engine hook. Begad! Avast, me proud beauty! Blimey!
Choose which cardboard rectangle will be t' aft support and which will be forward. Arrr! Begad! 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. 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. Blimey! Blimey! This step is important - be sure t' test fit before doin' any gluing. Well, blow me down! T' notches must all line up correctly. Ya scallywag!
Glue t' aft support rectangle onto t' motor mount tube 3/8" from the aft end o' t' tube. When this sets, 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. Aye aye! At this point, motor tube should protrude about ¼" from aft and be flush w/ front o' matzo box. Blimey!
Glue t' front support in, but set it 3/8" t' ½" down from the front end o' t' box. Blimey! Begad! Blimey!
Cut out four fins from t' balsa stock. T' fins are a clipped delta with a 3" span, 2 ½" root cord, and 1 1/4" tip cord. Arrr! Ya scallywag! Blimey! Airfoil these if you desire. Aye aye! Blimey!
Take one dowel and glue a fin with t' fin’s trailin' edge flush w/ the aft end o' t' dowel. Ahoy! Blimey! Blimey! Blimey! Glue a second fin t' this dowel at a 90 degree angle to t' first. Ahoy! Blimey! Blimey! Blimey! Blimey! Blimey!
Repeat with t' second dowel and 3^rd and 4^th fins. Ahoy!
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. Arrr! Begad! T' dowels should pass through t' top support but nay past t' top lip o' t' box. Begad! Avast! If t' test fit is good, me bucko, glue t' dowel/fin assemblies in. Blimey! Avast! be sure t' fins angle away from the box at 45 degrees so they are symmetric.
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.
Attach parachute t' shock cord. Begad! (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!

Launch Report

While it be impossible t' Rocksim, arrr, swin' tests in both long and short axis’s confirmed t' model is very stable. Aye aye! I chose a C5-3 for t' first flight. Weight was light enough that a C6-3 would also probably be fine.

T' first flight was at t' South Jersey Area Rocketry Society field in Gloucester County, me bucko, New Jersey. Avast, me proud beauty! Blimey! Sky was partly cloudy, shiver me timbers, winds were nil, and temperature be 70’s. Ya scallywag! Blimey! Blimey! Blimey! Nay a bad day! Blimey!

T' rocket got off t' pad nicely and perfectly stable. Ahoy! Blimey! As it got about half way t' it’s 200’ or so max altitude, it started doin' a very cool oscillation. Ahoy! Ya scallywag! Most o' us thar felt that t' flat front was likely spillin' air o' t' side and it as it oscillated front t' back. Ahoy! Begad! Parachute ejected right near apogee. Well, blow me down! Begad! Although it didn’t fully open, me bucko, it prevented the rocket from nosin' over and it instead tumble recovered (without much tumbling) onto t' grass with no damage. Blimey! Only problem was a scorched shock cord that will need t' be replaced for t' next flight.

For those that are curious, I’d like t' thank t' fine bakers at t' B. Manischewitz Company, L.L.C. and remind you all that "This product is lactose free and vegetarian," a good source o' fiber, 98% fat free, cholesterol free, sodium free, shiver me timbers, 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, matey, Yolk Free or Whithe Grape flavored matzo boxes.

Editor’s 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, shiver me timbers, 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. His Great grandfather be t' Rebbe Mordechai ben Estes o' Vilnius. Aye aye! He insisted that all rocket products meet t' strictest rabinnical standards, ya bilge rat, me hearties, and it is this way even today! If you check date codes carefully, no motors are made on Saturdays."

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