Stubbies Rocketry Page

The Sonic Locator is constructed from a Radio Shack personal alarm system, part number 49-417, at a cost of about $10.00. Other R/S items are 1 submini phone jack 3/32" or 2.5mm in size, part number 274-292A, at a cost of about $1.25, and a 9volt long life Nickel metal hydride rechargeable, with an output of 150 mAh, part number 23-526. If you wish, you can add a cds cell in lieu of phone jack to complete the circuit when the locator is exposed to a light source. Other items are Plastruct styrene rod, part number MR -100, 2.5mm in diameter at a cost of about $1.40, and 2 snap rings, part number 1330, at a cost of about $1.90 I found these items for retaining the top lid at a NAPA auto parts store. A PVC tube coupler is used as the housing, with a D ring to link it into the recovery system, both found at a local hardware store. A 17" x 8.5" x 1/8" sheet of SIG ABS plastic was found at my local hobby shop at a cost of about $3.35 to make both bottom & lid for the housing.

Results: The sonic locator built here is louder - 120 Db vs.110 Db, cheaper in cost - $19.00 vs. $29.95,

has less weight - 2.8 vs. 6.0 ounces, and is smaller in size - 4.5" vs. 6.5" in length, than the Transovle Transbeep.

I wish to thank Scott Eakins who submitted the article to Rocketry Online's Tech Series where I drew my ideas from.

The Flight computer system I have chosen to use is a G-Wiz LC Deluxe 800 Some of the reasons I have chosen to use it are:

1. It uses an accelerometer over a barometric sensor which can be prone to false readings during Mach transitions. This may lead to early recovery system deployments, resulting in shredding or zippering of your beloved rocket.

2. It's small, 4.0" x .7" x .6", and lightweight, 1 ounce without batteries. It can handle the current flow for electric matches. You can if necessary add two 9 volt batteries for more amps & current flow. It also has 3 firing circuits - 1^st. is staging, 2^nd. is apogee recovery deployment, and 3^rd. is final chute deployment.

Update Nov 27 2000 After surfing rocket sites if found a good article on current & amps needed to fire different types of electric matches and igniters. Done by Frank Broidy and his son Scott

q1. Rubber band shock cord into two, 6 inch loops either side of center parachute hook up.

qb. Talc upper section bore, secure parachute to shock cord talc chute, fold, and place in upper section.

qc. Attach upper end of shock cord to nosecone. Seat nosecone into upper section.

q1. Safety the G-wiz flight computer by inserting open circuit dowel into ground safety jack & removing all batteries and wiring harnesses from flight computer.

qa. Set electric matches into charge canisters and holders, Qty. 2. After installing electric matches into charge canisters re-shunt and cover bare ends.

qb. Measure black powder FFFFG, Qty. of .02 to .03 grams, into the charge canisters, place paper disc on top of black powder to seal BP from tracking powder, add xxx grams tracking powder to canisters and seal with orange plastic covers. Convert xx Grams x 15.43 = xx Grains or xx Grains x .0648 = Grams

qc. Disconnect all batteries and wiring harnesses from G-wiz flight computer. Before installing charge canisters and electric match, hook up to Output Terminals of flight computer.

qd. Trim wire to length, strip and hook up upper section charge canister to Terminal Block # 5 & 6 or Pyro ch. 3

qe. Trim wire to length, strip and hook up mid section charge canister to Terminal Block # 3 & 4 or Pyro ch. 2

q2. Check lower piston & strap for damage. Rubber band piston strap into 6 inch loop.

qd. Align flight computer with window on rocket to allow visual confirmation of computer power-up at launch pad.

q1. Rubber band shock cord into two, 6 inch loops either side of center parachute hook up. Attach upper end of shock cord to lower piston in lower mid section. Prep sonic locator by installing fresh battery, test by pulling arming pin. If sound is made, device is working. Re-arm locator by replacing arming pin. Attach at center point of shock cord

qa. Talc lower end of mid section bore, secure parachute to shock cord talc chute, fold, and place in the lower end of mid section.

qb. Attach lower end of shock cord to Sustainer Fin can. Eyebolt. Seat fin can into lower end of the mid section.

qMid Section Complete

Sustainer Fin Can Motor Assembly

qc. Fill out flight card and indicate whether or not the flight is for cert. level.

qb. Have igniter, flight card, rocket and rocket simulation flight data for RSO.

qa. Place igniter into motor and secure it to rocket. Load rocket onto launch rail

qb. Connect leads to igniter. ARM G-wiz flight computer by pulling open circuit dowel out of normally closed ground safety jack

qc. Check Pyro Status LED for Continuity channels #2 & #3 a and check Status LED for proper condition: 2 flashes = Staging 1 flashes = Clustering

Notes _______________________________________________________________________________

____________________________________________________________________________________

Electronics

qMid Section Complete

Sustainer Fin Can Motor Assembly

Next Page

Notes _______________________________________________________________________________