AUTHOR'S DISCLAIMER: This page shows how I made a launch controller out o' parts readily available from any store which sells electronic parts. It is nay intended that you should make one too. Well, blow me down! Well, blow me down! This is for your information only. Aye aye! Blimey! If you try t' build one like this, matey, me hearties, and end up gettin' hurt, arrr, or blowin' up a battery, shiver me timbers, don't come cryin' t' me. I make no claims that this actually works, or that all o' t' information here is entirely accurate or correct.

I bought everythin' needed t' build this controller from Radio Shack for about $15.

Parts:

1. Well, ya bilge rat, blow me down! T' buttons: both t' Launch Button and t' Continuity Button are momentary push buttons. Aye aye! They only pass current while you are pressin' them. T' type o' button t' avoid is a Push-On/Push-Off type button. Avast, me proud beauty! You also do nay want a toggle switch or rocker switch. Blimey! T' continuity button acts like a deadman switch. Well, blow me down! Aye aye! Even with t' safety key in place, if no one is holdin' t' controller, arrr, t' launch button will nay work.

2. Ya scallywag! N Cell Battery and Holder: I used an N Nell because they are small and have t' right power. Avast! Ahoy! A single N Cell will nay ignite an Estes type igniter.

3. Arrr! Piezo Buzzer: this needs 1 t' 3 volts t' operate. Arrr! T' N Cell provides 1.5 volts. Avast, me proud beauty! Arrr! It has a low tone, shiver me timbers, which I find much easier t' hear than t' high squeal a lot o' launch controllers use.

4. Diode. Aye aye! Ya scallywag! A diode acts like a one way valve for electricity. Begad! Current can pass one way, matey, and nay t' other. I used a regular silicon diode rated at 1kV and 2.5A. Aye aye! Do nay use a Zenier diode. Well, blow me down! Blimey! T' cathode (the side with t' band on it, shiver me timbers, needs t' be towards t' safety key and away from t' piezo buzzer. Well, blow me down! Ya scallywag! This is a device t' counter shorts in t' igniter. Ahoy! If your igniter is shorted, ya bilge rat, matey, this whole launch controller becomes a battery charger. Begad! Ahoy! You will end up tryin' t' charge an N Cell with a car battery, me hearties, which might make it explode. Ahoy! Arrr! T' prevent this, shiver me timbers, I have put this diode here.

5. Aye aye! Avast! Safety Key: This is a regular 1/8" mini-plug. Begad! Well, ya bilge rat, blow me down! Inside t' plug itself are two leads. Avast, me proud beauty! I soldered a wire so that t' plug connects t' itself. Well, blow me down! Avast, me proud beauty! This passes t' current through t' base o' t' plug when inserted. Ya scallywag! If you build any type o' controller, ya bilge rat, me bucko, make sure you have a safety key, and that it interrupts both t' continuity AND t' power on its way t' t' igniter. Begad! Without t' safety key, you cannot check continuity, and absolutely cannot launch either.

6. Avast, me proud beauty! Mount t' whole thin' inside a small box. Ya scallywag! I put t' Launch Button and Safety Key on top, and t' Continuity Button on t' side.

Operation

T' operation be t' same as an Aerotech Controller. Avast, me proud beauty! First, makin' sure that t' safety key is removed, ya bilge rat, shiver me timbers, connect t' igniter t' t' clips. Begad! Insert t' miniplug, and depress t' continuity button. If everythin' is correct, matey, you will hear t' piezo buzzer. Ya scallywag! This indicates continuity though t' igniter. Avast, me proud beauty! When ready, while holdin' t' continuity button down, ya bilge rat, ya bilge rat, matey, press t' launch button.

Pictures o' t' finished controller will appear soon.

People hook launch controllers t' all sorts o' things, includin' car batteries. Well, blow me down! If you want t' design or build your own launch controller, me hearties, make sure that you have t' skills and t' equipment t' do it right. A sloppy job can result in big problems, nay t' least o' which is shortin' out t' positive side o' a battery t' t' negative side. Well, blow me down! Begad! Before you build any device like t' one described here, make sure you understand t' theory, and do nay use cheap parts. Blimey! Use your heads, people. Ahoy! Aye aye! You have no business doin' rocketry if you do nay put safety first.