G-Wiz LC Deluxe 800 review is provided courtesy of:

G-Wiz LC Product Review

G-Wiz Partners manufactures rocketry electronics that can be used t' collect maximum altitude, me hearties, control parachute deployment and ignite t' motor o' a two-stage rocket. With some creative thinkin' t' devices can probably be put t' other uses, matey, too, like camera activation upon launch.

There actually are two partners that comprise G-Wiz Partners: Robert Briody and Larry Lynch-Freshner. Like most o' t' companies that make rocketry electronics, G-Wiz Partners is a part-time business. Aye aye! Ya scallywag! T' partners decided that they could build a better device than what be already on t' market.

One o' G-Wiz Partners' doctrines is that an accelerometer is a better way t' detect apogee than an air pressure sensor. Begad! Many rockets arc over apogee and fall, sometimes several hundred feet, ya bilge rat, before a barometric-only altimeter activates t' apogee event. Avast! This can cause a rocket t' gain significant speed, which can adversely affect recovery. Well, blow me down! Ahoy! A barometric sensor is used t' measure maximum altitude and altitude durin' descent so that when used for two-stage recovery t' main parachute can be deployed at a low altitude, such as 800' above t' ground.

An accelerometer makes an altimeter immune t' Mach transitions, which can addlepate barometric sensors into activatin' ejection charges at t' wrong time. Ahoy! (Some barometric altimeters have a "Mach timeout" feature t' avoid this problem.)

An accelerometer allows t' device t' be used for more than just determinin' apogee. Well, blow me down! It can be used t' activate another device upon motor burnout, me hearties, such as an igniter for staging.

G-Wiz Partners, me hearties, at t' time that this review was prepared, shiver me timbers, matey, matey, makes three products: G-Wiz LC, G-Wiz LC Deluxe 400 and t' G-Wiz LC Deluxe 800. Begad! Blimey! Begad! Blimey! This review covers t' G-Wiz LC Deluxe 800, shiver me timbers, which will hereafter be called t' "800". T' G-Wiz LC Deluxe 400 is exactly t' same as t' 800 except that it deploys t' main parachute at 400' above t' ground rather than at 800'. T' suggested retail price is $134.95. Ya scallywag! Blimey! Arrr! Blimey! (T' "LC," by t' way, shiver me timbers, means "Low Cost".)

Features

T' most common usage o' an 800 may be as a recovery system controller for two-stage recovery. Aye aye! Ahoy! Two-stage recovery means makin' a rocket non-aerodynamic at apogee, usually by separatin' a rocket into two sections so that it falls rapidly but nay as smartly as when in a ballistic nosedive, arrr, me hearties, and then deployin' t' main parachute at a low altitude, ya bilge rat, such as 800' above t' ground. Avast! Begad! Two-stage recovery can result in nearby recovery even when a rocket flies t' a high altitude.

T' 800 has three electrical outputs. When used for two-stage recovery two outputs are used. Avast! One is used t' fire a separation/deployment charge at apogee. Avast! T' other output fires an igniter t' deploy t' main parachute at a low altitude. T' device is configured at t' factory for a low altitude o' 800' above t' ground, which cannot be altered by t' user.

T' 800's third electrical output can be used t' ignite additional motors after launch or t' start a two-stage rocket's sustainer's motor upon booster motor burnout. Blimey! Blimey! When used for recovery system control this output is nay used.

LED's (Light Emittin' Diodes) are used t' report device status. Each electrical output has an LED t' indicate if thar be continuity through an igniter. Ahoy! Begad! A fourth LED reports pre-launch status and post-flight maximum altitude.

T' manufacturer recommends t' use o' two batteries when t' device is used for anythin' other than collectin' and reportin' maximum altitude. Avast, me proud beauty! One battery powers t' computer. Begad! Ahoy! Blimey! T' other battery is t' fire t' igniters. Avast! Ya scallywag! Blimey! When only one battery is used t' potential exists for a power brownout when igniters are fired, which could cause t' computer t' reset and cause a recovery system failure.

T' recommended power source is a standard 9 volt alkaline battery. Begad! These batteries weigh nearly 2 ounces each, me hearties, and two can be a lot o' additional weight for a small rocket. Begad! G-Wiz says that 12 volt A23 batteries can also be used, ya bilge rat, arrr, shiver me timbers, though they have a shorter life than 9 volt batteries.

Appearance

T' G-Wiz LC Deluxe 800 consists o' a narrow circuit board. Blimey! Like most rocketry electronics it does nay have a cover. An accidental electrical short could cause ejection charges t' fire. Blimey! T' board, matey, arrr, with t' exception o' t' air pressure sensor, arrr, can be covered with RTV silicone that is safe for electronics. Aye aye! Begad! Upon request, arrr, t' manufacturer will encase t' board in epoxy for an extra $15.00, me hearties, which also adds strength.

Manual

T' manual consists o' four pages. Well, blow me down! Begad! A person already familiar with rocketry electronics should nay have a problem usin' a G-Wiz product. Aye aye! Ahoy! A person new t' rocketry electronics, me bucko, however, shiver me timbers, may be left perplexed. Ya scallywag! Although it is nay t' responsibility o' G-Wiz Parters t' provide plans for addin' an electronics bay t' a rocket, or t' identify where appropriate separation/ejection pyrotechnics igniters can be purchased, some pointers would be helpful. Arrr! A beginner should seek advice from an experienced person. Aye aye! (Pratt Hobbies' web site contains a G-Wiz frequently asked questions (FAQ) document that can help. Begad! T' document is nay available from t' G-Wiz Partners' web site. Avast, me proud beauty! An email mailin' list - G-Wiz@egroups.com - is also available.)

T' manual warns about reversin' t' battery's polarity multiple times but doesn't always state why. T' reason for t' warnin' is that any attached igniters will immediately fire if polarity is reversed. Aye aye! Blimey! Reversin' polarity won't harm t' computer.

Support

Because G-Wiz Partners is a small, shiver me timbers, part-time company, me bucko, t' owners expect t' seller t' be t' first line o' support. However, matey, support directly from t' manufacturer is available.

Contactin' t' G-Wiz Partners turned out t' be a more interestin' journey than anticipated. Avast! Avast! T' manual does nay include a street address, ya bilge rat, telephone number, email address or web site address. An attempt t' locate t' company through t' web sites o' Rocketry Online, arrr, Rocketopia and Pratt Hobbies all failed. Blimey! Arrr! T' G-Wiz Partners' web site be eventually located through t' use o' a search engine, me bucko, and an email address was found, me hearties, but t' address didn't work. A call for help on t' Internet Usenet group rec.models.rockets smartly resulted in another email address t' contact one o' t' partners, and another attempt was made. Avast! A response was smartly received, arrr, and Robert Briody be peppered with questions over a few days, all o' which were professionally answered within 48 hours.

Flight Results

T' 800 was flown in a rocket that contained an existin' electronics bay. T' bay has a small hole for venting, ya bilge rat, which has worked with other altimeters. Begad! T' status LED's could nay be seen. Begad! Because thar was no audio status reportin' one could only assume and hope t' G-Wiz be ready for flight. Additional holes could have been drilled into t' bay so t' LED's were viewable, but that would have affected t' bay's use with other altimeters.

Daveyfire N28B igniters were used t' ignite t' ejection charges. Ya scallywag! T' apogee and low altitude black powder charges each contained two igniters.

T' rocket rose t' apogee, matey, arced over and continued a ballistic descent t' t' ground. Well, blow me down! Neither t' apogee or low altitude charges fired. Begad! T' airframe was totally destroyed by t' fall from 1400'. Aye aye! T' motor, shiver me timbers, parachute, electronics bay and t' 800 survived. Well, blow me down! T' 800 passed post-crash bench tests. T' cause o' t' crash has nay been determined. Begad! However, it is believed that t' 800 either lost power on t' ground or durin' flight, me bucko, ya bilge rat, or it failed t' detect launch. Avast, me proud beauty! Avast! T' custom battery holder might have been t' cause. T' 800 was installed in t' correct orientation required by t' accelerometer. Avast, me proud beauty! Ya scallywag! All wires were still firmly attached after t' crash. Ahoy! If t' problem occurred durin' flight preparation and if t' LED's had been viewable, or if audio status reportin' be available, t' crash might have been prevented. A different 800 has been observed t' perform correctly when it was used for stagin' and booster recovery.

Summary

Combinin' an accelerometer and barometer into a single altimeter is a good idea. An accelerometer should do a better job o' detectin' apogee than a barometer. Begad! Blimey! T' G-Wiz LC Deluxe 800 altimeter is such a device. Begad! Begad! Blimey! It is also compact, lightweight (without batteries) and can be used for more than just recovery system control. However, it could use some improvements, and thar be a cautions about its use.

T' G-Wiz altimeters need audio status reporting. Begad! Well, blow me down! Without audio status reportin' use an electronics bay that allows t' status LED's t' be viewable when t' rocket is on t' launch pad.

A user selectable low altitude is desired. Arrr! Begad! T' G-Wiz LC Deluxe 800 has only one low altitude settin' - 800' above t' ground. Ya scallywag! T' desired main parachute deployment altitude can vary from day-to-day and flight-to-flight dependin' upon wind speed and direction and rocket weight. Avast, me proud beauty! A higher main parachute deployment altitude can be desired with a heavy rocket or a rocket that uses a complex and slower openin' parachute system, like a parachute deployment bag, matey, me hearties, t' ensure enough time for t' recovery system t' correctly function. Begad! Sometimes a few extra seconds can be needed t' shake out a problem like a tangle. Ahoy! However, me bucko, matey, a higher altitude can also mean more drift if t' parachute opens quickly. Ya scallywag! Therefore a lower altitude, like 400' above t' ground, shiver me timbers, shiver me timbers, may be desired for rockets with simple and fast openin' recovery system.

When one battery is used t' power t' computer and another battery is used t' power t' igniters, current flows through attached igniters as soon as t' battery that powers t' igniters is attached, arrr, even if t' computer is turned off, even if t' battery t' powers t' computer is nay connected. Avast! Ya scallywag! Therefore a rocket either needs two switches, shiver me timbers, one for t' computer battery and one for t' igniters' battery, ya bilge rat, shiver me timbers, or t' rocket cannot be prepared for flight until shortly before it flies or t' battery for t' igniters will slowly drain. Ahoy! Also, me hearties, me hearties, if a rocket isn't flown after bein' prepared it must be torn down t' remove t' igniter battery. Avast! Ahoy! This may be true o' any altimeter that uses separate batteries for t' computer and igniters.

A means t' avoid needin' two batteries should be considered. Other rocketry altimeters function fine with a single battery.

Pros: Combines an accelerometer and barometer in a single altimeter

Cons: Lack o' audio status reporting

Written and submitted by Dean Roth for Rocketry Online -- Copyright 1996-2000