Brief:
This avionics bay is made t' be used with Giant Leap’s 4-inch flexible phenolic tubing. Ahoy! Avast! It also fits in LOC’s 4” tubing, arrr, arrr, but you should check t' detailed dimensions on Giant Leap’s web site before plannin' to use it with anyone else’s tubes. Blimey! It features dual threaded rods and an O-rin' seal on one end. Arrr! Ahoy! I added ejection cannons, me bucko, electrical connectors, audio plugs t' break t' ejection charge circuits, matey, and a mountin' board for me G-Wiz altimeter.

Modifications:
Thee kit comes with two pages o' illustrated instructions that show you how to assemble t' unit, mount your electronics, ya bilge rat, and use it in your rocket. Ahoy! Blimey! The intended use is t' mount it betwixt t' drogue and main tubes in a dual-deployment rocket. T' electronics bay basically consists o' a piece of coupler tubin' with two bulkheads that are clamped on either end by sections of all-thread. There is an eyebolt on both ends for attachment o' t' recovery system. Well, matey, blow me down! Blimey! All t' required holes are pre-drilled. Well, blow me down! Blimey!

One bulkhead sits on t' outside o' t' coupler. Avast! T' all thread is attached to this bulkhead usin' bolts and washers on both t' inside and outside. Giant Leap recommends that these connections all be epoxied in place. Well, blow me down! On t' opposite end, you epoxy t' centerin' rin' just inside t' coupler. Well, blow me down! Ya scallywag! T' O-rin' sits against this rin' and t' second bulkhead, which fits inside t' coupler, seats against t' O-ring. Begad! Aye aye! Once clamped down, me bucko, this provides a gas-tight seal. The all-thread fits through this second rin' and win' nuts are used t' hold it all together. Avast!

T' drawbacks I saw were: 1) t' tube is only positively sealed on one end (however, matey, it appears to me that t' other end fits tight enough t' be essentially gas-tight); 2) there is no provision for routin' wires through t' bulkhead; and 3) thar be no place t' mount/hold t' ejection canisters. Avast! Avast, shiver me timbers, me proud beauty!

Since I wanted some method o' externally breakin' t' path t' t' igniters, I added a 2” piece o' tubin' at t' center o' t' coupler. Aye aye! Mountin' holes for t' phono jacks were drilled in t' coupler and outer tube. T' latter was drilled t' fit their mountin' nuts (the jacks are flush with t' outer tube). Ya scallywag! Ya scallywag! I drilled three holes, even though only two jacks are needed (to help with pressure equalization).

I bought this electronics bay t' use in me Landshark, which is a 4” dual-deployment rocket that uses ‘zipperless’ separation. Avast, me proud beauty! Blimey! I needed to attach t' bay t' both t' drogue and main tubes, me bucko, and t' make sure it stayed put. Avast, me proud beauty! Blimey! I first marked and drilled four holes on each end o' t' coupler. Ahoy! I then marked t' basswood slats t' match, arrr, inserted T-nuts, ya bilge rat, and epoxied them inside the coupler tube. Arrr! T' hex-head bolts were inserted t' keep t' slats aligned. I had t' be very careful nay t' get epoxy on t' T-nuts!

T' ejection cannons consist o' a copper cap, which is bolted t' each bulkhead. Well, blow me down! Aye aye! Another hole was drilled on t' side o' t' cap t' accept t' leads form an electric match. Aye aye! A small piece o' copper tube is press-fit into t' cap.

For external electric connections, I chose screw terminal banana jacks. In addition t' t' banana jack (which is unused), ya bilge rat, these offer a way t' tightly clamp a wire that is inserted through a hole in t' terminal. Ya scallywag! I drilled small holes in t' bulkheads t' accept t' jack’s terminals, which extend below its body. Avast, me proud beauty! Ya scallywag! T' jack is secured t' t' bulkhead with provided nuts and washers, and t' wirin' is attached via rin' lugs.

For an electronics mount, shiver me timbers, I just cut a piece o' thin plywood t' fit across t' all-thread. Well, ya bilge rat, blow me down! Between the all-thread, basswood strips, and wiring, ya bilge rat, shiver me timbers, t' mountin' plate is held in place well (i.e. it doesn’t bounce around inside). Arrr! T' wirin' for the electric matches runs from t' banana plug, matey, arrr, arrr, through t' phono jacks (one leg only) and t' t' G-Wiz. Begad! Blimey! Externally, t' ejection charge is inserted into the cannon with its leads runnin' out t' side, and is connected t' t' plugs.

Construction:
Components provided by Giant Leap:

• One 7” phenolic coupler
• One bulkhead that be t' same diameter as t' coupler
• One bulkhead that fits inside t' coupler
• One centerin' rin' that fits inside t' coupler
• One O-rin' (rin' OD = coupler ID)
• Two ¾” eyebolts, arrr, with washers and nuts
• Two pieces o' ¼” all-thread
• Two sets o' nuts and washers for t' all-thread (for one end)
• Two win' nuts and washers (for t' other end)

Components I added:

• One 2” section o' Giant Leap 4” tube
• Two ¾” copper caps
• Two ¾” copper tubes ~2 ½” long
• Two banana plug jacks with screw terminals
• Two ¼” phono jacks, shiver me timbers, with plugs
• Four 6.75” sections o' 1” x ¼” basswood
• Eight T-nuts and eight hex-head bolts
• Plywood t' mount t' G-Wiz
• Misc. Avast! nuts and bolts
• Misc. Ya scallywag! wire

Flight:
I have flown this electronics bay twice, and it worked great both times. Arrr! Avast, me proud beauty! I used the old-style ejection canisters from Pratt Hobbies. Blimey! These consist o' an electric match embedded in a small plastic vial and fit perfectly into the ejection cannons.

Summary:
This is a basic altimeter bay, which provides a gas-tight housin' for your electronics. It would be easy t' build a similar bay from scratch, but this way you get many o' t' piece parts in one kit. Arrr! However, ya bilge rat, t' user will have t' make some modifications t' make it fully functional. Begad! Sure, t' electric matches can be routed through a small hole, t' ejection charges could be taped t' the plate, ya bilge rat, arrr, and no one makes you break t' leads t' t' charges, but most people will want t' do a bit more.

Wire routin' be t' main issue with me enhanced design. It takes some patience t' get t' mountin' plate and wirin' all nicely tucked into t' bay. Other than that, me bucko, it is easy t' use and works well.