54mm, 65mm, 75mm Hybrid Bay Kits

The Hybrid Bay Kit is a complete set of SMT Designs parts that can be assembled into fully functional electronics bay (customer supplies coupler tube, device, & battery).
Manufacturer: SMT Designs
SKU: BKC-20587
Shipping date: 5 - 40 days depending on order size

Note: This is not an all encompassing list. Manufacturers do change their

products, add new materials, and can be different between sizes of tubing.

Please measure to assure a proper fit.

Thin Wall (select if wall thickness is 1.1mm or under)

Mach1 BT55, BT60 - 1.1mm

Normal Wall (select if wall thickness is over 1.1mm

and 1.6mm or under)

Blue Tube 2.0 - 1.6mm

LOC Cardboard - 1.52mm

PML Phenolic - 1.5mm

Thick Wall (select if wall thickness is over 1.6mm

and 2.1mm or under)

MadCow - 1.9mm

Rocketry Warehouse (Proline) - 2.1mm

Ultra Thick Wall (select if wall thickness is over

2.1mm and 2.6mm or under)

LOC (larger tubes) - 2.6mm


Single slot tray supports single and dual deploy in at least a 5 inch long coupler tube

Mid sized tray supports any configuration in at least a 6 inch long coupler tube

* Note: mid sized does not support some larger altimeters such as the RRC3

Two Slot tray supports any configuration in at least a 7 inch long coupler tube


9 Volt - 47.4 x 25.8 x 16.7mm / 1.86 x 1.02 x 0.66"

2S E-flite 30C 280mAh LiPo - 39 x 20 x 13mm / 1.5 x 0.8 x 0.5"

1S Sparkfun 110mAh LiPo - 15.5 x 27.0 x 4.2mm / 0.61 x 1.07 x 0.17"

1S Sparkfun 400mAh LiPo - 26.5 x 36.9 x 5mm / 1.06 x 1.48 x 0.2"

2S Turnigy Nano-Tech 35-70C & 45-90C 300mAh LiPo - 45 x 18 x 12mm / 1.7 x 0.7 x 0.5"

1S Turnigy Nano-Tech 35-70C 750mAh LiPo - 45 x 25 x 9.2mm / 1.7 x 1.0 x 0.36"

2S Venom Fly 30C 300mAh LiPo - 38 x 20 x 12mm / 1.5 x 0.8 x 0.5"


Kevlar cord loop good to 200 pounds

Eye Bolt good to 500 pounds


The Hybrid Bay Kit is a complete set of SMT Designs parts that can be assembled into fully functional electronics bay (customer supplies coupler tube, devices, & batteries).

The electronics bay is a completely self-contained bay with an accessible through-wall arming switch, charge canisters (if needed), shock cord attachments for a recovery system (if needed). The bay is available to support Mach1 thin wall fiberglass, 1/16 inch thick walls such as Always Ready Rocketry Blue Tube 2.0, and thick walled tubing such as Rocketry Warehouse.

The bay includes bay mounting on both ends to allow for a wider variety of construction options.

Additional device support and battery carriers are available, as well as, replacement charge canisters.

The bay can be ordered in any configuration from no deployment connections, single, dual and redundant deploy.  A bay with no deployment connections could be used as a tracker or for other electronic devices for example.  Single deploy can be used for nosecone bays or a bay designed to replace standard motor ejection. Please contact SMT Designs if a nosecone bay with dual deploy is needed for the single ended bay.

For all configurations, the number of deployment channels is selectable (two isolated connections per channel - four maximum channels).

The number of charge canisters for deployent bays can be set to none, one, two, three or four. While the charge canister mounts are proprietary to SMT Designs, we do recognize that there are other options available for deployment such as cable cutters and CO2 ejection systems, so charge canisters may not be useable in all bays.

Important notes:

  • redundant (two altimeters ) bays requires two module slots, so the minimum length coupler tube for redundant bay is 7 inches.  If a redundant bay is needed for something shorter, then please get in touch with SMT Designs to discuss solutions.
  • The threaded rods included with be a length required for either the specifc bay length or to support the longest adjustable bay that is ordered. They may need to be shortened if the tube is shorter.  Shortening them can be done very easily with one of the crimp tools that have the feature to cut machine screws. A sander or file can be used to chamfer the rod ends.
  • hard plastic centrifuge tubes should not be used as an insert into a charge canister.  The hard plastic actually becomes shrapnel whne the black powder is ignited which can damage the canisters as well as the rocket.
  • The AltusMetrum Telemetrum platform is available for just the device or with a battery holder for the 1S 850mAh LiPo available from AltusMetrum.
  • The EggFinder Apogee carrier is available for just the device or with a battery holder for the 1S 150mAh LiPo available from EggTimer.
  • LiPo battery use requires a very specific size battery. The manfacturer and model is listed with the various battery carriers that are available.


  • One or two selected device platforms or carriers
  • One or two selected battery carriers
  • One Switch end cap
  • One mounting ring
  • One end cap
  • One tray with one or two modular slots
  • Customer selected number of deployment channels
  • Customer selected number of charge canisters
  • Customer selected number of Shock cord ties (kevlar or eye bolts)
  • wire and all necessary hardware to assemble the bay

Customer Supplied Parts

  1. One coupler tube (single module requires at least 5 inches and double module at least 7 inches)
  2. Supported devices
  3. Supported batteries


  • Diameter 54mm/2.125 inch
  • 65mm/2.56 inch
  • 75mm/2.95 inch
  • Length 5.0 inch Bay (charge canisters - end to end) 187mm/7.375"
  • 5.5 inch and up (charge canisters - end to end) 64.6mm/2.5 inches plus coupler tube length
  • Weight 7.0" Bay (no battery or device) 200g/7oz
  • Charge Canister Volume - up to 2.5 grams of 4F Blackpowder
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