Assembly of Switch Kits
SMT Designs has bay, axial, and radial switch kits. The bay switch is designed for traditional electronic bays and features an end and bottom mounting. The axial switch mimics a motor closure that allows the use of a standard motor retainer to hold the switch (and the rest of the nosecone or payload electronics bay) in place. The radial switch fits into a coupler tube (CT) and is designed to be installed anywhere in the electronics bay (one or more switches).
The bay switch is really a standalone switch, so it differs from the axial and radial switch kits that share the same basic assembly and wiring.
Bay Switch Assembly
What you need for this
- Prepared switch from the bay switch kit - Switch Preparation
- Switch housing
- Hardware from kit
- Switch
- one 3/6" 2-56 machine screw
- one #2 internal lock washer
- phillips screwdriver
Step 1 - Layout the parts and orient switch, as shown, so actuator will be on the left side.
Step 2 - Install switch into housing with actuator to the left as shown (the left metal tab on the switch slides into a slot).
Step 3 - Attach switch to housing using a #2 internal lock washer and a 3/16" 2-56 machine screw, then tighten screw and dress wires.
This completes the Bay Switch Assembly
Axial Switch Assembly
Note: the example for this assembly is using battery wires that use a JST SYR-02T male connector to connect to a commercial 2S LiPo battery (usually just called a JST battery connector by hobby companies). If you are using SMT Designs 9 volt battery tray, then please prepare the included 9 volt battery connector in your kit for your assembly.
What you need for this
- Prepared switch from the axial switch kit - Switch Preparation
- Two prepared wires (red & black) with #2 18-22 AWG crimp terminals -
- Prepared Battery wires (red & black) with #2 18-22 AWG crimp terminals -
- Axial switch housing
- Hardware from kit
- Switch
- four 3/16" 2-56 machine screws
- four #2 internal lock washers
- phillips screwdriver
Step 1 - Layout the parts
Step 2 - Install switch into housing with actuator down. Use a 3/16" 2-56 machine screw with an internal lock washer to mount the switch.
Step 3 - Use three 3/16" 2-56 machine screws with an internal lock washer to connect the wires as shown. Note: the black wire goes to the top right post; the red wire goes to the bottom right post; one switch wire (doesn't make a difference which one) goes to the bottom right; the other switch wire goes to the bottom left; and finally, the black power wire goes to the upper right and the red power wire goes to the bottom left.
Step 4 - Guide wires down in channel by switch and dress wires for later installation.
This completes the assembly of the Axial End Cap Switch
Radial CT Switch
The Radial Switch Assembly has an optional LED installation section that is easier if done first. Being a person who can not typically hear any internal "beeper", I usually include a LED indicator. Also, when an altimeter does have some visual indication, it is never in the same place as another company's product unfortunately. In my endeavor to create a re-usable and upgradeable product line, a standard visual indicator location is imperative. What this all boils down to, if you want a visual indicator available now or later, the optional LED is a good thing. The SMT Designs kits do not include the parts needed for this installation, if you let me know when you order, I will throw in the #2 hardware and heat shrink tubing that you need for free, the actual LED will be up to you (the LED size is 5mm in diameter - T1-3/4).
Optional LED Installation
Continue to Radial CT Switch Assembly if not installing a LED
What you need for this
- Two prepared wires (gray & violet) with #2 18-22 AWG crimp terminals -
- T1-3/4 LED
- two 3/16" 2-56 machine screws
- two #2 internal lock washers
- phillips screwdriver
- wire cutters
- small needle nose pliers
Step 1 - Cut the LED leads to the same length (the longer lead is the anode, but the cathode side has the flat on the LED itself). Use the needle nose pliers to create a small "U" on the ends of the leads as shown.
Step 2 - Use two 3/16" 2-56 machine screws. Put the screws through the ring terminals and then the internal lock washers - gray wire on the left and violet wire on the right (don't tighten the screws yet - you are going to make the gray wire the anode and the violet wire will be the cathode).
Step 3 - Put the cathode wire under the internal lock washer on the right side and tighten the screw (cathode is the LED flat side).
Step 4 - Turn assembly to have a better view and push LED partway into hole in tab as shown.
Step 5 - Put the anode wire under the internal lock washer on the left side and tighten the screw. To keep anything from snagging, you can bend the LED wires in close to the tab and sides (there is a small wall between the LED and the switch to keep things safe).
This completes the optional LED installation
Radial CT Switch Assembly
What you need for this
- Prepared switch from the axial switch kit - Switch Preparation
- Three prepared wires (red, white, & black) with #2 18-22 AWG crimp terminals -
- Prepared Battery wires (red & black) with #2 18-22 AWG crimp terminals -
- Radial switch housing
- Hardware from kit
- Switch
- four 3/16" 2-56 machine screw
- four #2 internal lock washer
- phillips screwdriver
Step 1 - Layout parts for assembly (optional LED installation not shown for clarity).
Step 2 - Use arming screw threaded into the 6-32 machine screw nut to seat nut in well as shown.
Step 3 - Install switch into housing with actuator to the back. Use a 3/16" 2-56 machine screw with an internal lock washer to mount the switch.
Step 4 - Use a 3/16" 2-56 machine screw with an internal lock washer to connect the black battery wire and the black power wire to the top right post as shown.
Step 5 - Use the remaining two 3/16" 2-56 machine screws with an internal lock washer to connect a switch wire (doesn't make a difference which one), the red power wire, and the white power wire to the bottom right; and the remaining switch wire and the red battery wire go to the bottom left as shown.
