Altimeter Switch Ideas?

Have a small bay that is 2.6x6 inches and the sled inside is totally covered with an altimeter on one side and the other side has two lipo batteries filling it up (one for altimeter and one for charges). Even with one LiPo a majority of space is taken up due to the length of the LiPo (1200mAh).

There is a 1 inch peace of airframe on the coupler of the A-bay that has holes in it for the altimeter air pressure that are 1/16" in size. Trying to find a creative way of adding at least one switch if not two, to turn off the altimeter and the charges.

Also concerned about sending the rocket past mach, so am concerned about anything that would be exposed to the surface that might be plastic (ie may melt or deform due to heat, may be over concerned here, but am concerned).

Any suggestions or ideas?

What altimeter is it?

Why do you need such a big battery for?
Use an 850 or 350 mAh.

Twist and tape works for me.

JD

AIM XTRA is the altimeter, larger battery for longer life in the event I have trouble locating it, want it to last. They also recommend a 1000mAh or larger. Was going to piggy back two of the batteries, one for computer and one for charges. Could possibly get by with a smaller one for charges, but won't make a difference in space for switch due to length of the larger one.

How much past Mach? You are not going to run into problems until you get in the 2's. The only real option if you don't have the room for anything else is the twist and tape method as JD mention. There is most likely more room in there than you realize. You could probably build a elevated bridge over your altimeter for a magnetic switch or small screw switch and still clear the 2.6.

grouch said:

How much past Mach? You are not going to run into problems until you get in the 2's. The only real option if you don't have the room for anything else is the twist and tape method as JD mention. There is most likely more room in there than you realize. You could probably build a elevated bridge over your altimeter for a magnetic switch or small screw switch and still clear the 2.6.

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Most likely going to go with the screw switches attached to the side of the ebay, they seem the most logical for me from what I have seen others do in the forum. I should be able to seal them pretty good and they would work with any altimeter I put in there.

In my BLUE BY YOU 5 inch x 2.6 inch sled mounted batts top and bottom of rear of sled leaving the middle open.

Mounted std shruter rotary switch on backside between batts to align with switchband hole.

Made a switch stand off by cutting 1/2 inch estes spent c motor and threaded switch in. Took felt pin and blacked bottom of tabs below switch and touched them where I wanted to mount in sled . Then took small drill bit and drilled out the lines by drilling a few holes ..then used bit to ream ridges separating holes til I had slots. Switch whould sit flush and its bottom and engine case should seat against sled. You can test fit altimeter to confirm it clears the tabs poking though although on mine I had to bend tabs against sled to lay flat.

Once you are happy with the fit , unscrew the switch from engine case spacer . Mix some 5 min epoxy and place a bit inside case spacer and install switch again. After curing mount switch and spacer through tab holes and glue/ epoxy spacer only to sled. After drying carefully switch on to confirm mechanism is free internally. Ideally switch is glued to spacer and spacer is glued to sled.

On mine after confirming it would turn on and off and pass continuity after mounting I bent tabs over , soldered wires and retested operation. Then mixed a bit more epoxy and encapsulated twbs and wire headers to sled.

Kenny

I use a small push on/ push off switch lined up with a vent hole. Push it off and on with a paper clip or small screwdriver. Works great for me.
Steve

My first av-bay was my L1 rocket. It fit inside 2" ID tubes so the ID of the bay was about 1 7/8" I used a HiAlt45 and switch with tube and pin like Perfectflite describes in their manual for the altimeter.



The battery was tie wrapped on the other side of the 1/4" thick ply sled.



I also had two 1/4" all-thread rods that went through tubes glued to opposite sides of the sled.



What was nice about that switch was the pin was inserted to turn the altimeter off. The pin was attached to a ribbon and that had to be removed before flight. Made it almost impossible to forget to turn on the electronics because the ribbon was flapping at the side of the rocket until you removed it and turn on the electronics. The switched worked perfectly on all flights, including two at 80G with I1299N-P Warp-9 motors.

Thanks for these great pictures

I use screw switches from either Featherweight or MissileWorks, although the Featherweight ones are much smaller. Great for mounting inside small av-bays!

Depending on the length of your altimeter (in this case, shorter than 2.5") you could put it in sideways if it is barometric. Then you could add a CR and put batteries in side by side above or below the altimeter and still have room for a switch. But twist and tuck is a very reliable way to go. I am building a rocket that will have 2 batteries, 2 altimeters, and 2 video cameras in a 3" x 6" AV Bay and the only way to do that is to use the twist and tuck method to turn them on.