Altimeter Switches

[FredA]

Dave -- yes, but later.
I'm on the road without a real laptop so I can't make a nice wiring diagram.
Somewhere there's a thread where I already posted one but I'm not finding it quickly.
Perhaps somebody with more searching moxy can find it.

 

[FMarvinS]

David,

Please disregard my last post, I thought your question was directed to me.

Fred

 

[Cl(VII)]

I have used the screw switches and the rotary switches. I like them both, but lately I really like the pull pin switches. The pull of one pin can activate one, two or three switches. Lab Rat Rocketry has a pretty nice setup.View attachment 395309

I got the triple switches added to the web store: https://www.labratrocketry.com/product-page/triple-pull-pin-switch-kit

Also added extra pull pins to the store while I was at it.

Mods: I am a registered vendor, but the auto payment I made on the 9th apparently didn't auto renew my access (message in to Angie).

 

[Jozef]

I use these regularly.

How do you mount them?

 

[mpitfield]

How do you mount them?

2-56 machine screws fit the mounting holes perfectly. I usually use a flathead countersunk screw. I use a countersunk drill bit that I manually rotate in my hand a dozen times on one side of the switch if mounting on a flat surface.

Here are three mounted on the bottom of a 3D printed sled for a HED AV bay.

 

[Mugs914]

I really would like to try those switches, but Finger Tech seems to be out of them. Anyone know of any other source?

 

[mpitfield]

I really would like to try those switches, but Finger Tech seems to be out of them. Anyone know of any other source?

https://www.robotmarketplace.com/products/0-ft-mini-switch.html

I would say that Google is your friend, but I switched to DuckDuckGo

 

[Mugs914]

Thanks... I tried to do a search but apparently didn't use the right terms,

Thanks again.

 

[amiliv]

Looking for a pair of rotary or screw switches for my next project. My last build used the 6-32 PCB switch that missileworks sells. I have it mounted to the sled and access it through one of the static ports in the switch band of the AV bay. Works well.

The next build will use an RRC2+ and RRC3 and for full redundancy I would like to use two switches. I could use the same system as my last build, but getting the two stitches to line up correctly will be challenging. I like the idea of surface mounted switches, but I have read poor reviews on the rotary switches sold by doghouse. The ones that missileworks sells look to be the same.

So what say you? What sort of switch is your favorite?

And no, I'm not a twist and tape guy.

I just build my first AV bay using SMT Design Hybrid Bay Kit: https://www.smtdesigns.com/store/54mm-65mm-75mm-hybrid-bay-kits

It uses momentary slide switches. Both switches are located inside forward bulkhead (not really visible from the photo on that page). To turn them on or off, simply screw in or out the screw. You can see one of the switches on this photo. The screw goes through that metal hole on the side of the bulkhead. The other switch is not visible on the photo (sled is in the way).

 

[rharshberger]

I just build my first AV bay using SMT Design Hybrid Bay Kit: https://www.smtdesigns.com/store/54mm-65mm-75mm-hybrid-bay-kits

It uses momentary slide switches. Both switches are located inside forward bulkhead (not really visible from the photo on that page). To turn them on or off, simply screw in or out the screw. You can see one of the switches on this photo. The screw goes through that metal hole on the side of the bulkhead. The other switch is not visible on the photo (sled is in the way).

View attachment 395855

I really like both SMT Designs and Lab Rats products, different switches for different applications, but both vendors make a first class product.

 

[Jozef]

2-56 machine screws fit the mounting holes perfectly. I usually use a flathead countersunk screw. I use a countersunk drill bit that I manually rotate in my hand a dozen times on one side of the switch if mounting on a flat surface.


Sweet, Thanks!

 

[beeblebrox]

These puppies are the best, Inexpensive require a decent amount of force to depress, mount so the button does not protrude from the airframe so that a side bump wont activated it. Push-on, Push-off
40 switches for $10, can't beat that!
https://www.amazon.com/WGCD-Latchin...4KCPY70KTE5&psc=1&refRID=MSVBED8X74KCPY70KTE5

 

[beeblebrox]

These look usable too... more expensive and a bit bigger, but waterproof!
https://www.amazon.com/Button-Switc...4KCPY70KTE5&psc=1&refRID=MSVBED8X74KCPY70KTE5

 

[JoeG]

Oh yes, dual magnetic switches. To watch a student team waving their magnet back and forth alternately turning one on and the other off simultaneously is only amusing for a couple minutes. Then it starts to impact schedule

The magnetic switches use one pole of the magnet to turn them on and the other to turn them off. I usually put mine on opposite sides of the e-bay but if your rocket is small in diameter you could turn one on and one off at the same time. Most of my rockets are 4" or larger so I have no problem. On minimum diameter rockets you would want to place the switches at opposite ends or side by side. Putting them side by side will not cause a problem as the same end of the magnet can turn them both on or off at once if you want. Just my experience.

 

[GaryT]

Put together a small Av-Bay this weekend.

 

[Cameron Anderson]

Put together a small Av-Bay this weekend.

Where are you getting your charge well?

 

[mpitfield]

Where are you getting your charge well?

Ahh that there is an original GaryT "BLastCap", great OOP product.

 

[GaryT]

Where are you getting your charge well?

Cameron, Those are my Blastcaps that I designed and used to sell. Sold them for like 5 years but no longer.

 

[mpitfield]

The magnetic switches use one pole of the magnet to turn them on and the other to turn them off. I usually put mine on opposite sides of the e-bay, but if your rocket is small in diameter, you could turn one on and a one-off at the same time. Most of my rockets are 4" or larger, so I have no problem. On minimum diameter rockets, you would want to place the switches at opposite ends or side by side. Putting them side by side will not cause a problem as the same end of the magnet can turn them both on or off at once if you want. Just my experience.

Here is a 54mm MD AV bay. This is 8" long, and you can see one magnetic switch on the left. There is another magnetic switch, in the same spot on the other side, at the other end. From the pic, I am estimating that they are roughly 5-6" apart. This rocket has been launched 14 times, and I have yet to accidentally arm both altimeters at once by energizing both mag switches with one magnet wave.

 

[Voyager1]

I've been considering using these in my next build. I plan to have redundant DD. How does one deal with having two switches in close proximity? Wouldn't you run the risk of accidentally disarming one, while activating the other by waving the magnet around?

I have used them at opposite ends of the avbay for redundant dual deployment and haven’t had any issues. I might add that I mount them vertically in the same plane as the bulkheads. I find this orientation is more reliable. I have sometimes found that if you swipe the magnet horizontally across the switch it can actually switch on and off in the same motion.