Show us your switches

The Rocketry Forum

Help Support The Rocketry Forum:

Banzai88

Lvl 1,Wallet....Destroyed
TRF Supporter
Joined
Jul 15, 2015
Messages
2,701
Reaction score
874
designed and printed sled for RRC3 and screw switches

Most excellent. I'm taking it that you have additional holes in the coupler instead of going through the vent holes to get to the screw switches? I wish I had the skills, would be mega cool to have a sled that had the screw switch pads at 60 degree angles so that they lined up with 2 of the 3 vent holes of a 3 fin rocket in the switch band, probably placed about mid point on the sled.
 

blackjack2564

Crazy Jim's Gone Banana's
TRF Supporter
Joined
Jan 18, 2009
Messages
9,151
Reaction score
1,325
Location
Savannah Ga
Ya mean like this.
Slotted sled with hacksaw & slid vent band on from smaller airframe.
Placed into position, then reached trough vent holes, and marked for screw switch positions.

Mounted and done....no measuring etc. AND ya save space mounting under it!
This had Missleworks GPS & RRC3 alongside Strato CF 9v.battery on one side and 2 lipo's stacked on other in battery box

This from 4in Punisher using 3in. vent band cut from scrap tubing.

DSCN5501.jpg
DSCN5509.jpg
DSCN5511.jpg
DSCN5527.jpg
 

tfish

Well-Known Member
Joined
Dec 8, 2009
Messages
2,793
Reaction score
942
Or, drill the hole(s) and then mount the switch(s) where the holes are.

Tony
 

BDB

Absent Minded Professor
Joined
Aug 22, 2015
Messages
2,243
Reaction score
500
Does anyone use DPDT switches? It seems like that might be an interesting way to simultaneously activate a charge and break a safety shunt.
 

Steve Shannon

Well-Known Member
TRF Supporter
Joined
Jul 23, 2011
Messages
7,096
Reaction score
4,133
Location
Butte, Montana
Does anyone use DPDT switches? It seems like that might be an interesting way to simultaneously activate a charge and break a safety shunt.
I did on the charge side for my L3. It is a good way. Fred Azinger also does it.
 

BDB

Absent Minded Professor
Joined
Aug 22, 2015
Messages
2,243
Reaction score
500
Then the follow-up question...do you have a link to the switch that you used?
 

manixFan

Not a rocket scientist
Joined
Feb 15, 2009
Messages
2,196
Reaction score
1,242
Location
TX
Like many of you, I have used most of the switches presented in this thread. My favorite (except for the cost!) is the Featherweight magnetic switch. But I've used dozens of the green screw switches like the ones that Aerocon sells. However I bought mine from a electronics surplus place (Electronics Goldmine) years ago for a few cents each. (I recall I bought 100 and now I wish I had bought 1000!) Bulletproof and take up very little room. Here's a couple that a friend embedded in a screw-in aluminum base. Almost always I use the altimeter vent hole to arm the switch.


Tony

with and without screw:
screw-switches.jpg
 

Steve Shannon

Well-Known Member
TRF Supporter
Joined
Jul 23, 2011
Messages
7,096
Reaction score
4,133
Location
Butte, Montana
Then the follow-up question...do you have a link to the switch that you used?
I don’t. That was 14 or 15 years ago and I bought the switches from Radio Shack. Since then I’ve become picky about switches. Here’s what I would recommend now:
https://www.nkkswitches.com/pdf/cs.pdf

Added: Now, I don’t usually add switches on the charges. I just use one SPST power switch for each device. If I were staging, I probably would add a DPDT switch for the sustainer ignition.
 
Last edited:
  • Like
Reactions: BDB

beeblebrox

8 C6-0, 12 D11-9, 20 D20-0, 20 E5-0, 3 Cinerocs
Joined
Mar 19, 2016
Messages
748
Reaction score
371
Location
West Chester, PA
Push-on, Push off 680 gram force to actuate. (measured with digital scale)

switch.jpg
 

Dave A

Lifetime Supporter
TRF Lifetime Supporter
Joined
Jan 22, 2013
Messages
1,190
Reaction score
155
I bought a bunch of these mini switches when PML was selling them years ago. Very solid when slide to off or on.
I can reach both of them easily through the vent hole with an ink pen.
Never had one fail.
1243.jpeg
 

Steve Shannon

Well-Known Member
TRF Supporter
Joined
Jul 23, 2011
Messages
7,096
Reaction score
4,133
Location
Butte, Montana
I bought a bunch of these mini switches when PML was selling them years ago. Very solid when slide to off or on.
I can reach both of them easily through the vent hole with an ink pen.
Never had one fail.View attachment 382043
I’m still using some of those as well. According to PML they are rated at 50 gees. I’ve not had one fail either.
 

Dave A

Lifetime Supporter
TRF Lifetime Supporter
Joined
Jan 22, 2013
Messages
1,190
Reaction score
155
I’m still using some of those as well. According to PML they are rated at 50 gees. I’ve not had one fail either.
My last Patriot came down only on the small drogue. Every section came down horizontially on to some hard, packed ground. Every one badly damaged. Inside my GLR aluminum av bay, the g forces broke the printed sleds in half, batteries popped out and dented plus the rods were bent. The sleds were only hanging on by the Perfectflite screws. When I attempted to replay the stats, both switches and alts were NOT damaged, audio readouts were perfect for both.
20190413_214804.jpeg
 

Dave A

Lifetime Supporter
TRF Lifetime Supporter
Joined
Jan 22, 2013
Messages
1,190
Reaction score
155
I’m still using some of those as well. According to PML they are rated at 50 gees. I’ve not had one fail either.
Steve, I haven't checked but do you know where they got them?
 

Handeman

Well-Known Member
TRF Supporter
Joined
Jan 18, 2009
Messages
7,867
Reaction score
432
Location
Stafford, VA
My last Patriot came down only on the small drogue. Every section came down horizontially on to some hard, packed ground. Every one badly damaged. Inside my GLR aluminum av bay, the g forces broke the printed sleds in half, batteries popped out and dented plus the rods were bent. The sleds were only hanging on by the Perfectflite screws. When I attempted to replay the stats, both switches and alts were NOT damaged, audio readouts were perfect for both.
I'm still using a Perfectflite HiALt45 that survived a lawn dart at 300 mph. The ply board broke at the battery which was on the opposite side of the board from the altimeter. The 9V battery was pour out of the remains in a dozen pieces.
 

Dave A

Lifetime Supporter
TRF Lifetime Supporter
Joined
Jan 22, 2013
Messages
1,190
Reaction score
155
I'm still using a Perfectflite HiALt45 that survived a lawn dart at 300 mph. The ply board broke at the battery which was on the opposite side of the board from the altimeter. The 9V battery was pour out of the remains in a dozen pieces.
After I saw both of mine were 100% I went out and bought 2 lotto tickets!
 

manixFan

Not a rocket scientist
Joined
Feb 15, 2009
Messages
2,196
Reaction score
1,242
Location
TX
Wow, what a great thread! Got some really great ideas, especially using recessed charge wells to save space on a 4" rocket I am working on. I launch out of towers a lot and it never occurred to me that there could be a magnetized component on the tower that could kill the mag switch. My new tower is all aluminum but still, a very good point to know. Thanks to the OP for starting the thread.


Tony
 

RocketDestroyer

Well-Known Member
Joined
Jul 31, 2014
Messages
329
Reaction score
116
Here is my version of the screw switch and ebay. It fits inside a 54mm coupler. It is made from a sandwich of single sided PCB and 3D printed PLA. It is made tall enough to place the switch just beneath the body of the rocket to make it easy to reach with a screw driver. I used copper foil for the connections from top to bottom of the stack. During assembly I can adjust the friction on the screw so that it turns easily with a screw driver but wont turn due to vibration.
upload_2019-5-7_9-27-41.png


The top view of the rest of the ebay. There is a cut out area underneath each altimeter to allow for the components on the bottom side of the PCB. The board are spaced off the surface of the sled by a flat washer to allow air flow.

upload_2019-5-7_9-32-23.png


The bottom of the ebay. I don't like the idea of putting tie wraps around LiPo batteries to hold them in place so I created a well with a cover to hold mine in place. The SL-100 is powered by two batteries wired in series. Each battery has a plug so I can just unplug them to recharge them.
upload_2019-5-7_9-35-8.png


The ebay has survived several hard landings with no ill effects. Not the lightest way to build it but it works for me.
 

RocketDestroyer

Well-Known Member
Joined
Jul 31, 2014
Messages
329
Reaction score
116
"so is there a nut soldered to the bottom pcb and the screw contacts the top pcb when tightened?"

Yes. The copper foil just connects the bottom foil to the top side so that both wires come off the top side.
 

RocketDestroyer

Well-Known Member
Joined
Jul 31, 2014
Messages
329
Reaction score
116
Should also point out that I don't use a switch band with this configuration. There is one switch hole in the upper body and one in the booster section. I use three vent holes arrayed around the upper section near the top of the ebay. For flight I place a small piece of electrical tape over the switch holes so the ebay can only breath through the vent holes. I have left the tape off a few times to see if it made a difference. If there was any difference it was so small that I didn't notice it.
 

Steve Shannon

Well-Known Member
TRF Supporter
Joined
Jul 23, 2011
Messages
7,096
Reaction score
4,133
Location
Butte, Montana
"so is there a nut soldered to the bottom pcb and the screw contacts the top pcb when tightened?"

Yes. The copper foil just connects the bottom foil to the top side so that both wires come off the top side.
That’s pretty neat. Do you check the foil for cracks before flight? In the photo it looks like one may be starting. I would be tempted to use copper braid instead of foil.
 

Nytrunner

Pop lugs, not drugs
TRF Supporter
Joined
Oct 15, 2016
Messages
8,005
Reaction score
3,725
Location
Huntsville AL
I've used apogee push switches on mid power rockets well enough, but for my L2 I used these flat rocker switches
They're not tiny, but they're solid and don't have much unsupported mass susceptible to g-loading.

Only good view of them in use I have at hand is from laying out the ebay on Long Tom

 

Latest posts

Top