Drilling Holes in Switchband.

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jeff2space

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Does anyone have any tips or tricks to drilling holes in switchband so they line up perfectly with altimeter switch inside?
 

Steve Shannon

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Does anyone have any tips or tricks to drilling holes in switchband so they line up perfectly with altimeter switch inside?
I install my switches on the switchband and run wires to the sled. It's much easier that way.


Steve Shannon
 

Steve Shannon

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I did that for my L3 bird. Recently I've been building using the 3D printed sleds with the switches mounted on the sled.
I haven't gotten that fancy yet, but I do have some kind of sled from Missileworks I'm going to try. I considered making some kind of LED to temporarily mount where the switch will mount with a standoff to bring it up to the inside of the coupler's inner surface, then drill where the light it.
I get a little nervous seeing people jam screwdrivers into switchband ports. The guides some people make to keep the screwdrivers on the straight and narrow seem like a good idea.


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Steve Shannon

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My L3 rocket had a rectangular hatch that could be removed to access the switches inside.


Steve Shannon
 

ChrisAttebery

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Drill the hole through the switch band first. Then use the drill to mark the spot where the switch needs to be.
 

timbucktoo

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I mostly use screw switches. I'll drill vent holes first, mount the switch about midway on sled and then adjust sled so switch lines up with one of the vent holes.
 

Crumb fire

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"My L3 rocket had a rectangular hatch that could be removed to access the switches inside"


I do that too, but the switch band is free to rotate and trapped between two glued switch bands. A rectangular hole is made through both coupler and band. I retrofitted all my fleet like this; It's just a "p.i.t.a" to glue since you don't want the center band to stick on the coupler. In flight position align 3 static port holes, and a screw stop the center ring to rotate by passing through the switch band and the coupler (drill & tap). Next step would be a push on/off switch inside for locking this center band through a hole. No screw to provide.

5inch Brocken Arrow Av-Bay.JPG


F98 switch band.JPG
 

FMarvinS

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Similar to Chris, drill the 120 degree or ninety degree vent holes apart through the switch band first. Then I use a toothpick dipped in nail polish placed through the vent holes to mark the switch position on the coupler. If the coupler switches are approximately 0.25 inches recessed from the vent holes, you'll have easy access to the screw switches without the need for a screw driver guide. You can initially practice with a cardboard coupler (in lieu of FG). Also, if you find it difficult to appropriately place the switches 120 degrees apart, you can use 4 vent holes with 2 switches placed on the sled. One switch is placed at the edge of the sled facing the vent hole and the second switch can be placed straight up at 90 degrees on the sled opposite the appropriate vent hole.

Fred
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manixFan

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I have a number of rockets that use a common altimeter mount design based on the PML CPR mounting system. I have about 4 altimeters mounted on sleds that all have the screw switches in the same location. So I need to drill the holes right on the money for any rocket that uses that design. What I found worked well for me was to make a drilling template in a drawing program and then tape it to the rocket as a guide. In my case everything is indexed from the forward lip of the CPR mount so I do have a common starting point. In the dozen or so rockets that I've built with that design I've never been off enough to cause any real alignment issues, especially once I got a drill press that made it easier to keep everything in place.

Good luck,


Tony
 

Nathan

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I install my switches on the switchband and run wires to the sled. It's much easier that way.


Steve Shannon
Unless it is a 2.6" diameter rocket and you are installing a Schurter rotary switch. Because then after you install the switch there isn't enough room left inside the av bay to slide the sled in. Don't ask me how I know that . . .
 

Steve Shannon

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Unless it is a 2.6" diameter rocket and you are installing a Schurter rotary switch. Because then after you install the switch there isn't enough room left inside the av bay to slide the sled in. Don't ask me how I know that . . .
The first dual deploy I did used the PML CPR system in a 2.6 inch rocket. Using the PML switches it fit okay. I kind of went crazy and converted all of my small rockets using the CPR. I like the PML slide switches and their commercial equivalents from NKK.


Steve Shannon
 

Buckeye

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Does anyone have any tips or tricks to drilling holes in switchband so they line up perfectly with altimeter switch inside?
A ruler? Measure twice, cut once.

Unless it is a 2.6" diameter rocket and you are installing a Schurter rotary switch. Because then after you install the switch there isn't enough room left inside the av bay to slide the sled in. Don't ask me how I know that . . .
I have a Schurter rotary switch in a 38mm av-bay. It can be done! Switch is on the sled.
 

pondman

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Schurter switch installed on an Additive Aerospace sled from a Wildman Blackhawk 38. Tight but it does fit.IMG_1296.JPG
 

mike2wander

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These extremely reliable and positve push on - push off switches will keep you from fishing in the dark. Without a switch bridge they fit nicely in 54mm air frames, and with the correct switch bridge they work with air frames up to 4". The switch bridge places the switch button just inside your vent/access hole close to the air frame. The 1/2" diameter button makes for easy arming.
Check them out @ https://shop.macperformancerocketry.com/collections/hardware/products/copy-of-hardware

IMG_20160918_155215_680-1.jpg

Mike Crupe
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FLY CANVAS!
 

woferry

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I did that for my L3 bird. Recently I've been building using the 3D printed sleds with the switches mounted on the sled.
Are you using other's 3D-printed sleds, or printing your own? I guess you're probably saying the former.

I design my own sleds and print them, so I can generally position the 'switches' where I want them to go. I always use the FeatherWeight Magnetic Switches, but I care about their placement so that I know I can see the LED through a vent hole, and it also helps to know where to swipe the magnet. If something restricted my placement (particularly tight AVBay or something), I'd also print a drill guide to help me drill the vent holes in the right places, instead of my normal guide that's designed for holes at 45/60° increments. :)
 

Buckeye

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The question here is really how to design/mount switches on a sled so that they match the switchband. Using a switch band really limits your av-bay layout by forcing the switch to the center (assuming your band is in the middle of the coupler, which is typical).
 

jeff2space

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The question here is really how to design/mount switches on a sled so that they match the switchband. Using a switch band really limits your av-bay layout by forcing the switch to the center (assuming your band is in the middle of the coupler, which is typical).
Using the current 3D sleds available you are limited to location of switch. Of course one solution would be to make own sled (either 3D or wood/fiberglass). I could update my original question to: When using an manufacturers 3D sled, how do you drill hole(s) in switchband accurately?
 

Buckeye

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Using the current 3D sleds available you are limited to location of switch. Of course one solution would be to make own sled (either 3D or wood/fiberglass). I could update my original question to: When using an manufacturers 3D sled, how do you drill hole(s) in switchband accurately?
I guess I am not following your question. You don't have many options when drilling a hole in the switchband. It is only 1 inch wide, usually. Just drill the hole anywhere. The key then is to line up the switch directly beneath it. If your sled is on threaded rod, then use some spacers or nuts to lock it in place so that the switch is beneath the hole.

I drill 3 holes around the circumference for altimeter venting (120 deg apart), and at least one is big enough for a screwdriver to activate the switch. I also ensure that these 3 vent holes are not directly behind a rail button or the screws/rivets holding the av-bay coupler to the payload airframe.
 

Lowpuller

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In my most recent rocket I drilled 3 holes in the switch band. One for each altimeter and one extra, they also serve as my vent holes.
 

Viperfixr

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Drill the hole through the switch band first. Then use the drill to mark the spot where the switch needs to be.
+1. Doing it this way, I get great alignment every time and do not need to drill a separate vent hole. Securing the sled on threaded rods with a few nuts allows for 'adjustments' too.
 
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