Using standard screws for terminals?

[Zyzzyva1000]

I am putting together a 38 mm minimum diameter rocket and decided to add an electronics bay. I have not needed to work in such a tight space before, and I am trying to figure out the best way to setup the bulkheads. I have 3d printed some charge well to fit, so I have that taken care of.

My standard terminal blocks I use are too bulky and won't fit. I was thinking of just doing screw terminals (similar to what I have done using the mounting kit available from eggtimer for my nose cone mounted apogee altimeter). Is there any reason a long machine screw wouldn't work as a terminal? My plan is to have a standard nut up against the bulkhead on each side to keep it in place, and then 2 washers (between which I will trap the wire), with a final nut on top to compress it all together. Anyone know of better ways to do this? I have always had room to use a terminal block on my larger projects, just trying to figure out how to conserve space here.

 

[Titan II]

Forget the terminals. Run the wires directly from the e-match to the altimeter through a small hole that you seal with something like putty or silicone.

 

[waltr]

That would work fine and I have seen some pictures of ebays setup this way.

Do inspect and clean before each flight.

I have never used terminal blocks on ebays. What I do is run the ematch wire through the bulkhead and connect directly to the altimeter terminals. Then a little bit of 'duct seal' (putty) to seal the wire holes.
Yes, the ebay must be opened to do this but one needs to check/change the battery anyway.
I install the ematches at home while preping the rocket. Then add BP before launch.

Just saw Titan I suggests the same thing.

 

[Handeman]

I only open my av-bays every couple of years when they need new batteries so I always use terminals. The machine screws will work. I would suggest ring terminals on the wires to the inside of the machine screws in case you tighten the nut too much and make the screw spin slightly. It could break a wire, but not the ring terminal.

The screws do add weight where wires through to the altimeter doesn't. That may be a big consideration on a minimum diameter rocket.

 

[Zyzzyva1000]

Yea Maybe I am over thinking this. Since I have less space to work its probably better to just keep it simple. I was wondering what to use as a sealant - I will get some of that duct seal putty. Thanks!

 

[Zyzzyva1000]

I only open my av-bays every couple of years when they need new batteries so I always use terminals. The machine screws will work. I would suggest ring terminals on the wires to the inside of the machine screws in case you tighten the nut too much and make the screw spin slightly. It could break a wire, but not the ring terminal.

The screws do add weight where wires through to the altimeter doesn't. That may be a big consideration on a minimum diameter rocket.

Good call on the ring terminals. I will keep this in mind for future projects.

 

[Kane]

I have used Lab Rat's terminals I'm the past. They work very well - especially for smaller airframes.

 

[mbeels]

I've used screws before just as you describe, and it worked fine. For the final nut, I used "thumb nut" to make it easy.

 

[Voyager1]

Yea Maybe I am over thinking this. Since I have less space to work its probably better to just keep it simple. I was wondering what to use as a sealant - I will get some of that duct seal putty. Thanks!

I often just use masking tape to seal over the ignition lead holes in the bulkplate.

 

[Antares JS]

Just got these for my Airstrike 3829... Integrates through-bulkhead connectors with your charge well in a small form factor.

(scroll down to the very bottom)

http://binderdesign.com/store/charge-wells.html

 

[Rocketclar]

On some ebays, I run the wires directly from the altimeter thru the bulkhead to the charge well and seal both sides with hot glue.

 

[OverTheTop]

On some ebays, I run the wires directly from the altimeter thru the bulkhead to the charge well and seal both sides with hot glue.

Hot glue does a wonderful job for sealing or even holding wires to bulkheads. Relatively easy to remove when needed too.

 

[Crazyrocket]

I also use the non-drying kids putty that comes in different colors (cannot think of the name right now). Easy to use and I put it on both sides of the ebay lids. When done, just remove the putty and clean the holes with a toothpick.

 

[Banzai88]

I was wondering what to use as a sealant - I will get some of that duct seal putty.

Poster putty and never look back. Replace every flight.

 

[SolarYellow]

The OP's proposal is pretty close to what I'm planning. Brass hardware and ring terminals that also crimp the insulation in sizes down to M2 are readily available in bulk quantity for cheap on AliExpress. M2 doesn't add much weight.

 

[cerving]

Just got these for my Airstrike 3829... Integrates through-bulkhead connectors with your charge well in a small form factor.

(scroll down to the very bottom)

http://binderdesign.com/store/charge-wells.html

Those are basically the Doghouse Rocketry through-bulkhead charge wells, they work fine but I've had a few crack on me when they fired. Hopefully they've improved that... I haven't used them in a few years.

 

[cwbullet]

Just got these for my Airstrike 3829... Integrates through-bulkhead connectors with your charge well in a small form factor.

(scroll down to the very bottom)

http://binderdesign.com/store/charge-wells.html

I like them but I do not like their shipping costs.

 

[JoePfeiffer]

That's what I use, though I use brass machine screws and nuts.

 

[pbahorich]

Those are basically the Doghouse Rocketry through-bulkhead charge wells, they work fine but I've had a few crack on me when they fired. Hopefully they've improved that... I haven't used them in a few years.

They've worked well for me with up to 3 grams of FFFFg black powder, so they must have improved that..

 

[Zyzzyva1000]

Poster putty and never look back. Replace every flight.

I actually saw some while I was at Lowes finding other hardware and got this instead - then I saw your comment