Favorite terminal blocks?

[GrouchoDuke]

Does anyone have a favorite terminal block they use on the outside of their av-bays for ejection charges? The ones from Apogee seem to work fine, I'm just curious if there's anything better.

Thanks!

 

[woferry]

The ones from Apogee seem to work fine, I'm just curious if there's anything better.

Those are certainly the 'standard' from what I've seen, I bought some long ago (they're available lots of places, I got mine from AdaFruit) but have never used them. Personally, my favorites were Dog House's charge wells with integrated terminals, never needed to use anything else until very recently. Unfortunately, when Binder picked up Dog House's catalog they seem to have dropped this part (instead there's a kit that goes around their existing charge well). They are selling a thru-bulkhead terminal here (second item on this page). I happened to be the one who gave Bill @ Dog House the idea for this (really just the charge well terminals without the charge well), I have some early prototypes and bought a set of the real thing once they were available, but honestly I haven't used them. Personally I've elected to just use the screw set without any actual plastic part, I've put the terminals far enough apart that I didn't need any sort of divider between them. Here's an example of a 54mm avbay bulkhead where I use 2 altimeters and 2 e-matches in a single charge well, so the one match connects to the terminals on the well, the second match to the terminals on the bulkhead. I like these because the inside wiring can be permanent and doesn't need to be played with (never exposed to the charge gasses, etc), and the only holes through the bulkhead are for the screws carrying the signals, so there are no wire holes to seal, etc.



If the bulkhead itself is conductive then this is obviously a bad idea (though passing wires through might also require some protection to keep the insulation from shaving off the wires and shorting out), there are insulating sleeves available further down on the same page linked above.

 

[blackjack2564]

You can get the full strip [12] from Radio Shack for about the same price.



Just cut off what's needed with a knife.

 

[Bat-mite]

Binder Design sells nice AV bay wiring kits, terminals, etc. Used to be Doghouse Rocketry.

 

[MikeyDSlagle]

You can use a #6 machine screw through the bulkplate right into the hole in the center of the terminal. Perfect fit. A dab of epoxy if you think it's needed.

 

[Buckeye]

You can get the full strip [12] from Radio Shack for about the same price.

View attachment 334316

Just cut off what's needed with a knife.

What is "Radio Shack?" [emoji6]

Seriously, I bought a couple of these strips from a brick and mortar RS years ago. Plenty for many rockets.

 

[Binder Design]

Personally, my favorites were Dog House's charge wells with integrated terminals, never needed to use anything else until very recently. Unfortunately, when Binder picked up Dog House's catalog they seem to have dropped this part (instead there's a kit that goes around their existing charge well).

Those were only available in two sizes, had excessively thick bases, had to be machined from larger diameter rod which is more expensive, took too much machining labor to be profitable. So a bunch of different factors involved in their phasing out. Our new holders are available for every size charge well, the new charge wells are machined from delrin which has a higher resistance to heat, and the new mount kits are more complete than the old style. They even include silicone caps to prevent a quick-link or swivel from shorting the terminals. We are even considering including some of the red plastic snap on Caplugs for these kits.

https://binderdesign.com/store/page29.html

 

[Binder Design]

Binder Design sells nice AV bay wiring kits, terminals, etc. Used to be Doghouse Rocketry.

It's still Dog House Rocketry

 

[Kallahan11]

Those were only available in two sizes, had excessively thick bases, had to be machined from larger diameter rod which is more expensive, took too much machining labor to be profitable. So a bunch of different factors involved in their phasing out. Our new holders are available for every size charge well, the new charge wells are machined from delrin which has a higher resistance to heat, and the new mount kits are more complete than the old style. They even include silicone caps to prevent a quick-link or swivel from shorting the terminals. We are even considering including some of the red plastic snap on Caplugs for these kits.

https://binderdesign.com/store/page29.html

Used these on my Level 3, they're very nice.

 

[Tim51]

You can get the full strip [12] from Radio Shack for about the same price.

View attachment 334316

Just cut off what's needed with a knife.

+1.

 

[blackwing94]

+1 on Binder's new Dog House charge wells with integrated terminal. Reminds me, I need to order some more.

 

[AeroAggie]

I bought a few of these in 2-terminal and 4-terminal blocks from Mouser:

https://www.mouser.com/search/ProductDetail.aspx?r=651-1725656

They're PCB mounted, same/similar to ones used on several altimeters (like Raven). I haven't installed one yet but my plan is to solder wires to the tabs and pass those through the bulkhead, then either 5-minute epoxy or hot glue the terminal to the bulkhead. If drilling teensy holes at proper spacing proves to be difficult, then I'll revert back to a 4-40 or 6-32 screw and nut arrangement.

 

[Worsaer]

I bought a few of these in 2-terminal and 4-terminal blocks from Mouser:

https://www.mouser.com/search/ProductDetail.aspx?r=651-1725656

They're PCB mounted, same/similar to ones used on several altimeters (like Raven). I haven't installed one yet but my plan is to solder wires to the tabs and pass those through the bulkhead, then either 5-minute epoxy or hot glue the terminal to the bulkhead. If drilling teensy holes at proper spacing proves to be difficult, then I'll revert back to a 4-40 or 6-32 screw and nut arrangement.

These actually work really well. They have become my default connectors.

 

[Dugway]

I've had success with these:

https://www.digikey.com/products/en?mpart=HA0470500000G&v=1818

Quick and easy attachment, don't need to worry about how hard to crank down the screws.

 

[ECayemberg]

Just because it hasn't been said yet....

My favorite terminal blocks for connections are the ones that are soldered to the altimeter board.

I used to use various connectors or terminals for going through bulkheads, but...

-BP charges are very corrosive. Corrosive to terminal blocks, and any other connector type as well.
-Running the wire directly to the altimeter eliminates at least one connection. One less failure point.
-Running them direct is just as simple, in my opinion. Instead of a bulkhead peppered with more stuff, there's a single hole for the wires to pass.

Simply run the charge wires through the hole in the bulkhead, make a loop or loose knot in the wire on the inside of the E-bay to prevent any tugging from ripping out the terminals, tighten the terminal on the altimeter board, seal the hole with a piece of masking tape or clay...done.

Many different ways to do it...USED TO have terminals or connectors on bulkplates. Eliminated one failure point and simplified the setup...happier with the current state!

 

[Dad Man Walking]

My current, most favorite-est (for now) solution -- Instead of using terminal block for connections to the e-matches, I use Scotchlok butt splices:



I tape down the loose wires and connectors so that nothing is flopping around. No terminal blocks or screw connections to clean up afterward. I leave the wire outside of the AV bay long enough that I can get several flights (or scrubs ) before I need to replace the wires.

 

[FredA]

Many different ways to do it...USED TO have terminals or connectors on bulkplates. Eliminated one failure point and simplified the setup...happier with the current state!

These days I try to buy altimeters built without terminal blocks.
I eliminate that point of potential failure.
Every rocket gets an altimeter built in, so the terminal blocks are just failure points with no upside - best to solder the wires.

Everything is hard-wired up to the terminal blocks on the Ebay ends. I still like term-blocks on the Ebay caps for quick match attachment.

Do remember to put a piece of duct-tape over the terminal block once the match(es) are connected.
This does three things:
- Insulates connection from wondering quick-links and the like.
- Shields the terminal block from the bulk of the corrosive gasses.
- Provides a small amount of strain-relief on the match wire.
Doing this I've never seen a corrosion problem.

 

[djs]

For those of you who have everything soldered together, how are you charging the batteries on your altimeters? Normally i use terminal blocks and JST connectors, so I can disassemble an av bay down to it's component parts. Maybe a few extra points of failure there, but generally for me, it's improved my failure rate on electronic deployment.

 

[ECayemberg]

Many different ways to do it...USED TO have terminals or connectors on bulkplates. Eliminated one failure point and simplified the setup...happier with the current state!

These days I try to buy altimeters built without terminal blocks.
I eliminate that point of potential failure.
Every rocket gets an altimeter built in, so the terminal blocks are just failure points with no upside - best to solder the wires.

Everything is hard-wired up to the terminal blocks on the Ebay ends. I still like term-blocks on the Ebay caps for quick match attachment.

Do remember to put a piece of duct-tape over the terminal block once the match(es) are connected.
This does three things:
- Insulates connection from wondering quick-links and the like.
- Shields the terminal block from the bulk of the corrosive gasses.
- Provides a small amount of strain-relief on the match wire.
Doing this I've never seen a corrosion problem.

Can't disagree with the fact that soldering eliminates one connection point....assuming that the solder joint is good.

But unless I read your description wrong, you still have one connection between the electronics board and the match head; on the outside of the bulkhead. Essentially, you traded a screw terminal in the bay for one outside the bay....still one connection: net amount of connections same as the method I described.

Many ways to skin the cat. As long as one's rocket ascends and descends in a safe manner as intended, RSO's, Prefects, Land owners, and concerned observers shall be content; regardless of how one achieves safe flight!

 

[FredA]

Yep, one terminal block still in the path.
And yes, the solder connection is good.....I learned to solder when I was 8 so I could help on my Dad's train set.

One of the ways to do it....

 

[markkoelsch]

Just because it hasn't been said yet....

My favorite terminal blocks for connections are the ones that are soldered to the altimeter board.

I used to use various connectors or terminals for going through bulkheads, but...

-BP charges are very corrosive. Corrosive to terminal blocks, and any other connector type as well.
-Running the wire directly to the altimeter eliminates at least one connection. One less failure point.
-Running them direct is just as simple, in my opinion. Instead of a bulkhead peppered with more stuff, there's a single hole for the wires to pass.

Simply run the charge wires through the hole in the bulkhead, make a loop or loose knot in the wire on the inside of the E-bay to prevent any tugging from ripping out the terminals, tighten the terminal on the altimeter board, seal the hole with a piece of masking tape or clay...done.

Many different ways to do it...USED TO have terminals or connectors on bulkplates. Eliminated one failure point and simplified the setup...happier with the current state!

Eric, you beat me to it. I like to eliminate failure points, and terminal are a potential failure point. The leads go through the bulkhead directly to the altimeter. A little rtv silicone over the hole and there you go.


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[Handeman]

Eric, you beat me to it. I like to eliminate failure points, and terminal are a potential failure point. The leads go through the bulkhead directly to the altimeter. A little rtv silicone over the hole and there you go.

Sent from my iPhone using Rocketry Forum

I can certainly appreciate the direct connect, but I connect everything in the av bay and don't open it until the altimeter reports the battery is below 8.9V I always figured the less you make and break connections and wiggle wires around (especially solid core) the more reliable it will stay and less chance of a handling induced failure. The only unproven connection I have on each flight is the matches to the terminal blocks. When the altimeter reports a match on the channel, I consider that sufficient and more reliable then opening the av-bay every flight and messing with the wiring of channels and power.

 

[FredA]

I connect everything in the av bay and don't open it until the altimeter reports the battery is below 8.9V I always figured the less you make and break connections and wiggle wires around (especially solid core) the more reliable it will stay and less chance of a handling induced failure. The only unproven connection I have on each flight is the matches to the terminal blocks. When the altimeter reports a match on the channel, I consider that sufficient and more reliable then opening the av-bay every flight and messing with the wiring of channels and power.

+1

 

[RocketFeller]

Since nobody has mentioned well nuts, I will. Missileworks sells these and they work great for sealing the pass-through holes in the bulkhead. They are easily removed, reusable, and add lots of strain release.

https://www.missileworks.com/store/#!/Bulkhead-Sealing-Well-Nuts/p/38076738/category=5760489


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[GrouchoDuke]

This is all great info. Thanks everybody & keep it coming!

 

[pcalviln]

I bought a few of these in 2-terminal and 4-terminal blocks from Mouser:

https://www.mouser.com/search/ProductDetail.aspx?r=651-1725656

They're PCB mounted, same/similar to ones used on several altimeters (like Raven). I haven't installed one yet but my plan is to solder wires to the tabs and pass those through the bulkhead, then either 5-minute epoxy or hot glue the terminal to the bulkhead. If drilling teensy holes at proper spacing proves to be difficult, then I'll revert back to a 4-40 or 6-32 screw and nut arrangement.

+3, these work really well.

 

[GrouchoDuke]

Those do look nice. Hmm.

 

[Normzilla]

This is a really helpful thread. Thanks all!

Nate

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[tbonerocketeer]

How about for airstarts, where the motor tends to cook everything? What block do you like there? If this needs to be in its own thread, please move it.

 

[tim cubbedge]

How about for airfstarts, where the motor tends to cook everything? What block do you like there? If this needs to be in its own thread, please move it.

For all my air starts, I just use twist and tape.