How-To: Anti-Spark XT-90 Loop Key

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How-To: Anti-Spark XT-90 Loop Key

Post by sl33py » Sep 13 2015 11:41pm

It's not a marvel of engineering. It doesn't light-up blue. It's not as nice as the push-button anti-spark.
It's also not $60.

This might be a bit remedial for some of you (you know who you are), but i wanted to show how i built one in case someone else wants to make their own. You can do it easier/simpler, but i had some time to fiddle in the garage and enjoyed making it for my next build.

Starting off with the anti-spark XT-90:
Image
Image
I took some 12/2 wire i had laying around and the copper ground wire works perfectly to bridge the contacts for the loop.

I like modular. If it ever fails or i want to do something differently i can easily swap it out without cutting it out.
6mm connectors:
Image
The slot is so i can squeeze it to better fit/solder.
Image

Mocked up:
Image

Finished with some heatshrink and paracord so i can easily pull to disconnect.
Image
Image

Finished:
Image

Only issue i can imagine is depth to fit. I will likely turn it flat and secure the bottom down. I might also attach a small cord/wire to the paracord loop to prevent it from getting lost.
Image

Nothing too special, but i think it turned out well. I plan to install on my new e-Omen (ongoing slowly).

Hope it helps!

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by torqueboards » Sep 14 2015 12:18am

Perfect tutorial!

Now I can refer everyone to this page whom don't know what a XT90 Loop Key is :mrgreen:
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Re: How-To: Anti-Spark XT-90 Loop Key

Post by whereswally606 » Sep 15 2015 5:26am

I like this a lot, I would say the straight through (I.e) using more 6mm connectors is unnecessary more an aesthetic thing but the loop part is great.
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Re: How-To: Anti-Spark XT-90 Loop Key

Post by camyboy » Oct 18 2015 1:32pm

I got some 4mm HXT connectors instead of the 6mm. Would it work the same?

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by vince086 » Oct 18 2015 1:59pm

camyboy wrote:I got some 4mm HXT connectors instead of the 6mm. Would it work the same?
Not really.
The XT90 connectors used for this have a resistor built in (under the green bit). That resistor prevents the spark.

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by Simonvtr » Oct 18 2015 2:16pm

I order some xt90s to prevent sparks when I attach my battery to my controller.
I thought it was straight forward soldering like it would normally with a plug?
May you explain to me what is the purpose of the loop key?

Thanks
Simon

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by camyboy » Oct 18 2015 2:47pm

vince086 wrote:
camyboy wrote:I got some 4mm HXT connectors instead of the 6mm. Would it work the same?
Not really.
The XT90 connectors used for this have a resistor built in (under the green bit). That resistor prevents the spark.
no no I bought the XT90 anti spark, But Im talking about these Image to make these Image. Instead can i just use 4mm connectors. instead of the 6mm

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by torqueboards » Oct 18 2015 3:08pm

You don't need to use the 5.5mm bullet connectors. You can also just solder 10awg wire directly into the connector.
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Re: How-To: Anti-Spark XT-90 Loop Key

Post by camyboy » Oct 18 2015 5:20pm

torqueboards wrote:You don't need to use the 5.5mm bullet connectors. You can also just solder 10awg wire directly into the connector.
Oh okay, sounds good

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by sl33py » Oct 19 2015 1:12pm

torqueboards wrote:You don't need to use the 5.5mm bullet connectors. You can also just solder 10awg wire directly into the connector.
Correct! I mentioned i like modular:
I like modular. If it ever fails or i want to do something differently i can easily swap it out without cutting it out.
6mm connectors:
Image
The slot is so i can squeeze it to better fit/solder.
So i guess i wasn't totally clear. You can easily wire this in by just soldering directly to the bottom XT-90. I set mine up to be modular so i can swap it or bypass it with just a simple plug/unplug. I made it more complicated than necessary, but wanted that feature so i can swap to another board later, or remove it entirely.

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by camyboy » Oct 21 2015 10:08pm

So im still lost. This is how im assuming i would connect it all together. Image
Im just lost. There are 2 input (red n black) from batteries that need to reach the ESC but only 1 input and 1 out for the anti spark loop connector. Do i plug the red wire from battery to the black from ESC? or black from battery to red on ESC?

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by torqueboards » Oct 21 2015 11:36pm

Image

This is the direction. The only thing that the loop key does is break the full circle connection.

So when the loop key is removed - your system is off.

When plugged in - you allow the current to flow to your ESC to your motors.

Everything else is just different connectors with different amp ratings to make it happen.

Of course, use less wire and less connectors to prevent more wire bulk in your setup.
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Re: How-To: Anti-Spark XT-90 Loop Key

Post by sl33py » Oct 22 2015 12:55pm

nice simplified drawings. Torque has you squared away.

the loop key is merely an in-line interrupt on one of the wires. Positive or negative. When removed it disconnects power like a breaker in the open position. When connected it allows that wire to complete the circuit (the anti-spark plug also suppresses the spark when connecting). Simple.

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by camyboy » Oct 28 2015 8:06pm

sl33py wrote:nice simplified drawings. Torque has you squared away.

the loop key is merely an in-line interrupt on one of the wires. Positive or negative. When removed it disconnects power like a breaker in the open position. When connected it allows that wire to complete the circuit (the anti-spark plug also suppresses the spark when connecting). Simple.
This is only copper wire i have? i just stripped the silicon http://imgur.com/TbWLSej would it work?

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by torqueboards » Oct 28 2015 8:13pm

That works. You just need conductive wire. You could even just use 10awg wire.

Of course, you should tin/solder around the loop key to strengthen it.
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Re: How-To: Anti-Spark XT-90 Loop Key

Post by camyboy » Oct 28 2015 8:39pm

torqueboards wrote:That works. You just need conductive wire. You could even just use 10awg wire.

Of course, you should tin/solder around the loop key to strengthen it.
I tried before like u told me and http://imgur.com/rngfZTT. The cable is too thick. just gonna heat up the end to remove the cable and try the copper

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by camyboy » Oct 28 2015 9:40pm

torqueboards wrote:That works. You just need conductive wire. You could even just use 10awg wire.

Of course, you should tin/solder around the loop key to strengthen it.
Hows mine http://imgur.com/JEIUonv

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by sl33py » Oct 28 2015 11:37pm

camyboy wrote:
torqueboards wrote:That works. You just need conductive wire. You could even just use 10awg wire.

Of course, you should tin/solder around the loop key to strengthen it.
Hows mine http://imgur.com/JEIUonv
Looks good! Make sure to insulate it so no exposed wire.

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by camyboy » Oct 29 2015 6:37am

sl33py wrote:
camyboy wrote:
torqueboards wrote:That works. You just need conductive wire. You could even just use 10awg wire.

Of course, you should tin/solder around the loop key to strengthen it.
Hows mine http://imgur.com/JEIUonv
Looks good! Make sure to insulate it so no exposed wire.
How do I do that if I already soldered it on

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by torqueboards » Oct 29 2015 9:22am

Your suppose to put the heat shrink to the side and finish off the soldering on the last end.

You should be fine though since that single plug doesn't cross polarity. You can just heatshrink the entire connector. And/or wrap with electrical tape and then heatshrink the connector.
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Re: How-To: Anti-Spark XT-90 Loop Key

Post by sl33py » Oct 29 2015 12:55pm

torqueboards wrote:Your suppose to put the heat shrink to the side and finish off the soldering on the last end.

You should be fine though since that single plug doesn't cross polarity. You can just heatshrink the entire connector. And/or wrap with electrical tape and then heatshrink the connector.
Agreed. I'd wrap a simple loop of electrical tape around the top of your loop to insulate it, then use any short length of string to pull on to disconnect. Heatshrink the whole thing and poke your string through, or you can simply pull on the plug/loop. I like the string option obviously. I also used a bright cord w/ reflective bits in case it gets dropped it's easy to spot w/ a bright light (headlamp, flashlight, etc.).

I'm just not a fan of exposed wire. Think if it got wet (not sure where you are placing it). Worst case i don't want to short if i can avoid it!

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by camyboy » Oct 29 2015 9:51pm

sl33py wrote:
torqueboards wrote:Your suppose to put the heat shrink to the side and finish off the soldering on the last end.

You should be fine though since that single plug doesn't cross polarity. You can just heatshrink the entire connector. And/or wrap with electrical tape and then heatshrink the connector.
Agreed. I'd wrap a simple loop of electrical tape around the top of your loop to insulate it, then use any short length of string to pull on to disconnect. Heatshrink the whole thing and poke your string through, or you can simply pull on the plug/loop. I like the string option obviously. I also used a bright cord w/ reflective bits in case it gets dropped it's easy to spot w/ a bright light (headlamp, flashlight, etc.).

I'm just not a fan of exposed wire. Think if it got wet (not sure where you are placing it). Worst case i don't want to short if i can avoid it!
Hows this? I can wrap some electrical tape too if needed http://imgur.com/a/cwo4I

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by sl33py » Oct 29 2015 9:59pm

Looks good to me!

I would heat shrink it to seal it up as well, but that's overkill. Yours is fine as is.

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by camyboy » Oct 29 2015 10:38pm

sl33py wrote:Looks good to me!

I would heat shrink it to seal it up as well, but that's overkill. Yours is fine as is.
Sweet thanks, I just wrapped some electrical tape. So this is my wiring set up, http://prntscr.com/8wxelw
For the XT90 I dont think It matters which +/- connects to but positive from battery is going in positive and exiting negative which enters the postive ESC,
The circle means I am going to replace that connector the the opposite. I believe its female connector.
The two X's near the XT90 means Im just going to remove them and soder them to the XT90 connector it self

Just scared to connect everything because I did before this and spark came out from the red series connector and burnt the connector. And of course I dont want to fry anything because this is 750$ from a minimum wage high school student is a lot.

Thanks for the help, really do appreciate it

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Re: How-To: Anti-Spark XT-90 Loop Key

Post by sl33py » Oct 29 2015 11:08pm

You need to make sure your batteries are connected correctly in series. The middle + and - should pair up and you should have one red positive and one black negative go to your esc.

Don't connect until that's clear!

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