# Recreating Tana's Judco Switch for Z41 Tailcaps / How To



## mk2rocco (May 7, 2015)

This is an attempt to recreate Tana's Judco switch mod, his original thread can be found here: http://www.candlepowerforums.com/vb...igh-amperage-DD-triple-quad-setups&highlight=. In this thread I'm going to track my progress and hopefully document some mistakes so you guys won't have to make them.

The supplies:

- A couple Judco switches: http://www.digikey.com/product-search/en?mpart=40-4520-00&vendor=78
- A threaded Mcclicky adapter ring
- Mcclicky switch boot
- Washer

















The 10A Judco switch:






Cut the switch so there it is even with the opposite side of the button:






Be extremely careful not to cut into the contacts coming out of the switch body. I made cuts on all 4 sides, then had to carefully pull the scrap plastic away with pliers.











After clean up with a file:






You can see in this picture that I had to file the 4 corners of the switch body so it would fit in the threaded adapter (Mcclicky adapter). One of the contacts is also folded over, this is for the spring that will contact the negative terminal of the battery. *Be very very careful when bending the contacts*, you only have one shot when bending them. If you attempt to unbend and re-bend them the contact will snap right off, ask me how I know 






I also filed off the lip around the top of the button so I can fit a spacer.






I used a washer I had lying around, it fits the inner diameter of the Mcclicky adapter perfectly and is very snug around the switch. Without this washer the button of the switch protrudes too far out of the top of the tailcap. 






It fits the adapter nice and snug, now we have to trim the other contact:






Perfect!






I did not get a picture of the contact soldered to the side of the adapter but you get the idea...

Now fill with your favorite epoxy and wait for till I get some copper sheet and springs 






I'll update this thread when the rest of my parts come in, I'm really excited to finish it up!


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## mk2rocco (May 7, 2015)

I'm also going to make some Z41 switches out of an ebay 6A+ forward clicky. It looks like the ebay switches will easily fit inside on a tailcap without being modified.

Ebay Switch: http://www.ebay.com/itm/141172162679?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT

I have seen some testing of these running 16A for hours with no damage


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## Tana (May 7, 2015)

mk2rocco said:


> I'm also going to make some Z41 switches out of an ebay 6A+ forward clicky. It looks like the ebay switches will easily fit inside on a tailcap without being modified.
> 
> Ebay Switch: http://www.ebay.com/itm/141172162679?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT
> 
> I have seen some testing of these running 16A for hours with no damage



Looking great...

That 6A+ switch from eBay looks like a copy of Omten switch... 

Edit:
Uh, oh... that JB weld went over the contact area of the adapter, there will be no contact with the body...


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## mk2rocco (May 7, 2015)

I'm going to be using this switch in a TnC 26650 tailcap with makes contact via the threads. I was kind of disappointed because there is no lock-out function. I should have noted that for people trying to make one, thanks for pointing that out. I'll check out the Omten switched also, I would love to have a forward clicky switch capable of 10A.


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## mk2rocco (May 8, 2015)

Tana pointed out that I covered the top of the adapter ring with jb weld. The end of the ring is what completes the circuit and why the tailcaps can have a lockout function. Here it is all cleaned up [emoji41]


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## nfetterly (May 8, 2015)

Thanks, great write-up.


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## mk2rocco (May 12, 2015)

Thanks! I still got a long way to go, just waiting on my springs to come in.


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## mk2rocco (May 19, 2015)

Springs are in! I can finally get these switches wrapped up [emoji2]


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## weed099 (May 21, 2015)

Looking good. You know you can't start a thread like this without the rest of us wanting you to make us some too.


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## mk2rocco (May 21, 2015)

weed099 said:


> Looking good. You know you can't start a thread like this without the rest of us wanting you to make us some too.


Haha, I'm trying to figure out if I can sell them as they take quite a while to make. I think I could produce them in 10 switch batches, just want some practice making a few for myself and friends first.


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## mk2rocco (May 22, 2015)

Made some good progress tonight on the design. Instead of bending the contact for the spring all the way around the top I made a little leg off the copper plate and bent it over.


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## mk2rocco (May 22, 2015)

Came out great!





Thanks Tana for showing us this awesome mod [emoji1]


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## mk2rocco (May 22, 2015)

And one last shot in the tailcap [emoji41] 






I tried epoxy on this one and really didn't like it, I'm going back to JB Weld. I think is looks so much cleaner and stronger.


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## Tana (May 22, 2015)

Great progress, mk2rocco...

All that one person need is soldering iron and some craftiness to pull this thing through... count on destroying one or two Judco's in the process but it's all the part of the fun (plus they are not expensive)...

They are however time consuming which is why I limited building mine only for my own builds/mods that really need it (triple and quad MOSFET builds)...


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## mk2rocco (May 22, 2015)

Thanks! One switch probably took me 3 hours total. I absolutely understand why you don't want to sell a bunch of these things.


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## mk2rocco (Jun 5, 2015)

I got these things down now. Probably took me 15 switches till I figured it all out. I got a wire soldered in on this one to bypass the spring.


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## Tana (Jun 7, 2015)

Here are two of mine I made in the past few days, prepared for two high amperage Quad XPG2 builds:


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## mk2rocco (Jun 7, 2015)

Such clean work! What Springs are you using? The copper beryllium springs work well but are a little short for some cells.


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## Tana (Jun 8, 2015)

mk2rocco said:


> Such clean work! What Springs are you using? The copper beryllium springs work well but are a little short for some cells.



Heavy duty spring, I think it was from intl.outdoors... 1mm thickness... inside is a piece of wire that takes care of most of the current but I needed something that will not be "fluffy" under high currents... I do use that spring like you have on driver side (so cell is safe and snug between them two)...


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## mk2rocco (Feb 21, 2017)

Bump!


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## knucklegary (Mar 8, 2022)




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