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HOWTO: Cricket's Magnetic Shin Closures


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After being asked a gazillion times about how I built my magnetic shin closures, I've finally compiled everything from my TK build and put it all in one post!

Let me begin by stating that I followed the tutorial here for the most part when building these magnetic shins.  However, I deviated from it in order to make the closures super strong by using a magnet-to-magnet closure rather than the magnet-to-steel method outlined in the tutorial.  I have worn the magnetic shins I made for my RS Props TK out on over a dozen troops, and I have never had them come apart on me.  I've only had to reglue magnets twice on these shins over a two-year period:  a single magnet came off after being handled a lot (opened and closed dozens and dozens of times at an armor party by those who were trying to figure out how they work), and regluing a single magnet after trooping underwater for a few hours (well, not exactly underwater, but it was a parade where it rained for HOURS and I had to walk in the rain the entire time- for hours I tell you!  My boots took days to dry out!). 


The small amount of maintenance I've had to do on these over 2 years of trooping is quite minimal.  Once you get this mod on your kit, I swear you'll never go back to anything less than a magnetic closure on your shins.

There are many steps necessary to build magnetic shins, so I begin with making a critical component for them:  ABS buttons.  The buttons are necessary to hold one half of the magnet assembly in place on the inside of the shin. 


I'm using 12mm x 3mm n50 magnets.  You'll need a total of 20 magnets for the shins (10 on each shin).  I strongly suggest buying more than 20, though.  I've found that they can easily break, and you'll want backups on hand!  You can find them in bulk- and cheap!- on eBay. 


First, I begin by making a template with a hole in it that is slightly larger than the magnets I will be using.  I trace the magnet on a sheet of ABS.




Here's what it looks like when done.  Yeah, I know my hole isn't perfectly round.  It's not terribly important for it to be perfect.




I used two magnets to make each button.  One on top to help me see where my hole template needed to go, and one underneath to form the button shape.




Heat up one section of the ABS sheet using a heat gun on LOW until it gets slightly warpy.  You can even leave the magnets attached to the ABS while you heat it up.  Once the plastic is soft, quickly press it onto a flat surface, pressing the hole template around the exposed magnet.  This is what it looks like on the top and underneath when you're done.




And here's how it looks from the side so you can see how the magnets attach to the plastic.  See how the bottom magnet sits flush in the new ABS button?



I spent about forty minutes repeating the process until I ended up with 10 buttons.




I will cut down and shape the buttons to fit each shin later.  There will be five buttons installed on each shin.  Still lots of work to do, but it's a pretty good start!



Another step necessary for how I make my magnetic shin closures is to make sure that the backs of the shins meet up as perfectly as possible.  This is to avoid any unnecessary strain on the magnets.  This was acheived by some gentle shaping via a hot water bath.  Before putting the shins in the water, since I don't have any cover strips installed on the outsides, I reinforce the closure with blue tape.  The e6000 gets really soft when subjected to boiling water, and I don't want to weaken the join in the front.  Blue tape holds up nicely for this application!




Here's a before and after of my shins so you can see how the backs line up a bit better.  I will be doing some further fine tuning on the lengths at the bottom later as I move along in my fitting.  




This stage involves making and securing the "holes" part of the closures for the magnets.  I begin by cutting out two 3/4" x 12" strips of ABS.




You should have this when you're done.




Next make a lengthwise mark in the center of each strip to help keep your holes lined up in the middle.  Then mark 3/4" in from each end.  That will be the center point for the magnets on the end.  I like using magnets with holes in the middle for this, so I can easily find the 'crosshairs'.  Trace the magnet.  I like to use extra magnets underneath to help keep it secure while I trace.




Next, find and mark the center of the strip.  It should be at the 6" point.







From there, measure 2 5/8" from the center mark on either side.  Mark and trace your magnets.




When you're done, your plastic strips should look something like this:




Next, I used my drill press and a step bit to drill out the holes.  It went really quickly!  When you're done, you should have two strips with holes in them that can easily fit the magnets.



The next part is where people tend to get confused, so I took this photo to show what goes where.  The "hole" strip will be glued to the inside half of the shin on the inside.  It sounds kind of confusing, but it's not all that bad.   Remember that the "hole" strip will be hidden!




I begin with my left shin.  I mark the center of each hole to assist when I line up the edge of the shin.




Next, I test fit the strip on the shin to verify placement, clamping on both ends.




Then I apply e6000 to the area of the strip that will be in contact with the shin, clamp and add magnets.  This is what it looks like when glued together:




Here's the right shin after gluing, but before I added the magnets.




Here are both shins as the e6000 cures.  




I'll be allowing a few days for this to cure, which will give me ample time to get my ABS buttons ready for installation.   


Once the glue had cured on the hole strips inside the shins, I removed the magnets and clamps.  With a light behind the shins, you can see how the hole strips are mounted, hidden inside.




Using that light as my guide, I traced the approximate location of the holes with a pencil.  This helps me to get a good idea of where my holes are going to be drilled.  Yep.  I'm going to make some Swiss cheese of my shins.  



Using a small Dremel sanding band, I carefully cut a notch out, just large enough for a magnet to fit through.  Here's what it looks like at this stage when the shins are closed.



I'm just focusing on drilling out the holes on the inside edge, following the holes of the hole strip that was glued in.  I'm not ready to drill the outer half of the shins yet.




Next to clean up my buttons that will hold my magnets.  I rough trimmed them all to start.




Then cleaned up the corners with a Dremel.  I don't want anything poking at my legs!




*Important!* If you want to make sure your magnets stay stuck on your shins, you must use e6000!  CA glue will not keep the magnets stuck to the buttons; they will fail.  I have heard this from several troopers when I have been contacted about their magnets not holding up.  I repeat, use e6000 for this next step!  


I applied a liberal amount of e6000 to the inside of each button, then put the magnet inside to get all cozy.  Make sure that you've got the polarity of all the magnets in the same orientation before gluing!  Wipe away any excess glue from the top.




To make sure that the magnets are firmly mounted in the buttons, I use the magnet intended on going on the opposite side of the shin to clamp it.  In the pic below, you can see how I've got all the matched magnet buttons and magnets together as they cure.




Back to the shins now.  I like this ridge (where the pencil is pointing) to line up at the tops.  For me, it makes the closure in the back look much cleaner if this is lined up.  I tape it off there to make sure that the opposite side doesn't shift while I'm making my marks for completing the holes.



I have an OttLite that fits nicely inside the shin to provide a clear light so I can make outlines for where I'm going to drill out the rest of the holes.  Holes were already present on the left side in the photo below.  




I made sure that I drilled out the holes very conservatively as I went.  I used an extra magnet to make sure that the hole was just the correct size for it to fit through. 




Now time to attach the outer cover strip!  I use a 25mm cover strip on my shins for this.  I taped off the edge of the inside half to keep any glue from transferring over.  



Then making sure that the cover strip was straight, I clamped the heck out of it.  Praying to the TK gods that it doesn't shift!!!!




Now time to wait for everything to cure really, really well.  I am going to give these 3-4 days to fully cure just to be on the safe side!


One shin is complete, with the outer rear 25mm cover strip glued into place.  Woo!




Here's a look from the inside, before magnets are installed.  Be sure to clean up all excess glue from the inside edges in order to have a clean closure when you're done.  If there's extra glue in there, it may not close correctly.




I've tucked the outside cover strip to the inside so you can see how the magnets on the "cover strip" half are glued on.  No magnets yet.




I add a dab of e6000 to the magnet (be sure to check the polarization of the magnet before gluing!!!), and set it so that it fits inside the semi circle and on the outer cover strip.  Like this:




I wiped away the excess glue from the magnets and then positioned the inner "hole strip" over the magnets to ensure everything is lined up correctly as it dries.  I tape the tops and bottoms of the shin to ensure it doesn't shift around during this stage. 




I'm not completely happy with how the inside cover strip is cooperating here.  It sits flat on the top and bottom, but it pulls away in the middle a bit off to the right.  I will have to heat bend this before installing the magnets onto the "hole strip".  :/  Ideally, the inside cover strip should be sitting completely against the outside part of the shin, and it doesn't want to do that right now.  This additional stress could cause the magnets to fail.  It's annoying, but I'll need to address this before proceeding any further.  Gah!


Using the magnet buttons I created earlier, I clamp the magnets into place while the glue cures.




Once the glue has fully cured, I'll reshape that inner strip to prepare it for the final magnet button installation.



Now that the e6000 has had lots and lots of time to cure, it's time to attach the other halves of the magnets.  Make sure that the halves are super clean and free of extra dried glue.  It will prevent the shins from closing well.  You can do this by touch.  Rub all of it off where you feel it.




Once everything is cleaned off, close the "hole" half over the "magnet" half.  Your shin should be closing correctly at this point.  The "holes" should lock around the magnets and prevent the shin from opening at all, even without the additional magnets at this point.  If the "hole" strip is not fully engaged over the magnets, you won't have a very strong bond between the magnets to keep the shin locked. 



Easy part next!  Apply e6000 around the prepared ABS button.  No need to go crazy with the stuff.  You don't want it oozing all around in there.




And stick it on!




This part goes really quickly.  




For additional strength, I add some extra magnets on top.




Check those clean closures!  Left shin.




Right shin.




I will open these up in a few hours just to make sure that there isn't any extra e6000 that has spilled out and might lock those shins closed where I don't want them locked.

Now to allow several days to dry, and these shins will be good to go!

Here's a short video so you can see them in action.


Have you tried this on your own shins?  Loved it?  Hated it?  Made a few mods of your own to improve this method?  Comment below and let me know!




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  • 8 months later...

Just wanted to say a big thank you for this tutorial - it worked brilliantly for me, and I'm pleased to say I passed Centurion the other week!


Pretty much followed the tutorial to the letter, although I did accidentally order magnets that were half the thickness that I needed, so ended up having to sandwich two magnets with a bit of E6000.


One thing to note is to shape the bottom of the shins with boots on - I found that the extra thickness of the back of the boot does push against the bottom magnet a little so that's something I wish I'd made more effort to take into account during my build.


Thanks again!

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Hey Simon!

First, congrats on earning your Centurion!  :th_AnimatedBravoSmiley:   You need to update your signature to reflect that you are *done* with your TK now!  ;) 

Second, thank you for the kind words about my little tutorial.  I'm glad that it was able to guide you through your build!  Aren't magnet closures simply awesome?!  I couldn't imagine trying to fuss with velcro or bra hooks now.  Magnets make TK life much easier.

Yep, it's always important to account for the additional material on the inside of the boot when you're fitting these for sure.  I didn't really highlight this because I've always built my own shins on the smaller side, so it's never been on my radar!  It's true that you don't want to size your shins to be super-duper snug before installing the magnets.   Maybe leave an extra few millimeters around the bottom to allow for the buttons at the ankle, I suppose.  That said, those magnets should still remain closed, even if they are a little tight at the ankle.  Definitely a great tip for sure, Simon!


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  • 1 month later...

Thanks!  I used some thin, non stretchy fabric.  Kind of like cotton duck cloth, but thinner?  And small zip ties.  Use one color for one polarity, another color for the mate to keep pairs easy to match.  

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  • 1 year later...
On 12/7/2018 at 2:26 AM, Cricket said:

After being asked a gazillion times about how I built my magnetic shin closures, I've finally compiled everything from my TK build and put it all in one post!

definetly on my todo list in the future those look awesome.good job.

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