Introduction: Functional Retractable Assassin's Creed Hidden Blade (Xiphoid)

Picture of Functional Retractable Assassin's Creed Hidden Blade (Xiphoid)

About a year ago I was inspired by a friend to make a xiphoid, commonly known as the Assassin Creed hidden blade. After making a video on YouTube that showcased my first design I received endless requests to make tutorials or sell my model. However, I wasn't satisfied with my first design and I came up with a second one that is sleeker, easier to use, and just plain cooler :D Since I'm a visual and hands-on learner, I've also created a a two part tutorial on YouTube that goes through all the steps and shows you the entire process. However, before you watch the video or go through the steps below I just want to let everyone know that while you can follow this tutorial and copy my design, I think it would be more beneficial if you tried to understand how everything works so that you can make your own changes to improve my design. Enjoy! I'll post the links to the videos when they're uploaded.

Don't forget to vote for this if you liked it!

Youtube Video Part 1:

Youtube Video Part 2:

Step 1: Materials

Picture of Materials
  • Richelieu 16" 400mm Center Mount Slide (Lowe's $5)
  • 9" or 22.8 cm Letter Opener (Staples $3)
  • Hillman Extension Spring 1/4" x 3" x .025" OR use a spring with a longer length only that can be cut down to size (Lowe's $4)
  • 14-Count #6-32 x 3/8-in Round-Head Standard (SAE) Machine Screws with Nuts (Lowe's $1.50) AND some panhead screws of the same size
  • IRWIN Tap and Die Set 6-32NC (Lowe's $5)
  • 6" 150mm General Steel Rule (Ace $4)

Step 2: Modifying the Drawer Slide: Dismantling & Large Slide

Picture of Modifying the Drawer Slide: Dismantling & Large Slide

The first thing you need to do is take apart the draw slide. On the back there should be some tape that you need to pull off. Where the tape was is a part that you can slide off, remove it. You won't be needing these pieces so you can toss them away.

Now you need to separate the slide into its three parts which I call the Large Slide, the Slider, and the Small Slide. To do this you need to fully extend the slide. Once you have done this you'll notice a notch in the Large Slide that prevents the other pieces from falling out. You need to remove this piece in order to modify each piece. In the photo above you can see where I cut Large Slide, the angled cuts are purely for aesthetics so it doesn't matter if you prefer to cut straight down. Just make sure to keep the hole within where you cut so that you won't have to drill another one.

Once you have removed this notch you should be able to slide each part out. MAKE SURE THAT YOU HAVE A CONTAINER OR MAGNET TO CATCH ALL THE BALLS WHEN YOU SLIDE OUT THE SLIDER.

Take the Large Slide and measure out 9 7/8" (if you go with 10" it's not a big deal, I'm just going with what worked for me the first time). Once you have marked it go ahead and cut it. Make sure after all your cuts you grind down the edges to make it smooth.

Step 3: Modifying the Draw Slide: Small Slide

Picture of Modifying the Draw Slide: Small Slide

This part is straight forward, you need 3" of the small slide. Make sure that the 3" that you use do not have pre-drilled holes in them. We are going to make and tap our own holes. Once you have cut your small slide place it in a vice, with just the bottom edges in the grip, and compress it gently. The purpose of this is to allow the small slide to slide back and forth smoothly and easily once placed back on top of the slider and large slide. If this is confusing refer to my YouTube video, it's a lot easier to see what I'm trying to explain.

Step 4: Modifying the Draw Slide: the Slider

Picture of Modifying the Draw Slide: the Slider

The next thing to do is cut a slit in the Slider to hide the spring in. In my previous model I had the spring on top but I decided I didn't like how it looked on top and so I have hidden it in this model. When cutting this slit make sure that it's 2.5" long and just a hair wider than the spring so that it doesn't scratch on the sides when extended. When cutting try not to bend the metal. Remember patience is key, so cut this gently and slowly!

Step 5: The Blade/Letter Opener & Small Slide

Picture of The Blade/Letter Opener & Small Slide

For my Xiphoid I decided to use a letter opener as the blade. However, if you want something that looks a little more lethal and want to make your own blade just understand that where we drill our holes may be a little different. If you use the letter opener I used you will already have a hole drilled into it and will only have to drill three more holes. Using the photo above line up the letter opener on the small slide and make sure that the blade curves down (this only applies if you are using the same letter opener as me). Once you have marked everything go ahead and drill your holes and then tap and counter sink the appropriate holes (refer to photos). Now you need to take three of your flat screws and screw them all the way into a nut. Once each screw is in a nut place it in a vice and cut the portion of the screw that is not in the nut. Once you are down unscrew the nut (the purpose of the nut is to reform the damaged threads of the screw once you cut it) and use these where you tapped your holes.

Step 6: Large Slide Drilling: Blockers

Picture of Large Slide Drilling: Blockers

So now that we have cut our large slide we need a way to prevent the slider and small slide from coming out. If you have been following me exactly you will already have one hole at the end of the large slide. All you need to do for this is place a screw and three nuts in this to block anything from going out the back. For the front we will need to make our own hole. Because the blade is in the center of the design the block at the front will need to be off set. In the photo above you can see that I drilled my hole on the right. Once you have drilled this hole counter sink the bottom side of the large slide and use two nuts on top.

Step 7: Assemble

Picture of Assemble

Now that you have the large slide, slider, small slide, and letter nearly finished you need to put them together. Slide the slider on and use one ball for each segment (the slider has segments that have three holes for balls, I only use the center hole of each segment to cut down on friction) and them force the small slide on with the letter opener on. It should start to look like the finished product. When you put the small slide on push it all the way forward and then force the slider all the way forward as well so that they both hit the front block together. This is key otherwise the design won't completely work.

Step 8: Ruler

Picture of Ruler

Take out the ruler or piece of metal that you are using for the locking mechanism (any spring metal will do) and place it on the back of the large slide with enough protruded from the front so that when bent the metal will touch the letter opener at an angle. I highly recommend you watch the video for this part since I can't explain it very well. You can also use the photo above and just copy the dimensions. Once you have cut the ruler to size you will have to drill three holes into it. Two holes will be used to mount it to the large slide and one hole will be used for the string, which I will explain later on. Tap the holes on the large slide and use panhead screws to attach the ruler.

Step 9: Spring

Picture of Spring

Take your spring and make it 3" long. 3" is from the outer loop to the outer loop NOT the compressed portion of the spring. Once you have cut it and bent a new loop at the end take this spring and put one loop underneath the nuts of the back block on the large slide.

Step 10: String

If you have been following me exactly, the back of the large slide should have a hole that was already drilled. Take your string and knot it up and then pass it through this hole. Then thread the string underneath the slider towards the spring. Loop it around the spring and then thread it over the slider but underneath the small slide. Then pass it through the hole on the letter opener. Next, move the letter opener and small slide all the way back until the small slide hits the back block. Pull the string taunt and then knot it as close to the letter opener as possible. Now take a new piece of string and tie it on the ruler/locking mechanism. Next create a loop or tie the string to a key chain ring.

Step 11: Finished

Picture of Finished

If you assemble everything together now you should be finished. When swung the blade should be locked by the ruler and then release when the string is tugged. If the blade doesn't contract all the way you could 1.) compress the small slide even more 2.) Use less balls so there's less friction 3.) Use a different spring

Step 12: Dimensions

Picture of Dimensions


xGuardianHaven (author)2014-07-14

Freaking awesome dude. I was searching for 2 weeks on how to make one and this by far is boss

JasonE39 (author)2016-03-30

Do you think the springs could handle this blades load?? It is much hardier than previous blades i've seen done on here.. Around 3.35 oz.... Please help any tips would be appreciated..

michaels989 (author)JasonE392017-07-10

Im having that issue right now, im doing upgraded springs in a shoulder piece, led to a brake style cable to the blade. If youre still interested let me kniw illlet you know how it turns out.

Daniel Stabile (author)JasonE392016-03-31

Yes I think so, you might need to tweek the spring size and strength but I think you can definitely make it work

EvanR36 (author)2017-04-18

Just finished Hidden Blade Mk. I! Thanks for the tutorial!

oKtaveus (author)2017-04-18

im going to to try to make it, possibly.

EvanR36 (author)2017-04-13

First let me say, this was a ton of fun to build! I'll bet I was really making my neighbors upstairs mad while I was sawing away!! It's all good though, because the one guy walks around really really loud...

Secondly, has anyone found any creative ways of fixing a cover over the exposed side of the device?

ameliagns2004 (author)2017-04-01

Could you include a list of the tools you used to make this?

ESTEBANR46 (author)2017-01-23

Is this easy to make please reply

MikeW334 (author)2016-12-26

what size counter sink did he use

KnightCrawler777 (author)2016-07-22

Is it possible to make it so the blade doesn't stick out about half an inch, after being retracted, for safety reasons? And make it so that it extends the same way it retracts?

I would guess that you should shave down the pointy end of the blade, remembering to make an even point and yet sand it dull

Appl3s (author)KnightCrawler7772016-08-10

I'd say to cut the letter opener down the amount you need

AmirO3 (author)2016-10-03

like it

Appl3s (author)2016-08-10

Hey, how would I go about attaching this to some Velcro or something to strap it to my wrist

Ayahne (author)2016-05-10

Hi ! I don't have a ready hole in the slider : could i have the measurment of where it is ? Thanks !

Daniel Stabile (author)Ayahne2016-05-10

Unfortunately, I'm at college right now and don't actually have the xiphoid with me. The best I can do, is suggest that you look at one of the diagrams I made above and use the measurements on their that I put to best approximate the location of the the hole

Ayahne (author)Daniel Stabile2016-05-10

Okay, thanks, i've done it and it seems to work nicely ! (Good luck at college ! :) )

Daniel Stabile (author)Ayahne2016-05-10

Thank you!

JMFogster (author)2016-04-19

Just one thing I'm having trouble with: How do you lock it in place when extended? Please Reply

Daniel Stabile (author)JMFogster2016-05-10

Please watch the videos, they will explain everything

AdilJ3 (author)2016-04-17

Is this legal in canada?

ArmaniT (author)2016-04-16

Instead of a single ring, why not add an armoured gauntlet and bracer to go with it.

ViktorRockatansky (author)2016-03-16

Nice! I plan to make this with a few variations. Blind rivets instead of screws, as they have a smaller profile, and I plan to make it so that it rests on top of the forearm. It will be for a post apocalyptic bounty hunters set!

Theluke (author)2016-01-13

Would a 5/16 inch spring work, I can't find any 1/4 inch ones long enough.

Daniel Stabile (author)Theluke2016-01-13

Yeah, you might have to change some things in the design but you should be able to make it work

amias71214 (author)2015-05-25

Hi! I was wondering what we could use if we didn't have the tap and die kit

Sorry for the late response, tapping the holes were mainly for aesthetic reasons so you could get away with not doing them. However, I would try to find screws that had smaller heads to give the blade a more compact look. Hope this helps :)

ReginaldS1 (author)2015-07-13

I really liked this! This is what a hidden blade should be like: gravity-driven. You cannot expect to freerun with a double-action hidden blade for you might accidentally flick your wrist while say, you're vaulting, and suddenly releases the blade out.

Also, I've seen a lot of tutorials just like this but the fact that you used a letter-opener which is thinner than normal blades is so cool and practical. We all know that the thinner the blade, the lethal it gets; talk about an ice pick puncture vs. knife stab.

Overall, it's great. May the Father of Understanding guide you.

Thanks! I'm really glad you liked this and I really agree with you about it being better gravity driven. Sorry for the late response :P

SLAYGAMERZ (author)2015-11-04

I will like to make one but I'm wondering do you need to push out the blade with you hand or can you just swing your hand down and it will pop up

I'm sorry for the late response. I designed this model so that all you have to do is swing your arm. You can change the amount of force it takes to extend the blade depending on the amount of string you use and your spring

ElvenAssassin77 (author)2015-12-08

Are you willing to make and sell one to someone and how much?

I'm sorry, I don't sell these because I don't know what people will do with them and I don't want to get anyone hurt

This is my version I made a while ago. you should check it out! Very nice build here!

SLAYGAMERZ (author)2015-11-04

Can you swing your arm and the blade will come out? Or do you need to pull it out yourself

MilesB4 (author)2015-08-30

Hi there! i'm trying to create a pair of claws for a wolverine fancy dress costume i've got everything else but walking around with claws constantly between my knuckles didn't seem appealing i was wandering if you knew a way to edit your design so it could encompass three blades instead of one?

Daniel Stabile (author)MilesB42015-08-30

Hey, so my design probably won't work for you but I know I've seen some pretty cool wolverine claw designs on YouTube and I know that some are even adapted from similar Assassin Creed Blades

SlashingAssassin (author)2015-07-29

hey dude I was just wandering how much would you want to sell one of those

burgeroti (author)2015-06-08

Pretty awesome

thunderca (author)2015-05-30

good work

lukemills (author)2015-05-03

Thanks I've been looking for a good tutorial for months
However could the spring be replaced with an elastic band

Daniel Stabile (author)lukemills2015-05-03

Yup but you'd have to play around with it to find the right length/strength

Karim Assaf (author)2014-10-17

It's awesome. Very ideal. But there is something that you have forgotten. It's to make the brace that will handle it. Thanks for the idea i've been searching for a hidden blade like that one!

If you get another slide large enough or mold one that won't cause friction you can bolt leather to it (if done properly) making it all one full bracer. I did it with mine, sharpened it, and it's amazing. Doesn't break, doesn't rip, slides nicely.

wiimaster181 (author)2015-03-30

Where can i just buy one?

originNightwing (author)2015-02-05

Great design! I have been looking for a good homemade hidden blade tutorial for awhile now.

gksmainali (author)2014-11-02

Will these drawer slides work...because the one which you showed is not available in India...

LarryM1 (author)2014-10-15

If I may, I would like to see the PDF files for this instructable as I would not like to pay to be able to see them. I am in the progress in making a AC4 cosplay costume, and all I need now is the hidden blades. I do not want to waste my money on a toy object that could break in less then a few uses; I would like to make something durable that is worth my money to be spent. Thank you for reading this, just send the files if able to me. Again, Thank you.

Daniel Stabile (author)LarryM12014-10-21

I'm sorry if this comes too late

About This Instructable




Bio: I'm an engineering student at Cornell University with a passion for making things!
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