Assassin's Creed Hidden Blade - Functional Prop!!

In this Instructable I will be teaching you how to build a working replica of the Hidden Blade from the Assassin's Creed video game series. Don't be intimidated by the number of steps involved, this is a fun project that should only take you a few days in your workshop and should only cost you around 30 or 40 dollars.

My Design Goals for this Project:

I wanted the Hidden Blade to be functional, (to either extend or retract by moving my hand or wrist).
I wanted it to look as nice as possible and as real as possible.
I wanted it to be easy to build.
I didn't want it to require a lot of special parts or tools.

The process of making the Hidden Blade can be broken down into two main parts:

Building the blade mechanism (Steps 2-6)
Making the Leather Bracer (Steps 7-13)

Materials:

Hidden Blade Mechanism Materials List:

16” Drawer Slide – This will be what holds the blade and allows it to extend and retract. You can purchase this from home improvement stores like Lowes or Home Depot for about $6. It is important that you get exact same one that I used otherwise the measurements won't work out properly. examine the included picture for product details.
Replica Blade – I used a replica WWII dagger for this. the measurements of the blade are 10.5"long, 3/4" in width at the widest point, and 1/8" in thickness. These measurements, especially the 1/8" thickness, are important because there is not a lot of clearance between the moving parts of the hidden blade so be prepared to do some file work to make things fit. To get the blade, dismantle the dagger and discard the handle, pommel, and cross guard components. The blade I used came very dull with smooth rounded edges, if yours is sharp or pointy I highly advise that you sand away the edges so that they are nice and dull, this will make it safer to use and may keep you out of trouble. Cost $12, purchased at local flea market.
Small Coil Spring – This spring will be what retracts the blade when it is extended. It needs to have very light pull strength and should be 3 to 4 inches in length and approximately 1/4" in diameter. I purchased mine from Lowes home improvement store as part of a variety pack of springs for around 3 dollars.
Flat Spring – This will hold the blade in place when it is extended. you can make this component out of an hacksaw blade, simply cut off a three inch piece of the blade and grind away the teeth.
Assorted small nuts, bolts, and washers – The size of the nuts, bolts, and washers doesn't really matter, anything around 1/8” will do fine. You’ll just have to drill your holes based on the size of bolts you are using.
Small Nails – These will be cut and turned into rivets to attch the blade lock in step 5.
Rubber Washer – when the blade retracts it retracts with a lot of force, this will be used to dampen that force i.e. shock absorber. you can purchase rubber washers in various shapes and sizes at hardware stores, you do not need to have the exact one pictured, just something similar.

Leather Bracer Materials List:

2 square feet of 5 or 6 oz. leather – This can be purchased at leather suppliers such as Tandy Leather, however you can also use leather from an old suitcase or coat to cut down on cost.
Leather Dye – For coloring and finishing your leather, if you use repurposed leather from an old suitcase or coat you won’t need this.
Button Snaps – These can be purchased from retailers such as Tandy Leather or Michaels Crafts.
Rapid Rivets – These are used to attach the blade mechanism to the bracer. They can be purchased from Tandy Leather or Michaels Crafts.
Ring – Pick something that fits either your middle or ring finger.
String/Cord – Pick something strong but light, kite string or the inner strands of paracord work very well. You’ll need about 1 foot of this.

Tools:

Dremel Tool and Metal Cutting Disks – You will use these for cutting and modifying the draw slide parts. If you don't have access to a Dremel, you can also use a metal hacksaw for the cuts.
Files and Sand paper – For removing sharp edges left by Dremel cutting disks.
Drill and Drill Bits – You can use a hand held drill or a drill press, both work well.
Wire Cutters – For cutting your spring to adjust its strength.
Screw Drivers – Installing screws.
Metal Center Punch - For marking where you are going to drill holes on the drawer slide and blade.
Hammer – for peening down rivets.
Xacto Knife/Utility Knife – For cutting your Leather.
Paper or Poster Board – For creating patterns for your bracer.
Leather Working Tool (Beveler) - This tool is used to create the Assassin's Creed symbol and designs on the leather bracer. The one I used is known as a B60 Craftool Beveler Stamp and is available from Tandy Leather for around 8 dollars.
Awl/Drill/Leather Hole Punch – Some way of putting holes in leather.
Ruler – Creating patterns.
Pencil – Marking patterns on leather.
Permanent Marker - For making patterns and cut lines.
Safety Glasses - Always wear eye protection when drilling and cutting the metal parts of this project.

Disclaimer: Please use common sense when making and wearing this prop. If you have any concerns about the blade material feel free to replace the steel blade with a wooden or acrylic analog. If you're planning to tackle this project then you most likely already have all the skills necessary to make whatever changes you deem necessary to make this prop suitable for your specific situation and needs. Be safe and be smart!

Step 1: HIdden Blade - Dismantling the Drawer Slide

Start building yoru Hidden Blade by taking apart your drawer slide. The slide is built with little tabs of metal that are bent up to keep the inside parts of the slide from comming out, so the first thing you have to do is find those tabs of metal and pound them down flat with your hammer. The tabs are located on the front and back of the outside slide, if you're having a hard time finding them, use the pictures for reference.
Once the tabs are pounded flat the drawer slide will pull apart. As you dismantle the slide the bearings that sit between the inside and outside slides will fall out, use a small dish to catch them as they fall, don't worry if you lose a few, you won't need them all.
When everything is taken apart you should have the parts shown in the last picture of this step, the outside slide, the inside slide, the bearing track, the bearings, and the bracket.

Step 2: Hidden Blade - Modifying the Slide - Cutting

Now that your Draw Slide is disassembled it's time to start cutting the pieces apart to make the parts we need. Take a look at the pictures to see what to cut and where to cut, (cut on the black sharpie lines and use the ruler for measurement reference). Use your Dremel Tool with the Metal Cutting Disks (or hacksaw) to make the cuts and always remember to measure from the correct end. Once your cuts are finished you may have to file or sand the raw metal edges so that they aren't rough and sharp. Don't forget to wear safety glasses!

Step 3: Hidden Blade - Modifying the Blade & Attaching It to the Inside Slide

With the drawer slide parts cut it's time to move on to the blade. Start by cutting off the part of the blade that went through the handle so that you only have the blade left. Next you need to drill holes to mount the blade to the modified inside slide. Use the holes on the modified inside slide as a template for where the holes in the blade should go. Mark the holes with a sharpie and then use a center punch to make an indentation so that your drill bit stays in place as you drill. You will be using your counter sunk screws to hold these parts together once the holes are drilled so use a bit that is slightly larger than size of your counter sunk screws shaft to drill the holes.

Note: Even though the blade is from a replica dagger it may still be a hard type of steel so take your time when drilling and use a lot of lubricant to keep the friction and heat to a minimum, otherwise you'll wear out your drill bit quickly.

Note: DO NOT try to hold something you are drilling with your bare hands, doing so can result in serious damage to your hands or loss of fingers. Always use a vise or clamps to hold the piece you are drilling and keep your hands well out of the way.

Once you’ve finished drilling your holes switch to a larger drill bit, 1/4 or 3/8 and redrill the holes part way to create counter sinks for your counter sunk bolt heads to fit into.

Lastly use your counter sunk screws, washers, and nuts to assembly the blade as shown in the pictures.

Step 4: Hidden Blade - Modifying the Slide - Drilling Holes

With the blade assembly finished, there are only a few more things to do before we can assemble the Hidden Blade mechanism.

Making the back stop of the Hidden Blade
This will be the piece that keeps the blade from shooting out the back of the hidden blade when it is retracted. Start by drilling a hole in the center of your modified bracket. Next lay this piece on top of the outside slide as shown in the picture and use it as a template to drill a hole through the outside slide so the two can be bolted together.

Drilling holes for attaching the Hidden Blade to the bracer
Take this time to drill a few holes down the center of the outside slide, (3 or 4 holes should be plenty). These holes will be used to mount the Hidden Blade to the bracer later on in this instructable. Drill the holes just big enough for the shank of the rapid rivets to fit through.

Step 5: HIdden Blade - Reassembly and Creating the Blade Lock Mechanism

Now that you have all the cutting and drilling done it is time to reassembly the blade mechanism so that you can move on to the next step, creating the blade lock. To reassembly the blade mechanism reinsert the ball bearings into the ball bearing track and slide it into the outside slide as shown in the picture. Once you have the bearings and bearing track installed into the outside slide, insert the blade assembly into the bearing track. Lastly install the bracket onto the back of the outside slide using a bolt through the holes we drilled in the previous step. If this is a bit confusing take some time to examine the pictures and you should be able to see how it all goes together.

You should now have an almost complete Hidden Blade. Take a moment to admire your workmanship and get a feel for how the Hidden Blade will extend and retract. Once you're done, slide the blade out so that it is fully extended and get ready to create the blade locking mechanism.

The blade locking mechanism works to keep the blade locked out once it has been fully extended. The lock is made of a 3 inch length of hack saw blade that has had the teeth ground away. the flat spring (hacksaw blade) is ground to a point on the front end and is riveted to the underside of the blade mechanism as shown in the pictures. Once the blade is fully extended the flat spring snaps into a recess drilled in the underside of the blade which keeps the blade locked open until the flat spring is pulled down, releasing the blade.

Step 6: Hidden Blade - Adding the Coil Spring

Alright this is the home stretch! Simply take your coil spring and bend down a few coils at either end so that you can loop them around the bolt posts on the blade assembly and bracket as shown in the picture. This spring will act as the retracting force that pulls the hidden blade into the closed position. You may have to remove a few coils from the spring with your wire cutters to adjust the tension so that the blade retracts with enough force to completely close. Once you have the spring adjusted to the proper tension simply screw nuts onto the posts where the spring is attached to hold it in place.
And that's it! Part one of the build is finished and you should now have a functional Hidden Blade Mechanism. To deploy the blade give it a quick flick of the wrist, the force of gravity will overpower the coil spring letting the blade deploy and allowing the flat spring to click into place locking the blade in the extended position. When you want to retract the blade all you have to do is pull the flat spring out of the depression in the blade, and coil spring will pull the blade closed. Later on in the Instructable we will be attaching a ring to the flat spring via a piece of string so that you can disengage the lock through the movement of your hand.

On to making the bracer!!

Step 7: Bracer - Measuring & Creating the Pattern

With the hidden blade mechanism finished it is time to move on to the bracer. The bracer is made of two pieces of leather, one that fits the underside of your arm and supports the hidden blade and another that fits the top of your arm and is more decorative. The two sections are attached to each other with button snaps so that it is easy to put on and take off the hidden blade.

The key to building a nice bracer is to design it to your measurements, so measure oftern and measure well!

To start measure the diameters of your wrist and your forearm and add about 1/4" to 1/2" to each measurement for comfort. With these measurements create a pattern on your posterboard like the one pictured. Note that the black marker lines are my measurements and the orange marker lines are the actual pattern. As the bracer wraps around your arm it helps to have the top and bottom arced as pictured so that they fit your wrist and forearm better.

Once you're pleased with your pattern cut it out and test fit it to your wrist, I found the sharp corners on my pattern to be uncomfortable so I rounded them off. Make adjustments until you are pleased with the fit and then set this part of the pattern aside.

Grab another sheet of poster board and cut out a rectangle that is the same height as your bracer, (9 inches for me), with a width of about 4 inches, this will become the decorative top part of the bracer. Using tape test fit the bottom and top of the bracer together on your arm so you can get a sense of what the bracer will look like and feel like. If you're pleased with your patterns you can move on to the next step. Note that I made some decorative cuts in my top piece of poster board; these aren't necessary but they do add to the look of the finished bracer.

Step 8: Bracer - Tracing the Patterns Onto Leather, Cutting, & Punching Holes

Place your patterns on the leather and carefully trace around the outside edges using a pencil. Once your patterns are traced use your xacto knife to cut them out, note that leather can be difficult to cut so it is better to make several shallow passes with your blade as opposed to trying to cut the whole way through the leather on the first cut.

After you have finished cutting your leather bracer parts out it is time to create holes for the instalation of button snaps. To make your hole placements symeterical, fold your template in half down the middle, mark where you want the holes, use an awl to punch through both thicknesses of paper and then unfold. place the template over your piece of leather and transfer the hole locations with your awl, then use an awl, hole punch, or drill to make your holes. Note that the holes should only be big enough to get the staft or your button snaps through, 1/8" should be perfect.

Step 9: Bracer - Installing the Snaps

Before installing button snaps consider what detail work you would like to do with your bracer. Snaps can get in the way of designs you may want to stamp into you leather so only install snaps once you are ready.

Installing snaps is a pretty straight forward process. When you purchase a pack of snaps you get a snap set tool and an anvil tool for the bottom of the button snap to set in, With the anvil tool setting on a flat solid surface order the parts of the snap as shown in the picture, note that the black circular piece is the anvil and the silver tool with the flaired end is the snap set tool. Once you have everything lined up correctly use a hammer and the snap set tool to hammer the snap parts together. Install snaps into all the holes you punched/drilled in your leather paying close attention to how the snaps mate together so that the top of the bracer snaps to the bottom of the bracer correctly.

Step 10: Bracer - Surface Detailing, Finishing the Edges, & Applying Dye

Now it's time to get artistic. In this step we will be tooling the leather bracer to add detail and make it more interesting. We will also be dying the leather and finishing the edges so they look more polished. Tooling leather is a fairly involved process so don't be afraid to consult more detailed tutorials for more detailed instructions.

Tooling - The method I use for tooling the bracer is a combination of stamped patterns, (background), and leather carving, (Assassin's Creed Logo). Stamping is pretty self explanatory, just set the tool down on the leather and smack it with a hammer to leave an imprint. Leather carving is a bit more involved, for this process you use an xacto knife to cut your pattern into the surface of the leather, making the cut fairly shallow (about 1/3 of the leathers thickness). Once you have cut around your pattern you use a tool called a beveler to push down one side of your cut line so that the other side appears to be raised, this creates a shallow relief that lets your designs stick out. To use a beveler tool, place the toe of the tool in your cut line and smack the tool with your hammer. Each time you hit the tool move it along your line, overlapping your previous hit and then hit it again. Continue the process of move, hit, move, hit, move, hit, until you have traced along all of the lines you cut with your xacto knife. what you will be left with are areas that appear to "stick out" from the background.

Note: Bevelers come in many shapes and sizes. For this project I used a B60 Craftool Beveler Stamp from Tandy Leather. http://www.tandyleatherfactory.com/en-usd/home/department/tools/6060-00.aspx

Tooling Leather Step by Step

Sketch or find a pattern that is the same size as the piece of leather you wish to decorate.
Lay the pattern on top of the leather and use a pin or awl to mark along the lines of the pattern.
Use an xacto knife to trace the pattern, cutting about 1/3 of the leathers total thickness.
Moisten the leather using warm water. The moist leather is supple and will hold the patterns you stamp into it.
Use an beveler tool and hammer to trace along the cut lines and push the leather down to raise your pattern.
After you have finished with the beveler tool, use a stamp tool to fill in the background area. I used the handle end of a butter knife as a stamp tool to get the hammered texture for my background.

Finishing Edges - Finishing the edges transforms the rough cut edges of the leather into smooth polished edges like the ones you would find on a nice leather belt. this helps the leather keep it's shape and improves the overall look of your bracer.

Apply water to the edge of the leather.
Use a smooth piece of wood or plastic to rub (burnish) the edge of the leather until it is smooth.
This technique will yield a nice smooth edge, however if you're looking for an even smoother edge you can rub the edge of the leather with a piece of bee's wax. The friction of rubbing will melt the bee's wax into the leather and will allow for a higher quality finish. (Thanks to Instructables member Jack of Most Trades for this tip).

Dying Leather -Dying seals the surface of the leather so that your bracer will look nice for years to come. Leather dye comes in a variety of colors so choose the color that is right for you and your project. For my bracer I used Fibing's Leather Dye #121 medium brown. As noted in the materials page you can purchase leather dye from companies like Tandy Leather.

Moisten your leather.
Apply some dye to a clean cloth or applicator.
Wipe the dye evenly across the surface of the leather.
Wipe off excess dye with a clean cloth.
Allow leather to dry.
Buff surface using a clean cloth to remove any remaining excess dye and to polish leather.

Although you can get infinitely more technical with they processes, the steps listed above, if done well, will result in a quality piece of work.

(Notice that I ended up removing my snaps half way through this step and had to reinstall them later. Remember that the snaps can get in the way of your design so only install them when you're ready).

Step 11: Finishing - Attaching the Hidden Blade to the Bracer

So far so good!! You should now have both the Hidden Blade and the bracer finshed and all that is left to do is put them together. Start by partially disassembling the hidden blade. Disconnect the coil spring and remove the blade to give you access to the holes you drilled for connecting the Hidden Blade to the bracer earlier. Now line the outside slide up with the underside of your bracer and use a marker to transer the location of the attachment holes. Once the bracer is marked, create the holes.
Now use your rapid rivets to rivet the blade to the bracer as shown in the GIF image. 3 or 4 rivets will be enough to securely hold the blade mechanism to the bracer.

Alright, only one more small step until you have a finished Hidden Blade, continue on to the next step to learn how to attach the ring that activates the blade release.

Step 12: Finishing - Attaching the Ring to the Blade Locking Mechanism

Now that your Hidden Blade Mechanism is attached to your Bracer, the only thing left to do is affix the ring that activates the blade retracting mechanism, i.e. pulls the lock out of the hole. Start by drilling a small hole in the flat spring close to the end you ground to a point. Next tie a knot in your string and lace it through the hole so that the knot acts as a stopper keeping the string from pulling completely through. Now tie the free end of the string to your ring, you may have to play around to find the proper length for the string so that when you pull your hand back the string pulls up on the spring and releases the blade.

Congratulations, you should now have a working Hidden Blade prop!! To deploy the blade, simply give a flick of your forearm and the blade will slide out and lock in place. to retract the blade, lift your hand to pull the flat spring out of the depression in the blade releasing the lock.

Step 13: Finished

Now that everything is finished you're ready to impress your friends and fellow Assassins Creed enthusiasts with your awesome Hidden Blade! Thanks for taking the time to check out my Instructable, I know there were quite a few steps but I hope they were detailed enough so that you can successfully follow them and make your own Hidden Blade prop. I hope you enjoyed this project and found it to be informative, If you have any questions or comments please feel free to leave them in the comments section and I will do my best to get back to you as soon as possible.