Introduction: SA OTF Xiphoid MK IV - Arm Mounted Blade

 Single Action Out the Front Xiphoid Mark Four

This is the fourth xiphoid I have made. It's pretty simple, and works very well.
This is NOT meant to be from Assassin's Creed! Though I love the game, this is UNRELATED.
Made from a drawer slide, 5 bolts, 9 nuts, strips of homemade faux leather, 4 keyrings, wire, springs, and a ring.

Thanks to Nightshade for the latch design.
Thanks to NightHawk22 for the awesome song.
Thanks to SINZA for his epic forum, you rock! 


SlashingAssassin (author)2015-07-29

if you make another how much?

Udit Mathur (author)2011-03-04

can you make a retractable blade??spring loaded or motorized any will work for me

Techie_Gary (author)Udit Mathur2012-07-29

wanna see my concept??? its a design that allows minimal force to eject or retract a very long object, like the blade. Details are on my instructable:

Hope i helped you......

Kaiven (author)Udit Mathur2011-03-05

I can, though I can link you to a tutorial that has already been done well.

Udit Mathur (author)Kaiven2011-03-06

send me the link

Kaiven (author)Udit Mathur2011-03-06

Udit Mathur (author)Kaiven2011-03-06


curvy77 (author)2011-12-05

assasins creed!!! i to am planning my own design frm that game. >=) i am working on the wrist pistol. i have the general design and have come up with a (hopefully) safe way of firing a revolver round. withou fireing off my hand too but we'll see.

BLR25 (author)2011-10-25

is there any way you could make me one, i would buy it if you made it

jumper17 (author)2011-09-24

Could you post specifics on either where to salvage a latch like the one shown in the video, or how to obtain/construct one? Thanks. (P.S. What is that EPIC music played in the sped up section?)

Kaiven (author)jumper172011-09-27

I just cut it out myself from scrap metal. It's shaped like an L with a hook.

Lt. Duct Tape (author)2011-07-15

Any idea where you might have gotten your springs? I used 2.4 pound springs from home depot, but they turned out to be made out of crappy material- Stretched out like nobody's business.

mulletman6 (author)2011-06-03

What width draw roller do you use?

Kaiven (author)mulletman62011-06-04

Umm not sure, all the drawer slides are the same width from the hardware store...

mulletman6 (author)Kaiven2011-06-05

Ah fair - It looks like quite a wide one, so i shal have to have a look for a bigger one :)

knights1224 (author)2011-03-29

I like it

some tips / things you could do different:
- have some sort of arm protector, that looked kind of uncomfortable with the bare screw/nuts against your arm
- have it to where you can stab and slash with out the blade retracting, because a real hidden blade can do that, so maybe have a locking pin that can be removed [see below for details]
[see above for unnecessary use of brackets with words in them]
possibly switch the ring to your ring finger and have a locking pin wire and ring on your pinky-finger. so somehow you could bring out the blade and keep it from moving when you stab, and you could also bring it back in when you wanted

I would buy a wholly completed one

alcemy_FTW (author)2011-02-15

what could i use for the blade?

Kaiven (author)alcemy_FTW2011-02-16

Anything... depends on what you have.

sithstalker (author)2011-02-15

av just made 1 from shin gaurds havin a bit troulbe with the latch

lilparis47 (author)2011-02-02

fitting music

larslovespeace (author)2010-09-05

could you post more of the specs of the design for those who want to make it? - even a project for DIY purposes.

Kaiven (author)larslovespeace2010-09-05

Specs like what? Everything is shown and described in the video.

EwwieImp (author)Kaiven2010-12-24

It would be helpful though if you could put the exact things such as bolt size, length, etc.

Kaiven (author)EwwieImp2010-12-24

I never designed it on specific measurements. EVERYTHING has to be adjusted according to materials and the wearer. The drawer slide is 10 inches, that is the only fixed measurement.

larslovespeace (author)Kaiven2010-09-06

I guess your right- I will just try to fabricate it based upon video

Sarthex (author)2010-12-21

i think this is the first instructable i ever favorited O.O
awesome job man

Kaiven (author)Sarthex2010-12-21


11richie21 (author)2010-09-29

Where can I get or how can I make the release "thing" (metal piece that releases the blade)?

i think the word you're looking for is a "latch" and you could always bend some 8 gauge heavy duty wire to fit

Kaiven (author)11richie212010-09-29

Just cut an "L" shape from a piece of thick sheet metal and make a "barb" on it, like seen on a hook.

pkthunder (author)Kaiven2010-12-14

hey just wondering... i have been looking for instructions on how to make one of these. could it be possible for you to make a tutorial?

Kaiven (author)pkthunder2010-12-14

I wouldn't be able to do much besides another disassembly.

11richie21 (author)Kaiven2010-10-02

Thank you that help! I made the piece and actually made one of these with a blade but i was going to ask how much tension your springs have? I used only one because it was around 11.5 lbs but around the same size as your larger spring. the spring I have makes it hard for me to put the blade back in :( Thanks

you could just make it out of a piece of thin wood, it would work just as well and would be easy to replace

(YOUR N (author)2010-11-07

Hey hey it's me again I'm shocked y arnt u wearing
That cool :) t shirt great Ible do

IneXtrikabul (author)2010-10-11

Would it be too much trouble to make a tutorial for this thing? It's too awesome to not want to make!

greatnameless1 (author)2010-09-16

How much should I expect to pay if I want to build one of these?

Kaiven (author)greatnameless12010-10-01

I paid about $3, because I had most of the stuff. I'm not sure how much it would cost to buy all of the parts.

knex 711 (author)2010-07-21

when it has a blade how will it retract automatically other things ive seen

Kaiven (author)knex 7112010-07-22

Sorry, I do not understand your comment. Please use punctuation and complete thoughts.

Pumpkin$ (author)Kaiven2010-08-19

Hey CCK!! I love the design, it seems like retracting is the only final step, and I had an idea, you could take a Velcro ring, attach it to your shoulder, and run a cable down to the blade-deployment-mount (thing) and Extending your arm downwards could retract it and lock it into place!!

Kaiven (author)Pumpkin$2010-08-20

An idea, yes, but I prefer relying on just my hand and the mech. Involving my shoulder brings complications when jumping over buildings. You understand, yes? :D

im_madman (author)Kaiven2010-08-05

What he means is..."When there is a blade, how will it automatically retract like other things ive seen?"

Harpes1 (author)im_madman2010-08-14

its an out the front blade which from what i gather means its only powered on the way out, if you want one that can go both ways easily a gravity blade is probably best, but even then it's not automatic, fully automatic (out and back in again) like in the game are quite fiddly to make and are less reliable unless done correctly

apocolips85 (author)2010-07-28

can you show us a video of how to mount the front lock then please???

flashcre8or (author)apocolips852010-08-11

If you go to his youtube channel he has an earlier model of the hidden blade. That blade had a locking mechanism. Maybe you can figure it out and make it? Good luck!

Rokko8652 (author)2010-08-05

So you ARE cowscankill from that forum. I was this close to asking you if you were. Anyways, very nice design. I plan on starting one that will be pretty much a clone of Nightshade's gravity Xiphoid.

Kaiven (author)Rokko86522010-08-06

Good, always a nice place to start.

kidmosey (author)2010-07-31

Now, you need to make it auto-retract, too. :D Not sure how to do it using strictly mechanical means, though.

Kaiven (author)kidmosey2010-08-01

There is a way... look up double action out the front knives. Many switchblades use a similar design.

About This Instructable




Bio: AKA Roborovski, and Cowscankill for several years. I'm a mechanical engineering undergrad.
More by Kaiven:Lathing Pistons on a Drill Press With a Homemade Collet Reusable, Water Resistant Blowgun/Airgun DartsEasy Bacon Chocolate Truffles
Add instructable to: