Introduction: 90-SS 'Desechos' - P-90

Finally ! After 4 months i've managed to do it! The 'Desechos' is here. I don't want to sound wimpy but it is my first proper Instructable... If something's majorly missing or i've spelt lots wrong then just tell me and PLEASE COMMENT. First i'll quickly give you some Pros & Cons :

- Does'nt need too many pieces
- TOTAL customisability compared to other knex guns (explained later)
- Strong
- Comfy and instinctive to hold
-Easy maintenance (on and off battlefield)
-Fires 6 shots from the hopper in quick sucession (30 secs) or a sniper shot (muzzle loaded) is the same average time but goe's further.

- You probably think this is bad but not nessacarily; it shoots no more than 50 feet but that's with my crappy rubber bands - if i had #64s it could go MUCH further.
- Bulky (?)

Right. The total customisability. Whereas of course, all knex is interchangeable, the difference here is that the pieces that you must attach whatever to are very simple - look at th stock for example ... or the grip - not hard to make a bayonet that can click onto 2 yellow semi-circle connectors from 7 to 10 spaces apart or something. If you don't like it , that's understandable (:D)

Anyway, Another feature, whether you like it or not is that this particular hopper shoots blue rods - 6 of them , though it's 10 if you make it taller. Or , you can remove it and breech load. Ive got 6 shots every 30 secs off with this, hopper and breech - whereas a hopper of shots takes much longer to load, it can be fired much quicker.

Great thanks go to Ednator55 for his Truly-Semi-Automatic Gun and , more improtantly for me, the hopper . Though mnay rival designs have come out since this gun was first made, this is still one of if not the best. This gun is at :

Also, the original creator of this sort of gun has to be thanked. It's the 2nd picture here. Some people may say i'm copying, but its been modded so much i dont think thats nessecary. I've improved the trigger, stock, firing pin and runner, handle, grip, barrel and it fires shots from a hopper too (if you still want it too) ... Unfortunately i cannot find the original creator but when i do (or he finds me) i will give him credit for the basis - none of this would have happened if it wasn't for him.

One hint just to get you thinking : Take off the handle, put the stock in line with the rest of the gun, replace the grip with a foldable bipod and remove the hopper (phew! take a breath) and you should have a mean sniper rifle.

Step 1: Stock and Handle

Simple. Build what you can see.

The rubber bands arent needed of course, i just put them there for if one on the gun breaks.

Step 2: Firing Pin, Runner and Sears

Ditto. Build what you can see.

N.B : If you are left handed you can put the extended part of the firing pin on the other side.

Step 3: (Oops!) Barrel Components

I think you can guess ... build it.

Sorry about the blurriness :(. I can still make it out though - and if you cant see something , its not there ! (proverb)

Step 4: Joining the Barrel Together.

The red rods with peices attached click on to the whites and yellows with the red peices facing outwards - it's simpler than it looks.

Also you need to make the hopper. My computer crashed when i tried to put it on the instructable (?!) but you can find the pictures here ( - just make sure it's 9 reds long, not the 6 shown - it must fit blue rods.

Step 5: Back of the Central Mechanism, Trigger and Grip

Slightly blurry again, i know. Anyway, i know you've lots of little peices but they'll start to come together now. I hope you can build them.

Step 6: Connecting the Rear Parts of the Gun Together

Some tinkering may be needed here if you have missed out a piece or 2 but i think it's clear enough.

Click the handle pieces into each other, then into the 'back of the C.M'.

Click the stock into the back of 'the back of the C.M'. (lol)

Make the new peice (This is the front of the C.M) and put the trigger on it.

Step 7: Grip Holder and Attaching the Hopper and Barrel

I know, blurriness again ... Anyway, Attach the hopper and barrel like you do on the other instructable page i showed you earlier.There may be a few different pieces here but just ignore them.

Also make the grip holder. This connects the grip, front of the C.M and the barrel together.

Step 8: Connecting the Firing Pin Runner and the Barrel

Step 9: Attaching Grip & Holder to the Main Body of the Gun.

Once again , I apologise for the blurriness.

Connect the grip and the grip holder together. Attach them to the front of the gun you have so far - the big bit you made earlier.

Step 10: The Final Connection

Now you can connect the 2 main pieces. It's a bit blurry again and I apologise for that. You can see where they connect clearly - then you just have to attach the rubber bands.

Step 11: Adding the Rubber Bands

Now to attach the rubber bands. Follow the notes on the sears and the firing pin area.