Introduction: Me and KnexBulid's Project

Picture of Me and KnexBulid's Project
Here is a railgun me and KnexBuild are working on. This is what we have so far, its getting closer to  completion but we're working on it. This ible is really just ment for KnexBuild and I but you guys can add some feedback if you wish.

FOR KNEXBULID: UPDATE 1 So this is the prototype I pm'ed you about it contains the new trigger, over vacation can you give it a mag of some sort and try to improve the trigger, I won't be active all vacation. 

UPDATE 2: This is the new trigger, ok there the new pictures are there the last pic is the part that resets the trigger (non-

For Didexo: UPDATE 3: I have made a new trigger, pin and handle. The trigger should be able to take a lot of pressure.

UPDATE 4: I made and added a stock. Also, added a new and better handle and made a dot sight.

UPDATE 5: New trigger still can hold same amount of pressure, details explaned in the video, slighty different handle

Update 6: I made limbs pictures will be up later

For Didexo: UPDATE 7: Here is the magazine area. It has a removable, top loading magazine the can hold 8 yellow rods. The
magazine can be put in and taken out at any time. The gun also has a magazine release.

For Didexo: UPDATE 8: Here is my working prototype. It gets only about 50 feet. The gun uses bending crossbow limbs. Sorry for the blur; my camera didn't want to focus for some reason.


Sharir1701 (author)2012-09-21

when i first got on here i was like "ughh... another compound bow..." but then i looked at it a bit more and i actually have to say i like it. the mech looks clean and seems as if it would work well. i would like to see this posted, but no pressure (if it already is, excuse me for the lack of patience to look it up, but i see a comment made yesterday down below and i assume it wasn't posted then so it isn't now).

didexo (author)Sharir17012012-09-22


Knex.X (author)2012-09-21

Why won't you post this? It takes so long I'm getting a little impolite

didexo (author)Knex.X2012-09-22

It won't be posted mabey you can ask Knexbuild and he will but I've been busy, sorry.

headlessknight (author)2012-06-12

not to mean or anything but is this gun done yet?

didexo (author)headlessknight2012-06-13

No not mean at all, I haven't heard back from Knexbuild yet so I'm not sure.

~KnexBuild~ (author)didexo2012-06-13

Did you send me a PM? I haven't gotten any new PM from you. I thought you were working on it; I was just waiting for you to finish your mods, but you never posted the mods.

didexo (author)~KnexBuild~2012-06-13

They were bad mods basicly I tried a different firing mech instead of a mag but it didn't work I think its pretty much done.

TheRacker (author)2012-06-02

Well this looks awesome. Is it done yet?

didexo (author)TheRacker2012-06-03

Well the prototype is done but a few mor mods need to be done.

TheRacker (author)didexo2012-06-03

Awesome. I'm really a fan of the magazine system. I love self contained mags with internal pushers that aren't open on the top, so convenient.

didexo (author)TheRacker2012-06-03

Yes the mag is really nice made.

TheFoofinator (author)2012-05-21

The Mag looks solid. I will keep an eye on this one. Looks promising.

I have made a working prototype, but it only shoots about 50 feet. The pin sometimes breaks, even though I made a strong pin.

didexo (author)~KnexBuild~2012-05-22

Really can you post a picture of it ?

~KnexBuild~ (author)didexo2012-05-24

The pictures are posted.

didexo (author)~KnexBuild~2012-05-24

Ok I show you the likbs I made then we can mod. I like the body.

~KnexBuild~ (author)didexo2012-05-22

I'll post a picture of it tomorrow.

didexo (author)TheFoofinator2012-05-22

Yes its looking pretty good, I plan to post instructions when its completed. I'm glad to see someone enjoing this. Thanks.

didexo (author)2012-05-21

Good, its coming along.

~KnexBuild~ (author)didexo2012-05-21

Do you like how I made the magazine area?

didexo (author)~KnexBuild~2012-05-22

I like your mag. Should we consider a 8-shot turret.

~KnexBuild~ (author)didexo2012-05-22

Would an 8-shot turret make the gun more powerful? It might make it less powerful because of all the energy transfers. Also, you would probably have to manually rotate the turret like on Zak's Turret Bow.

didexo (author)~KnexBuild~2012-05-22

Mabey. I'm not sure.

didexo (author)~KnexBuild~2012-05-21

Yes I do I haven't made it yet. What should I make besides the limbs?

~KnexBuild~ (author)didexo2012-05-21

I already made some limbs, but you can build some also and maybe yours will be better. I made a working prototype, and now I am trying to keep it from breaking pieces, because it has already broke a lot of them.

didexo (author)~KnexBuild~2012-05-22

Ok I also have a prototype working my doesn't break pieces. But, it doesn't have the mag yet.

~KnexBuild~ (author)didexo2012-05-22

How far does it shoot for you? Mine shoots only about 50 feet. The only thing that sometimes breaks now is the pin. I also made a stronger pin than the one we had before.

TheFoofinator (author)2012-05-11

Well, It's nice to see someone making something on the Railgun platform.

Tips: I've attempted to build Zak's, and it's a lot harder that it seems. If you are firing from a turret, you would have to put some kind of power transfer that goes through the impact area of the gun, and the Turret already has an energy transfer pin, so energy is lost through this new transfer.

If you are firing from a magazine, you will have to put a short pin on the Rail Block, so it easily transfers that power to the Bullet in the mag. this method is more efficient, however, a longer pin is sometimes needed, which can wobble up and down as the Block accelerates, and hit the internal structure instead of entering the hole where the bullet is.

Here is an example of one with a longer pin, which snapped off quite often due the block having a tendency to bend down, so If do choose to put a pin on it, make sure you have a trigger on top as well as the bottom, so the pin stays flat, or a longer block to ensure it can't bend down when under strain from the trigger.

Lastly, the whole point in the rail system is the infinite length you can make it over a firing pin method. You get more power out of firing pin gun of a similar size to a rail-gun, so make it long! Longer rails usually mean more length for the rails block to accelerate.

More Velocity= More Kinetic energy. 

Likewise, the longer Length you have to accelerate means you can add more mass to the block, this will reduce acceleration, but if you make it long enough, the muzzle velocity will stay the same than if you had a lighter block accelerating quickly. 

More Mass= More Kinetic energy. 

Research 'SUVAT' equations and KE= 1/2*m*v^2 for the more info. 

Lastly, if you are going to make it long, make it strong. Adding another layer to the bottom will decrease flexing by a LOT. For reinforcing the top, just continue what you are currently doing by using y-clips and red rods, they fit perfectly on these kind of rail thanks to Zak :)

I hope this helps, Railguns are my favourite type of Knex Gun. 

Sorry for the long post, I hoped it would answer any questions you may have. 

didexo (author)TheFoofinator2012-05-11

Yes I attempted zak's too. But failed. I'm only 13 so I haven't got into that KE*1/2*v^2 stuff yet. But I understand the basics. Thanks for the time to help us. BTW railguns are my favorite to :)

TheFoofinator (author)didexo2012-05-11

It's not complicated. I just wrote it the proper way :)

Here it is simplified:

Kinetic Energy= (1/2) x Mass x (Velocity)Squared.

didexo (author)TheFoofinator2012-05-12

Ok thank you though.

Knex.X (author)2012-05-08

I'm sorry but what is a railgun

~KnexBuild~ (author)Knex.X2012-05-08

Technically, a railgun is a gun that propels a projectile using electromagnets. K'nexers use the term "railgun" to refer to guns that have a
small pin that slides between two long rails.   

Knex.X (author)~KnexBuild~2012-05-09

Thank you for your detailed explanation ;)

~KnexBuild~ (author)Knex.X2012-05-09

No problem. =D

didexo (author)Knex.X2012-05-08

Knexbuild is right. We use them because the slider has more space to accelerate compared to a gun with a grey firing pin, thus allowing more power.

didexo (author)2012-05-07

I can't I toke it apart becaue it was flimsy. Do you like the stock or should I make a new one

~KnexBuild~ (author)didexo2012-05-08

The stock is great! =D The cheek rest looks like the one on a SCAR. You took apart the whole gun?

Kinetic (author)2012-05-06

Woah this looks like its coming along really well. Good job guys!

didexo (author)Kinetic2012-05-07

Thanks we ran in to a problem though. The part where the red connector in the trigger connects to the rail is really unsturdy.

~KnexBuild~ (author)didexo2012-05-07

Are you sure it is going to be flimsy? We still need to make the barrel; that will strengthen it.

didexo (author)~KnexBuild~2012-05-07

Yes I kinda went ahead and made the barrel, its flimsy.

~KnexBuild~ (author)didexo2012-05-07

Can you show me a picture?

~KnexBuild~ (author)Kinetic2012-05-06

Thanks! I am going to add a removable magazine and bending crossbow limbs (similar to the ones on your D-TAB) for more power. Didexo is going to make the stock.

didexo (author)~KnexBuild~2012-05-07

No just the barrel.

didexo (author)2012-05-07

The video explains the problem we are currenty facing with the gun

The Cannoneer (author)2012-04-18

Looks cool. Hope it gets completed some time soon. I really want instructions!

didexo (author)The Cannoneer2012-04-18

Sorry, I couldn't help but notice, but are you new to this site. Are you planning on becoming a knexer?

The Cannoneer (author)didexo2012-05-06

Actually I am a knexer >:P
The problem is i dot have a camera :(
btw your creations are pretty cool keep up the good work xD

About This Instructable




Bio: An aspiring engineer, who enjoys long distance road biking, hiking, astronomy, and economics just to name a few. I've been using KNEX prior to ... More »
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