A model of the MP7 Personal Defense Weapon - shoots Lego rods
About this creation
This is the latest addition to my armory, the Heckler&Koch MP7. The MP7 is classified as a Personal Defense Weapon, which means it was primarily designed for non-combatants like cooks and engineers. However this weapon was also quickly adopted by Special Forces in several countries.
My model features:
- working firing mechanism that propels 3 stud long technic axles. Max range is about 20-25 feet (6-7 metres). However most bullets reach around 15-20 feet (5-6 metres),and most of the bullets don't follow the same trajectory, but I'm working on that.
- 11 round magazine capacity
- empty cartridge ejecting after shot
- usable foregrip
- pistol sights that can be flipped up to create rifle sights
That's about it. There is no fire selector and the stock cannot move, as there simply was no space (because of the mechanism) to put either a working fire selector or a retractable stock in.
The gun might be a bit blocky but that's just how it is, I can't change it without removing the entire mechanism...
Well, have fun looking at my creation, I have tried to explain everything as well as possible.
NB: I will not make instructions. Don't Ask Please.
NB 2: Please leave a review, or at least rate my creation. Constructive critisism is always welcome and I'll be glad to answer any questions.
Front. Notice the air vents and front grip.
Ejection port & trigger.
The following pictures are some different views of the MP7.
Down the sights (pistol sights).
The pistol sights can be flipped up to create rifle sights.
Clip goes in like this...
The piece with the rubberband attached to it will push the clip up.
There is now a round in the "chamber"
The following pictures will show the inside of the weapon, where the firing mechanism is placed.
The spring is attached to a stick and because of that it doesn't bend while being compressed. The spring I used is commonly found in ballpoints. Some ballpoints have bigger springs than others, I'd say the bigger the better, however it needs to fit around the stick and it needs to fit inside those black tubes I used as cartridges.
Notice the bended piece in front of the clip. This piece will move up when the spring is fully compressed against the bullet in front of it.
The following pictures show the firing process in "slow-motion". When the spring is completely compressed against the technic axle in the black tube in front of the spring, the piece in front of the axle moves up and the axle is shot out of the gun by the spring. Afterwards the empty black tube is pushed out by the tube with axle below.
The process ends by ejecting the empty cartridge and a new round is now pushed up into the "chamber".
Thanks for looking at this creation! Please rate it if you liked it.
In response to Tom's question:
You are right this can happen, if you use rubberbands that are too weak/strong the mechanism might not work properly and the spring could get squished like you mention. I used a fairly strong rubberband to pull the spring back after each shot, but not so strong it is hard to pull the trigger.
For the piece that pushes the clip up I would suggest a rubberband long enough so it can push the clip all the way to the top but weak enough so it doesn't squish the spring afterwards. The thought behind this is that the spring is pulled backwards first and then the clip moves up instead of the other way around so that the clip squishes the spring and the mechanism cannot move back after a shot is fired. It also helps to have some spare room left between the clip and the spring when it is in resting position so that when the spring is pulled back after a shot the front end won't get stuck because it is almost directly placed against the clip.
In response to Carlo's question:
The smooth beam that holds the bullets does in fact go through the top of the gun. I think you might be able to see on some of the pictures that there is a little gap in the rail on top of the weapon. After 5 or 6 shots or so the beam comes out of the top of the weapon, which looks kinda weird.
The beam can move up along the right side of the upside down roof brick (see the firing mechanism pictures)
However, in my newer models this doesn't happen anymore, (I don't know if you have seen any of them), they do not use a clip anymore. Instead they hold single rounds stacked on eachother. You might want to take a look.
ECHT GENIAAAAAL!!!!!, hoe heb je het uitgevonden om zoiets te maken want ik probeer ook al heel lang een lego pistool te maken(ook MP7 want het is mijn lievelings wapen) maar ik heb paar vraagjes_#1-wat is dat gekleurde ding dat je gebruikt_#2-Zou je PLEASE een instructie kunnen maken en als laatste-zou je me als het niet te veel moeite kost een beetje kunnen uitleggen hoe zo een mechanisme werkt want dan kan ik miss wel mijn eigen maken^^
This is probably the simplest, most effective lego firing mechanism I've seen. The pics were helpful, Im gonna see if I can use it at some point. One thing i dont know is how do the cartridges keep moving up on the megazine?