So i have spent alot of time with this project, so i figured i might aswell share it with you guys that also likes lego!
The machine folds paperplanes, propoply the worst paperplanes you can fold but still it does it fully automated.
At the moment it can only fold one plane at the time. If i order 2 or more planes on the nxt it folds 1,5 planes then it stops working. I am not really best friend with the nxt software. (its something with the IR link sensor it suddenly seems to tell the motors to run in low speed instaid of max.)
Here is a video of the machine in action. (You can also check out V1 that uses 1 rcx unit instaid.)
V2.0 the working machine: http://youtu.be/TDiIOTjyHzU
V1.0 the almost working machine: http://youtu.be/nxywiTLe3oM
Station 1, paper magazine
The level of the paper is automatically adjusted so that the paper at the top always go straight into the machine.
I do this with a lego accelerometer sensor that is maunted on a arm the rests on the top of the paper pile, so as the machines runs and the paper pile gets smaller and the angel of the arm changes.
The accelerometer sensors tilt function then tells the motor to raise the magazine. And when i fill the machine with paper the motor will lower the magazine.
Station 2, Tip fold
Using a colour sensor the check when the paper is in the correct spot and then the machine holds the paper in 3 spot with pneumatic cylinders.
It hold the paper right at the edge of the folds so that the paper dosent move. Becouse i have to hold the paper at the tip aswell and not be in the way of the fold i get a gap of 2-3mm at the tip that dosent get folded. So the tip is not perfect.
Station 3, Wing fold
The wings fold automatically by the forward motion. How its done is hard to see in the clip of V2 and the picture above but you can see it in the V1 clip at 1:01.
Station 4, Middle fold
This station is the one im most proud of.
The motors that drive the wheels is inside the two moving parts (1 motor for each side). The folding is done with a XL motor that drives 4 linear units.
As the fold is happening there is 1 arm at each side that hold the paper to make sure that the paper dont starts to fold in the wrong direction and right before the fold is done the arms get pulled away with small pneumatic cylinder.
Also here i use colour sensors to tell when the paper is ready.
Station 5, Throwing
When the plane been moved into this station and is ready to shot the 2 XL motors start the throwing wheels and then the driving wheels(the ones that transport the paper) get pulled away with pneumatic cylinders right before a pneumatic cylinder pulls the throwing wheels together.
Compressor ( the unit next to the two nxt controllers.)
I use a motor that drives 2 small pumps.
To check the pressure i use a pneumatic cylinder that press on some springs. The pneumatic linear motion i then convert to a roation movement. and then on a wheel i have taped on a paper"shading scale"(dark in one end and gets lighter unti its completelly white). Then i have a light sensor that looks at it and i get a analog reading of the pressure.
(so this is the only part thats not lego, a small printed black/white piece of paper. + tape)
Servo relay ( the unit next to the compressor)
For some reason the drive motors for station 4 didnt like to be controlled by IR recievers (could be cable length or that the motors was too stress so that current got to high) So i had to use a battery box directly to the motors, and then used a servo motor to control the battery box.
All the pneumatic valves is controlled by servo motors.
5x NXT Servo motors
4x NXT Color sensors
3x NXT Touch sensors
1x Touch sensor multiplexor
1x NXT accelerometer sensor
1x NXT Infared Link sensor
5x Normal Power function motors
5x XL Powerfunction motors
4x IR recievers
about 7149 lego pieces
For the 3d drawing i used SR3D builder. (did the drawing after the machine was complete)