How to Make a Robot for Children (Sentry Gun)

Who is engaged in robotics, definitely wants to make a robot. And the the question immediately arises, how to make a robot with his own hands? To create a robot you will need a variety by a difficulty radio components. Also, for the construction of the robot, you'll need select a suitable chassis. Of course, all the parts for the robot can be purchased ready-made. By bringing all together the you receive robot. Will agree much nicer to contemplate his own creation, the process of creation begins his journey by sketching on a paper to full production of of the robot with their hands in the scale conceived....

I offer the option of a robot assembled from a cheapest materials (combat Sentry Gun). Of course this is not a robot, but based on of my project, you can create different entertaining device. Moreover, all made from available materials.

Well, it's time to get down to work!

Parts needed in this project:

1. Steklotekstolit the foil t.1,0mm double sided FR4 for rigid trucks
2. Servo SG90 2 pcs
3. 3 springs
4. metallic marbles diameter of 10 - 8 pieces
5. metallic marbles diameter of 8 - 12 pieces
6. bolt diameter 4mm length 20mm - 1pc.
7. bolt diameter 3mm length 10mm - 2pc.
8. the nut 3mm - 3 pcs.
9. the nut 4mm - 2 pcs.
10. microcontroller Atmega16
11. the various radio components according to the scheme

Rotating chassis is made of double-sided of the textolyte a foiled. This material is very light and easy to process and has sufficient strength. Usingscissor on the metal can be cut any appropriate item. For lack of a 3D of the printer is quite good alternative turned ). Given that the design of details can be changed, then it is sufficient resolder detail of, to another location. Which in turn saves material and time. For thepossibility change the direction of the shot cannon, the chassis must be the turning.The circlerotation weapons this draft is not required, need a small arc of fire. Given that the arc of fire is needed not big, for this project I found Servo SG90. Another object of the chassis to keep in place Sentry Gun at a shot, and did not give a turn over. When testing the model, the return of the guns was rather big. I had to even a bit to reduce the power of the shot. For swivel chassis I used a home-made thrust bearing. Thus in using of metal balls chassis is a turning and sustainable for shots. Because metal balls have a weight. Although

at a shot Sentry Gun moves slightly.

Of the numerous design options, I settled on this variant. As an projectile into the barrel could easily have been to implement loading of metallic of balls 8mm diameter.

By installing on a rotating chassis cannon, began the process of assembling the cocking mechanism. Effort servodrive SG90 sufficient to carry out the tension springs. As soon as the servo producing tension by triggered latch which holds the barrel in the cocked condition. In this position, cocking lever servo housed in bottom of the barrel, hindered make the shot. For the implementation of the shot was invented a simple and reliable way. As soon as mechanism fixes the the barrel, the servo should return to its original state. At some point, the servo clicked on the a trigger mechanism latch is reset. Is carried out shot.

The store is designed for 12 metal balls takenfrom the the bearing, although you can use the large beads. Loading metal balls into the barrel carried under its own weight, in simple words rolling down. The starting position in the barrel does not allow filing metal balls (photo 2). As soon as the mechanism is cocked, the upper ball falls. But there was a problem that during the fall of a metal ball started to roll. To solve this problem have been made side holes

in the barrel. The holes in the barrel keep the position of the ball preventing it from be moved. (foto.3)

For radio control robot Sentry Guns, I have applied earlier designed electronics for the the project siege catapult. But given that the complexity is unlikely someone will repeat the joystick radio made by me I represent option much easier in execution although the layout on the circuit board upheld the radio module. As you can see from the scheme, the joystick a fairly simple and consists of three buttons connected, with microcontroller. Two buttons carried out by turn Sentry Guns to the right or to the left. The remaining the button gives the team a shot. Possessing certain knowledge in programming of microcontrollers is possible to write his own version of the program for the microcontroller. For example, having equipped with the device proximity sensor can implement automatically fire as soon as the object is detected at a predetermined distance. Since I devised the model Sentry Guns as the basic model for the children, respectively, the complexity of equipment and the chassis of the robot may also vary. I hope my version of the robot Sentry Guns will like to someone and possibly someone Collect this model is for yourself.

P.C. First time peshu not ruskoyazychnyh audience, sorry for mistakes