Mechanical definitions and project of printed circuit

Wednesday (04/29^th) - Today define some things for the initiation of the mechanical part. In the base define how to position and coupling shaft that will have a crown that connected via a small strap to the engine will move the rotation axis of the base. The fact of the step motor is not mounted on top of the own axis has been discussed before, but remind that this model does not serve due to the distribution of the mass of the arm rests on the motor shaft, so to take it to center of mass that are technically Gear (crown-pinion). We took some measures regarding embuxamento of the bearings that make contact with the joints and the axle in order to avoid friction and to improve the handling of the parts already mentioned.
Also finished the first version to the printed circuit in Proteus. Although precisassemos make a double-sided card, because it would have trails going up the other one decided to simplify the design of most lines in order to do a double-sided board, but a single face. The tracks that would be passing over the other, we made a simple jumpeamento bringing to the front of the plate will be welded wire where the cable sleeve. That is simplifying the work of having to make the corrosion of other side with a very small piece of 4 channels of cable sleeve for each trio of ULN2003. Still have a tirinha cable sleeve over the plate and much better than having to print and erode both sides ...

Below is a screen print of the project in Proteus. I gave one a fairly ulhada and everything seems to be connected right. I leave here my thanks to student Bruno Cavalcanti for me oriented with the program.

Small progress in mechanical ...

Friday (04/24^th) - Today in the afternoon we took a small shift in the mechanical part of the project. We could do some measurements to have an idea of mathematic's sketch as an area of occupancy, volume and area of operation of the prototype. We also make some appointments to implement what we had on 3D design into reality. The result was, an idea of how will be when mounted.
Yesterday we bought the tap of nylon to provide a spacer between each link and also support for the bearings of the joints. Below we have two photos of the arm resting on the floor, did not like the seams yet this was the way to "mount" to have an idea of angulation. And talking about angulation, stress the importance of a difference in angle between the basis and "penpendicular's structure" to it. Indeed we opted for an angle of this structure on the basis of 30 °, so that the total mass of the prototype to be redistributed. We believe that this angle will serve as "counter-weight" still bet on the need of using any additional weight-control if the arm tends to front (structure of the claw).

Testing of the engine control via parallel port and C program

Wednesday (04/22^th) - Today in the afternoon we met again to test the control of motres via parallel port with our program of control (even in C) fully adjusted. Here is a video of the tests.

Saturday(04/18^th) - This week we start testing the engine via the control program done in C, with some difficulty managed to successfully complete and test the system, although it still needs a good review on the level of structure programming. But as the will and great to see a GUI (Grapich User Interface) ready by today evening began tweak the Visual Studio to win a little affinity with the collection of utilities that the editor offers us. Why not aliamos while still commands the structure of the program. We are only in the graphic, because we have to implement the controls that are working in C to C + +, and that transiçãod and code will be a little difficult, but the desire to see work in a graphical interface so that all the work it is worth . Here is a picture of how it would be the version 1.0 of the program.

Electrical circuit assembly. (Continuation)

Wednesday (04/15^th) - Today we meet in the NMR for the general assembly of the circuit (even in protoboard). Conclude the assembly of the whole circuit and test. Until then everything is working perfectly. You can explain the composition of the circuit as follows: the engine that will move the control of rotation of the base properly connected to 3's CI ULN2003 (in parallel) because the tests have little more than 1A for this engine, we decided to allocate more an IC to ensure the safety and reliability of the circuit. It is important to emphasize that also decided to use a Diode 12V 0.5 W for each ULN2003. Similarly use the same layout engine said to another step that will grab control of the prototype. And finally we have a DC motor that is controlled via two bridging H 12V relays and a ULN2003 IC, which also received a diode for rectification 12V 0.5 W of power.

After testing the circuit to begin programming in C. After a lot of headache to do a functional architecture simplória but the control of each engine separately, including the creation of simple menus for better control of each engine. So we started with the creation of source code with more elaborate conditional comment that the decisions of the user with the options menu.

We consider the present very productive, although we still have much ahead, mainly related to mechanical parts that goes way stop. As I engaged the circuit and software programming for the control, we have ahead to book more meetings for the development and assembling of the parts of the articulated arm.

Electrical circuit assembly

Monday (04/6^th ) - Today we set up in our protoboard the circuit with wires standardized and a better organization, but we couldn't test the pairing with the computer for lack of the parallel cable. In the hurry we bought the wrong cable. The next two photos of protoboard with the preparation of the door pararela (DB25 conector).

Cut the sheet of aluminum and testing of engines (complete !!! )

Wednesday (04/1^st ) - Thee group fineshed the cutting of the material structure of the arm. This structure is made of aluminum and is separated into 6 cards: 2 cards 500x75x2mm to be connected to the base prototype, 2 boards 550x75x2mm to be the arm's horizontal structure, 2 cards 300x75x2mm that sustain the support of the claw, that has principle of a pendulum moving and loose, and finally we have 2 cards that are literally the structure of a claw of 100x50x2mm and a 60x50x2mm. There will still be 2 boards in a twisted form of "u" to support the engine and move the arm to connect with their base.

Thursday (04/2^nd) - We may complete the assembly of the electrical circuit in lab's protoboard and test the stepper motor through the communication of computer and motor via parallel port. The group may conclude that all motors work perfectly and have set their resistance and current required in normal operation.
The next step is the assembly of the structure with the engine step, that is planned for next week.