Making the robot MDi #4 - part 3: pan/tilt mechanism of the chest

     Hello guys! Just a short update...

     I've shown this part earlier... but now it's ready!

     Although being small, it is very important... as it gives 2 DOF to the chest and joins the chest to the base.

     Below you can see all the Makeblock parts used in this step of the project.

• 1X D Shaft 4x56mm;
• 2X Timing Belt 112MXL - 140T;
• 8X Plastic Rivet R4120;
• 2X Socket Cap Screw M4x16 - Button Head;
• 14X Socket Cap Screw M4x14 - Button Head;
• 6X Socket Cap Screw M4x8 - Button Head;
• 2X Headless Screw M3x5;
• 3X MG995 Servo Hub;
• 1X Shaft Connector 4mm;
• 4X Timing Pulley Slice 90T-B;
• 2X Timing Pulley 90T;
• 1X Gear 48T;
• 1X Bracket U1;
• 3X Plane Bearing Turntable D34x24mm;
• 2X Timing Pulley 62T;
• 4X Timing Pulley Slice 62T-B;
• 1X Gear 16T.

     I'm a bit in doubt about the field of the "pan" movement... with the gear reduction it's limited to about 90 degrees. I have to see it in action to decide. If I want a larger field, I have to remove the limitation of the servo motor and exteriorise its potentiometer. Well, let's see...

Making the robot MDi #4 - part 2: fiberglass chest, arms preview and new parts received

     I would like to have finished the chest, but he suffered a small accident... yes, he fell to the ground when I was preparing it to apply spray primer... but it's repaired and fine now!

     I have uploaded a video of the Pepakura work and another that shows many steps of the fiberglass work.

     Now the chest is closer than ever to be ready. And it's super lightweight. I just need to finish some custom features that will be made with polystyrene (high impact polystyrene) sheets. When it is fully ready, I'll weigh it.

     Below you can see that I used polystyrene sheets in some flat areas. Certainly with fiberglass I could not do it so flat. And on the side became with a suitable reinforcement, where the arms are installed (3 layers of 2mm polystyrene).

     I was a bit concerned about the DC motors for the treads, but fortunately I found good ones with 25 kgf-cm and 233 RPM @ 12V at a reasonable price.

     I do intend to finish in the next days the pan/tilt mechanism.

     See you guys!

Makeblock Robot Gripper (unboxing and testing)

     Hello guys!

     I would like to share with you some stuff I made with the Makeblock Robot Gripper, which will be used as hands of my robot project MDi #4.

     The gripper is made of light-weight PVC and the inner side of the fingers was designed to be anti-slippery.

     Specifications

     Rated Voltage: 12V DC

     Operating Voltage Range: 5V - 12V DC

     Rated Current: 450mA

     Stall Current: 1700mA

     Gripper Weight: 0.1lb (0.05kg)

     Speed of Grip (from close to a fully extended grip): 1sec

     Maximum Load for Gripping: 1.3lb (0.6kg)

     Some info was taken from the product page in the Makeblock site (http://www.makeblock.cc/robot gripper/) and from the product packaging.

     Having fun

     Initially I made some tests with the Makeblock App running in an Android phone, connected via bluetooth to the mCore board, which is the brain of the mBot.

     To test the gripper in a fun way, I made a simple arm with 2 DOF plus the gripper.

     The set includes a base made of MDF, aluminum channels and brackets and Makeblock parts.

     The arm was controlled by a PlayStation 2 wireless joystick and an Arduino board.

     I'll be using this method to remote control the MDi #4.

     Additional info

     http://www.makeblock.cc/showcase/how-to-make-a-selflocking-robot-gripper-mechanism/ - How to Make a Self-locking Robot Gripper (Mechanism) - Makeblock

Making the robot MDi #4 - part 1: cardboard prototype, Makeblock parts and initial specs *NEW PROJECT*

     Hello guys! 

     I'm starting the big project for this year: MDi #4.

     It will be a tracked robot with chest and two functional arms. Will have a head for express some info about its interactions with the environment.

     I'll be sharing all the making process of this project, so I'll make many videos detailing the crafting of every part.

     To start, I have a video with some initial specs of MDi #4.

     I have already started to work in the chest and its tilt mechanism. So here's also a preview video of these parts, which will be detailed in the next episodes.

     I'm very glad to say that Makeblock have sponsored many parts for this project. I expect to make a cool and strong robot with these parts.

     Stay tuned!