hexapod robot

All posts tagged hexapod robot

Animabot Rev3 – Mecha – Lower Body Assembly

Posted by Emmanuel Sichet on 07/08/2019
Posted in: Animabot Rev3, Mecha. Tagged: , , , , , , . 6 Comments

After so many weeks of waiting, all Animabot’s parts are finally home !!!

I decided to start with the lower body assembly and then working the way up to the head. The legs will be the last parts to be mounted because I need to redo the PCB and the PCB should be mounted before the legs 😀 this, and also because I didn’t find the courage yet to disassemble the current version yet :/

 

The first I did was to check if the motherboard and the servos were properly fitting inside and yes they do! So from this, I started by mounting the screws inserts in place ( by using a soldering iron, then pressing gently them in the hole). Once this step done, I continued with the buttons on the rear panel which are inserted and glued (easy peasy) and placed the dust grid behind the air vents. To install them, I also used the soldering iron and kind of “soldered” to the inner side of the body (melted both together), the result is not particularly aesthetic but it’s easy and durable !

Rear Panel Connections
Rear panel connections
IR Telemeter
Motherboard placement check

Below the battery, is mounted the dock connector constituted of 2 concentric copper rings (no polarity inversion possible !) and also the dock sensor which is basically a simple magnetic switch (Reed switch). All this is isolated from the battery with some Kapton tape. Last but not least, the IR Telemeter is now fiercely mounted on the front. The switch on the very bottom is the battery kill switch which allows me to completely disconnect the battery from the system  ….  just in case…   😀

Rear Panel Test
Dock Connector and Reed switch
Rear Panel
Robot’s belly
IR Telemeter

Next Step will be the upper body 😉

Animabot Rev3 – Mecha – Parts are on the way !

Posted by Emmanuel Sichet on 30/07/2019
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Good news ! The body parts are done and on the way ! I’m really exited to see how Animabot will come along once assembled. For the moment, I’m still writing and testing the drivers of the Motherboard and testing all components…. So hopefully, within few weeks I will finish this, send a new motherboard to production and integrate it.

Now, let’s enjoy the beauty of SLA 3D printing with smooth finish :

Big Puzzle
Upper Body
Lower & Upper Body Interior
Some internal parts
Lower Body

He is gonna be AWESOME !!!!

Animabot Rev3 – Hardware – Motherboard

Posted by Emmanuel Sichet on 27/07/2019
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I finally received the rest of the components for the motherboard ! took me some hours to populate everything (QFN packages take a bit of time to solder when you are not used to 😀 )The smoke test passed for the Power supplies (7.6V, 5V) but I still have to test the battery charger… which gives me a bit of apprehensions because I don’t want to fry my battery :/

I will definitely have to make an improved version in the next few weeks to fix the following issues:

  1. Lack of thermal exchange for the PSU controller and MOSFET
  2. Change from 10DOF IMU board to a 9DOF IMU (LSM9DS1TR)
  3. Separate I2C bus for the Eyes (they use too much bandwidth forth rest of the sensors)
  4. Overall Routing & Layout improvements
  5. More detailled SilkScreen

But first I have to finish testing all the features and components to see if further modifications are required. But for now I’m pretty happy with the result, no big trouble. I did some thermal test and the PSU is around 40°C in idle mode without cooling and 35°C when the fan is active, even so the thermal dissipation of the component in not ideal and the fan is powered at 3V3 instead of 5V.

Motherboard in progress

As mentioned, I still have the rest of the features to test (around 15: Telemeter, Bluetooth, Charger, Raspberry Pi communication, Servos, etc…) so stay tune 🙂

Animabot Rev3 – Mecha – Leg Sample

Posted by Emmanuel Sichet on 15/07/2019
Posted in: Animabot Rev3, Mecha. Tagged: , , , . 9 Comments

The mechanical design is finished since few weeks, but I have been waiting some sample of the leg to check the tolerances, quality and color. This sample allowed to check the passage of the cable in the Coxa, the Tibia Cap (anti-slippery pad), servo mounting, etc..

I’m glad I ask I did that before the complete manufacturing because I found several issues. The passage for the cable needed to be deeper to protect it, the Pad was too small to hold in place properly and the color did not satisfied me totally… I’m still waiting for some more sample to compare and chose the final color !

 

Hopefully the samples will arrive soon, so I can order all the parts to assemble Animabot !

Animabot Rev3 – Mecha– Body design

Posted by Emmanuel Sichet on 07/06/2019
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It’s been few months now since I started the design and it is approaching the end \o/. The main body and legs are finally done, but I still have to do a final check of tolerances, clearances, cabling , mounting, etc.. before sending the parts for productions. As mentioned earlier, the design is very close to Rev2, however, the internal structure has been improved to be more rigid and more reliable. On Rev2, I had too much flexibility between parts and torsion on the body (due to the 5 parts body assembly) which basically ruined everything… The legs axles have also been redesigned or better performance and the legs will be equipped with a separate End-Cap (ground contact) with a rubber part to increase adherence.

So, hopefully I overcome all these issues with this version 😀

The ear design is also done and I think it gives a pretty nice look to the robot ! It will gives Animabot much more expression capabilities and at the end it doesn’t look to organic and not too mechanic either which I find to be a good compromise. In any case, it is difficult to make a functional machine looking organic when you have to install real motors, joints, PCBs, cables, etc..

I still have the dock to do, So this will be the next task…

 

Animabot Rev3 – Hardware – Motherboard

Posted by Emmanuel Sichet on 29/05/2019
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So I received the Motherboard and started populating it 🙂 All components are not yet soldered because I want to test the board step by step, starting with the MCU and the I2C bus (where all the sensors are connected).

Motherboard test

As of now, the following is working:

  • Flashing-Debugging the MCU
  • Flexible OLED via SPI
  • 10DOF IMU via I2C
  • Eyes via I2C
  • Gesture Module

I still have some trouble with the RTOS and the IMU, after some time the tasks start to be delayed and the IMU is not responding anymore… but that will be for later, I want to finish the Body design and send it for printing first ! the next step is to mount the PSU and the Charger.

But now that I have the Eyes working I started implementing some expressions 😉 not so bad for a first try !

Animabot Rev2 – Final Assembly !

Posted by Emmanuel Sichet on 04/11/2015
Posted in: Animabot Rev2. Tagged: , , , , , , . 2 Comments

It’s been a while since the last post… mostly because my new job is taking away most of my time…

But also because I had to fix several issues in Anima before mounting the legs and the upper body. First I had to fix the sound problem, curiously the IR sensor was generating noise which was propagated up to the audio amplifier, thus generating audible noise… To fix it I added to capacitors (100nF & 10µF) on the sensor’s power connection. Then I burned the Li-ion charger 😦 so I had to replace some mosfet and add some heatsinks.

Finally after 20 months of design, tests, doubts, bug fix, etc… Animabot is assembled and ready to walk !!!

 

Stay tuned 😉