After one year of thinking, design, manufacturing and assembly, Animabot is almost ready to be properly programmed.
Not much to say for this post, except that I’m relieved I could do all within this year and that it worked out almost as planned 😀
Now, it is time to verify that all works, then I will continue to write the missing drivers and subroutines before working on the gaits, behavior and so on…
Stay tuned 😉
The assembly is finally coming to an end with the Top Cover. This part holds the Raspberry Pi and the Head of Anima. This was most certainly the most difficult to assemble and to fit all the components inside in a nice way.
The cables beneath the RasPi looks a bit messy for now because before fixing them definitely, I want to make sure the motherboard and the Pi are properly communicating. This method of soldering all directly on the Pi seemed to me the most practical one, I only have one cable to connect to the motherboard, the rest is connected just beneath the Pi.
I could have done a custom PCB to Plug the Pi into but it would have been too high for the Hood… But thinking about it now, I also could have used a PCB as base for the elevator instead and inverting the 40 header pin. If I have issue later with the hood mechanism, maybe I will think about it seriously.
The mechanism was not easy to integrate and to make it work nicely but after many tweaks (and a lot of patience) it is finally working. It is not as beautiful as I hoped for but it will be hidden and as long as it works, I’m happy with it. So basically, the hood mechanism consist of a small servo pushing or pulling a lever making the platform going up and down.
The bottom looks quite messy with all the cables but unfortunately, there is not much I can do because at some point, cables need to be connected to the motherboard. However, this architecture allows me to install and remove the Top Cover from the body without too much trouble (for maintenance or bug fix). Having the hood held with magnets is also very convenient to access the Raspberry Pi and plug the HDMI or USB cable.
Now it is time for the head assembly, as always, this is kind of a headache because of all the tiny parts and dimensions… I started by mounting the eyes (OLED PCB) with the 5Mpx camera (between the eyes). The PCB is screwed in place. Then I continued with the gesture sensor with is directly glued, I couldn’t used screws due to the thin thickness of the head and the lack of space !
Eyes and Gesture sensor
Head inner side
Then, followed the servos of the ears, this step was pretty straightforward. Place the motors and screw them 😉 As you can see, there is not so much space for adjustment…
The most complicated part was to install the neck servos, due again to the small space, it was quite hard to fit all together with screws, bearings and cables… I had to make custom horns and spacers to fit everything in place. The overall tolerance I had to place the servos was exactly 1mm, and it took me a complete morning to assemble the head properly but that is the price for compactness.
Pitch servo assembly
Neck, bottom view
Neck, Top view
After mounting the neck onto its head, it was time to test if all was working as expected (I2C for the eyes and camera) and thankfully, it does :D. All the cables passe through the back of the neck for a rotation of about +- 60°. However, I have some doubts about the head connection to the yaw servo, I find it a bit weak and wobbly… I guess I will have to find a way to make it more robust.
All good !
Ready to connect
Servo for Yaw movement
The last part to assemble is the Top Cover, containing the Raspberry Pi, audio amplifier, speakers, the Hood and the tactile switch…
After the Lower part, the Upper body was the logical next step. Actually, there was not much to do on this one… I started by installing the insert for the Top Cover, using the same method as before, which went flawlessly…
After the inserts, only the Flexible OLED display was left to install. I placed it first to see how the active area will match the outline of the body,then, I simply added double sided tape on the inner frame and pressed it against. In order to protect it, I added some felt tape and it looks nicer as well 🙂
For the cable, I first wanted to use braided sleeve but it turned out to be too rigid on the connectors and bit tricky to do… so I opted for the automotive solution by wrapping the cable in automotive tape. This looks pretty neat and avoid rattling noise if the cable is moving against the body.
And voila! The result turned out to be much better than I thought, this curved display looks stunning ! I can’t wait to make a proper HMI and menus 🙂
Some sensors values
See you later for the Top Cover assembly !
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
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
Next Step will be the upper body 😉
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 :
Lower & Upper Body Interior
Some internal parts
He is gonna be AWESOME !!!!
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 !
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…
The past weeks have been dedicated to the Head design which is coming along nicely 🙂 The head is slightly smaller than the actual version but contains more devices:
- Gesture sensor on top
- 2x OLED displays for the eyes
- 5Mpx Micro Camera
- 2x Servos for Ears
- 1x Servo for Head pitch
The head is divided in 2 parts in order to allow me to assemble the devices inside. Both part are screwed together and for the first time I will be using threaded inserts in order to have proper mounting 😉
The ears design will be done later, I want to have the complete robot designed to see how they fit with the rest of the body.
I already order some samples of the head to see the print quality and tolerances, I’m glad I did it because I already found several errors I have to correct for the final version. I could also do a test fit for the parts and it looks pretty fine as you can see:
The color is not the definitive one and I’m not sure about the Display color… but it gives a pretty good idea of the future look 😉
So, while I have been silent on the blog, I have been working hard on the design. Basically, Upper and Lower Bodies are done, only some few tweaks here and there to make all fit together. As you can see in the renderings below, the body shape is mostly the same but I fixed many issues from the previous body. These issues mostly came from the FFM 3D printing process (lack of precision and build volume and my beginner level in 3D printing at that time). The new robot will be printed with SLA process allowing more complex shape and better precision than before.
The Lower body contains the battery, Motherboard and Control Interface. The upper body is composed of 2 parts which allows me much easier assembly and better reliability. The upper body will be constantly screwed to its lower counterparts and the Upper Cover (where most of the devices are placed) will be screwed on the Upper body. As you can imagine, this will allow me to access all the internal part of the robot without removing the legs (which is currently a huge problem on the Rev2), by simply unscrewing the Top Cover. The Head, Rpi, servos are directly mounted on the Top Cover, and connected by only 3 cables to the Motherboard for easy assembly/access.
The Kinematic to lift the Rpi will be a nice feature allowing me to program and access it by the push of a button 😀 The tolerances are quite tight so I hope it will work as expected… This time I also added a small switch on top with RGB led in order to have some feedback/control over the robot (mode selection, battery level, etc..)
Lower Body – topview
Lower Body – bottomview
Upper Cover – Hood opened
Upper Body – Hood closed