Echo, a BDX Droid
Hardware- 6 Devlogs
- 29 Total hours
My BDX inspired robot. Named Echo, he should be able to walk, talk, and interact all on his own.
Hi there! This robot is super cute and the cad is very detailed. However, I have a few things before I can approve:
Your CAD must be in .STEP format!
We need a wiring diagram!
Your BOM is way too expensive! We cannot fund an nvidia jetson nano, we cannot fund a $200 depth camera, and we certainly cannot fund such expensive actuators (you have $1500 of them in your BOM). A few things:
Do you really need the amount of compute a jetson nano has? Over something like, a raspberry pi? I don't think you do.
You do not need this expensive or this strong of actuators. Especially commercial actuators, which we really cannot be funding. You can design them yourself! I am using 3D printing cycloidal gearboxes for a project - I suggest looking into designing your own 3D printed actuators. There are a ton of youtube examples.
Great work! However, you have a bit of an expensive BOM that can be optimized to purchase this from cheaper. For example, you do not need $100 for a mic and speaker. Find cheaper parts for this. In addition, the assorted screws can be cheaper. Lastly, you do not need to purchase the 3D filament yourself. There is printing legion to do that.
Once you make these changes, resubmit, and we will take another look!
I finally finished the sheet metal parts, I ended up running into clearance issues with the legs and the chassis, so I redesigned it all. Now, it is significantly slimmer and should be theoretically stronger. I was also able to reduce the machined parts meaning I save time and money. I started printing everything out and found some small issues that were quickly resolved. I already have a couple of the motors, so I got those all wired up and they move!
Its insane how powerful they are. The strongest one, the RS03, has over 60Nm of peak torque, even on 24v (instead of 48v), I could overpower it using my entire body. This robot is beyond powerful, and should be an incredible platform for complex locomotion as well as environment mapping. Can’t wait for everything else to arrive and be integrated.
This looks like an insanely cool project, but you need to upload your full assembly in .step and firmware to your repo!
Finished legs and chassis. Forgot to record the entire process, which is very sad, but I don’t think design hours even count so I guess it doesn’t really matter. I simplified the legs, changed actuators, and designed a rigid but entirely plastic chassis to save weight. As things break in the real world i will switch over to metal. The design is still missing the head, but for the time being I will not give it one. It adds too much complexity and honestly for right now its not what matters.
I also changed the accent panels to be red, as when I checked the CNC fabs website’s they offered red anodizing but not blue.
The chassis has two batteries on either side in the rear, and then all computing goes in the front, hence the vent and spot for cameras/lidar/microphone.
Completed CAD for the droid’s legs. Finalized the metal sections, added more spacers for the shins, and made sure the tolerances were set for machining and 3d-printing. I will be entirely 3d printing for a quick fit test before sending off an order for metal parts. Now its time for fun part - building it.
Finished the shin section. I had previously done a plastic mount for the shin, but that wouldn’t have been strong enough. Now, I’ve replaced it with two aluminum plates (and an aluminum spacer) that should make it far stronger at the same weight.
Built out thigh section.
Added the frame, which is two aluminum plates with the actuators sandwiched in between. I plan to put some spacers in there for extra support. Mounted to the plates will be thin plastic facades for looks. The brackets on the right are for the wire tubes, which I hope will also be handles to pick up the robot, hence their rigidity. Now onto the facades!
Started working on the legs, and got a decent prototype. The model is based off the the Disney BD-X model they have showed online, but takes some creative liberties.
I decided to place the little blue shield over the actuator to help hide it and kind of blend in with the robot. In the world of star wars, it makes sense for them to protect these pieces, so it isn’t all that unrealistic. The shin piece might be too hollow, not sure how it will hold up to load and stress. I plan to reinforce it with an aluminum plate, and that will go sandwiched by the plastic to take the blunt of the force (if needed).
Good progress, plenty more to do though.
