As a hobby I developed (not fully yet) python-based electronic/physics educational kit. For mechatronic experiments I needed servo motor with position and torque feedback and customizable parameters, easily fitting into popular brick constructions...
Two hall sensors and magnetic ring are used for position sensing, current measured for torque. Different Chinese motors were considered. Steel bearings. I2C interface allows chain connection. Hollow nut shaft for different use cases.
I made a prototype, but due to lack of free time I did not tried to assemble its PCB yet.
Toy servo motor
Forum rules
Be nice to others! Respect the FreeCAD code of conduct!
Be nice to others! Respect the FreeCAD code of conduct!
-
openfablab
- Posts: 62
- Joined: Wed Nov 02, 2016 4:42 pm
- Contact:
Toy servo motor
- Attachments
-
- dYzNOflc4aw.jpg (89.81 KiB) Viewed 3266 times
-
- bvgnSxzs1RU.jpg (251.49 KiB) Viewed 3269 times
-
- fFx3d1LFi90.jpg (262.62 KiB) Viewed 3269 times
-
- HOD3vSGI6zk.jpg (475.4 KiB) Viewed 3269 times
-
- lpBQFbZQ8aw.jpg (158.5 KiB) Viewed 3269 times
Re: Toy servo motor
That is sweet, I would have loved this for my popular brick construction creations 
Re: Toy servo motor
That's cool!
You could make a version using a stepper motor also, they have lots of torque a low speeds. Then maybe you would only need to send it a command.
You could make a version using a stepper motor also, they have lots of torque a low speeds. Then maybe you would only need to send it a command.
Re: Toy servo motor
Very impressive.openfablab wrote: ↑Thu Sep 24, 2020 9:27 pm As a hobby I developed (not fully yet) python-based electronic/physics educational kit...
Were the parts in the images modeled with FreeCAD?
Which version, Part or PartDesign workbench, and which assembly workbench?
Top down or bottom up assembly?
"It is a poor workman who blames his tools..." 
-
openfablab
- Posts: 62
- Joined: Wed Nov 02, 2016 4:42 pm
- Contact:
Re: Toy servo motor
Yes, this all was FreeCAD 0.18, bottom-up assembly with Part/Body approach.ppemawm wrote: ↑Fri Sep 25, 2020 11:18 pmVery impressive.openfablab wrote: ↑Thu Sep 24, 2020 9:27 pm As a hobby I developed (not fully yet) python-based electronic/physics educational kit...
Were the parts in the images modeled with FreeCAD?
Which version, Part or PartDesign workbench, and which assembly workbench?
Top down or bottom up assembly?
Robot picture on the yellow background is application case illustration (made not by FreeCAD but with LDD)
I had some hard time making these parts compatible with plastic injection molding. This process assumes non-right angles, i.e. several degrees inclination of all vertical walls to take parts from forms easily. This was accomplished (not from first try...) with correct planning of part creation strategies.