The linear actuator is a subproduct of a previous project and we tought it would be useful to other makers. So, the idea is to make something like those Firgelli micro actuators but yourself and with the added bonus that you can integrate the inclosure of the actuator to the body of your robot or project.
This is the video of the actuator being assembled.
we hope to improve it and keep it to the bones so other can implement it, sugest improvements and make something useful together.
First of all, we are going to visit the WMF at NYC. Hackaday has a slot to speak about the Prize and they asked us if we would like to speak a little bit about the experience and we said yes! If you are going to be around the area come by and say hi.
So about the current actuator.... we had an idea.
We always tought that the design was pretty clunky, big, lots of mechanical components... and it comes for the thing that makes it "great", the potenciometer.
That thing its so hard to calibrate.
So the current desing we take the H bridge and the "position sensor"from the servo. So if we are going to replace the potenciometer.... no more H bridge. So thats an easy fix: https://www.adafruit.com/product/1438
We have use this board before in the OWI arms project and it works great, also the code its much much cleaner than having to simulate you have a servo attach.(also availabel for feathers)
So the potenciometer? we need something thats not mechanical so, hall sensor.
We tried out hall sensors from Adafruit and they work great as a digital ( you need a resistor) or analog sensor. Keep in mind the polarity of your magnet because that matters.
So the lighter, thinner, simpler, less patrs...er linear actuator:
Please let us know any sugestions... we will print it try it out and if it work... share the files with you.
So we have been asked how to print the actuator because theirs keeps breaking.
To address this concern we have uploaded the profile file from Cura in the file section(Perfilimrpresion.curaprofile) for you to implement it. Fare in mind that this configuration is with a 0.3 tip in a 30x30x30cms printer, you may want to adjust that.
It's in spanish but you'll get it.
Also two things, first we are thinking about redesigning the actuator in a way that yeah it will have like 5 cables BUT!!! it will be like so much slim so you can choose what works better for you.
Second thing, we have been invited to participate at the World Maker Faire. Like for 3 minutes in a panel but we tink its great! When we get more details we will share them with you.
So, remember when we said to all of you that you should put your filaments on a box with the biggest bag of silica gel that you could find?
About that... DON'T DO IT!
Really bad advise and sorry about that. The silica gel has a limit of water that can absorb and we are on a shared office space with full blown air conditioner, the silica disolved itself and became an oily liquid. This was all over our filaments and when it gets on the gear of the printer extruder, it grinds.... so a lot of unfinished prints.
The solution, we cleaned out all of it and replace it with rice.
Once every two weeks we take it out and let it rest on the sun. This happens because we dont have a lot of rotation on some filaments so....
However take this advise with a grain of salt( no pun intended), its working and we will keep you posted.
What will happen if you want to change the speed of the actuator? Sometimes we need to control some factors of our design for some types of applications, simplifying it could be said: changing the engine is the correct way, but we have found another way.
Whith modifying the steps of the screw can get good results, this can be done from the model. How? for many the answer is obvious but we will show how to do it with the designs we have made and are available for download.
In the Files section there is a file called Piston, this is available in various formats, We work in Autodesk Fusion 360, thus the instructions are made for this application but can also be used for help in other software. Changing the steps of the screw causes it turn faster or less quickly, in the post the screw have a five revolutions in the coil function so with other value the result would look like this
Also you have a change the piston in the same file,
If you want more details with how to do it, go to instructions section there are a step by step of the process.
Hello everyone, Jonathan and i wanted to say thank you for all the support and attention that made this project get to the finals. This project has given us so many thing like joy, peer recognition and a challenge.
To the people that asked us about the finger, that is a part from an old version of this project:
So that is why the finger exists.
We will continue the project as long as any of you sees an aplication and we can chip in to make it better. So feel free to use it and to ask any question or suggestion.
We will see you again at August at the Human - Computer Interface Challenge!