This is an updated version of my original Linear Actuator design. I decided to make it a bit more nice looking (less bulky) and found some super nice couplings for M8 thread and stepper motor also used on 3D printers with M8 z-rod.

I also made a T8x8 acme version of the actuator which is based on the same parts, only the coupling, nut and of course the threaded rod are different - ahh okay, you need a different coupling and a 8 mm collar to lock the threaded rod. But more on that in the BOM.

The T8x8 is of course way faster than the M8, but also has less torque and is also more costly because of the acme rod.

Again the idea is to keep it simple and scale-able !

Step 1: Parts & Performance

The actuator consists of both bought mechanics and 3D printed parts - printed at 0.2mm layer in PLA with 40% infill. Tested to be strong enough to not break under loads of 12 kg. I haven't really made other high load tests other than lifting the 12 kg NEMA 42 shown in the video - so it may be capable of more. However, 3D printed parts also have their limitations ;)

I have made the design in Fusion 360 and made available both the STEP models and STL packages for both the M8 and the T8x8 version of the beast ! Unfortunately I cant get it to upload here on Instructables - but you can find it here on GitHub

Step 2: Assembly of the Thing !

Added here are photos from the instruction manual showing the parts for the M8 version - just to show that it is really not a crazy amount of parts you need. And the electronics is of course free to chose, but i use uStepper and Ego Shield since it'll give me a fully stand alone solution.

Instructions for assembly are also added here as PDF documents.

Step 3: Making It Move !

To make the thing move I use uStepper and Ego Shield as written in the prior. With this I can just apply a single power source to the board and program it to run sequences using the Ego Shield.

Added is a video showing how to set it up - mounting of it can be seen in the instructions found in the previous step !

So, here you have it - a simple yet capable linear actuator made by accessible parts and powered by the widely used NEMA 17 stepper motor. Now you just have to put it into action !