Stripboard requires breaks in the tracks to stop current flowing where it shouldn't, so this is the first thing to do along with drilling the holes for bolts and for the power socket (which has elongated pins). There is a stripboard layout drawing at the top of this page (and schematic) and a guide on working with stripboard here: Drilling the board The circuit is built on stripboard/Veroboard but could be built on perfboard if you make the connections yourself.
We don't need the WiFi, only the Bluetooth and the IO. The circuit is based on an ESP32 which includes WiFi, Bluetooth and lots of IO pins. The cable from the turbo trainer the then hooked into the slider, and the outer of the cable is hooked into the holder on the end. You can either grip one end with some pliers or grips, or use an allen key in the set screw of the shaft coupler as a lever.
If you have a geared motor, it will be very difficult to turn the lead screw by hand. You might want to drill a pilot hole for the screws in the plastic to get them started Tighten the set screws in the bearing and on the shaft coupler.4 holes are provided, but you might only be able to get 2 of them in which is fine. Bolt the motor to the slider using the M3 machine screws.Place any spacers on the face of the motor and attach the lead screw to the shaft coupler but don't tighten the set screws.
On my Ender 3, these all printed fine without supports. You may also need some spacers for the motor depending on how far you need to pull the cable on the trainer. You will need the frame and the slider as a minimum.
They were modelled in Sketchup which doesn't export to STL as well as other software so you may get some errors in your slicer software about the model not being manifold which you should be able to ignore, but check the GCode looks like the STL model before printing. The STL files are attached at the bottom of this page. The frame and the slider for the linear actuator are 3D printed. The motor that I used has a 1:27 gear ratio which seems to work well and means that the motor doesn't need to draw too much current. You will need a stepper motor with a gearbox attached to it because it takes a lot of force to pull the cable. The linear actuator allows this to be done using a stepper motor which can be controlled precisely. The resistance of a turbo trainer varies depending on how much the cable is pulled: the more cable that is pulled the easier the resistance.