After reading some the Shapeoko community’s experience with mechanical end-stops, I decided to design my own hall-effect based sensor solution. I’m not saying I went about it the right way and there are probably better/cheaper/faster solutions, but it’s what I came up with. I should say, I was inspired by Kevin Patterson’s hall effect solution (love the red/green feedback LEDs.) https://www.youtube.com/watch?v=vqU_5wZAX3s6
NOTE: This design has not been implemented yet. Still waiting for one more board from OshPark to arrive.
* 24V separate power supply for the hall effect circuit.
* Nominally high (active low) design.
* Opto-isolated sensors
* Higher sensor voltage (24V) in combination with some simple pull-ups an caps to help ride out any coupled transients.
I’ve built some acrylic holders for the sensor boards and a small enclosure for the main board. The concept is similar to Kevin’s in that I will have 6 sensors (2 for each axis) connected with inexpensive phone cord connected by RJ11’s to the main board. I’ll mount my main board to the side of my control box where the grblshield/arduino lives.
After Hours now has 3D printing and CNC machining capability for all the custom electronic fixtures and enclosure work that’s done (better then a file and a Dremel!!) Well, of course the new toys tools needed to be put to the test. The kids have a wooden train set that had an important wye track missing and Ebay failed us on a replacement. What better opportunity? We started with a 3D printed prototype to get the “customer’s” approval before finalizing the design in wood. Good thing we had that design review because we needed a male coupling where a female coupling was.
One more thing, it’s a good idea to make sure when you export your g-code that you choose the right machine (MeshCAM has a selection of machines the g-code export is tailored to). I didn’t on the first couple attempts and ended up with a mill cutting right through the middle of the almost finished track. The final version in the picture is attempt # 3.