Touch Probe for CNC

thingiverse

I'm sharing my DIY probe design with you today. The Carrier and Hub need to be non-conductive (plastic) materials, while the bearing balls and pins must be conductive (steel). You can choose whether or not the Body and Cap are conductive. The idea is that you wire the ball bearings together in the large spaces, and the pins complete the circuit. The spring-loaded Hub that holds the pins in place is pressed into between the Cap and Hub. When the stylus is disturbed, the circuit breaks, sending a signal to the CNC controller. There are four 2.5mm holes in the body for tapping 3mm set screws. These screws allow you to adjust the stylus to center. The fifth hole is designed for routing wires to the CNC controller. The shaft on the cap is 1/2" in diameter, perfect for use with an ER20 collet. I'm using 5MM stainless steel bearings for the ball bearings. You can find them here: https://smile.amazon.com/dp/B07HVLWPF6/?coliid=I1YLY8779T1TE8&colid=1P82YNQPGJUAV&psc=1&ref_=lv_ov_lig_dp_it For the pins, I'm using 1/8" (3mm) diameter by 1/2" long stainless steel dowel pins. These will require you to grind a ball nose on one end. You can find them here: https://smile.amazon.com/dp/B00Z3VZDN0/?coliid=I105KP62XUIEFH&colid=1P82YNQPGJUAV&psc=1&ref_=lv_ov_lig_dp_it For the spring, I'm using a 15mm OD, 1.2mm wire diameter, 30mm long spring. You can find it here: https://smile.amazon.com/dp/B07883QTSN/?coliid=I4KEJTGRU68KX&colid=1P82YNQPGJUAV&psc=1&ref_=lv_ov_lig_dp_it I'm using a Chinesium Renishaw A-5003-4797 Stylus. You can find it here: https://smile.amazon.com/dp/B07G8DWBYF/?coliid=I372WOAA7OJN01&colid=1P82YNQPGJUAV&psc=1&ref_=lv_ov_lig_dp_it This is a proof of concept, and I'm waiting on parts. Since this may require some adjustment, I've included the Fusion file for you to work with.