From 459384ddc03fc61dc0aecc6f455e41421f5b0dd2 Mon Sep 17 00:00:00 2001 From: Sam Calisch <sam.calisch@cba.mit.edu> Date: Mon, 9 Oct 2017 16:28:16 -0400 Subject: [PATCH] Update README.md --- README.md | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/README.md b/README.md index cc7254d..9b74c9f 100644 --- a/README.md +++ b/README.md @@ -119,4 +119,12 @@ I did a quick 3D print of this design to check clearance and assembly issues. T <img src='v2/eden-prototype.jpg' width=310px> <img src='v2/v2-mill-max.png' width=310px> -Next task is designing the AS5013 board and its connection to the main board on the end of the cylinder. I'm thinking of using the four position Mill-Max spring contact connectors to save space over a wired connector. It should make a solid electrical connection for the I2C lines, power, and ground, while allowing room for fine adjustments of the sensor carrier boards. It's going to be a tight fit getting around the corner. \ No newline at end of file +Next task is designing the AS5013 board and its connection to the main board on the end of the cylinder. I'm thinking of using the four position Mill-Max spring contact connectors to save space over a wired connector. It should make a solid electrical connection for the I2C lines, power, and ground, while allowing room for fine adjustments of the sensor carrier boards. It's going to be a tight fit getting around the corner. + + +### Torque Cell + +I've also been looking at a similar mechanism for a non-contact torque cell. Most such torque measurement devices use a slip ring or radio telemetry to transmit the measured values to the stationary frame. We can design a flexure (similar to a helical shaft coupling) with a portion that translates in the axial direction when subjected to torque. Depending on requirements, we can dial up and down the stiffness and range. We can mount an axially magnetized ring magnet (or better yet, an opposite pair of ring magnets) and measure the axial displacement using a pair of differential hall elements in the stationary frame. This allows us to subtract out small deviations in the gap between the magnet and sensor. Below are some quick simulations of a candidate flexure geometry: + +<img src='torque-cell/tc-sim.mp4' width=300px> + -- GitLab