I wanted to slow down my Dewalt router to 12000 RPM so I started to investigate a closed loop controller. So I looked into SuperPID which seemed to be what I needed. However at $200 it didn’t seem to be worth it. So I designed my own, most of the parts I had n had to order about $30 of components. I’m using an Arduino Nano to measure speed using an optical sensor and control the router using a triac by changing the firing angles. I had to modify the router to bypass the internal speed controller. Speed set point is received from my GRBL board which is another Arduino Nano. Now I can slow down the router to 5000 RPMs. To view all the information and modify setting I use wifi and app. Just wanted to let people know incase they are looking for the same thing but felt SuperPID is too expensive. I’ll post pics soon.
Please do post the pics. I too was looking at SuperPID recently. I'm curious why you bypassed the internal speed controller and why not just set it at the highest speed and let your external logic regulate it down from there? Maybe the internal speed controller is smarter than I give it credit for. What was involved in disabling it? Your optical sensor, is that looking at the collet nut like SuperPID?
The optical sensor is aimed at a 3D printed speed pickup with 4 sides that I have foil tape on to make it more reflective. The pickup is mounted just above the collet. In the future I may test a Hall Effect sensor and use the pickup that the internal speed controller uses. I didn’t go this way at first incase things didn’t work out n I could simply go back to normal. I don’t think it would work without bypassing the internal speed controller, and that’s also the way SuperPID recommends doing it. In the pics you can see the speed pickup and optical sensor.
The Nano on the right is running GRBL and the one on the left is doing the speed control. I also added a feed hold input to the GRBL Nano incase RPM gets too low.
This the board that changes the power going to the router. I did it separate to keep the AC power away from the controllers.
Cool, thanks for sharing. I was thinking something along the lines of this PSSR ZC Tail would make it easier and less exposed for the router AC wiring. Though now that I look at it in detail, it may not have a high enough power rating.
Here are my schematics hopefully you can make sense of it. With a speed control Nano, it can configured anyway, LCD & Pot instead of Wifi interface or anything else.
Hello This is a very good build, in fact, I am planning to take benefit from it and build mine. My guess is that if we use DC rectified mains power (with proper power rectifier, capacitors and a mosfet in place of a triac), it would run with more torque and less noise (and probably more power efficient). By the way, is there a possibility to get the code for the Router Nano ? Does it implement a PID algorithm ? Thanks anyway : )
Yes I do use PID algorithm with adaptive gain for quicker recovery when speed droops. Attached you will find the Arduino files. One is the for the Nano and the other if for the ESP8266 that does the Wifi Interface to the Blynk App. Anything else I can help you with let me know.
Thank you very much ! I'll have a close look at these, they will certainly come in handy ! BTW, I already have modified my router, but instead of using large 5mm emitter/receiver, I've used a TCRT5000 sensor, wich is using the same working principle but in a smaller dedicated housing. Here are The schematic : The pcb : ..and layout : I'll gladly post pictures of my modified router if needed. As the sensor is very small, it requiered me to just drill two 3mm holes, 20 mm apart to mount it in the brush area housing, with long 12mm allen M3 screws. Works like a charm and is less sensitive to environment. Thank you again.
Folks this is a great project. Im keen to modify my router for a Lowrider 2 that i sm building. Speach could uou please post more details on your installation
Hello...as per my knowledge on routers and their control i can say the cheapo Speed controller says it is controlled by PWM which by the picture the dial is potmeter so what is that pot PWM controlling and if its the blue box on the PCB maybe thats the place to hook up the Leonardo, I have an ex colleague that has an oscilloscope. pcb manufacturer
