Hi I have a 52MM DC Spindle with the following specs; 12-48VDC Power: 400W Speed :3000-12000r / min (12V-3000 rpm, 24V-6000 rpm, 36V-9000 rpm, 48V-12000 rpm) I am looking / hoping to wire my Blackbox to an IOT Relay to support this spindle but not sure the best way to do it. Right now I have separate power supplies for my Blackbox and spindle as BB is 24V and I want to run my spindle at full speed using 48v. I have ordered a drop down buck converter for the 48v PS to go to 24v to support the BB and spindle from a single PS later but hoper to get this wired shortly. Can anyone provide some help?
NB we would recommend keeping spindle and controller PSUs seperate - DC motors create a tonne of dirty back-EMF and you do not want that in your power rails. Turning the motor off can also induce a lot higher voltages back into the rail. Keep it on its own PSU. - Buck converters does not all give clean power - by their nature they are switchmode, and the typical "bought online for a couple bucks" type have switching frequencies in the audible range, you don't even want to see what their output looks like on an oscilloscope - definately not powering an expensive control system. Plug the 48v PSU into the IoT relay just as if it was a AC spindle. Set the PSU up to be on all the time, and thus only turns on and off by switching the mains input into it via the IoT relay: docs:blackbox:connect-dewalt-iotrelay [OpenBuilds Documentation] For the cost of a DC spindle + PSU + buck converter etc, you could just consider the RoutER11 by the way a lot better Router11 CNC Kit
Thanks. I think I get ya. If I have an Estop button and manual speed control, I assume all should work the same as I currently have it connected without the relay. Estop is setup to only stop the spindle right now. If I use the relay method, I assume I could wire the Estop to the 24v PS to stop all as the relay single should stop the spindle correct? Quick simplified diagram below of current setup. I was definitely looking at grabbing a RoutER11 looks awesome.
Emergency stops should ALWAYS be wired into the mains supply, before any power strips, adapters, relays, power supplies, routers, spindles etc etc. You cannot always predict what the emergency will be, the power supply could be on fire, the power strip could be melting from an overload, the router could be chopping someones hand. Cut ALL power to EVERYTHING at once using an emergency stop wired into the power, before anything else. One hit, kill everything. In particular, you do not want to rely on cascading systems, where one e-stop has to trigger some other system, who in turn has to turn of some relay, that maybe will cut power to the spindle power supply - that is an unsafe approach One of these between the outlet and the first power strip on that bench for example: Safety Power Tool Switch - not an ideal switch (not magnetic, so if power fails, and power comes back on, tools can start by themselves), and check current rating and compare against everything you want to run off it, but at least it is prewired
