There seem to be two definitions of extruder. https://all3dp.com/1/3d-printer-extruder-nozzle-guide/ suggests extruder can either mean "exclusively the motor and associated parts that push and pull the filament" or "the entire assembly including the hot end". You seem to be using the former...
If I've understood this correctly you want to power a second extruder via a change-over switch but not amend the 3D printer ("a black box"). How is the unmodified printer controller going to cope with controlling the second extruder in a different position which it doesn't know about? Are you...
It seems that you are trying to drive two stepper motors. Given the complexity of suggested solutions to provide a relay driver and 4 poles of relay switching it would seem to be just as easy to provide a second stepper motor driver for the second motor.
When choosing which approach to take...
Agreed. It needs to be replaced with a proper 3-phase + Earth cable. Earth continuity should be checked from the supply to the control box and on to the saw assembly.
In the new pictures (thanks) I can't see any strapping on the T1 transformer for 240 V operation (top row) or 120 V operation...
Oops, missed this earlier. Is this the cable between the control box and the motor junction box that has been cut through? Awkward, if so. Still, the individual wires seem to be numbered at both ends which should help establishing where the replacements will need to go.
Can you just use faster PICs?
The table at https://www.microchip.com/mymicrochip/filehandler.aspx?ddocname=en588853 lists 200 and 252 MHz 32-bit PICs with 4 x 32-bit counter/timers which should meet your 5 ns resolution requirement. Using a fast PIC with a familiar toolchain might offset using...
I can certainly see lots of leads in the picture of the motor but many of them go to the light brown connector block or the flying blocks wrapped in duct tape (hmm...).
I think the connections to the motor field windings are in the 2 x 3 block with visible straps at the back of the connection...
It's possible. I'm not convinced it's particularly practical.
As davenn pointed out you'll be operating at the limits of what is possible in amateur radio. Whilst only a few amateurs get to build one moonbounce station you'll need two (for the IOT gateway and the Internet-connected ground...
Do you actually have 520 W of LED lighting to control or do you just mean you have a surplus 520 W PSU, perhaps from a PC, that you want to re-use with some LED lights? What is the power rating of your LED strips?
You can get LED driver modules that connect to the mains (without using a spare...
Yes, your supply frequency is 60 Hz for both single and three phase.
Canada seems to have a choice of 208 V, 480 V or 600 V for its 3-phase supplies. Do you have 208 V 3-phase available to you? That would seem to be compatible with the way your motor is strapped, just under-running it slightly...
I'm writing this as background information. As you say you are not very good with AC you really need to get this saw wired in by an industrial electrician experienced in 3 phase work in your jurisdiction. A 3 kW 3 phase motor connected to a circular saw blade is not a system to learn AC on for...
I'll go with garbage idea. If you want a DC power supply with variable output just buy one with that feature built in (you can google for the specifications you want to find some). Don't try to lash something together with a dimmer switch.
Also, are you looking for a power supply that takes AC...