Wiring a 19mm 2P 3P rotary switch for the jog multiplier function on the new Acorn USB BOB

[Chas]

Hi, i recently purchased the new usb bob for a conversion from mach3 to Centroid Acorn on my cnc router. I am building a new control panel (photo attached) and after looking at the Centroid USB BOB page and the control panel shown there i decided to use the same 3 position rotary switch as shown on the panel ( see photo) rather than 3 separate momentary push buttons to save space. Unfortunately, perhaps i'm just being dense but i cannot configure the switch to give 3 isolated outputs. However i test the outputs there are always two live which is obviously no good. I don't know whether Centroid built the panel on the website or one of the many contributors but i would appreciate any help in sorting this out because it can clearly be done. I wasn't sure initially whether this was a momentary or latching switch but soon realised a self reset momentary switch wouldn't work anyway as it's always returning to the central position. The switch is 2 pole and has has 2 NC and 2 NO contacts. Any assistance greatly appreciated.

[tblough]

That is probably a center-off switch. A 2-pole switch will not work. You need a 3-pole rotary selector, not a 2-pole switch.

[Chas]

Hi Tom, thanks for the quick reply. I have searched and searched for a 3 pole version of that switch without success hence my assumption that somehow it had been done with a 2 pole. As i've already cut the 19mm hole and i can't find a 19mm 3 pole rotary i appear to have shot myself in the foot. looks like i'll have to think of a plan B.
Cheers
Charlie

[tblough]

Yup. Most rotary selectors are going to be 3/8" or M10. You'll probably have to bush the hole, and find a knob large enough to cover it.

[Chas]

I think you're right but that still begs the question how does the one shown on the Centroid USB BOB page work cos as far as i can tell you can't get a 3 pole version of that switch.
cheers
Charlie

[suntravel]

Four position:

Off L1 L2 L3

https://de.aliexpress.com/item/10050073 ... ry_from%3A

Uwe

[suntravel]

Better quality for 22mm hole:

https://www.automation24.de/wahltaste-s ... oQQAvD_BwE

Uwe

[tblough]

You only need one pole, but either 3 or 4 positions. 4 position, if you want an off setting.

Something like this - https://digikey.com/en/products/detail/ ... CQ/3751952

[centroid467]

Do you have a part number or datasheet for that switch? With four terminals on each half I would have expected it to be DP3T but looking again, it seems to be a CIT AS series (datasheet here) or similar which really does only come in SPST or SPDT (with 2 or 3 knob positions). It will not be easy to make this work with three inputs on the USBBOB without some kind of scheme with relays.

I would take Tom or Uwe's suggestion and find something SP3T or DP3T.

[RogDC]

. The switch is 2 pole and has has 2 NC and 2 NO contacts. Any assistance greatly appreciated.

Make sure you have a momentary rotary switch with break before make configuration. At the outset of the BOB alpha testing I purchased a rotary NC 12x position for jog select which you could select limits of rotation on, but placed a constant low on the input pins on the BOB. With the constant input on the jog step inputs it was creating issues for homing, auto-square, and other problems which I was chasing intermittently.

I wasn't able to find a momentary rotary switch that suitable for my design. Since I was doing Arduino as it was for the joystick control interface I decided to use a rotary encoder to the Arduino to momentarily pull low the jog inputs.

I had other criteria for my build and used the Arduino to display the last selected jog output on an OLED ( x1, x10, x100 as well as MPG enable/disable ) so that I could utilize the LED pins from the jog step inputs for indicators on the rotary encoders of Feed/Rapid/Spindle. Still working on the PLC to repurpose.

If you find a switch you like you could use an Arduino to convert NC to momentary output on the jog step pins, and also de-bounce the mechanical switch. This would still work with the jog LED indicators from the BOB if you need to see the indicators. With your monitor that close, you may not need to have them if you are using the VCP.