Centroid Community CNC Support Forum

I'm 100% going to get the lathe running first but i am making my way through it.

I have the spindle running, limit switches working and homing, encoder done, coolant, light etc done. It's more relays, VFD control and cable management left and i'll be ready to make some chips at the end of the month fingers crossed (Minus the took changer). Why i'm looking to get the theory of the turret ironed out now so i can jump into it or order what i need preemptively.

Thanks for looking over the things i've posted, i took some photos of what i have and it seems to check out with the drawings and what was posted on that thread, 8 cables with 1 grey COM. (I took your advice and left the switch in place)

You can see the grey common between position 1 and 8

I also found this sheet that has the Rotary switch positions and the Turret positions labeled. The colors labeled match with what i have.

Agree. Though to use all 8 inputs you will need an Ether1616
COM= Acorn power supply COM
I think this may be fairly straight forward with the Gray logic Lathe ATC PLC

Just to chime back in. The diode board on the Mirac transforms the 8 rotary switch outputs into 4-bit BCD grey code. The arrangement of the diodes to produce the BCD output is shown in the linked document below and is easily implemented in stripboard or similar.

http://www.loreme.fr/fichtech/MDL107%20eng.pdf

We have implemented this on our Mirac and ran a check afterwards on the actual BCD outputs by pulsing the turret sequentially around the positions (also reversing it to ensure it locked at the right position). The Centroid 4-bit grey logic ATC program works fine and the turret reverse can be timed to lock back in position. At the moment we plan to use the turret clamp switch to simply verify that the turret is locked rather than directly interrupting the reversing action of the turret, but either should work.

If there are other pneumatic functions on the Mirac then there will be a shortfall of inputs and outputs on the Acorn and the the Ether1616 would be required.

I've done a list of the I/O i need and i come up short by quite a bit so the Ether1616 board was looking like a future purchase anyway.

I'm going to use a pneumatic collet chuck, DC brake on the spindle, potential bar feeder (be a little project on it's own), pneumatic door, where to put the turret clamp switch? so i'll order the board. Use 8 inputs for the turret + 1 for the clamp switch and that still gives me quite a few spare to do all the extra options i'd like.

Tom
you will still need the diode board to create the BCD inputs if you want to use Centroid's turret macro, unless you are planning to modify it. Plus you would be giving up 4 inputs needlessly.

kfm wrote: ↑Wed Jan 19, 2022 5:28 am Tom
you will still need the diode board to create the BCD inputs if you want to use Centroid's turret macro, unless you are planning to modify it. Plus you would be giving up 4 inputs needlessly.

KFM,
I agree with you, can you provide details about the diode board and how it is connected. It is not clear to me how the board functions based on the 3 pages Tom provided. If you can provide the circuitry based on your board, a sketch that would be most helpful.

Marty

Yep taking that all in, Analog/digital board required.

I had a quick look around and there is quite a few off the shelf boards for a couple of £/$ (Not even worth powering the soldering iron for that!), they come with truth tables but they all seem to top out at 6 VCD to power, the 24v coming off the headers would cook that fast.

https://cpc.farnell.com/sparkfun-electr ... %20Modules

Could take 5VDC off the DB25 + a common to power the board and lower the 24VDC header voltage to 5VDC for the Binary inputs?

Just an idea for using cheap off the shelf parts, i'm still learning.

Please consider not using imgur for links. When I click on the photo, I can not see it without refreshing the imgur link.
Please take the time to upload the native images here.
I am not sure what you are getting at.
Just know you must SINK the Acorn or Ether1616 inputs that are standing at 24VDC to activate them.

Marty

Noted on the images.

I need a Analog/digital board to convert the analog switch into 4 bit binary, i was just looking to see if there was cheap and readily available off the shelf part to do this and there are, but they all seem work on 5VDC and the inputs on the acron board want 24VCD.

Would of been a easy fix for the sake of $5