Centroid Community CNC Support Forum

Finally have the dual homing working, thanks to Marty. Here is my file in case anyone homes the PC Turn 55 like this.

M92/X L1 ;Move to X+ limit switch, back off until it clears.
M105/X P-4 F25 ;Move X minus at 25mm/min until input 4 closes
M26/X ;Set X home here

M91/Z L1 ;Move to Z- limit switch, back off until it clears.
M106/Z P-3 F25 ;Move Z plus at 25mm/min until input 3 closes
M26/Z ;Set Z home here


Next gremlin to deal with is why my encoder isn't working. Guess it's time to pull off the connector and see where I screwed up.

I'll post a vid link to some axis movement and homing. Then another of the turret spinning and tripping inputs.

Threedj16 wrote: ↑Thu Apr 05, 2018 9:17 pm Finally have the dual homing working, thanks to Marty. Here is my file in case anyone homes the PC Turn 55 like this.

M92/X L1 ;Move to X+ limit switch, back off until it clears.
M105/X P-4 F25 ;Move X minus at 25mm/min until input 4 closes
M26/X ;Set X home here

M91/Z L1 ;Move to Z- limit switch, back off until it clears.
M106/Z P-3 F25 ;Move Z plus at 25mm/min until input 3 closes
M26/Z ;Set Z home here


Next gremlin to deal with is why my encoder isn't working. Guess it's time to pull off the connector and see where I screwed up.

I'll post a vid link to some axis movement and homing. Then another of the turret spinning and tripping inputs.

Cool,
Where in your Z axis do you home to? Headstock end or tailstock end?

martyscncgarage wrote: ↑Thu Apr 05, 2018 9:30 pm
Cool,
Where in your Z axis do you home to? Headstock end or tailstock end?

It was already setup with a limit switch on the headstock end. Which I seriously need to adjust (as it's a long ways off from being able to use a side mounted tool). But I'm just started to get things setup....slow but sure. And the X homes to the left facing spindle (again existing limit switch).

But I maybe reversing things just for my own convenience of keep the stuff moving in the direction of the arrows on the screen. Took me the longest to get used to setting up my mill with the X and Y moving exactly opposite of the arrows (but finally just look at the spindle and not the bed). But to avoid confusion with the new lathe, figured I'd set it up easy for me to see.

Opps, forgot to post the vids earlier. Sorry, they are facebook links.

Video of the dual homing sequence and showing the limit switch and hall effect sensor inputs going green for both Z and X (inputs 1-4):
https://www.facebook.com/drunkj.smith/v ... 785505599/

Video of moving the turret forward (via jogging as I tied the output relay to the mist control button). Also shows the two optical switches closing and opening on the Acorn (inputs 5 and 6). Also shows when i turn it off, reversing up against the pawl.

FYI, this link states anyone can see it whether they have a facebook account or not. For some reason I don't have the same option on the other vid.

https://www.facebook.com/drunkj.smith/v ... 3065931059

D'oh, stupid DB9 plugs always get me on the second row. I get turned around and those tiny little numbers....argh. Well, at least I have my encoder working perfectly now. Also went ahead and got my signal converter/isolator installed tonight. Spend a little time tomorrow getting that calibrated, too much thinking involved for this late....LOL.

Really, now the only major hurdle is this turret PLC program. Any volunteers who have done it for an Emco PC Turn 55 six position turret yet using the original motor and the two pulses from optical switches (zero and each tool position)? I'm at the point of starting my wire cleanup and cosmetic stuff (back panel and general cleanup). So ready for a turret to work via Gcode. Pretty please? LOL Maybe even a turret wizard....I'm happy to beta test?

You need to post the exact sequence of events for turret operation. How the turret works.
What you have for sensors, which inputs they are connected to and what each sensor does.

Then perhaps it can be worked out.
Marty

Ok, I am completely new to turret operation, but I'll describe to the best of my abilities the operation of the Emco PC Turn 55 turret with pics.

First, it's a 6 position turret (3 forward tool and 3 side facing tools). It uses a 12v motor which when 24v power is applied to the turret board, the motor is always on in reverse, holding the turret position up against a pawl. The turret board reduces the voltage from 24v to 12v and in reverse, the current is limited by a resistor to ~60ma. When moving forward for a tool change, it runs at ~120ma. The turret board has an onboard relay, which when 24v signal is applied, turns the 12v motor forward for a tool change (output 1 on the acorn supplies the signal to this relay). When the 24v signal to the relay is removed, the motor is always in reverse, low current mode locking the turret against the pawl at it's current position. The turret has two optical switches and a metal plate attaches to the turret. The plate has a notch cutout for each tool position and passes a 5v signal to turret board when it passes this notch (tied to input 6 on the acorn). The second optical switch (tied to output 5) is aligned to a single notch for zero position or tool 1 (higher up on the rotary plate), which keep the optical switch blocked until it passes the deeper notch and then sends 5v out to the turret board. After the turret board, I have a second relay board which takes the 5v signal and opens or closes a relay to allow pin 5 and pin 6 on the acorn to receive the common signal and activating them. Currently they are setup when a notch it seen, the acorn board gets a signal, so normally open.

- So output 1 turns on - turret relay closes and drives turret forward for a tool change. Output 1 off, turret board relay off and turret motor in low current reverse mode which holds turret against the pawl at current tool position.

- Zero optical switch tied to input 5 turns on when zero notch is in position. Tool position optical switch, tied to input 6, turns on when tool position notch is at the location.

What I can surmise for how the operation should run:
1) Tool called by Gcode
2) Check which tool is in currently loaded (if unknown, run turret until zero position, tool 1 is reached).
3) If proper tool is loaded, continue with Gcode (from variable previously stored)
4) If proper tool isn't loaded, output 1 turns on and a count is performed until correct tool number is achieved. Then output 1 turns off and the turret locks back into place with the correct tool loaded.
A) To achieve this, when output 1 turns on, the turret looks for input 5 to close
B) Once input 5 blips on, start a count for input 6.
C) When count number equals tool number, open output 1 (which opens turret relay, reverses motor and locks to pawl)
D) Tool number is stored in a buffer.
5) Turn on mister if called for by tool via turning on input 2 (haven't install this part yet)
6) Continue Gcode operation

Also would need some method of keeping up with tool count if turret was manually jogged (a nice to have but not a requirement)

Ok, not sure what stuff I left out, but that is the basic outline as I can see it.

Pics:

Getting a little closer to finishing up the build portion. Just need to swap out the motor potentiometer box to the signal converter, mount the fan, mount the back panel slides and cutout my HDPE for the back panel.

Not perfect, but OMG what a pain getting the cable tray covers on in such a tight little area. So wasn't able to do all my wires as I wanted, but oh well, it's behind a cover anyway....LOL.

A few pics:

Also, while I was taking a break today, decided that chuck key needed a spot to hang out. So whipped up a little locking chuck key mount. I am terrible about misplacing my stuff, literally in seconds of setting it down. I had to do this will all my mill tools too....LOL.

Looks great!

martyscncgarage wrote: ↑Fri Apr 06, 2018 8:48 pm Looks great!

Thanks!

Started a new thread for help with the PLC turret program. That way I can continue my build thread and the PLC help part won't get buried.