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 tab for each tool position and passes a 5v signal to turret board when it passes this tab (tied to input 6 on the acorn via 5v to 24v relay). 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 (and again passes a high to input 5 via the 5v to 24v relay).
When the turret reverses and locks into the pawl, it also moves off the each position tab thereby changing states back to low. So going forward to the next tool, it will switch the current tool high, then back low and then finally high again for the next too. So the logic has to incorporate a feature to account for this extra transition once per call of the turret rotate.
- So output 2 turns on - turret relay closes and drives turret forward for a tool change. Output 2 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 tab 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 2 turns off and the turret locks back into place with the correct tool loaded along with turn off spindle and coolant.
A) To achieve this, when output 2 turns on, the turret looks for input 5 to close (once for current position, then again for each tool position)
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 1 (haven't install this part yet) and spindle.
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:
