Retrofitting a 1986 Maho MH400E

Ladder Logic is often easier for me. But I've had to spend some time browsing through the enormous PLCs of several other large commercial CNCs trying to fix problems.

Thanks for the feedback to HAL verses Ladder.

Your start relais seems to be for switching to low speed for the alternating left/right turning. On the MH700 this is done with an 70V transformer output.

So that would mean that 11K8 "Start" relay sets the main spindle motor power to star so when the twitch relays activate it only get 240V per winding right?

Since my machine is not currently operating, I have never actually seen or heard a MAHO do it's gear change, except for Müllernicks you tube videos of the simpler 4 speed MH700. Does the control command all three shifters motors concurrently or is gear changing done sequentially?
Mark

it has to be done sequentially, otherwise if one stage is between gears then for the other stages there will be no alternating turning.

On the MH700 the spindle is switched to star and additional the Voltage is set down.

db1981 wrote: the png are named as the movements : L_R = Position left to Pos right switching.

links,rechts,mitte,richtung are the four cams of on transmission stage (left,right,center,an one switch witch tells the siemens plc, in which direction the motors turns last and if it has to start in opposite direction) If you start in wrong direction the motors has not enough power to lock the gear in. Also its important from the timing that the gear motor starts with the right direction from the main spindle turning.
K7Richtung, K3 Motor, Wahlmitte, Bremse are the Outputs of the PLC to the Relais. (direction Motor, Motor Power, the relais witch enable the center switch, Spindle Brake) .

Thanks for clarifying that. I didn't catch on that you only need to scope one of the three shifters as are they are all functionally the same. On my schematic, the fourth switch is not called Richtung (Direction) but Links-Mitte (Left-Mid). Instead of a stand alone PLC, the gearbox control logic is programmed into the Phillips CNC on the MH400E. I hope they didn't change the function of that fourth switch.

Do you have a photo of the physical layout of switches around the CAM from that machine? I'll pull the cover off mine to compare.

it has to be done sequentially, otherwise if one stage is between gears then for the other stages there will be no alternating turning.

Thanks, I should have thought that through.

Interesting how many different ways you can accomplish a task in LinuxCNC. That Ladder, HAL or separate component all kind of tie in poularity as tools for getting this job done is suprising.

As I want to get the machine running under Phillips control before starting the retrofit, I noticed that four of the controller cards are no longer located in the same slots as when it was made. I doubted that the CNC backplane bus could deal with cards in the wrong place, and was hoping this was the reason that the Phillips 432 doesn't boot. Note, I pulled the PSU for Elko replacement.



I sent an E-Mail to DMG, and they responded that the physical location of those cards is not important. Shame, that would have been a nice obvious solution.
Mark

The function of all three stages is the same. On this MH700 the Middle Stage Motor has to turn in the opposite direction of the other two stages. Maybe someone changes some wires in the 25 years...
In 2014 i drawn a big logic diagramm to know what i have to code.

I don't know the Phillipps Control, this machine had an Heidenhain Control.

The fourth switch is originally called Links-Mitte.

Do you already have an solution for the Phillips Positions encoders?

What kind of Servo Amp is mounted in the cabinet?

RotarySMP wrote: Interesting how many different ways you can accomplish a task in LinuxCNC. That Ladder, HAL or separate component all kind of tie in poularity as tools for getting this job done is suprising.

With the recent information that the changes need to be done in sequence I no longer favour the all-HAL approach.
If it was my machine I would be working on a custom HAL component, It seems that db1981 already has one such.