Retrofitting a 1986 Maho MH400E

Hi, this is what I have done so far. I have included the ladder file and the pins (inputs and outputs) are configured for the 7i84 (in custom.hal file). I can’t test it because I don’t have 7i84. I haven’t assigned any input or output on the 7i77. You have to place the files in configuration folder and then you run pncconf and modify the MH400E . The ladder logic and custom.hal are safe from changes from pncconf wizard. Connect 5volt and 24 volt to mesa cards (7i77,7i84) and run the file from “application menu-CNC-LinuxCnc-MH400E”. to check the logic start from the axis menu “file-ladder”. When you start the spindle and choose a speed the ladder starts to enable the outputs on the 7i84. Don’t connect any hardware of the machine yet.

In my machine the gearbox is upside down compared to yours, so we have to check that the cams rotate to the direction that supposed to.

In MH400E.hal if you put a # in front of “sets spindle-at-speed true” than the ladder can control this item and pause the feed in all axis wen a change in speed is commanded. If this solution is not desirable than I will experiment with spindle-enable out command from LinuxCnc, using it to disable any gear change while the spindle is on. And enable the gear change when we stop the spindle. But the problem then is that when we stop the spindle the commanded speed is 0 and the ladder won’t know what speed to command.

Part of ladder logic

And the subroutine SR0

Hi John,

You are making good progress on that ladder logic. Thanks for sharing it. I need to power up the PC to install the touch screen drivers, and will try and test that ladder at the same time.

Yesterday I pulled the MAHO control panel.






The replacement will be something like this...

Cool, nice and simple. The 3 futures down right are usb?
John