1. #1
    I wonder if the clever and experienced members of this forum can help me with this problem. I have a Fehlmann Picomax 50 machine which I've retrofitted with up to date drivers/motors to be driven with Mach3. The machine uses a quick-change tooling system which is ejected when the quill is fully retracted. The following video will explain the problem far better than many lines of text:



    Here's a general introduction to the project:http://www.mycncuk.com/threads/11067...version-refurb
    Last edited by Agathon; 02-07-2017 at 02:44 PM.

  2. #2
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 8 Hours Ago Has been a member for 9-10 years. Has a total post count of 2,121. Received thanks 233 times, giving thanks to others 5 times.
    That could be a bit tricky in Mach3, as you can't reconfigure limit switches on the fly.

    My initial thought, is add an extra relay controlled by an output, that overrides/bypasses the Z upper limit switch.

    Then in your M6 macro, have it activate the Z upper limit override output/relay, then command a Z move until the tool change switch is triggered, change the tool, then move back down far enough so the Z-limit switch is cleared, then deactivate the limit override output.

    A safer option might be command a G53 g-code move up, which would avoid running into a mechanical limit, if the limit switch was to fail. The distance the axis has to move should not change, so using a specified move should work well.

    Once you have that working via your M6 macro, adding a button to control it should be relatively easy. In fact thinking about, you'll probably want your M6 macro to pause and wait for a manual input anyway, otherwise it'll drop the tool whenever it reaches an M6.
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  3. #3
    Quote Originally Posted by m_c View Post
    That could be a bit tricky in Mach3, as you can't reconfigure limit switches on the fly.

    My initial thought, is add an extra relay controlled by an output, that overrides/bypasses the Z upper limit switch.

    Then in your M6 macro, have it activate the Z upper limit override output/relay, then command a Z move until the tool change switch is triggered, change the tool, then move back down far enough so the Z-limit switch is cleared, then deactivate the limit override output.

    A safer option might be command a G53 g-code move up, which would avoid running into a mechanical limit, if the limit switch was to fail. The distance the axis has to move should not change, so using a specified move should work well.

    Once you have that working via your M6 macro, adding a button to control it should be relatively easy. In fact thinking about, you'll probably want your M6 macro to pause and wait for a manual input anyway, otherwise it'll drop the tool whenever it reaches an M6.
    Thanks for this - really helpful. I'll do a bit of research.

    I'm coming round to the idea of switching to LinuxCNC so may have to rethink this yet again.

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