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Expanding My Horizon In Digital I/O - CNC/General Interest - Page 2 — Parallax Forums

Expanding My Horizon In Digital I/O - CNC/General Interest

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  • I go and rent the laser by the hour. 6000watt. 5’x10’
  • T Chap
    I go and rent the laser by the hour. 6000watt. 5’x10’

    WOW!!! I wish I had a rental store like that near me :)
  • Oh it’s Not a store. It’s a laser place you just give them a file and material and they cut it at their place.
  • Oh I see.... Now that is interesting... I wonder if there is anything like that near me. I doubt it, probably the nearest would be Chicago.

    I would love that capability.
  • I would love that capability.

    That would allow me to do what I really love, which is designing and building, instead of machining.
  • I have a guy in Pennsylvania, that does laser work for me on steel... but of course that is not local to NW Indiana.
  • I have a guy in Pennsylvania, that does laser work for me on steel... but of course that is not local to NW Indiana.

    Speaking of which, it seems to me, the quality has gone downhill, since he changed from plasma cutting to laser cutting.....

    I will need to find a new supplier, because he has become undependable, and the quality has downgraded.
  • idbruce,

    Do you specify the surface finish that you want because if you don't then they will choose it for you.

    I tell people all the time that if something is not specified on the print then that means it's not important and can be whatever the fabricator chooses.

    I made the mistake once of not specifying that I wanted some Aluminum parts colored black when I sent in to be stripped and anodized.
    They were black so I assumed they would be black again. Wrong! Came out grey.
    My supervisor thought they looked neat since they had a gun-something (forget the word) color.
  • jmgjmg Posts: 15,173
    edited 2019-01-20 19:46
    T Chap wrote: »
    I used mach3 for 5 years with steppers and no encoders. Then WinCNC the last 5 years with no encoders. Rock solid with simple printer port connections.

    That 'simple printer port connections' is a key detail, but not so easy to find in 2019...
    Even there, the remote hardware usually sets a print-rate via the handshake lines.

    T Chap wrote: »
    Never once a thought entered my mind about timing issues. It is not a big task to toggle pins on LPT1 and see what kind of speeds and accuracy you get. Instead of timers (in your case with 1ms min)

    If 1ms is tolerable, along with 'most of the time', you could look at HS-USB based printer port emulators. That gives 125us granularity on the USB link, and they have decent buffers.
    The Cypress CY7C68013A part I linked above has code for parallel port emulation.

    Google finds http://www.cnc1.eu/en/UC100_en.htm , which is a custom USB-parallel with a high-IQ motion engine built in. Not sure what silicon that uses ?

    There are parallel printer adapters that claim to be 'high speed', but get vague on if that really means HS-USB :)

    Google finds this, which looks promising.... open source and CY7C68013A
    https://www-user.tu-chemnitz.de/~heha/basteln/PC/USB2LPT/ul-17.en.htm
  • Genetix

    Hmmmm... I am not fancy here, just a mill finish on everything. My priority is functionality. In addition to my previous complaints about a supplier, it also seems to me that laser cut holes are harder to drill out as compared to plasma cut holes.
  • jmg

    There is no doubt in my mind that you are obviously an electrical genius. I just wish I understood at least 1/16 of what you try to teach me :) But I do try :)
  • Can I throw LinuxCNC on a RPi into the discussion - I think this is now a workable approach (when
    I last looked there were issues with linux realtime extensions on the Pi, but I think that must have been
    solved by the look of it:
    https://youtube.com/watch?v=mGvYaL24R-k
  • Can I throw LinuxCNC on a RPi into the discussion

    :) Moist Soytanly
  • jmgjmg Posts: 15,173
    Mark_T wrote: »
    Can I throw LinuxCNC on a RPi into the discussion - I think this is now a workable approach (when
    I last looked there were issues with linux realtime extensions on the Pi, but I think that must have been
    solved by the look of it:
    https://youtube.com/watch?v=mGvYaL24R-k

    There is also 'bare metal' work being done on PI's (no Linux), but whilst that level of HW has good computing resource, you still need to get out of the Compute side, to the machine.
    One Pi video show Ethernet used as the link, so that's using a fairly smart remote end unit.
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