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  • BenHarper commented on BenHarper's instructable End Stop / Limit Switch Problems3 months ago
    End Stop / Limit Switch Problems

    Close enough butdont charge cap through the switch, like this:

    Glad it helped!

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  • BenHarper commented on BenHarper's instructable End Stop / Limit Switch Problems7 months ago
    End Stop / Limit Switch Problems

    My Pleasure.I think I need to reorganise this instructable to update it a bit and add some of the info we just went through. I stuck it up a long time ago as a quick note and am surprised so many people have read it, might be time for a revamp considering its been read 63,000 times.

    Also remember to update your limit invert param $5=1 as GRBL by default is expecting normally open switches.See https://github.com/gnea/grbl/wiki/Grbl-v1.1-Configuration for good info on all params.

    HiAlmost - NC switch wiring looks good - but Cap wiring needs changing.Excuse the even worse edited image.One side of the Cap to ground as I have shown edited on X circuit.The other side of the cap to pin X limit line which as noted on the image is the 5V side.You don't need to find a 5V source to connect anything unless you are looking to add an extra pull-up resistor in which case you can see I have added this to your X circuit.Do the same for Y & ZThere are some more also ugly but useful schematic images here: https://github.com/gnea/grbl/wiki/Wiring-Limit-Switches

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  • BenHarper commented on BenHarper's instructable End Stop / Limit Switch Problems7 months ago
    End Stop / Limit Switch Problems

    There is a debounce parameter in GRBL, did you try that?

    HiRegarding Normally Open (NO) vs Normally Closed (NC), see the limit switch section on this page: https://3dtek.xyz/pages/grblaioNC is a more safe practice - I have no idea why the GRBL/Shapeoko/XCarve standard is to use NO. Or why they home to the front of the machine, or why they cut in the positive space. I guess they are trying to simplify things?If wiring NC, you need the switches in series otherwise if in parallel they would both need to be tripped at once which won't happen as they are likely on opposite sides of the machine;) Wiring in parallel is for NO only.Your limit switches should be marked C for common, NO, & NC. Use common regardless and NO or NC depending on your preferred method.It's most simple to wire in series in the NO config and forget the filter caps, howev...

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    HiRegarding Normally Open (NO) vs Normally Closed (NC), see the limit switch section on this page: https://3dtek.xyz/pages/grblaioNC is a more safe practice - I have no idea why the GRBL/Shapeoko/XCarve standard is to use NO. Or why they home to the front of the machine, or why they cut in the positive space. I guess they are trying to simplify things?If wiring NC, you need the switches in series otherwise if in parallel they would both need to be tripped at once which won't happen as they are likely on opposite sides of the machine;) Wiring in parallel is for NO only.Your limit switches should be marked C for common, NO, & NC. Use common regardless and NO or NC depending on your preferred method.It's most simple to wire in series in the NO config and forget the filter caps, however, there is about a 100% chance that you will have false limit errors. So chuck a .47uf to 5V on each port, and your resistors too, not that I bother.I don't see a 5V pin on the X Controllers green plug so I guess you have to do this inside the box?

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  • BenHarper commented on BenHarper's instructable End Stop / Limit Switch Problems1 year ago
    End Stop / Limit Switch Problems

    Yes non electrolytic caps work too.No difference for optical switches, its the wires to the switches which are the antennas picking up noise.

    You need to increase homing pull off - when homing fails its usually because its trying to pull off the limit switches and doesnt pull off far enough for the switch to open again. Try increasing homing pull off to 3mm and then home again..

    No, use caps larger than 5V, always over spec the caps and consider that the noise voltages are likely higher than the logic voltage. Also its 0.47uf not 47uf! 47Uf would take way to long to recharge after being discharged and so when the homing cycle moves off then back onto the switch the state would not have had time to go back high to 5v and the homing cycle will fail!

    yes, they all share a ground at the arduino side and so can also share a gnd at the switch end as well.

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  • BenHarper commented on pussiedoctor's instructable Identifying LED pins2 years ago
    Identifying LED pins

    Not in all cases - as I have recently spend a little while troublshooting!https://media.digikey.com/pdf/Data%20Sheets/Lite-On%20PDFs/LTL-4266N.pdf

    Not in all cases - as I have recently spend a little while troublshooting!https://media.digikey.com/pdf/Data%20Sheets/Lite-On%20PDFs/LTL-4266N.pdf

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