How to set up Eleks machine limit switch in T2 Laser

  • Developer of T2Laser Software

    How do you want to have the switches configured?

    If you send me your email address in chat I will change the necessary files and send them to you with explanation for each change.

    For most people I would suggest using my firmware to begin with and putting both home switches on D9 to simplify things but you obviously have some idea what you're doing.

  • @Zax meaning that D9 pin has internall pullup activated?

  • Developer of T2Laser Software

    @jorgemarmo Yes, you just connect the switches to ground.

  • Hi Zax, thx again for the answer!

  • I'm using long arm home switches and T2laser doesn't back off far enough to do the final home run in. They're an easier installation than other setups I've seen but I get an error after the first back off. Any way to get about another 1/8th or 1/4inch of back off to alleviate the error warning while homing? Spacebar21

  • Developer of T2Laser Software

    @Spacebar21 It should back off enough to disengage the switch, no matter how long the arm is but if you prefer you can edit the $27 value.

    My default is 1mm, so $27=1

    The others are the homing speeds, called feed and seek. Seek is the initial contact and then feed is the slower second time.

    These are my default values.

  • Worked! Thanks. I needed 4mm as my arms are pretty long. Works pretty reliably too!

  • Developer of T2Laser Software

  • @Zax hahahahaha

  • Hi guys. I installed my limit switches and even soldered them very well. But, once I tried my laser it was cutting mirrored images. I resolved this by inverting the axis. Great now it cuts well but after installing limit switches, then home them to 0.0 then move the laser into position for cutting. It shows my coordinates in negative. I was looking into the settings of grbl but don't know which $$ to change.. could you help me ? 0_1511358335244_IMG_20171122_001031.jpg 0_1511358440084_IMG_20171122_001024.jpg
    Will it be better to just move the whole board and limit switches to the opposite corner ? (I don't want to do that kind of :/ )

  • Developer of T2Laser Software

    @rolx Usually the control board is at the back but it doesn't matter as long as your home switches are at located at what you consider front left.

    Once it locates the home switches the machine coordinates should be set to 0,0. If there's an offset I would clear them using Clear Grbl Positions in the Machine menu.

    If the switches are positioned as limits rather than home switches you can still use them, but would need to change some parameters and then setup one of the custom buttons to go to your home position and reset the workpiece 0,0. Yes the machine coordinates would be negative but this is no problem and actually fairly normal in the CNC world.

  • @Zax so there isn't any way to make them positive. That means I should just be careful to insert the coordinates every time negative.
    I have them just for homing. I still haven't tried cutting with it after installing the homing. Will do today or tomorrow. But won't the image be upside down again ?
    If you look at the photo front left are the switches. And after i put it into the position shown on the other photo it is negative. Now if I want to cut the paper, won't the picture be on lower left instead of upper right ?
    EDIT: Ok my problem was that I had changed the Y cables in my stepper motors. That way it was going the opposite way. Now in the software my arrow up means go up, right arrow the machine goes right. Perfect.
    But the problem with homing still persists. The homing goes the other way. Not left bottom but to right top.
    EDIT 2: I changed the $ homing invert to 3 and now it goes hoe it should.
    The problem with negative coordinates was that the LaserGRBL software wasnt supporting negative ones.
    Thank you for your support, I can now start making what I want :D

  • Developer of T2Laser Software

    Negative machine coordinates don't matter, change the display to show workpiece coordinates and use the custom button like I suggest. It will home to your limit switches, then you press the button and it will move to the lower left or center if you prefer and then set 0,0.

    Let me know if you need help setting up the custom button.

    The alternatives are to recompile Grbl with what you need or put in an automated move after homing but that's not recommended for safety.

  • @Zax
    I am awaiting delivery of my engraver and would like to add switches as described to automaticaly set the home position. I understand how they should work and will have no problem soldering to pin 9 on the arduino, but how do I get the machine to auto home on switch on? (how does it know the NO switches are connected) Is it a link on the board, a setting in T2 Laser or modified firmware (if so where can I download it?)

  • Developer of T2Laser Software

    @ztf Home switches are the best upgrade you can make. If you are using my default Grbl 1.1e firmware, just enable them from the settings menu and that's it.

    You connect 2 normally open switches in parallel from D9 to Gnd, one for the left and one at the front. Once enabled in the menu the house icon will change to red indicating it is going to auto-home, when you click it the head will move left to the switch and then back off, then forwards to the switch and back off. Then it sets that as machine 0,0. You can use the preset positions to move to any location accurately.

  • @Zax
    thanks for the quick reply, I have found the setting in the menu (I was looking in the wrong place) Where can I download your firmware (and is it different to any other Grbl 1.1e?)
    Sorry if the answer is obvious, but I'm new to the laser scene!

  • Developer of T2Laser Software

    @ztf The T2Laser default firmware is Grbl 1.1e (I compiled it, many others use it), it's in the Machine menu. I also include various custom firmware options including one for 3-axis homing and other purposes.

  • @Zax
    Ok, thanks for that, I did see it in the menu but wanted to make sure that it was the correct one for using the switches.
    (just waiting for delivery so I can make some smoke!!)

  • Where can I find a tutorial about how to add the home switches? What kind? How and where they are mounted, wiring, etc. Thanx!

  • Active Member

    here are several different methods including mine with pictures and explanations

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