Limit switches or not?

Thanks!

And at the risk of asking a question already asked (I searched but can’t find) - when you add hard limits you simply just add another switch inline for that axis and then enable a $ setting in GRBL to turn hard limits on, right?

If that’s the case (I’m assuming yes) - how does that work if you’re using NC switches? or does it?

Do the hall effect switches even support NC?

There is another setting in GRBL to use normally closed. $5 setting.

$5=0 - normally open
$5=1 - normally closed

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thanks @ErikJenkins and @PhilJohnson - I knew about $5 for NC, I guess for some reason I was thinking that series wouldn’t work for NC … not sure why, apparently it’s time for more caffeine.

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Phil,
I watched your video… very helpful. Just wanting to make sure I’m clear. When you are talking about a bump stop, you mean the “L” shaped piece of wood you have attached to your machine, and not something that your machine bumps into to go to a position, correct?

This overall discussion is convincing me that I need to build some physical protections for my switches and get them mounted and use them. It is somewhat sad that I have ALL the wiring completed except for connecting the switches. Unfortunately, I’m tied up this weekend and all next week so won’t be able to try it out for a couple weeks.

–Rick

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Great thread. Nice to see the exchange of ideas/opinions/facts without people getting ugly, which I have witnessed on other sites. One reason I like this site!

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I did long time ago, just one simple hole and thread. No possibility to break Z switch again.

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I drilled and tapped a hole for a bolt in my Z axis plate to protect the switch after the first one effectively vaporized in a crash, I think I’ve shared it before. Got the idea from someone else though…

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I installed a second limit switch on my ‘Z’ axis slightly behind the ‘homing’ switch. This is wired inline with my emergency stop button. If the ‘Z’ homing fales the power is cut off.

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I ordered and installed limit switches with my x-carve, but quickly found I had no use for them. I never did break any, but I discovered that so long as I was properly zero-ing my X/Y/Z at the start of every project, the limit switches served no function from my perspective. I ended up disconnecting them and haven’t used them since.

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This is great. It reminds me of: manual vs automatic, Beta vs VHS, Vinyl vs CD, film vs digital and on and on.

Bottom line is there is no right or wrong here. What works for you is the best way to go.

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You could always go cheap and just stand over the XCarve whenever it’s running with your hand poised over the E-Stop like you’re a contestant on Family Feud…

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I just got my second x-carve and the new z plate did have a drilled and tapped hole for a positive z-stop. I cannot remember if it came with the screw or not though

Do you use a separate shielded pair for each sensor?

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Seems like a ton of work, when instead of rewiring your whole system you can just plug in a shield

It most definitely would of fixed your issue, and It’s not false advertising (I take issue with you saying that, and out of 50 something cards there it has never failed) when I guarantee it or your money back. You need to understand like I explained to you weeks ago, your noise suppression with the 3 capacitors was a really bad design, that’s why you blew capacitors. It also was only trying to work on your steppers and not your power supply or which is also a cause of noise. I have stayed quiet till this point as you were not saying anything negative and only correcting where needed, and i’m glad your system is working for you now, but you should not be advising others with info you don’t seem to understand or have a background in. I say this because people spent a lot of money on their machines and it would be a shame if you blew their electronics on bad advice. While Soft limits is a great tool, let Larry advise these people on it, he has the knowledge and background to do so.

No reason for name calling. I flagged your post @PhilJohnson. Just so there is no confusion on who did it.

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I’m guessing you did the circuit wrong, you should of contacted me and I would of happily walked you through it. I’m guessing you only made one filter, where you need one filter or circuit for each switch.

The part that’s incorrect and annoyed me is A)that i’m pushing to sell the product when I (A) gave the circuit open source as I advised you to make one before spending the money and many other of which i have helped since the beginning and (b) that I push it as a fix all, which I don’t. I know what it will and won’t fix and only advise those it will fix.

As for flagging, you should ask if it was me who flagged it first before assuming.

? never tried to compare, just seemed like a whole lot of work to rewire your whole machine, but in theory that should work, always said that.

Out of curiosity, has anyone ever ran an always on lever switch inline of the stepper motor so that when the switch is triggered it kills power to the motor before it makes contact?

Switching motors wires directly is a good way to kill your controller.
It’s best to have an emergency stop switch that kills power to everything.