I am building a 25” x 25” cut area x axis is 37” pipes and y is 37.25. I want the dual endstops but will I lose on the 25x25 work area?
From the way I understand it, you shouldn’t.
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Ideally you would place your endstops such that the switch is triggered but the lever is not fully depressed as the core hits the truck. This configuration maximizes the cut area with dual endstops and also provides some protection in case you go negative. If you setup the endstops this way, you lose a small amount of the cutting area…3mm (1/8") give or take.
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Depends on your tolerances, initial squareness of your build, and your level of OCD. In theory, the amount of travel you would lose is whatever is needed by your limit switches to latch before running your trucks into the corners, which can be infinitesimal. But if your build is out of square, you’ll lose whatever travel is outside the square work area. But that would be true without the end stops. If your OCD is in high gear, then it’s a mixed bag. On one hand, your build is likely dead square. On the other hand, you probably have exactly the cutting area you want, and the few mm of space you’ll lose will drive you nuts, like that one floor tile rotated the wrong way in the laundry room. Under the washing machine.
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I lost a few mm with my end stops, I did not want the micro switches to trigger simultaneously with the trucks hitting the corner mounts. Just didn’t seem correct to me to allow that to happen.
During my 6week journey (so far) building the MPCNC & related infrastructure its been super charging my OCD, its completely nuts.
Plus…
Everything I look at leads me down a new rabbit hole;
- z Probe - why bother with 2 cables when you can do it with one, so down the rabbit hole of modding my Chinese 52mm spindle to ground the shaft.
- During testing I found the Jogging via the LCD frustrating. Found Joystick Jogging thread here, so joystick now ordered.
- During the 2nd practical job I did (wooden hold down clamps) I realised why the Gcode examples always end with a spindle off command, I don’t want to hang about watching the entire job LOL. This weekend’s project is to hook up a relay for the spindle power supply.
Ummm… Yes, you do. CNC machines are real fire hazards if one little thing goes awry. Or maybe two… Either way, you can go from a casual afternoon of robot assisted lumbercide to “oh, shit…” Followed by “glad I was here to hit the E-stop button”, or maybe “lucky I had a fire extinguisher, and it was just the MPCNC”, but it could also easily be “I hope the fire department gets here in time”, or worse “so this is what the burn unit looks like” (even worse still, the burn unit waiting room).
You get the picture. Never leave your robot, with no feedback control and a high speed bit in wood, alone for any amount of time.
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Yeah. We were just talking about this in another post.
Bring a book if you must, or clean up your garage, or bring in a recliner, a TV and some bluetooth headphones.
I trust my 3D printers (maybe I shouldn’t) but I will pause the cnc when I go to the bathroom.
That said, the relay is great. It is nice to have it start on its own. It is nice that it stops at the end. But most useful is that it stops when the controller is unplugged or reset.
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I’ll just leave this here…
One of my early cuts, I was going for a 19mm cut depth… And had about 18.5mm “stick out” on the tool. Second last pass I was looking at it wondering if I had quite enough… Last pass started, and it was just touching the material with the collet nut. I hit the emergency shut off when it started to smoke.
But for the original question, I lose less than 2mm with the endstops. I chose to set them there so that the switch would for sure get full travel. I could have made it less, but that’s where it was when the machine was dead on square, and I built with a little extra build space just in case of tool changes, or whatever might happen.
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Exactly what I do. Recliner and earbuds under ear protection is my vote.
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Alas, we hardly new you. RIP
That’s not Barry’s machine, btw. That’s just a video we post to remind people what is possible.
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