Author Topic: Home switches (CLOSED)  (Read 151 times)

pedwards2932

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Home switches (CLOSED)
« on: January 08, 2017, 07:26:26 AM »
Does BCL have the ability to use home switches?  I anchored my engraver to my waste board by gluing down 1/4" strips of balsa around the legs of the engraver so it can't move but can still be removed. What I did to line up my work position is I created a .dxf file that runs 8" exactly from the 0,0 position both x and y.  Then I engraved that line on my waste board.  I used double back foam tape and placed it exactly on the line I engraved.  It is about 3/32" thick so it is easy to slide the sheet against the edge. Now I have a repeatable position.  Now to my question.  I used the jog to make sure the position is all the way in the lower left corner. Does it hurt the stepper to jog all the way till it hits the end?  That is why I am wondering if it would be better to set up homing switches so I can have repeatability of getting 0,0 without having to home with the jog.  For what I am doing (cutting airplane parts) I have some room for positioning accuracy as it isn't as close a tolerance as some of the jobs I have seen here......just needs to fit on the 3" sheet.
« Last Edit: January 08, 2017, 04:34:31 PM by Administrator »

ggallant571

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Re: Home switches
« Reply #1 on: January 08, 2017, 07:39:11 AM »
Easy answer - use homing switches. If you hit the limits the motors will stall and consume current. Not being a motor expert I can't say anything about how long is ok or what the effect is on the motor driver chips will be but I don't think it is positive.
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Zax

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Re: Home switches
« Reply #2 on: January 08, 2017, 07:55:50 AM »
Yes, add homing switches. They make a world of difference with positioning.

Stalling the motor won't harm the actual motor but it isn't good for the drivers or machine (belts etc).

pedwards2932

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Re: Home switches
« Reply #3 on: January 08, 2017, 08:35:11 AM »
Any idea on the best switches to get?   I have this laser:  http://www.banggood.com/2500mW-A3-30x40cm-Desktop-DIY-Violet-Laser-Engraver-Picture-CNC-Printer-Assembling-Kits-p-1003863.html?rmmds=search

Do all the different controllers support switches?  Will this work with BCL?

ggallant571

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Re: Home switches
« Reply #4 on: January 08, 2017, 08:48:35 AM »
With the L7 controller you will need to solder wires to the pins on the back side of the controller board. Elsewhere on this site I have published reversed engineered schematics for the L7. Other Eleks controllers have headers for the limit switch  wires.
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Re: Home switches
« Reply #5 on: January 08, 2017, 08:49:13 AM »
I don't have limit switches on my laser machine.

I don't find it to be an issue to just jog into my 0,0 corner. I can do that using the mouse and/or keyboard keys and fine tune the position. A press of the b key turns the beams on momentarily so I can check the 0,0 position. Arrow keys alone or with Ctrl allow me to finely tune the position. Then a press of the r key to reset to the new home position.

I'm always testing something on my laser machine and often times I want '0,0' to be out in the middle of the material somewhere...so I set that as the new home position. Probably for that reason I have not felt the need to add limit switches.
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pedwards2932

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Re: Home switches
« Reply #6 on: January 08, 2017, 09:32:07 AM »
That is kinda how I am handling it now......if I manually put it in the far left corner at the bottom then it is at 0,0 but if I need to check it I have been using jog and I set the smallest arrow of motion to .01 and move it left till it stops then down till it stops.  Wasn't sure if that would cause a problem, maybe manually moving it is better?

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Re: Home switches
« Reply #7 on: January 08, 2017, 09:51:05 AM »
You can manually move it but you have to move it very slowly...moving it manually reverses the current and feeds into the controller board which is not a good thing. You've been warned.

If you're jogging the last bit to the physical stop at 0.1mm I doubt you will hurt anything when you finally hit the stop. I never thought of doing it that way. I may try it.
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http://www.BenCutLaser.us/BenCutLaserSetup1.8.3a.exe.zip
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BCL Paid license: $39.95
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