touch probe ideas?

New Home Forum Mostly Printed CNC – MPCNC Advice – MPCNC touch probe ideas?

This topic contains 27 replies, has 13 voices, and was last updated by  Fabien 2 days, 15 hours ago.

Viewing 28 posts - 1 through 28 (of 28 total)
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  • #63392

    woodknack
    Participant

    Anybody make there own touch probe? I’m looking for ideas. Love to see other peoples designs.

     

    #63394

    Dalton Porter
    Participant

    Mine is pretty simple.  I scraped the paint from a  thin piece of conductive material (e.g. hacksaw blade) and place that on top of my material at the origin.  In repetier, I do a home operation, followed by a custom script that sets x0,y0,z-t  where t is the thickness of my hacksaw blade.  In theory, this sets the origin to the surface and lower left corner of my material.

     

     

    #63395

    woodknack
    Participant

    Hmm hacksaw blade.  Creative!

    #63396

    JDGreen
    Participant

    @Dalton Porter

    Do you mind to share your script?

    #63397

    Dalton Porter
    Participant

    Printer Settings ->Scripts

    “Script 1”

    G92 X0 Y0 Z.6


    This drops the origin by .6 mm

    This will be stored in the manual tab under the “1” button.

    I connect my zprobe wires (one to the bit and the other to the hacksaw blade) using alligator clips.  I do a home, then I press the “1” script.

    1 user thanked author for this post.
    #63398

    woodknack
    Participant

    Printer Settings ->Scripts

    “Script 1”

    G92 X0 Y0 Z.6


    This drops the origin by .6 mm

    This will be stored in the manual tab under the “1” button.

    I connect my zprobe wires (one to the bit and the other to the hacksaw blade) using alligator clips. I do a home, then I press the “1” script.

    Can you use the G38.2 probe command in marlin? I know in GRBL you can. By using this command makes the cutter come down to the touch plate and when it gets contact it stops. Then you can use the G92 command the set your new z height.

    #63400

    Dalton Porter
    Participant

    I’ve not tried G38.2, at least not directly.  It may be what the home button is doing.  When I use home, the cutter does a slow dropdown, touch, then doest a retract, then does a slower drop down to get a more refined location for the touchplate.  It stops the 2nd time it hits the touchplate.

    I’m using Marlin.

    #63401

    woodknack
    Participant

    I’ve not tried G38.2, at least not directly. It may be what the home button is doing. When I use home, the cutter does a slow dropdown, touch, then doest a retract, then does a slower drop down to get a more refined location for the touchplate. It stops the 2nd time it hits the touchplate.

    I’m using Marlin.

    I have not set up a probe yet. but from what I’ve ready for GRBL by running this does something similar to what your doing in marlin.

    G38.2 Z-20 F1; G92 Z 16.82; G0 Z20;

    g38.2 starts the probing going down 20mm at feedrate of 1mm

    after it touches it sets G92 to the Z thickness of your touch plate(which is whatever yours is)

    then it has the Z move up 20mm and your ready to go.

    1 user thanked author for this post.
    #63411

    Barry
    Participant

    I’m pretty sure we don’t have that command for marlin.  I could be wrong, I’ll have to try it in a few minutes.

     

    Yea, that’s what I thought, we don’t have that command.

    1 user thanked author for this post.
    #63444

    Aaron
    Participant

    I don’t think we need that command in marlin, since the Z homing function basically does that. You use G28 Z to home just the Z, Attach probe to the Z endstop pins.

    #63452

    woodknack
    Participant

    I was really just looking for touch probe ideas. Looking to make one.

    #63456

    Jason Dentler
    Participant

    Here’s a touch plate I added on to Ryan’s pen holder. It may give you some ideas.

    Foil tape (for AC ductwork) and alligator clips are cheap & stupid.

    2 users thanked author for this post.
    #63458

    Barry
    Participant

    Here’s mine.  I don’t even take the thickness into account.  For 99% of the stuff I do with it, it doesn’t matter.

    2 users thanked author for this post.
    #63459

    Aaron
    Participant

    I was really just looking for touch probe ideas. Looking to make one.

    Okay, just responding to your question if we can use G38.2 in Marlin.

     

    I just took a piece of bar aluminum, screwed a wire on to it. My particular piece is 5.5mm thick. That wire goes to one pin on the Z endstop pin, and the other pin goes to an alligator clip on the bit.

    1 user thanked author for this post.
    #63466

    Tim W
    Participant

    I just use a piece of aluminum tape .1mm and  alligator clips 1 to tape and 1 ground to bit. I’m using gerbl and UGS and it works great as long as you remember to remove the clips BEFORE you start the router 🙁

    1 user thanked author for this post.
    #63471

    Barry
    Participant

    I just use a piece of aluminum tape .1mm and alligator clips 1 to tape and 1 ground to bit. I’m using gerbl and UGS and it works great as long as you remember to remove the clips BEFORE you start the router ?

    That was exciting!

    #63473

    woodknack
    Participant

    I just use a piece of aluminum tape .1mm and alligator clips 1 to tape and 1 ground to bit. I’m using gerbl and UGS and it works great as long as you remember to remove the clips BEFORE you start the router ?

    Did you get a video of that? 🙂

    #63475

    Tim W
    Participant

    Nooo video but Even if I did nobody would ever see it 🙂  There was a high pitch whistle and everything within 3 inches whisked off the table and I was left with a shorter wire than I started with while I scratched my head for a second thing what the H___ just happened.   Fortunately I had improvised and used a wire with alligator clips on both ends connected to a wire connected to my Rambo mini otherwise I see my mini flying around the room but i never have found the second clip yet

    #63487

    Ryan
    Keymaster

    And there it is a new use for the CNC, you made the worlds first CNC Weed Whacker!

    1 user thanked author for this post.
    #63490

    woodknack
    Participant

    And there it is a new use for the CNC, you made the worlds first CNC Weed Whacker!

    LOL.

     

    #63499

    Tim W
    Participant

    My lawn is “covered in little crowns the neighbors are starting to talk behind my back?

    1 user thanked author for this post.
    BT
    #87524

    Duarte Vasconcelos
    Participant

    Hello,

    I want to use a touch probe with a user command from the LCD panel, and I’m thinking in changing the Marlin file with this line:

    Home-Z

    Can I do this?

    Basically, my touch plate is around 20mm in height. And after it touches the plate, I want to rise the Z by 20mm, so I can remove the touch plate from beneath it.

     

    Thanks

    Attachments:
    #87572

    Mike Pensinger
    Participant

    Drilled a hole through my table way out in the back right corner and bolted a fender washer to the table. Measured it and recorded the thickness. Clipped on side of the Z limit switched to it and the other to the bit.

    The machine homes to the spot and touches off. When I do a tool change I set a macro in CNC.js that sends the tool to home and touches off then raises the tool and sets the offset for the washer thickness. I am running GRBLMega-5x on a RAMPS 1.6

    I built the machine for the 24×24 size but am going to expand it a little so that my limit switches do not interfere with the travel like they do now and to allow the home spot to be outside that area. Right now I have about 22×22 working area.

    #87574

    Guffy
    Participant

    Remove space between z and 20 in g92

    Of you need +20 above the probe then use g0 z40

    #87584

    Duarte Vasconcelos
    Participant

    Remove space between z and 20 in g92

    Of you need +20 above the probe then use g0 z40

    Yes, I removed the space after I wrote the post. But thanks!

    About the G0 section, doesn’t this raise the Z axis by 20mm independently of the current height? You make it sound that it raises the Z to 20mm absolute, and that I should put 40 so it goes to 40mm absolute from zero.

    But I’ll try it with some considerable height above the table so I have time to reset in case it doesn’t stop! 🙂

    #105144

    Yann Vautrin
    Participant

    Feeler gauge!

    Attachments:
    #105166

    Barry
    Participant

    Nice!

    #114366

    Fabien
    Participant

    Hi!

    I’ve just published my version of a touch-probe, so far it’s quite accurate! This version doesn’t require to have something metalic (I’m still waiting for my spindle to arrive, so I’m trying to have some fun in between ^^)

    https://www.thingiverse.com/thing:3865285

    2 users thanked author for this post.
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