How to move workpiece inside work area in linuxcnc?


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    Default How to move workpiece inside work area in linuxcnc?

    Is anyone here able to tell me how to move my workpiece or my machine zero so that it (my workpiece) is inside the work area?

    The first time I opened my gcode file everything was perfect. I.e. The machine's zero and the cone was at the bottom left corner and inside the work area. But, every time since the cone has started in the center of the workpiece (so 3/4 of it is outside the work area) or in some random place where all of the workpiece is outside.

    Zeroing the machine and touching off on all three axis does not help. It moves the cone a little but still leaves the workpiece outside the work area.

    I tried reading the Linuxcnc instructions and they make no sense at all (at least to me).

    I don't really understand what any of the G54 / G92 options do but all of them only seems to make the problem worse. And, once selected, there seems to be no way to undo the damage aside from turning it off and on again....

    So, is there a simple method of moving the workpiece or telling Linux CNC where to start?

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    Default Re: How to move workpiece inside work area in linuxcnc?

    With my machine I move the tool to the workpiece and enter the approximate coordinate in the "touch off" box for each axis.At the completion of the sequence the tool lifts up to the programmed Z clearance height.It might help if you could post a screenshot of the monitor showing the problem as we don't know what version of LinuxCNC you are using or which screenset. How to move workpiece inside work area in linuxcnc?-screenshotof-3dpath-jpg

    This shows one of my toolpaths and you can see the G54 values.There is a dedicated LinuxCNC forum at https://forum.linuxcnc.org/ .There is a lot of knowledge there but I don't find it the best explained piece of software,which is a great shame because it is very capable.



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    Default Re: How to move workpiece inside work area in linuxcnc?

    Might this be resolved with attention paid to XYZ machine zero relative to workpiece in CAD? My experience is, if you are able to locate the workpiece consistently and accurately within the machine work envelope (say against fixed stops with known values), then you can make a template of this in CAD and place the stock model within that virtual space. When you post out and use machine zero for reference (after homing), the control already "knows" where the stock is. Perhaps I'm missing something.



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    Default Re: How to move workpiece inside work area in linuxcnc?

    Move the spindle to the lower left corner of your workpiece and zero the X and Y axis.

    If that's not working, then your part is probably not placed at the origin in your CAM program.

    Gerry

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    Default Re: How to move workpiece inside work area in linuxcnc?

    Quote Originally Posted by Goemon View Post
    Is anyone here able to tell me how to move my workpiece or my machine zero so that it (my workpiece) is inside the work area?

    The first time I opened my gcode file everything was perfect. I.e. The machine's zero and the cone was at the bottom left corner and inside the work area. But, every time since the cone has started in the center of the workpiece (so 3/4 of it is outside the work area) or in some random place where all of the workpiece is outside.

    Zeroing the machine and touching off on all three axis does not help. It moves the cone a little but still leaves the workpiece outside the work area.

    I tried reading the Linuxcnc instructions and they make no sense at all (at least to me).

    I don't really understand what any of the G54 / G92 options do but all of them only seems to make the problem worse. And, once selected, there seems to be no way to undo the damage aside from turning it off and on again....

    So, is there a simple method of moving the workpiece or telling Linux CNC where to start?
    Do you have home switches?

    Please shows us a screenshot / photo of the LinuxCNC screen showing the graphical plot.
    Please post the gcode file also

    What do the work extents show (you may have to turn these on in the view menu)?

    7xCNC.com - CNC info for the minilathe (7x10, 7x12, 7x14, 7x16)


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    Default Re: How to move workpiece inside work area in linuxcnc?

    Quote Originally Posted by ger21 View Post
    Move the spindle to the lower left corner of your workpiece and zero the X and Y axis.

    If that's not working, then your part is probably not placed at the origin in your CAM program.
    I thought I'd done both those things although I'm still learning so it's possible I did something wrong on the cam side.

    I think there is something I'm not understanding about setting the origin on the cam side. I assumed that I was telling it where to start in relation to the work piece, not where on the cnc machine axis it should start.

    There's nowhere to input how far down each axis you mounted the work piece in cam. I thought that's why we touch off to find the edge. I don't really understand why any workpiece would be outside the work area after setting the zero and touching off unless it was too big for that machine's envelope.

    After I touch off, linuxcnc puts the spindle cone in the center of the round work piece with 3/4 outside of the machine's available travel. If I move the origin in Cam to the other side (or any side), the issue would be the same (as it's round).

    In Fusion360 I put the origin at the bottom left corner of the work piece. Something I'm doing wrong is causing linuxcnc to ignore this.

    Could it be a touch-off error? E.g. Are you meant to touch off for each axis at the exact origin point you set in Cam or can it be anywhere on the part edge for each axis?



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    Default Re: How to move workpiece inside work area in linuxcnc?

    Quote Originally Posted by Goemon View Post
    I don't really understand what any of the G54 / G92 options do but all of them only seems to make the problem worse. And, once selected, there seems to be no way to undo the damage aside from turning it off and on again....

    So, is there a simple method of moving the workpiece or telling Linux CNC where to start?
    ...short answer Yes. It's a process. The G92 is handy but, can be dangerous when used. Its a good idea to use a G92.1 at the beginning to clear the Preset Offset (if any) that has been stored from previous Operations/Programs.
    G Codes

    The G54-G59.3 is a little hard to understand at first, but is your new friend. The manual is thin about how to use the LinuxGUI screen buttons/tabs/etc so, get more screen time with all the buttons may help ya
    Coordinate Systems

    DJ



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    Default Re: How to move workpiece inside work area in linuxcnc?

    I figured it out. Well after rechecking the cam part like you guys said to...

    After rechecking the Cam (which was from someone else's cad file for an online tutorial) I saw they'd added a fixture which sits outside the work area. Once I moved the stock and touched off further down my X axis, everything worked the way it's meant to. I.e, the work piece moved back into the work area.

    I feel a little stupid for missing that. It seems so obvious now but it didn't occur to me to check that at the time.

    Thanks for helping me (again).

    I thinks it's slowly starting to sink in.

    It's like the lottery numbers. They always look so obvious after they've been drawn....



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    Default Re: How to move workpiece inside work area in linuxcnc?

    Quote Originally Posted by machinehop5 View Post
    ...short answer Yes. It's a process. The G92 is handy but, can be dangerous when used. Its a good idea to use a G92.1 at the beginning to clear the Preset Offset (if any) that has been stored from previous Operations/Programs.
    G Codes

    The G54-G59.3 is a little hard to understand at first, but is your new friend. The manual is thin about how to use the LinuxGUI screen buttons/tabs/etc so, get more screen time with all the buttons may help ya
    Coordinate Systems

    DJ
    I didn't know anything got stored from previous operations. That's worth remembering to avoid future headaches...

    The only issue I've had with Linuxcnc buttons and menus is when they use jargon like G54 instead of saying what they mean. I had no problem homing because the button is called home.

    G54 and G92 are a problem because G54 and G92 doesn't mean anything to me. It's not at all obvious what they do when you select them either which makes learning by trial and error harder.

    I can see that Linuxcnc is a good program or at least not noticeably worse than the ones you have to pay for. It seems relatively straightforward. It would just be a lot easier to learn if they cut all the jargon but... the same could be said for all software and processes...

    The official instruction manual for Linuxcnc and that entire linuxcnc forum is of zero value to me. For anything that is not self explanatory the manual is poorly written and just makes things more confusing.

    I didn't even bother signing up for their forum when I saw what sort of answers people were getting. Grumpy and unhelpful.

    This forum is way better.



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    Default Re: How to move workpiece inside work area in linuxcnc?

    I didn't even bother signing up for their forum when I saw what sort of answers people were getting. Grumpy and unhelpful.
    It's a hangout for developers, linux geeks and power users. With that type of membership questions are often answered with links to documents. Much work goes into those documents and pointing users toward them is not being "grumpy and unhelpful" but it could come across as a RTFM kind of attitude,.

    If the UI buttons refer to things like G54 it's because offsets are defined that way in g-code. G-code is cryptic but it's what we have to work with. Quit confusing yourself with G92, include G92.1 at the top of the g-code and then forget G92 exists. G54 is easy when you get clear on the concept, it's a coordinate system offset some distance from the machine origins. It's active by default so that's something to keep in mind. Also the UI can display machine position or relative (to G54) position depending on the selection under the View tab.

    Nobody says this is easy. Hang in there, it gets easier. And then it gets dangerous

    Anyone who says "It only goes together one way" has no imagination.


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    Default Re: How to move workpiece inside work area in linuxcnc?

    Quote Originally Posted by cyclestart View Post
    It's a hangout for developers, linux geeks and power users. With that type of membership questions are often answered with links to documents. Much work goes into those documents and pointing users toward them is not being "grumpy and unhelpful" but it could come across as a RTFM kind of attitude,.

    If the UI buttons refer to things like G54 it's because offsets are defined that way in g-code. G-code is cryptic but it's what we have to work with. Quit confusing yourself with G92, include G92.1 at the top of the g-code and then forget G92 exists. G54 is easy when you get clear on the concept, it's a coordinate system offset some distance from the machine origins. It's active by default so that's something to keep in mind. Also the UI can display machine position or relative (to G54) position depending on the selection under the View tab.

    Nobody says this is easy. Hang in there, it gets easier. And then it gets dangerous
    It's not so bad. I actually like the simplicity of Linuxcnc - Both in terms of not needing additional hardware and the relatively simple dashboard for the software's default frontend.

    There doesn't seem to be much that's complicated once the jargon is translated. Given the potential dangers from a mistake, you just sometimes need a sense check from those who know more (like you guys) until you find your cnc legs...

    I've been figuring out the starting coordinates by adding offsets when I touch off and repeating until it ends up where I want it. It often doesn't move where I expect and I don't usually understand why but so far I've been able to get it there eventually.

    I've been making a few parts over the weekend and they came out really well. The quality is way better than I expected. It makes all the work so far feel worth it.

    The cut quality, finish and speed in aluminum and hard woods is amazing. I'm also happy with how quiet it is. I can't hear it at all from the rest of my house.



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How to move workpiece inside work area in linuxcnc?