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Post by bowhntr7846 on Mar 9, 2017 4:46:24 GMT
Hello All, I have been cutting and carving with my M3 and have had success and failure. Something that I am confused about, I will describe my problem kind of in step form and anyone that may have a suggestion please feel free to reply. Thank you in advance!
Step 1 I draw an image in Easel, let's say a circle. Gonna cut out a wooden disk for example. I set my tool diameter and shape. I set the depth of the cut, the dimension of the stock. Generate the Gcode, export it out in mm.
Step 2 I startup gcode sender I perform a homing sequence (my M3 has homing switches) I then bring my X and Y to the lower left corner of the stock. Then I bring my Z using the sheet of paper method to set my "top of stock" with my tooling. So now I zero all axiss. When I start my spindle and send the Gcode to cut, my spindle will move to the upper right portion of the stock and start cutting. My dilemma is, if I set zero at the bottom left why does it move up and start the cut wherever it wants. When it does this most of the time it only cuts half on the stock and half off. Why would it not start at where I zeroed everything. I hope this makes sense. I find myself wasting a lot of material because if the design goes off the board it's ruined. Any help would be great. And forgive me if this isn't making sense, but hopefully someone gets what I'm fighting with Thanks JR
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Post by Derek the Admin on Mar 9, 2017 5:22:18 GMT
First, for the sake of keeping our technical terms straight... I'd call your procedure "zeroing" instead of homing. Homing is the intentional driving into fixed switches (the homing switches) for the purpose of obtaining a known position in machine space. Now, that techno mumbo jumbo out of the way, let's get to your question/
Where in the drawing space does this part get drawn in Easel? If, for instance, it's 6 inches from the origin in Easel then it's going to try to traverse 6 inches from the zero point that you set. I'm not saying this is the issue, but it would behave this way if that were the case.
Can you start by attaching some g code that you've had this issue with and let's have a look?
Also, (I'm not sure that Easel does this), but some programs (like Fusion 360) will designate a work coordinate system in the header of the code. You can set your origin using the zeroing procedure you described, but the g code program might have a line in there that says "Change the origin point for this operation to this..."
Anyway, let's check out the code and go from there.
Derek
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Post by bowhntr7846 on Mar 9, 2017 5:39:21 GMT
Let's say in easel I make the stock dimension 5in by 5in, I draw a square to be cut out of the stock that is 4in by 4in. That gives me 1in of clearance. It will move the spindle to start the cut to the upper right corner. But it goes to o far up and right and starts the cut in "air" until it meets the wood. I will have to get on my Surface Pro to get G code examples for you and I will attach them here. Thanks Derek
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Post by Derek the Admin on Mar 9, 2017 6:04:00 GMT
No problem bud. Cuts aren't coming out mirrored by chance are they? If you get into UGS under machine controls and press X+ does the X plate move to the right? If you press Y+ does the bed extend out over the front of the machine?
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Post by bowhntr7846 on Mar 10, 2017 1:41:10 GMT
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Post by bowhntr7846 on Mar 10, 2017 1:47:40 GMT
Derek, They are not coming out mirrored. My Axis move correctly..
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Post by andrew on Mar 10, 2017 4:45:42 GMT
So this might be a dumb question, but when you say "So now I zero all axiss" How exactly are you doing that? after your homing cycle, when you jog to the machine to your intended project starting point (bottom left of your material) are you putting in the "G92 X0 Y0 Z0" command in to tell the machine your project zero? Just curious, your .nc file looks like it should cut fine. Seems to me like maybe your project zero is off somehow?
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Post by Derek the Admin on Mar 10, 2017 12:02:46 GMT
Andrew brings up an important point on zeroing procedures. This particular cutting program actually exceeds the M3's range. The bounding box on it is 125.11mm by 268.43mm. It's really about 8mm too long. Check out the screenshot I uploaded. Part of the issue is that the bottom of the design is 11mm in Y+ from zero points you've set. You really want the bounding box (click here for an explanation of a bounding box) to have it's lower left corner at your origin. Here's another thing that gets you that most people won't think about until they crash into the frame a few times. It's not necessarily the case here, but something to consider in the future: Suppose you have a part you want to profile out with a 1/4" end mill that is almost the exact movement area of the M3. You set your origin 1mm from the bottom left of machine travel. Will it machine out without a crash? No, it won't. In this hypothetical scenario, the machine is going to try to profile out the part to the dimensions modeled so it will try to offset itself from the part accordingly.
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Post by bowhntr7846 on Mar 11, 2017 18:32:16 GMT
So this might be a dumb question, but when you say "So now I zero all axiss" How exactly are you doing that? after your homing cycle, when you jog to the machine to your intended project starting point (bottom left of your material) are you putting in the "G92 X0 Y0 Z0" command in to tell the machine your project zero? Just curious, your .nc file looks like it should cut fine. Seems to me like maybe your project zero is off somehow? When I refer to zeroing. I am resetting x,y, and Z to zero at the bottom left corner, I don't type in the command I use the hot keys to set zero. I need to put another piece of wood in my machine and cut the same file, I will GoPro video it and post it up. Thanks again!
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Post by bowhntr7846 on Mar 11, 2017 18:35:17 GMT
Andrew brings up an important point on zeroing procedures. This particular cutting program actually exceeds the M3's range. The bounding box on it is 125.11mm by 268.43mm. It's really about 8mm too long. Check out the screenshot I uploaded. Part of the issue is that the bottom of the design is 11mm in Y+ from zero points you've set. You really want the bounding box (click here for an explanation of a bounding box) to have it's lower left corner at your origin. Here's another thing that gets you that most people won't think about until they crash into the frame a few times. It's not necessarily the case here, but something to consider in the future: Suppose you have a part you want to profile out with a 1/4" end mill that is almost the exact movement area of the M3. You set your origin 1mm from the bottom left of machine travel. Will it machine out without a crash? No, it won't. In this hypothetical scenario, the machine is going to try to profile out the part to the dimensions modeled so it will try to offset itself from the part accordingly. This makes perfect sense! "Suppose you have a part you want to profile out with a 1/4" end mill that is almost the exact movement area of the M3. You set your origin 1mm from the bottom left of machine travel. Will it machine out without a crash? No, it won't. In this hypothetical scenario, the machine is going to try to profile out the part to the dimensions modeled so it will try to offset itself from the part accordingly."
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Post by Derek the Admin on Mar 11, 2017 19:40:36 GMT
Glad that helps.
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Post by aforww on Mar 11, 2017 19:49:26 GMT
Just FYI with GRBL 1.1 if the commands send the machine outside its maximum travel from the home position, it automatically pauses the job so that you can go back and correct the boundary situation.
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Post by Derek the Admin on Mar 12, 2017 2:02:40 GMT
Just FYI with GRBL 1.1 if the commands send the machine outside its maximum travel from the home position, it automatically pauses the job so that you can go back and correct the boundary situation. For what it's worth the version we are on can do that with homing. Its referred to as a soft limit. I don't remember the feedback it gives on a soft limit violation (I think it goes into alarm lock), but I do recommend it for anyone who thinks it would help. There was a time we were shipping units with soft limits enabled for those who had homing switchees but it ended up that people weren't always using homing switches at first and were booting without homing so the machine never knew its true position and they tripping soft limits all the time. I found it just caused a lot of confusion so I changed our hex file to leave soft limits disabled. For those that have homing and understand the concept it's a great tool.
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Post by aforww on Mar 12, 2017 2:11:19 GMT
Just FYI with GRBL 1.1 if the commands send the machine outside its maximum travel from the home position, it automatically pauses the job so that you can go back and correct the boundary situation. For what it's worth the version we are on can do that with homing. Its referred to as a soft limit. I don't remember the feedback it gives on a soft limit violation (I think it goes into alarm lock), but I do recommend it for anyone who thinks it would help. There was a time we were shipping units with soft limits enabled for those who had homing switchees but it ended up that people weren't always using homing switches at first and were booting without homing so the machine never knew its true position and they tripping soft limits all the time. I found it just caused a lot of confusion so I changed our hex file to leave soft limits disabled. For those that have homing and understand the concept it's a great tool. Ahhhhh that explains why I never noticed it lol. Sure would have saved me some crashes. But honestly, until I upgraded and researched GRBL I wasn't savy on all the $ options. Being aware of them all changed how I set up my machine and run it. Maybe that's another write up. Modifying GRBL parameters. Way down the line.
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Post by Derek the Admin on Mar 12, 2017 18:28:16 GMT
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