viddall
New Member
Posts: 33
Location: Maryland
Machine: Power Route
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Post by viddall on Jan 8, 2019 0:57:56 GMT
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Post by Derek the Admin on Jan 8, 2019 2:42:55 GMT
.01 mm for x and y and .005mm for Z.
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viddall
New Member
Posts: 33
Location: Maryland
Machine: Power Route
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Post by viddall on Mar 8, 2019 1:10:02 GMT
I thought you guys and gals might like a little spreadsheet that can be used to fine tune the movement accuracy. For instance, you might cut a 100x100mm square and end up with a 100.25 by 98.65 square. This sheet allows you to type in the actual versus modeled dimension of a feature and get a corrected value for the steps per mm setting in Grbl (your machine's control firmware). You may want to run two or three test, but I find that a couple adjustments is about all you need to get within about 0.1 to 0.15mm consistently. See attachment and feel free to share it wherever fellow CNC nerds are found. Edit: Don't forget to tighten the V wheels so they sit snugly against the rail and to square the machine and plumb the router for best performance. So I followed the procedure here of CNC a 100x100mm contour to check for travel. And it turns out that my X = 100.57 adn Y = 100.25. I followed the spreadsheet and adjusted, using the console in UGS, X using $100=39.772 & Y using $101=39.900. But it seemed to have scaled my WCS. I tried to run the same 100x100mm NC program and I got a scaled down version of what the part should look like. Any thoughts. Attachments:
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Post by Derek the Admin on Mar 8, 2019 4:27:00 GMT
The power route used 100 steps per on the X and Y so you'd need to adjust with 100 as the base instead of 40 like on the m3
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Post by sternman318 on May 4, 2019 22:26:20 GMT
Looks like you start to get into this over shoot under shoot scenario eventually, I'm getting about a thou (.02mm) and decided to call it close enough since the sep/mm isn't approaching a limit... I guess that's about within the machine's tolerances. I also figure I'd mention you can do the same with the Z axis, just make sure to calibrate to 80 steps/mm. $$ lets you check what the machine is currently set at. For the Z if you can attach a dial indicator it's super easy to calibrate since you can read without cutting. Attachments:
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Post by S. Ronin McGowan on Jun 29, 2019 0:32:18 GMT
and to square the machine and plumb the router for best performance. Ok, I am drawing a blank and feeling lazy for a split second... plumb the router? (Hell, if nothing else it'll spark up new conversation?)
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Post by Derek the Admin on Jun 29, 2019 1:46:53 GMT
and to square the machine and plumb the router for best performance. Ok, I am drawing a blank and feeling lazy for a split second... plumb the router? (Hell, if nothing else it'll spark up new conversation?) Plumb means to make sure the router is straight up and down and not csbted forward, back, or side to side. If it is not reasonably plumb, it will introduce a taper onto the sides of the part.
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Post by S. Ronin McGowan on Jun 29, 2019 2:23:07 GMT
Ah, right, makes sense. I guess I need to do some searching on how to do that, because my facing operation resulting in a mildly -X tilted face on each pass
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Post by Bruce on Jun 30, 2019 4:24:25 GMT
"Pumb the router" also called "tramming" can be done by following this guide. Check the tram of the router and decide what direction needs adjustment. Essentially you adjust the tilt (forward and backward tilt) and roll (left and right roll) of the router by loosening connection points and move just slightly those points. The left/right roll adjustment is usually made at the router bracket. The forward/backward tilt has to be done at the X axis 2040 V Rail Extrusion connection to the side of the M3 base. Additional adjustment may be found by adjusting the bed Y axis mount at the front and back of the M3 base. millrightcnc.proboards.com/thread/1468/tram-spindle-on-cheap
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Post by S. Ronin McGowan on Jun 30, 2019 8:29:00 GMT
thanks!
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Post by bstanley72 on Jul 10, 2019 1:16:28 GMT
Want to make sure I'm understanding the calibrating procedure. The X and Y adjustments are absolute values, right? They don't build on the current (or previous) value? So if I cut the 100mm square box, make adjustments but I'm still off, I don't need to worry about the previous adjustment, just use the spreadsheet and calculate the adjustment based on the new measured value?
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Post by Derek the Admin on Jul 10, 2019 2:03:23 GMT
You need to make sure the spreadsheet "knows" your current value. If, for instance, the steps/mm had been changed to 6 from 5 (just making up a number) and the square ended up 100.5mm, the spreadsheet would need to know that the value in grbl was 6 when the cut was made so it can give you a good adjustment value.
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Post by bstanley72 on Jul 10, 2019 14:50:34 GMT
Ok, that makes sense, I've written down the figures I put in originally, but to verify what is the command to display the current settings?
Also, I assume I can use the spreadsheet and a dial indicator to set the Z? $102 I'm guessing is the command.
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Post by bstanley72 on Jul 11, 2019 1:57:41 GMT
I've got things figured out now. I've been able to get the X and Y within about .05-.06mm and the Z to about .04-.05mm. I'm thinking it's probably time to call it good, do you agree?
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Post by Bruce on Jul 12, 2019 2:24:22 GMT
Yes, I think I would call that good.
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