Hi all,
I am running a fairly long job on the Maslow4, and I noticed that there is some inaccuracy, namely that lines that are supposed to be straight are curved near the start of the cut.
I am cutting 3/4" plywood, and I realized that when generating the Gcode, I never marked the flag to keep the cutting bit down. As a result, when cutting out a contour, it runs the depth at -0.3", then moves to +0.2", then cuts at -0.55, back up to +0.2, then -0.8, then up to +0.2 to move to the next piece.
I have set up the maslow using cement anchors, meaning that the Z- anchoring is way lower than the cutting surface.
I have observed that the tension in all 4 belts is correct at the top of the Z axis (+0.2"), but as soon as it plunges down, the trailing belts are very loose.
Is it possible to make some software adjustment for tension when moving down the Z-axis, as the current behavior isn’t great?
Is it possible to make some software adjustment for tension when moving down the Z-axis, as the current behavior isn’t great?
The software does adjust the belt length for the Z position, but that requires
that the Z offsets in the maslow.yaml are correct and that the Z axis is all the
way down till it stops moving when you do the calibration is done.
Oh! Does this mean that I need to set the z-offset as SUM(material thickness + spoilboard thickness + spool offset from base + height of Maslow when the bit is inserted and just touching the board) ?
And do I recalibrate every time I change bits as they may have different lengths?
Also, is there a global z-offset in Maslow.yaml? That’d be easier as I can leave the spool offsets as default, and just enter one value for the global shift
Oh! Does this mean that I need to set the z-offset as SUM(material thickness +
spoilboard thickness + spool offset from base + height of Maslow when the
bit is inserted and just touching the board) ?
no, Z stop is the point where the router is all the way down with no bit in it
(run it until the Z steppers both just humm and can’t turn any more)
that should be set before you do calibration.
Z offset is SUM(material thickness + spoilboard thickness + spool offset from
base with the z stop at zero
then when you put in a bit, you set Z home as the point where the bit is just
touching the workpiece
And do I recalibrate every time I change bits as they may have different lengths?
No, you should only have to recalibrate when the frame size changes (or we come
up with a better calibration routine that makes it more accurate)
Also, is there a global z-offset in Maslow.yaml? That’d be easier as I can
leave the spool offsets as default, and just enter one value for the global
shift
No there is not (at this time, @bar it would be a good idea to add one to make
it easy to change workpiece/spoilboard heights), just the 4 individual offsets.
Just realized that I need a confirmation:
after I finish the calibration with the correct Z-offset, I will then insert a bit. At this point in time, my usual workflow involves setting the 0,0,0 coordinates, for which I use the x,y from my CAD software and the Z-0 to be exactly where the bit is touching the top of the cutting surface.
Does Maslow preserver the Z-values from the calibration? Or would setting it to a new 0 start breaking things? (in which case, I would need to update all the z-values in the gcode)
z stop (when you run the router all the way down)
Z home (where the bit is touching the workpiece)
in theory, Z home should be set every time you change the bit, Z stop should be
stable, but it’s not a bad idea to set it periodically, as it is possible for
the leadscrews to be turned while the machine is off.
Before you run the calibration, remove the bit and lower the z as far down as the machine will go. Begin the calibration with the machine in that position. You should not need to do anything else here unless you changed to a new frame.
When you are ready to cut, insert your bit and lower the z down until the bit first touches the material. Set the “Z Home”. The Z location should now read as “0”. Any time you change the bit, you will need to re-set the Z Home. Also, if the machine crashes mid-cut, you may need to re-set the Z Home. While doing the CAM (i.e., telling the machine how and where to cut), whatever program you have should have an option for a Z “safety” or “clearance” or another similar name which the machine will raise the Z above the material in order to jog to another cut location and avoid accidentally cutting through the material during the jog. I often set this to about a 1/4" or so, but whatever amount you feel comfortable with should be fine.
XY Home has more options and I think depends on the CAM program you are using. Depending on your CAM software, you may have different degrees of customization of your XY Home. The biggest thing is to set the machine’s XY Home wherever your CAM is set to. Sometimes, this may be on a corner of your workpiece. Other times, it may be in the center of your workpiece. Or, depending on what you’re doing and your CAM software, it may be anywhere in between. As long as they match closely enough that it won’t accidentally go over the edge of the workpiece while cutting, wherever you choose should be fine.
I like to set my XY Home right in the center when I can. After calibrating, when you extend and tighten your belts, the position the machine is in right after the belts are tightened should be the mid-point. So if I am starting something new, I will extend and tighten the belts with the new material underneath, I will make small adjustments to the material centering it under the M4. Then I’ll secure the material and quickly set the XY Home right there.
