Scanning / software weirdness

I am having this weirdness, that I just can’t figure out why / I have my speed @ 100 (to allow bigger image) when I do a bed scan I get the full Size, but as soon as I hit focus, it reduces, anyone have any ideas? – do I need to have the wood further away (1" wood, but scan defaults to .5")

Thanks! (you awesome nerds)

Jonathan

As soon as it focuses, the image is adjusted for the maximum allowable printing size, which is 11 inches tall…is that cutting board 12" tall by any chance?

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YES, the cutting board is 12" tall, but what keeps happening, is the image doesn’t center when its printed, even if I center the image in preview, when it prints it shifts to a 1" gap on top

I have set the height of the wood both low and high - with no change.

here is what I get…

A center edge jig…

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jig aint doing jhit. till I get the center justified.

.5” is the max height GF understands, it can’t be told 1”. Your crumb tray looks out, is the surface of the cutting board in the right height zone?

yup - tried different heights to see if maybe that would make a change. . :frowning:

12” tall material can’t be fully seen by the camera - how are you deciding you art is looks centered, is there a center mark you’re aligning to?

Ok, I am trying something… I have a PRO - I switched to Passthru mode, telling the GF its a longer piece of wood… (fingers crossed)

Guess it’s time to get out the table saw on that one. No one will know it wasn’t supposed to be 11 inches high. It’s heartbreaking when this happens though.

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You may not be understanding my jig idea then, or I may not understand the physical dimensions of the cutting board. Unless it’s very wide, (a fair bit more than 19.5"), this is how I’d do it.

Measure your board carefully. The more accurate the better. I am guessing 12x18 here, so that’s what I’ll use for a illustration of the concept.

Draw a rectangle to scale in your vector program of choice.

Now you need a registration mark, make a tiny pip of a line:

Snap that line to your rectangle and center them vertically. You have a tiny mark on the left side of the rectangle.

Now center your art on your rectangle…

And then delete all but the left side of your rectangle:

Now shorten the edge line so that it fits in the cut area…

And you’re ready to go. Insert jig material into the glowforge, it should be smaller than the cut line. Represented here by a brown rectangle.

Cut the jig, ignore the engrave. You’ll end up with a straight edge with a tiny pip indicating the center registration point.

Now, put a piece of masking tape or something on the edge of your cutting board, and carefully measure and mark the center point. (You use the tape so that you don’t have to mark the board, but be careful that it won’t tape over where you’re trying to engrave…) Align that center mark with the pip on your jig and carefully seat your cutting board right up against the jig. Turn off the cut. Turn on the engrave.

Voila, perfect alignment. (as perfect as your measurements were anyway. Should be able to easily get sub-mm accuracy, just don’t let the jig move or it’s completely blown. If you do, it’s a simple thing to recut some cardboard to re-jig it, of course. Pro tip, place the cardboard in at an angle so the corrugation doesn’t run parallel to your jig cut line. You want the corrugation to support the edge, if that makes sense. )

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A semi-easy alternative…
The problem that we get is that once the Focusing happens, the top 3/4 inch or so of the board can no longer be seen in the camera view …there is an overlay that prevents us from seeing it. (Size goes down to the 11.47" that the head can reach, measured from the front of the board, at the exact correct start of the cuttable area.)

So when you try to center visually on the whole board showing, if you don’t realize that the top approximate 3/4" is hidden from view, you are treating the bottom 11.47 inches like a full 12 inches…with the result that there is always going to be the hidden unengraved portion at the top of the engrave, added to whatever space you left.

What you can do, is limit the total height of the engraving to 9.5 inches, and then place it exactly 1.25 inches above the bottom edge of the board, as measured from the lower left corner. That will leave 1.25" unengraved at the top and bottom as a border.

Where the bottom edge of the board is going to fall will change based on how you place it, so you need to shift the design each time, after the Focusing happens. Then just shift the engraving using the numerical Precision Placement. (Just place the lower left corner of the engraving at the left lower edge of the board, then subtract 1.25 inches from the Y-axis number showing…it pops right up.)

If you want to try for 10 inches (or more) engrave height and just 1" (or less) border on each side, you’ll need to be very precise with the placement of the board in the machine to allow it…you need to hit the exact edge of printable bed, and that’s hard to hit on the nose.

Anyway…that’s what I do with oversized prints and cuts.

Pic…

image

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It’s generally a bad idea to depend on the camera for accurate positioning. The nature of the way the camera has to work to “flatten” the bed image using a lens that’s extremely wide-angle means even the slightest shift in the position/orientation of the camera will impact alignment. And since the camera is attached to the lid, which isn’t “positively located” when closed, the camera moves a little each time you open the lid. Camera calibration will get you close, but it needs to be done periodically and you won’t know the calibration is off until after you’ve ruined a workpiece by thinking the camera alignment was still good.

The best way to ensure your print lines up perfectly with your workpiece is to use a jig. It only adds a minute or two to the effort of making your print and it guarantees each time the print will be aligned regardless of the camera. I haven’t attempted to use the camera for alignment for as long as I can remember. Jigging always works.

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that is @evansd2 statement as well… I have to agree with him on this, but I also must learn.

Semper Forge!

For this one, put it into the :glowforge: upside down and engrave the name of the recipients in that top area.

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blow torch the top, dragon style.

Or a gradient sanding

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