Live edge board outlining

[Old Gaffer]

I have a shop full of live edge boards that I mill from hardwood logs a arborist friend supplies me. Wood such as Black Locust, Dogwood, Yew, Arbutus etc. I want to be able to carve around the complicated perimeters and defects but don’t know how to establish the perimeter. Somehow I need to be able to enter the board into Aspire, to scale. Any advice would be appreciated.

[Hermie]

I just finished doing 5 maple burls and had the same problem.
The best/fastest way I found was to lay a ruler on it and take a picture, import and trace.
If someone has a better/faster method I’d love to hear about it.
The other way I’ve tried is to use a probe to trace it, but depending on the resolution you want
can be really time consuming.
Another way, that I haven’t tried yet is a video probing. Where you mount a webcam on your gantry take a series of pictures,stitch them together and trace.

[dealguy11]

Photograph and trace is the best method I've found. Make sure you get far enough back to minimize the effect of perspective and take the picture as straight-on as possible.

[IslaWW]

I'm with Steve on this one.

A trick to gain accuracy: Place a small (3 or 4" square) mirror in the center of the piece. Make sure you see the lens in the mirror in the center of the image. Reduces parallax. (thanks Brady)

[Old Gaffer]

Thanks for the information. I’ll give it a try. I especially like the suggestion of the mirror to reduce distortion. Some of these pieces are quite complicated and elongated so easy to move the lens too far one way or another.

[Leo]

I have a VERY VERY accurate method with NO guess work, BUT it is a tedious and time consuming method.

1) Place the workpiece on the machine.
2) Put a pointer in the spindle - I have a 1/4 steel rod with a 60 degree point - anything will work
3) move the pointer to as close to the center as possible - by eye - MARK the location on the workpiece
Move the pointer in one axis only longest way - mark two points - for alignment
4) zero x & y in the control software.
5) In Vectric - plot points on the screen to approximate the shape. ROUGHLY
6) move the pointer around the perimeter point by point
7) I edit the node properties to match the pointer position
the mode nodes - the more accurate.

After all the points are plotted, you can tweak in the lines for curves or sharp corners.
You can take a JPG of the work and convert it to a material file for Vectric.

This is tedious, but the most accurate way I have found.

I have also done as others have suggested - but I caution - make sure the picture is taken DIRECTLY on - don't have the camera lenze at an angle, or the scale will be off. If something is 4 feet long, that is near impossible.

I don't mean to contradict the suggestion, it IS in fact a very good method.

[IslaWW]

I agree with Leo, it is a very good method. My son and I used this method to digitize over 200 panels during an interior retrofit on a 100+ ft yacht.

Along with the mirror trick from Brady, we painted the floor flat gray and added pinstripe grid lines, lit from all 4 sides and suspended the digital camera from a quad pod with a remote cable shutter. Not likely for all of that for this job, but it works well and is very fast and accurate

[highpockets]

Interesting ideas, haven't tried large planks, but taking a picture has worked good enough for my needs so far.

Gary, I like the mirror alignment idea. On large boards instead of putting them on the floor and trying to get the camera over the top why not put the board horizontal against a wall or garage door and put the camera on a tripod?

Leo, I like you very accurate way mapping the material seams you could combine it with a probe to log the information to a dxf file..... Just manually put a stop where the next edge probe would be.

[martin54]

Gary, I like the mirror alignment idea. On large boards instead of putting them on the floor and trying to get the camera over the top why not put the board horizontal against a wall or garage door and put the camera on a tripod?

I do that sometimes John depending on the job size but it is generally just easier to lay it on the floor

The most important thing no matter how you place your board as has been said already is to photograph from straight on which can take a bit of practice to get right

I've been doing that for years with all sorts of things that needed to be scaled up accurately to put vinyl signs on

[Bob Jr]

I sure do learn a lot from these forums! Thank you.

Instead of using a camera, I scan the slab of wood on a scanner. It works well for the small bowls I make.
I'll attach the directions. I hope they make some sense.
Bob



This Is How I Make Bowls From Firewood
1. Obtain a dry slab of wood. I cut a small log into 1” thick pieces and let it dry for two years.
2. Draw a vertical line of a known length down the center of the slab, and make a line across it where the center is. This step is crucial for size, design and proper placement for milling.
3. Scan the slab on a flatbed scanner. Use previews first, to adjust until the center line is vertical. Start a folder called “log bowls”. This is where you will store all related files and toolpaths.
4. Start a new drawing in VCarve. Make it large enough to accommodate your slab.
5. Import the scan of your slab. Adjust the size of the scanned slab so the vertical line from step 2 is the same as the one on the slab.
6. Draw a vertical, and horizontal line on your work area that intersect in the exact center of your work area.
7. Jog the jpeg of the slab so that the center that was determined in step #2 is moved over the intersection of the lines drawn in step #6 (There are other ways to get the same result. I simply chose this one.)
8. Trace around the inner bark area of your slab, then offset inward by .5”. Use Bezier curves to smooth the vector if needed. Delete the original perimeter trace.
9. Turn off the bitmap layer.
10. Delete the horizontal line from step #6.
11. Select the vertical line from step #6, and use the circular array tool to make 300 copies around the rotation center at X:0 Y:0. Total angle =180
12. This will give 300 lines crossing at the center of your drawing.
13. Select all 300 lines and use the trim tool to trim all lines to the perimeter vector determined in step #8. (Clear outside boundary.)
14. Select, don’t group, the 300 lines. (At this stage, you should be checking to see that starting points are on the same side for all vectors. Adjust using node editing if necessary.) Select the fluting toolpath. Input the depth of the cut. (I use the full depth if less than 1 inch. Or, within the cut length of the bit.) Ramp at start and end. Select the length of the ramp. (I used 1.5”) Check the Use Vector Selection Order box. Ramp type is smooth. Calculate
15. This step is real important! At this point the bowl vectors will be cut with single passes to full depth. This will create lots of problems for the first cut. The first cut needs to be cut in shallower passes down to the full depth. Subsequent passes will be full depth, but only cutting a little off the side of the previous passes. To find the first pass, use this feature: . It will preview one pass at a time. On the preview, locate the start point of the first pass, and note the X Y locations on the lower right of the screen. Record these coordinates and use them to locate a small circle in your drawing. This small (.01”) circle will then be drawn near the end of the first vector. Create a fluting vector for just this one vector (Not the circle. It was just used to identify the proper vector.). I used .0625” passes for this vector. Preview to see if it is in the right place. Adjust if needed. Be sure to move this first vector up to first position in the toolpath menu. Slow the preview down to be sure that cuts are being made in the proper order.
16. Save these two toolpaths as one. Put it in the folder from step #3.
17. Save your crv file in the folder from step #3.
18. Setup your slab on the cnc so that the vertical line drawn in Step #2 is parallel to the Y axis. Set X Y Z zero based on the line drawn on the slab.
19. When making the cut, I start with a FRO of about 30%. This gives time to react if something was done wrong…Like setting XYZ zero, then forgetting to tell the controller. Or forgetting to match the slab center with the job center, way back during the design stage.
20. After determining that the cut is working properly, increase the FRO.
21. It has averaged 45-60 minutes to cut a bowl.