Hoping that this is the right place for this; I’m happy to put it somewhere else, if not.
I designed (Adobe Illustrator) a family tree to be carved on a 10" X 16" substrate. (rough prototype shown below; the stain that I used for the letters got smudged, but I think I have that worked out, now)
I’ve done a number of carves like this before, but everything was on a much smaller scale, and usually I could get it right pretty quickly.
At this larger scale, I’m seeing interesting things happen, and I wanted to share my methodology and compare notes with others. Here’s what I’m doing, with thoughts about problems and possible refinement:
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I surface 3/4" pine, using 1/8" endmill. The idea is to give a consistent surface to carve, so I’m not having to adjust for different thicknesses. I don’t like the pine; it’s crummy/grainy, but I don’t know from where to source better wood (alder?) for plaques at a reasonable price. I’ve looked online some, but need recommendations! Also, does everyone have success surfacing like this on our X-Carves? It doesn’t seem like it really works. I wind up having to tweak my depth here and there, as if there is still a difference across the board.
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I sand the surface methodically evenly with 220 grit. Ok, yeah, I could be introducing a little bit of unevenness, but I think I need to do this before poly.
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I brush on 2 coats of Polycrylic. This seals the grain so the stain doesn’t bleed out. Works ok if I’m very careful about coating it.
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After it dries, I do the carving, as seen in my prototype. This is a delicate process. I have to start shallow, and tweak it down 3-4 thousandths at a time 'til it’s deep enough to take stain, but doesn’t lose clarity. If I go 5 or 10 thousandths too deep, the letters get crappy. Is there a better way to do this?
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I use a small brush and put stain on the letters.
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After it dries, I sand with 220 to get rid of excess and make the letters crisp.
So summarizing…is there a better way to prep for/do VCarving on the XCarve, so it’s not so finnicky? I’ve had 2 XCarves, a big and a little, and they’ve both been this way.
Is there a better way to prep or use the board so that I have an even surface to work with?
It seems possible that a lower angle VBit might help the situation, but I haven’t found a source for a nice 1/4 shank bit.
Anyways, I’m open to tips about how to optimize this! 
Thanks for any info
-Ray
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I like your design, that is a really nice way to do the family tree.
I highly recommend using poplar. It is easy to find in large widths and is relatively inexpensive. The best thing about it how well it carves and takes stain.
I can’t imagine using a 1/8 inch bit to surface a large board, I use a .85 inch fly cutter with a quarter inch shank. It will surface the top so smooth it does not need sanding. I found my fly cutter on ebay for about $10
I usually use a two or three coats of shellac to seal the wood and to prevent the stain or paint from bleeding when I fill in the carving either rub stain over it or spray paint. The shellac is impervious to mineral spirits so any over spray is easily cleaned off the surface.
Using a 30 degree vbit will give you very sharp lettering if the letters are small (half inch or less) for larger letters I find a 60 degree vbit works very well. If you use a program like Vcarve you do not need to worry about the depth of cut it will take care of that for you.
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Thanks for the response, this is good stuff!
You’re right about surfacing and the 1/8". It takes forever…I have a 1/4" that I have used, but it seemed to leave very clear tool marks that were a problem. I’ll look into a fly cutter.
I forgot to mention that I’m using a 60 degree vbit. Do you have a good source for quality 30 degree vbits? That seems like it would be a good move. I currently can accommodate 1/8 and 1/4 shanks, with the equipment that I have.
So for Vcarve to do what it does, you need to have a consistent way to home the Z-Axis, as well as some assurance that your substrate is consistent in thickness. Hopefully the flycutter can help with the latter; what’s your process for homing? Currently, I lower it down to the wood until it just kisses the piece of paper I have in there.
Before I started using the touch probe I used the paper method with good success. For better accuracy you can set the zero at a few different places on the work surface and write down the Z value at each one to be sure you have a nice level surface. I think the paper method will get you close enough with to a good surface Z. Just practice getting a consistent feel for when the bit touches the paper.
I purchased all my vbits on ebay, but in order to get lower prices on them I had to buy either 4 or 6 mm shank sizes. So I purchased a 4mm and 6mm collet from ELaire. The money I saved on bits more than made up for the extra cost of the collets.
Hmm, point taken about being 90 degrees cutter to surface, and being level to the gantry. I’ll search around to see if there are good writeups on how to do that properly. I’d really like to enjoy the benefits of being able to use a fly cutter; it would speed things along for me nicely.
You definitely want your wasteboard square to your spindle, otherwise any relatively flat wood will always be higher or lower in some areas than the rest of the board. The fact that you’re seeing marks when using your larger bits to flatten the wasteboard just shows that you’re not square, since any indication of out of square will increase with a larger bit size. I went into a little bit of detail about diagnosing an out of square spindle at 9:05 in my secondary wasteboard video, if you’re interested: 39 - X-Carve Secondary Wasteboard - Manhattan Wood Project - YouTube
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You happen to have a link to that fly cutter. I’m using a .75 router bit like something a lil bigger.
Here it is, I was wrong about the shank size the one I have is 6mm with a cutting diameter of .866 inches. But the price is lower than I remembered.
http://www.ebay.com/itm/1PCS-CNC-router-bottom-cleaning-router-bits-6mm-22mm-/231886742812?hash=item35fd86e51c:g:jH4AAOSwaNBUiXvc
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Thanks I use them to face mill end grain projects and soft metals.
Thanks, I’ll check that out!
When I was doing sign carving (not on X-Carve, but on my old ShopBot Alpha), I would do the following:
Assemble, mill edges (or buy plaque)
plane or rough sand face to be carved - we used a planer.
v-carve
paint the entire face, including the carved areas
let dry
sand off the finish – v-carve paint remains
varnish, shellac, etc.
Since you’re having tool marks, others are correct about the need to perform calibration. I’d like to add that before you call calibration finished, you should surface your spoilboard with a fly cutter so that it is perfectly planar and flat. Then re-check your calibration (use a feeler guage on four corners and the middle - between the bit and the spoilboard). You should have the same clearance everywhere you check.
Now you’ll be ready to surface your work piece, and it will be in the same plane as your spoilboard and xy axes.
