[Arbo]

I bought some cutting boards from Wal-mart that are 5/16" thick with the intent to carve the 3D Haab calendar into if I can invert the tool paths and cut it from the rear. It has a slightly textured surface on both sides and I want a smooth outer surface. Haven't had time to do anything with it so far.

Think it will work ok when backlit?

I don't know, if you vcarve it, inverse, it might look strange, since you'll get 'darker' fading to lighter near what would be the surface. It may just need straight cuts rather than 'v'... I should make a relief of it and try it as I can invert and fiddle with it to see what it might look like.

What's up with these spammers around here?

[CarveOne]

Dunno why anyone would just aggravate site members by just registering and copying part of a post to make a post. Dumb. I just report them using the triangle icon to the right of the Post # and they get busted by the CNC Zone zombie spam bot assault team.

I never really thought about whether it needs inversion to look right from the outer flat side, but if you want to try it be my guest. I don't have time for it in the next few weeks. Just thought it would be a good one to try, since the Aztec calendar looks good when backlit.

[Arbo]

Perhaps the first wave of the zombie apocalypse is online...

BTW, I spent a few seconds messing with the myan calendar, I think I can get it to 3d, a bit different than yours, without those 'ledges' around the piece. More on that after work.

[CarveOne]

Perhaps the first wave of the zombie apocalypse is online...

BTW, I spent a few seconds messing with the myan calendar, I think I can get it to 3d, a bit different than yours, without those 'ledges' around the piece. More on that after work.

I can get rid of them by raising the second Vcarve cleanup pass flat depth setting. It's below the model depth and that ledge is a transition between the edge of the model and the 30 degree wall of the cleanup pass. If I raise the model height much more than it is the model looks too puffy.

For the backlit test I was going to set the flat depth to 0.001" above the model depth and leave the model as it is. I think that would not go too deep into the 0.310" thick plastic material.

[Arbo]

Well, long long long long ago, a friend back east sent me some messed up ribber grips and molds of the handle of his llama IX-C in the hopes I could draw up and cut some nice wood ones.

After that long period of time, I got back to it, and just made my first test, double sided cut of one of the grips. It fits on the mold good, will have to send it out to him to put on the real gun to ensure it's right before cutting into nicer woods.

[CarveOne]

In a brief period of nothing to do last spring, I started modeling the Ruger Vaquero revolver grips with my then newly acquired Aspire. After getting the front side shape and cutouts on the backside done, I dropped work on it. The gunsmith I was doing it for is still waiting. And waiting. Good thing he is patient. He competes in Cowboy Action Shooting events and he wants some quilted maple grips made for his competition revolvers.

There is still a lot to do before cutting the grips.

[CarveOne]

Well, long long long long ago, a friend back east sent me some messed up ribber grips and molds of the handle of his llama IX-C in the hopes I could draw up and cut some nice wood ones.

After that long period of time, I got back to it, and just made my first test, double sided cut of one of the grips. It fits on the mold good, will have to send it out to him to put on the real gun to ensure it's right before cutting into nicer woods.

Which program are you using for this?

[Arbo]

Which program are you using for this?

Rhino.

Now I need to spin that one 90 degrees, and mirror it so I can fit two in one cut.

[harryn]

I bought some cutting boards from Wal-mart that are 5/16" thick with the intent to carve the 3D Haab calendar into if I can invert the tool paths and cut it from the rear. It has a slightly textured surface on both sides and I want a smooth outer surface. Haven't had time to do anything with it so far.

Think it will work ok when backlit?

I am not sure, but I think it is worth doing some basic testing before you spend too much time on this approach.

Of course you can invert the image, but I am more concerned about how the light paths work. My impression is that the reason these scenes come out is that the back lighting has a chance to diffuse coming through the back and then the image is actually from a change in refractive index. (the cut) If the image is on the back and the front is rough, it seems like the image will become highly diffused. That is my guess, not based on direct experience.

It might also depend on just how rough the two surfaces are. I guess if the front surface is not too rough, you could try smoothing it with a flame (surface remelt) or maybe a solvent of some kind.

It might be worth a quick test just using a simple image of any kind, inverted or not, before you spend too much time on the CAD inversion aspect.

If my perception is correct that the image projection is from a change in RI, then in theory at least, you could find a clear filler material with a higher (or lower) RI and fill in the cut, and still end up with the image. Some silicones have quite high RI so that is a possibility if you go that direction.

[CarveOne]

Rhino.

Now I need to spin that one 90 degrees, and mirror it so I can fit two in one cut.

Yeah, that was partly why I posted the simulation images. My plan was to start with a flat block, cut both backsides, flip it over, then cut the front sides of the grips. The first operation was going to drill a registration thru-hole at x/y zero location somewhere between the two grip halves and pause while I insert a 1/4" pin of appropriate length through the block and into a temporary spoil board that is clamped to the table.

I have an L shaped guide rail that will help align the material block with the x axis. Once the backside is cut, flip it along the x axis and reinsert the pin, and cut the front sides. Roughing passes first, then the finishing passes. The reference pin will be a hardwood dowel. The profile will be done last and should clean up the edges a little.

[CarveOne]

I am not sure, but I think it is worth doing some basic testing before you spend too much time on this approach.

Of course you can invert the image, but I am more concerned about how the light paths work. My impression is that the reason these scenes come out is that the back lighting has a chance to diffuse coming through the back and then the image is actually from a change in refractive index. (the cut) If the image is on the back and the front is rough, it seems like the image will become highly diffused. That is my guess, not based on direct experience.

It might also depend on just how rough the two surfaces are. I guess if the front surface is not too rough, you could try smoothing it with a flame (surface remelt) or maybe a solvent of some kind.

It might be worth a quick test just using a simple image of any kind, inverted or not, before you spend too much time on the CAD inversion aspect.

If my perception is correct that the image projection is from a change in RI, then in theory at least, you could find a clear filler material with a higher (or lower) RI and fill in the cut, and still end up with the image. Some silicones have quite high RI so that is a possibility if you go that direction.

You get the gray shading from the depth of cut at any given point. The more you cut away the brighter it becomes when looking at it from the opposite side. This is a direct lighting effect from the rear of the material, and the edge lit signs use the refracting light effect that causes the cut surfaces to glow, but the acrylic plastic doesn't glow.

The cutting board I mentioned has a very fine texture that I presume helps keep slippery foods and vegetables from sliding around too much. It will probably cause some blending, but I doubt that it will cause it to not work.

The only slick surface cutting boards I found are 0.140" thick and are more opaque than the 5/16" thick boards. They won't be useful for the Mayan Haab as they are too thin. I bought some of both types just to have them on hand.

[Arbo]

Yeah, that was partly why I posted the simulation images. My plan was to start with a flat block, cut both backsides, flip it over, then cut the front sides of the grips. The first operation was going to drill a registration thru-hole at x/y zero location somewhere between the two grip halves and pause while I insert a 1/4" pin of appropriate length through the block and into a temporary spoil board that is clamped to the table.

I have an L shaped guide rail that will help align the material block with the x axis. Once the backside is cut, flip it along the x axis and reinsert the pin, and cut the front sides. Roughing passes first, then the finishing passes. The reference pin will be a hardwood dowel. The profile will be done last and should clean up the edges a little.

I set mine up for both grips, I cut the back first: roughing, cutout, hole drilling, then finishing, then flip the piece on the Y and cut the top sides, roughing, finishing. I align x,y in the center of the wood, so I mark the center and get the bit to center of x and y on those marks. Then when I flip it, it's already lined up. I put marks on the table where I first set the block so flipping it just goes to that outline. Cutting both of them now so I have both sides to send out to the guy to test fit on the actual gun.

[Arbo]

In other projects, here's a preview of the mayan haab, haven't done any smoothing to it yet though.

Also, the first of many gargoyles for the 'headboard' project my wife wants.. this a sleeping one... also not done, but the basics are there.

cutting both grips at the moment.

[CarveOne]

The simulations look a lot smoother than what I see in Aspire. I have a much faster computer with better video and memory now and may try installing Aspire on that one to see if it improves it any. My CNC machine is duplicating some small perturbations that I see on screen that are supposed to be in flat areas. Don't know if it is the computer or Aspire.

[Arbo]

Well, this weekend I'll be replacing the worktop on my machine. It's been long enough and tore up enough. That will be followed by a major cleaning and straigtening up in there so I can work a little better. Hopefully work doesn't call me for anything today so I can get started on it today.

Also need to play with the auto tool zero stuff, I started to yesterday but was getting some funky actions..

[Arbo]

Yes, work didn't bother me much today, so I decided to cut down the surface I have rather than get new wood. Remounted the copper plate for auto zero tool stuff first, used that zero to level the table. Loads of cleaning as well. Much much much more work tomorrow throwing out stuff that's been sitting and reorganizing the shelves and such so I know what I have and what I need and have it all handy. Also got all my bit's organized rather than just laying out in dust.

Fun day tomorrow. Strange how you can be excited about cleaning and organizing.

[Arbo]

Another 8x10 litho done and mounted in a red oak box.

Now cutting parts for my first pbox. Going stock design to start with. Already had issues adjusting to using tool changes... getting it worked out.

[Arbo]

The pistol grips I drew up and cut for test fit were sent out to the owner. He says 'perfect fit'. Screw holes slightly off, minor adjustment to make.

[CarveOne]

Which wood are you going to make the grip set out of? Will there be any carvings on it?

[Arbo]

Not sure, I have a few of the exotics I picked up at Woodcraft. I think I need to find the 1911 grips and see how they do the cross hatching stuff on them... I might put some sort of symbol in the middle.