Deep engraving 3D Topo Map

I have been working on this engraving project on and off for several months now and my time has mostly been spent setting up the data.

In case you are interested I thought I would share my procedures.

I get map data from USGS. It is freely available.

I found a program that allows me to read it. Not freely available. I found a program, Voxler, that sells for $450 or so but got student discount : ) so paid around $125. (Finally my kids education is of value to me).

Voxler takes the recorded data which is in a spreadsheet like format and displays it in graphical format.
I used Voxler to create 10 meter contours each in a different color. Unfortunately, when exported to Corel, Voxler antialiases the borders and blends the colors so I lose the distinct colors that I had chosen. As such I cannot separate the layers easily. So what I had to do was export each and every layer separately....about 50 bitmapped layers for the current map I'm working on.

In Corel, fortunately, I can import each .bmp layer to a separate page all at once and each is located in the center of its page.
I then do a high quality bitmap to vector trace for each page, color each layer one of 5 colors and then copy and paste the 5 layers onto one page and then export them to a .dxf file. I'll sometimes do up to 12 different colors.

I import the 5 layer .dxf into LaserCut (which takes several minutes) and save as map1.ecp, map2.ecp etc. These load very quickly when I need them later.

Each 5 layer group is uploaded to the engraver in order from the highest elevations to lowest and engraves all of the map and then the subsequent layers engrave everything but the previous layers. 50 times. I sometimes do 10 layers at a time but LaserCut doesn't always allow too many layers to get uploaded without the infamous "Soft Dog" error.

Well, that was the easy part.

The engraving part, which I hoped would be a no-brainer, is giving me quite a bit of trouble.
I'm running the speed at 1000 and power at 14% ..just above the 12 or 13 minimum power setting. Air and exhaust fan are on. I'm only trying to cut a 10 meter depth so the 1st layer for example is just a light browning. As I do larger maps I'll have to up the power a bit and use thicker wood.
I adjust the tip down every few cuts to keep the focus tight.
My desire to get lots of detail is holding me back some. I have used many wood types-Rock Hard maple, Sugar Pine, Cedar, Fir, Plywood(LOL). The problem with the harder woods is that the grains really show up after 50 rounds of engraving. I want to do this in wood but wood grains are very irregular in cut-ability.
I tried different type of rock like river rock, which works good at 1st but then becomes pitted because of the high power required. Brick actually is pretty good for regular engraving but I haven't tried it with the maps and don't know that I want that look. Sandstone engraves well too and am going to try that as well.

Any suggestions for other material that might work well for depth engraving?



Also, I have seen some very detailed DEEP 3D engravings on this board but cannot find them but would love to see some of your best deep engravings.

Need to add:

It seems that the deeper I go, even with the very light power and high speed, I get charring that seems to protect the lower layers from being vaporized. I have tried my underwater engraving by wetting the piece but I need more depth not less. Going to try with higher power and different protective layers instead of water. It is time consuming testing anything because it takes time to do 50x of anything of size so I can see the results. I know some of you have fantastic results. Would love to hear more about your techniques.