This project is similar to my previous one, but a bit more complex.
It is also a CNC routed tombstone that I made at the Tech Shop in San Jose.
See previous instructable here: basic CNC tombstone
In this design I mount the main tomb in-between two pillars or columns. Part of the reason is decorative. The other reason is that it seems Home Depot will no longer be carrying the basic ingredient, the Foamular (pink) insulating foam. This foam is much easier to work with that the white foam. In my area they no longer have any of the 2" thick foam but have plenty of the 1" thick foam still in stock. This design uses the 1" thick foam and provides for a place to hide the mounting PVC without having to fully laminate two sheets into a 2" thick tombstone.
Step 1: Tools and Materials
• Foamular foam board (4' x 8' x 1" sheet, you will use less than half of it: $12)
• DryLok paint, tinted light grey (you'll use about 1/6 of a gallon @ $30/gal per tombstone)
• Liquid nails (you'll use 1/2 of a $3 tube); other glue suitable for foam is OK
• small amounts of black, brown, green latex paint
• paint brushes and small roller
• 18" to 24" of 1/2" PVC pipe
• two 24" lengths of 3/8" rebar or other stakes
• razor and/or saw (table saw- razor and/or saw (table saw, band saw or hack saw blade) for cutting the foam
• small soldering iron or other tool for melting cracks in the foam
• ShopBot router (at the TechShop) or Dremel; plus 1/8th inch bit
• (optional) Dremel instead of ShopBot
Step 2: Design your Tombstone
Choose your text, graphics and overall layout in a drawing program such as Corel Draw.
Different from my simpler design, you will also need to layout the pillar design. There are many ways to do this, but it is best to do one single pillar as one object. Then paste this into the full tombstone on both the left and right sides and then connect the two at the top with some shape such as the oval I used. Then you must eliminate the lines on the main section that will not get cut. You must make this one continuous set of vectors or you'll have to fix it up later before setting up the toolpath.
Layout all your text, be sure and take note of the general rules for cutting fine text in foam. Set the Character kerning to 120-140%, use at least 100-125 point type, even 150 point.
In this design I made the pillars 4" wide and 36" tall. The main tombstone is 28" wide and 36" tall, but the pillars take away 4" from each side, leaving just 20" for the text. And you'll need to not use ~1" of that on each side.
In this design I arranged the R.I.P. text to follow the shape of a curve...you can draw any curve and make the text follow the shape.
Save and export to a dxf file format so it can be imported into the VCarvePro software at the Tech Shop.
Step 3: Toolpath preparation
Once you have your dxf file, import into the software for the ShopBot. The best choice is the VCarvePro. In this software you can highlight one or more objects and create a cutting toolpath. You also select the cutting tool itself and the cut depth.
In VCarvePro you start by setting your material size and thickness. Be careful to note where the x,y origin point is so when you go to cut your coordinates match up. To cut a few lines of simple text follow these steps:
- select the text
- open the toolpath tab and choose a cut depth (0.15" is a good choice)
- pick a "pocket" cut for the text. A pocket means you want all material inside the lines to be removed. (You would use a profile to just cut on a line). Since the default tools sizes are 1/2" and 1/4" you must enter your own custom tool for a 1/8" bit. The default speed is usually to fast for cutting foam, (it makes a rough fuzzy cut) you should slow it down to 50% to 75% of the default RPM (5000 - 8000 RPM is OK). The feed rate for text of 5 inches per minute works well. However, you will probably still get some fuzzy edges which can be fixed by brushing gently with an old toothbrush.
- create your cut path and view the tool's path (as seen in photo) so you aren't surprised by what the machine does. Export the toolpath for the ShopBot.
- for the pillars you can select the pillar object, then choose a "profile" cut. There are three choices: on the line, inside the line or outside the line. You probably want outside the line, keeping in mind the cutting tool has some width to it. Make sure to do the same on the main surface of the tombstone.
Cut four pillars. Including the portion on the main tomb, this gives each pillar 3 thicknesses on each side.
Step 4: Cutting the foam
You are now going to follow the same steps for cutting...but you'll also be cutting out 4 pillars.
When using the ShopBot after you cut one pillar you just reset the origin ~5" over and cut again. You could layout 4 and cut at one time as well...but then if you make a mistake somewhere and need to restart the machine it isn't as easy.
Mount your raw foam material on the ShopBot table. It is fine to just use wood screws with washers. Be sure and screw down all four corners in places where you will not be cutting. The holes can be patched up later or the damage can be made part of the aging process. If your material isn't kept flat the depth of cut will vary because the vacuum on the ShopBot may suck the foam off the table a bit. You may want to leave the vacuum off.
Run the ShopBot3 cutting software, following all applicable safety guidelines taught at the Tech Shop such as proper eye protection. Set the tool Z height somewhere in the center of your foam. Set the X and Y zero points at the lower left corner of your foam (if you followed the normal origin point in all the software).
Load and run your toolpath file exported from VCarvePro.
Alternative cutting by hand
If you do not have access to the ShopBot, instead you will print out your text from your design software. Even PowerPoint will work for this. You'll have multiple sheets of paper. Tape to your foam then using a knife or razor carefully outline each letter on the paper cutting through to the foam. Poking with a small nail or pin may also work.
When done you might want to fill in each letter with a marker. Now use your Dremel to do the cutting. This can be time consuming so take it slow for best results. I've only cut one tombstone this way and switched to the ShopBot for increased speed, quality and detail.
You can cut out simple pillar design by hand with a razor blade or on a bandsaw, for example. But if using a bandsaw I'd do a rough cut, then do the final cut step after gluing.
Step 5: Pillar Construction
Prepare the pillars and cut a notch for the PVC pipe stands as shown. Slather with glue with the PVC in place and clamp or put weights on the pillars overnight. When dry, trim a bit, as needed...do not worrying about damaging the foam too much since you will now proceed to make it look old. You can round off any rough edges or shape as desired.
Step 6: Build a base
To give your tombstone a little more status in the graveyard you need to give it a nice base. Use your tomb to trace an outline, then cut it out with a razor. If you make multiple levels it means your deceased is more important. It is up to you whether this means more important before or after death. But if you've watched "The Walking Dead" you know that Hershel was pretty important so he rates two tiers in his tombstone base.
The bottom tier is just a flat sheet with holes cut out where the PVC pipes for the rebar go.
If you use multiple tiers then you should glue them together after cutting. I prefer to not glue the base to the main tomb which makes it easier to store for Halloween.
Step 7: Add cracks and textures
Add cracks with a soldering iron, break off chunks, smack with a rock (looks better than smacking with a round headed hammer.
Step 8: Aging with paint
As with my previous project you will now age and creep up your tombstone.
The basic procedure is to dab small amounts of black, brown and green watered down paint, then lightly spray it with water and allow it to run down in a "natural" way. Be sure to dab various colors into all the nooks and corners. With the base installed you may need to tip the tombstone at different angles to get a nice runoff. Work your way from the top down.
After allowing to dry you should dry brush to highlight the stains. Start with a dry brush and lightly dab with a small amount of light gray paint. Dab off most of it on a paper towel and lightly vertically brush the tomb. Make sure to get mostly just the tips of the areas with dark stains.