Introduction: Laser Cut Foam Inserts for Tool Boxes
This is my first Instructable. Any constructive criticism in the comments will be gratefully accepted.
Lately I'm doing more machining at TechShop SJ. As a result, I've been carrying a lot of cutting and measuring tools back and forth from home. Many of the tools have precisions surfaces or are somewhat fragile. Remarkably, some of these came with no protective container. So, I decided to make some.
All of the work in this Instructable was done at TechShop SJ, my home away from home.
This Instructable is all about finding the best, least expensive foam from which to laser cut inserts to hold the tools safely in their boxes. Maybe I'll cover the finding/making appropriate boxes some other time.
Since all my projects get out of hand almost immediately, I also did some foam inserts for one of the tool boxes in my home shop.
Using inserts in tool boxes to protect and organize tools is called "shadowing" in the aerospace industry. It's a standard practice aimed at preventing tools from being left some place they shouldn't be and subsequently causing "foreign object damage." For an appropriately horrifying image, think about a big pair of ViseGrips left inside a jet engine when it's fired up.
Step 1: Making Foam Inserts
For foam to protect tools during transport, it needs to fit closely around them. Too bad that hand tools tend to have complex shapes. The usual way to make close fitting DIY inserts around complex shapes is to trace the outline directly on to the foam with a Sharpie and cut out the recess by hand with an Xacto knife or scalpel (there are lots of YouTube videos on the subject).
It's way too much work to do this manually if you want to do a clean job of it. It's also unnecessary for anyone who has access to the Epilog lasers at TechShop SJ or their equivalent.
To make inserts, we need foam, vector artwork of the tool outlines, and a recipe for cutting the foam. The last part is the main purpose of this Instructable, but we need to get the first two straight before we can start zapping foam.
Step 2: Finding Good Foam
Most stuff sold as "tool box foam" is polyethylene (PE) or ethylene-vinyl acetate (EVA) and is way too expensive. I went on a hunt for other, less expensive sources for the same stuff. Both of these types of foam are okay to cut on the Epilog laser at TechShop SJ.
The lowest cost PE foam I found was a blue camping pad from WalMart. It's about 2 ft. x 6 ft. x 1/2 in. (~610mm x ~1825 mm x ~13mm) for $7.97. Call it $0.67/sq. ft. You can't get this online, so you'll have to grit your teeth and go there.
EVA foam is available at Harbor Freight. They have 2 ft. x 2 ft. x 1/2 in. (~610mm x ~610mm x ~13mm) gray EVA interlocking tiles, 4 for $10. Call it $0.63/sq. ft. The also have rolls of foam with a diamond plate texture. A 2 ft. x 6 ft. x 5/16 in.(~610mm x ~1825 mm x ~8mm) roll is $8. Call it $0.67/sq. ft. The quality of the roll material is not nearly as good as the tiles. The roll I bought has a lot of voids in the back surface and even has some on the diamond plate (front) surface.
EVA foam covered with other materials is available at Daiso California, a Japanese dollar store (okay, truthfully it's a $1.50 store) . 30 cm x 30 cm x 7 mm (~12 in. x ~12 in. x ~1/4 in.) interlocking foam tiles are $1.50 ea, so call it $1.50/ sq ft. I chose a carpet covered tile and a cork covered tile. Daiso also has every kind of plastic container known to mankind if you ever need such things.
Finally, 2 mm (~0.080 in.) thick EVA foam is available at craft stores (locally here in the SF Bay Area at Michael's or JoAnn's). A 9 in. x 12 in. (~230mm x ~305mm) piece is about $1. I've used this foam before and it cuts great in TechShop SJ's Epilog laser. However, it's too thin to be cost effective for tool box inserts. By the time you buy enough to layer up a reasonable thickness and a can of 3M Super 77 spray adhesive to hold it all together, the cost is crazy high. Even so, keep some thin foam around...it makes a good complement to the thicker foam (more on that later).
Apologies to any non-US readers for having such a US-centric take on sourcing these materials. I hope this Instructable gives enough information to help you find equivalent materials in your part of the world.
Step 3: Laser Artwork
No rocket surgery here. You have three options:
1) Get out your ruler/tape/calipers and start measuring. Then draw up your outline in Adobe Illustrator or its equivalent. This method is practical for tools with simple outlines like 1-2-3 blocks, V-blocks, squares, and the like. It takes a lot of time to measure and draw more complex outlines.
2) Trace the tool outline onto a piece of paper and then scan it. If you do this, it's best to convert the scan to a vector format (using LiveTrace in Adobe Illustrator or its equivalent) so you can tweak it if needed. This method isn't as easy as it sounds because, if you are using a normal pen or pencil, it's a bit difficult to keep your pencil or pen tip at a fixed distance from the edge of a complex object while you trace it.
I've found two tools that make it easier to trace. The first is a FastCap Long Nose Pattern Marker (promo video above). The second is an old school drafting lead holder (photo above). Both of these have long, skinny ends for close tracing around something thick. The marker is good up to about an inch (25mm) and the lead holder is good to 2+ inches (50mm+) as long as you are careful to not break the lead as you trace. If you use the drafting lead, go over the line with a dark pen before you scan it to get better contrast.
3) Set the tool directly on your flatbed scanner, scan it, convert it to vector, and tweak as above. This sounds easy too, but be prepared for a lot of fussing with the scan before it will convert to a usable vector outline.
I've used all three options successfully. I mostly use method 2 with the drafting lead.
Which ever way you make your outlines, be sure to check the outlines before cutting foam. The best way to check is to cut some corrugated cardboard test pieces. If that's too much trouble, at least print out the outlines and lay the tools on top of them to check that all is well. Throwing away some scrap cardboard or scratch paper beats a miscut $10 piece of foam any day.
Before spending a lot of time making outlines of individual tools, it pays to make sure everything is going to fit in the drawer/box. A quick and dirty test layout doesn't take too long and you can move the outlines around in Illustrator to fine tune everything. The final check is a full size cardboard cutout.
Step 4: Test Cuts
I use the Epilog lasers at TechShop SJ for cutting and engraving all sorts of things, but the way I test a new material is pretty much always the same.
First, check the recipe sheet at the laser work station to see if the material is listed there. Even if the exact material isn't listed, you might find something close enough to get you started.
Second, check Google to see if someone has figured this out and posted a recipe. If you do find something on Google, remember that even if it's the same material on the same laser, you need to do test cuts. Things like the condition/age of the laser tube, how clean the optics are, etc. can have a big impact on how a laser cuts on any given day. Test, test, test before committing your good material.
After I find my starting point I just put some scraps onto the laser and start cutting. My test cuts are simple squares about 1 in x 1 in (25mm x 25mm) so I can run a lot of tests without using up too much material.
Now, start varying the recipe from your starting point to find the right power, speed, and frequency to use. Don't forget that multiple lower power passes is sometimes better than one high power pass.
It's difficult to give much help on exactly how to develop the recipe for any given material. It's a bit of an art. Beyond the general rules that slower speed or higher power takes more material and low frequencies are good for materials that char while high frequencies are good for things that melt, its largely a matter of trying some combinations to see what you get.
Be sure to take notes while you are testing. It's almost impossible to keep track of lots of different recipes without notes.
Step 5: Results: WalMart 1/2 In. Thick PE Camping Pad
This material works great. It's cheap, easy to get, and the color isn't too offensive.
For the 60W Epilog laser at TechShop SJ, I used vector mode at 20% speed, 60% power, and 1000Hz. I probably could have cut a little faster and that might have reduced the distortion in the narrow cut out show above. Since it didn't matter for this piece, I didn't worry about it.
Since the V-block clamps (the black wishbone looking thing on the top left in the picture above) were only about half the thickness of the foam, it would be hard to get them out of the box. Here's where the 2mm EVA craft foam comes in handy. I cut a shim the same shape as the tool from a double layer of black craft foam and put it in the bottom of the recess. More about the craft foam in a later step.
If you plan to do full size drawer inserts, be sure to pay attention when you cut up the roll to fit in the laser bed. I cut my roll across the width without thinking about it and ended up with no pieces wide enough to fill the drawers in my roll around tool box. Very annoying.
Also, since the material comes rolled up, you need to flatten it out before laser cutting it into pieces to fit the laser. I ended up just unrolling it in the bed of my pickup truck (which happens to have black bed liner), putting some small weights on the ends, and letting it bake in the sun for a couple of hours. The material came out plenty flat enough for our purposes here.
Step 6: Results: Harbor Freight 1/2 In. Thick EVA Foam Tiles
This stuff also works great, it's cheap, and I'd sure rather go to Harbor Freight than WalMart!
For the 60W Epilog laser at TechShop SJ, I used vector mode at 35% speed, 60% power, and 1000Hz. Many thanks to Tim Q. for the assist with this recipe. Tim was in the middle of making something super cool out of this kind of foam at TechShop SJ when I stopped by to pump him for info.
This material also isn't wide enough to fill a Kennedy tool box drawer in one piece. Turns out that the 2 ft. x 2 ft. (~610mm x 610mm) size includes the interlocking features! Not counting them, the tiles are actually less than 23 in. (585mm) square. As you can see from the pic above, trying to use the interlocked tiles resulted in an ugly seam in the middle of the drawer. Also, so much of the interlocking feature was cut away that the pieces didn't hold together at all.
I also cut some long test slots for rulers in this material. As expected, there was a lot of distortion in the foam but ultimately it worked.
To try to salvage the drawer insert even with the non-interlocking mess, I used some Beacon FabriTac to glue the ends of the foam pieces together. It worked okay functionally. But, it's an extra step, the glue line takes away from the clean look of the drawer liner, and it was a pain to keep all the ends pressed together while the glue dried (I used 3M blue painters tape to help).
If it turns out I want to use a lot more of this material, I plan to try some 3M VHB transfer adhesive. The transfer adhesive might make it easier get a clean seam by butting the edges of two sheets together before cutting. It might work...VHB tape is miraculous stuff.
Step 7: Results: Harbor Freight 5/16 In. Thick Foam Roll
Another easy to use material. If you don't mind the cosmetic defects in the surfaces, it's pretty much the same as Harbor Freight's EVA tiles, only thinner.
This material comes rolled up (like the WalMart PE camping pad). So, it got the same flattening treatment in the bed of my truck as the camping pad. It came out just as flat.
In order to get a thick enough insert to securely hold thicker tools, I laminated two layers of the foam together using 3M Super 77 spray adhesive. An annoying extra step, but 5/16" (~8mm) is just too thin. Also remember that having to laminate the stuff means that its true cost has doubled, even ignoring the cost of the spray adhesive and the time to glue it together. That said, it is a way to get some big pieces of foam to feed to the laser.
The double thickness material cut well on the 60W Epilog laser at 20% speed, 60% power, and 1000Hz. For a single thickness, 55% speed, 60% power, and 1000Hz. was enough.
Step 8: Results: Daiso 7 Mm Thick EVA Tiles
These materials look cool, but were pretty much a bust.
The cork covered tile was hard to cut without getting excessive charring of the cork layer. The best results I achieved were at 4 passes of 65% speed, 60% power, 1000Hz, but that's not saying much.
The carpet covered tile worked okay, but it's thin and more expensive than the other materials I tested. Also, the label didn't clearly show the material used to make the carpet fibers and so it could be something like PVC. We don't want PVC in the laser cutter due to the hydrochloric acid vapors produced during cutting. Bad for you and bad for the machine. 40% speed, 60% power, 1000Hz cut fine, but there's no point in doing anything more with this.
Step 9: Results: 2mm Thick EVA Craft Foam
This material is great to have around for making shims to put under tools that are too thin to fit well in the box/drawer inserts. See the step about the WalMart camping pad material for how I used it here.
The thin craft foam is also useful when you want to make a container for something with a complex shape in all three axes and you want the foam to fit really well.
The best settings for cutting the foam obviously depend on how many layers you are cutting through. For 2 layers, I found that 60% speed, 60% power, and 1000Hz worked well.
Step 10: Conclusions
My foam cutting journey proves that there is no reason to pay the outrageous prices for "tool box foam" that is sold for that specific purpose.
Making box and drawer inserts is straightforward although not particularly fast. But if you've got high quality or precision tools you want to keep in good condition, it's worth the effort. The process is easy enough that it won't bother me if I need to remake the inserts some day if I change the tools I use most frequently.
Without the access to the Epilog laser at TechShop SJ, I doubt I would have made the effort to make these inserts. Having access to the lasers and other expensive equipment I couldn't justify owning (let alone afford to buy!) is the main reason I'm a member at the TechShop. Well, that and the free popcorn...
I hope you find this as useful as I found it fun to do.