Machining EVA Foam tool organizers with inexpensive cutters

How To Machining
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Just wanted to share a project I have been working on. I recently bought an inexpensive tool box specifically for my CNC equipment from Costco. Nothing fancy. Just a metal three drawer number with a carrying handle. I wanted to include an organizer for my endmills, collets, and various hold down clamps. My old organized did not fit and was made of wood. Not that there is anything wrong with wood, but I wanted something that would actually grip my tools a bit better. During my last move my endmills came out of their compartments and one actually got chipped. I decided a foam organizer would be great as I could make the walls slightly narrower than the tools and it would hold onto the them.

Now I wanted to do this project on a budget, I wanted to use my existing endmills, and I wanted the foam to grip the tools really well. This ruled out Kaizen as I am not made of money. This ruled out the lower density foams used for things like upholstery as they wouldn’t grip well. After some searching EVA foam seemed like the best option, but I could not find it in thicknesses greater than 10mm. I already had some 10mm EVA foam mats from Harbor Freight laying around so I figured I would give those a try and hope for the best.

And so began my experiments. First thing I did was watch Winston Moy’s video’s on machining foams:

and

These videos were a great place to start, but he only used foam cutting endmills in the EVA foam. I cannot justify paying for expensive endmills for a hopefully one time project.

During my experiments with different endmills I tried multiple RPMs, feed rates, DOC, stepovers, etc. Like Winston I found that you want your cutters going FAST. Both in RPM and in feed rate. I ended up running my spindle at 30k RPM. With the mods I made to my spindle electronics, it could technically go even faster but the bearings start getting annoyed with me. I ended up with a feed rate of 4000mm per minute. For depth of cut I settled on 3mm. More than that and the foam was turning into noodles. For stepover I found that 2mm gave the best results. More than that and the foam would not get fully cut. There would end up being a big chunk in the center of the pocket that on occasion ripped free.

Now I have a #201 endmill from Carbide3D which Winston used in the first video. While it worked, like Winston says it left a very ragged top edge. The floor of the pocket did not look very good either. Mind you this is literally the oldest endmill I own as it came with my Shapeoko 3. It is very possible that the floor finish was a result of the tool not being as sharp as it could be.

I also tried several other endmills like a brand new single flute endmill from Amana. It left a decent floor finish but also tore the top edge of the foam.

Next I tried a SpeTool two flute upcut endmill I got from Amazon:

This one had been used a few times, but is still very sharp. This one left a great floor finish, but again the top edge was torn to bits.

The last endmill I tried was a brand new Freud two flute downcutting endmill. I purchased mine at the Woodcraft near me a little while ago, but I found it on Amazon:

This one gave an amazing top edge cut, but the floor finish was quite fuzzy. I am pretty sure that the down cutting was compressing foam while it cut rather than trying to pull it up.

Ultimately I settled on using the 2 flute downcutting endmill for most of the pocket. I would then machine the last 0.5mm with the 2 flute upcutting endmill. I used the same settings on both:

30,000 RPM
4000mm/m Feed Rate
3mm Depth of Cut
2mm Stepover

This gave a great floor finish, decent wall finish, and great top edge.

Once I finished my experiments I needed to get some more floor mats to actually make the tool holders so I took a trip to Harbor Freight. While there I found these:

https://www.harborfreight.com/foam-kneeling-pad-56572.html

1.5 inch thick hunks of EVA foam. Much better for tool holders. They do include the piece of foam they cut out for a handle. I just super glued it back into the foam.

I just finish machining the first half of the top storage area. Here are the results:

PXL_20230624_185129444
PXL_20230624_1851294441920×1446 299 KB

The white in the top right is the residue from the super glue I used. I am debating on putting a layer of spray paint over the top to hide that, but it would be purely cosmetic.

EDIT: One thing I forgot to mention. I used blue painters tap and CA glue to hold down the foam. The knee pads have that textured finish on both sides so I really had to rub the tape into the surface to get full adhesion there. I used thick CA glue to help bond the two strips of tape down to each other.

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I don’t think my foam was quite as rigid as yours

I used the Amana 51404-k bit and it produced pretty nice cuts. This foam was in layers with glue between so you could in theory cut the perimeter and then peel up the layers to the depth you desired. In practice it didn’t peel that well so I just cut pockets to the depth I wanted. Only issue was when one of the pockets was at the exact depth of a glue layer. It was a little messy then, other than that the bottom and the top cut cleanly.

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A further consideration on this sort of thing is that there is a specialty tool for cleaning up the bottoms of pockets:

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Yeah this is some pretty dense EVA foam. What you are describing is Kaizen foam (or a knock off), which to me is way more expensive than it should be. The 7 dollar Harbor Freight knee pads are a fantastic value and hold onto my tools really well.

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Actually what I bought wasn’t too bad. $21 for a 4x2 sheet: https://www.rockler.com/rockler-foam-organizer-sheet

My drawer is the full width of the table that my Pro 4x4 sits on.

I would have had to buy 4 of the ones from harbor freight to cover that but looks like a great solution for smaller drawers.

I will check it out because I want to go to HF anyway to get a rolling stool for bit changes to save my knees.

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I’m definitely going to use some of this info as I fit out drawers in some new assembly tables I’m building after my shop is expanded. thanks for the links.

And thanks for the reference to Winston’s video - you know, foolish me, I’ve been lugging around my ketchup packets without any protection…never again. :slight_smile:

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An electric turkey carving knife work’s excellent on foam, while not the tool for cutting out notches works great on sheets.

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Damn. When I checked Rockler was completely out and it looked like the discontinued the product. Of course a week later and its back in stock.

Still knowing how to cut EVA foam will come in handy the next time a friend needs Cosplay armor.

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I need to check out the HF foam I’m always there ha. I did order and cut foam from foamfittools.com and it went pretty smooth with an Amana foam bit #46564 1/8 need a 1/4 bit now.

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Yes, I bought mine several months ago and the next time I looked it showed out of stock. Then popped back up recently.

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What do u guys do if u wanted to cut out slots for wrenches. How would you measure it so it cuts the specific tool dimensions?

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See:

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I kind of figured that

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I might just lay out the tools, trace them and use a foam cutter n my palm router to see how that works.

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Would it be possible to do this with the Nomad that only goes up to 10,000 RPM?

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I copied them and imported and traced. I would be happy to share my C2D file if you want. Your wrenches may be different though.

My file also has a nice cutout for the SST mini tramming gauge. That one was a good bit of work.

EDIT: Added the files. It is broken into two as my foam was 48" wide. The most interesting stuff is in part 1. Overall there is a spot for a tape measure, square, tramming gauge, 2 wrenches, cam clamps and angles, three allen wrenches, lots of bits and collets. There are some random pockets as well.

I always find myself using the wrenches the other way and have to flip them around for storage every time.

FoamFullPart1.c2d (336 KB)
FoamFullPart2.c2d (280 KB)

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Sure!

See:

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I am wanting to do a whole tool Box and a extra drawer for my CNC tools but everything I have found doesn’t seem feasible. I think I will trace the tools and use my palm router with a foam bit.

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It isnt that hard in Fusion360. Put your tool on something with a high contrast background. For instance my shiny Dewalt collet wrench I put on a sheet of black paper. Take a picture from above. Bring it into Fusion360 as a canvas. Take a physical measurement off the real thing. Scale the same section in the canvas to match. Then use the sketch tools to sketch the outline and add any additional features.

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I tried it on white paper but there were shadows messing everything up. I will try it on black. Thanks

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