Table of Contents
Introduction
I’ve got a set of SMA adapters that I really don’t wish to lose. They are used with a Vector Network Analyzer (VNA). Some of the adapters came in a little wooden box, that was getting full! It doesn’t shut very well, so I’ve been on the lookout for a different storage box rather than just throwing them into a zip lock bag! I decided to use EVA foam.
The three-minute video explains what I did.
Using Steel Cutters
Searching around revealed that there’s such a thing as shaped cutters for material like leather. They were cheap, so I figured I’d try using them on foam for shaped storage.
I got a box of about 52 cutters, for just over £10. The are quite greased-up in their delivered state, so you’ll need to clean them up (I simply squirted dishwashing liquid into the box, filled it under a tap and closed it and shook it for a minute or two).
The cutters have one sharp side, and the other side is blunt. There’s quite a variety of sizes and shapes to explore.
I didn’t have an appropriate press, so I decided to just try hand pressure. I cut some grooves into a block of wood to hold the desired cutter in place. This is not super-essential, I did manage to use the cutters without grooving the wood block too, but it makes it a bit easier.
To support the other side of the material, I found some scrap soft wood (I think it’s pine).
Check out the earlier video to see a steel cutter in action. It’s fairly obvious how to use it. I used 6 mm thick EVA Foam (which is used for craft projects, and is commonly available).
Results
After all the shaped holes were punched out, I glued a thinner (2 mm thick) EVA sheet to one side.
And here’s the result! The items are held snugly, they won’t accidentally fall out. The box came from a Muji store, they have various sized small boxes, and this one had space to store some additional tools I’d be needing for the VNA.
After that, I PowerPointed and printed the details I needed and folded them into the lid with a sort of spectrum-like color scheme. There’s a bit of extra foam there too. The kit is complete!
I was really impressed how good the cutters were, considering the low cost, and the variety of shapes is pretty good. Incidentally you can make composite shapes by doing subsequent cuts. For instance you can see in the photo below that two large rectangles were cut, and then a smaller cutter was used to slice part of the bridge between them, so that the USB connector could fit in that middle space.
Summary
The steel cutters have been a great problem-solver for making shaped storage. The main downside is that the cutters are only suitable for small parts (unless you make multiple overlapping cuts).
It would be interesting to learn how to cheaply refine the technique (maybe use a vice instead of pressing the wood block by hand), but overall the current method is good enough for small tools/items.
Incidentally it is also possible to get custom-sized cutters made up, either purchased, or DIY’d. If you have a CNC router or a milling machine, then half the battle is simply to route a groove into a wood or metal block, for the desired shape. That metal strip the cutters are composed of, is called rule die steel, it’s available in long strips. You’d have to shape the metal strip, and glue the blunt end into the grove. That’s possibly worthwhile if you’re selling products in storage cases.
I’d like a decent storage method for tweezers next!
Thanks for reading.
