Trunks for my Junk

I have had four very conveniently-sized plastic storage crates in my possession for about 30 years, having carted them between homes, and even half way across the world and back once. But I was never able to find them again since the year I bought them, so never had enough (I need about 8 to store all my stuff). And now the plastic is starting to degrade and one has already developed a split in the lid, and another has lost a latch somewhere along its travels, so I guess it is time to make some new ones.

Since I went to all the trouble of inventing my own convenient units of measurement, I am going to make the crates match those. My origional plastic crates are quite close in size to that anyway, by pure coincidence. Actualy, that is too harsh: they were very close to that size because my octal-Plank-length unit is very human-scale-friendly in the first place, so other things designed for human-use tend to gravitate to that scale as a matter of practicality!

I am using 17mm form-ply as I have enough suitably-sized off-cuts of this lying about to make at least two trunks. They are designed to be stackable, with Teflon™ (PTFE) feet arranged somewhat like (up-side-down) Lego™ blocks (or even more like Modulo™, since they are based on 1:1:1 proportioned cubes), though only for stacking-alignment: they won't actually lock together tightly like Lego™/Modulo™ bricks!

As mentioned, I am normalising my dimensions on my personal (base-8) measurement system, accounting for 17mm plywood thickness, 1mm Laminex™/Vinyl cover thickness, 0.5mm inside over-dimension for fit-tolerance, and 2.6mm (1/128th) outside air-gap, all together providing a (virtual) wall thickness of 1/16th. This means I get a 7/8th unit internal dimension per cubic volume and an external stacking offset of exactly 1 unit in every direction. Nice and neat. As the crates are going to be double-length, I added a 1/16th extra length to the 14/8ths internal length, to accept an optional divider, and that gives me a 13mm air-gap at each end, which works well with the handles I have as those need around 10mm of clearance when (mostly) folded into their recess. It all seems to work out nicely!

The plan for the trunks.

I have made cases like this before, though not normalised to my personal dimensions. I used to do nice 45° cuts on all the joints, but this time, as I intend to cover it all with Laminex™ or Vinyl, visible butt-ends don't matter. In fact, the directions of the 90° joins are specifically chosen to optimise the case strength against anticipated stresses (from when lifting with the handles, the contents weight on the bottom, and the stacking-weight on the lid) when held together with screws, by keeping the directions of force perpendicular to said screws as much as possible. They will also be glued, but that is more about waterproofing the joints and any extra strength from that is just a bonus.

I make things to last - sometimes to my own undoing, if I later change my mind and have to dis-assemble something I made earlier!

Other componets:

Recessed latches. I ordered 2 standard (in black) and 2 with barrel locks (enough for 2 trunks), as I don't really need to lock many of my crates (most just contain spare kitchen utensils or clothes or old computer parts, but one contains personal files). I couldn't get lockable ones in black, unforunately.

Standard recessed latch Lockable recessed latch

I also have, some nice recessed handles (spring-loaded pop-out):

Recessed crate handle

I could have gone with matching-silver for the whole lot, except I already had the handles (salvaged from some damaged road-cases I got to break up some time back).

Concealed hinge mechanism

I have used standard fold-hinges, and also cupboard hinges before on crates. This time I am going to try out some concealed hinges, which will leave no parts extending awkwardly outside or inside the case, when closed.

Body and lid of trunk assembled from scrap formply.

The body and lid of the first trunk is assembled from the cut-up scrap form-ply. Lots of screws for strength and, as mentioned, also glue, predominantly as gap-sealant.

Trunk open showing 'concealed' hinges.

Here are the 'concealed' hinges. Quite nice. The plastic plate sitting in the lid of the trunk is the marking template for the hinges I laser-cut/engraved so that I could get the alignment perfect.

I have decided to cover the outside of this trunk with some black leather-look vinyl. Possibly with metal corners and/or edges to cover seams. Then come handles and latches. And finally the eight Teflon™ feet.

Trunk base with template.

I printed a template (as three A3 sheets cut and glued together) to guide placement of the Teflon™ feet. I was originally going to have these 3D-printed in nylon, but found 38mm Teflon™ feet ready-made online, which was close enough to 42mm for my purposes here.

Trunk base with feet.

And the eight feet are on.

Trunk top with divots.

And a pair of laser-cut sheets with divots for the feet on the trunk are glued on top.

...

To come: The metal bit to stop the lid over-opening, and covering the top with leather-look black vinyl.

 


 

I also had a few made up to my dimensions by a local road-case manufacturer:

3 externally-manufactured trunks.

And, of course, I modified them to my stacking system, with an extra plate of wood glued on top, drilled out with divots for the feet of a case above to seat into, painted-in to match the plastic laminate. And I 3D-printed some extenders for the feet to get them to the right height (mainly needed because of the sticky-outy corner bits on the pro-cases).

They were definitely not cheap! But considering all the time and effort I put into the top home-built wooden one, against what my workplace thinks I am worth (in hourly take-home pay), it actually is more cost-effective to use my time for other things. And I expect these to well-outlast the rest of my life!

I'm still happy I made the first one myself, just for the experience of doing so (which is my idea of fun) beyond the time it takes. I might even make one more myself, since I will have enough suitable scrap wood to do so when I strip down another project I am almost done with.

 


 

Cardboard Variant

Wooden trunks, while very strong, are hard to build, and expensive to have custom-made! That is fine for storing items I value, but I also have a bunch of stuff that don't really require that level of storage-security.

After unboxing a new classroom whiteboard at work, I had a couple of huge pieces of flat corrugated cardboard, so decided to make some cardboard trunks to match the wooden ones. These are designed to be strong enough for the storage of relatively-light goods, and be stacked on top of the stronger trunks.

Cardboard cut out plan. Cardboard cut out.

I cut out the shape desired. In this case there are 3 pieces on each 'end' which fold+glue together to make it nice and thick and strong. Also some flaps on the top to fold over for a little extra strength there.

Cardboard folded and clamped for glue to dry.

I found that when folding and gluing, each side had to be left lightly clamped, with a flat surface holding it down, so that it doesn't bow annoyingly while the glue dries. This meant doing one side each day with 24-hours drying time. I use PVA glue, which for light porous surfaces is far stronger than people generally give it credit for.

Cardboard trunk with handle holes drilled out.

And for the handle holes, I drilled 42mm holes spaced 84mm apart. Just using a hole-saw, not pushing too hard, and doing half the drilling from each side was sufficiently neat. Then did the strait cuts between them with a stanley knife.

I also had some smaller pieces of double-corrugated card, so cut this to glue to the inside base, to also make that extra-strong.

Cardboard trunk lid cut-out.

The lids required much less material, and I had a spare smaller sheet of cardboard I could use for this.

Cardboard trunk lid glued and clamped.

I am less concerned with the strength of the lid, which is mainly just a dust-cover, so I made it a bit more simply.

2 cardboard trunks completed and painted.

And a quick coat of paint (colours were somewhat determined by what I happened to have in old paint that needed to be used up before it went hard anyway).

 


 

Toys

I even just happened to have (from unrelated projects) just the right colours to print some wee little (8:1 scale) toy trunks. Not for any good reason, other than having a bit of fun.

4 wee little 3D printed trunks.

These are more what they would look like if I had the resources to have them injection-moulded from plastic (or even cast in titanium, ideally). I can dream!