Tower of Art

I have 'a few' 17/18ml dropper style paint bottles from Army Painter, Vallejo, Reaper MSP and others, and needed a way to store them that didn't take up too much space on my desk, or floor... I also happened to find a carboard tube of the type used when casting concrete pillars.
The tube has an innder diameter of 150mm, and 4mm wall thickness, so I based this project off of those measurements. (You will be able to use other sizes when I finish parameterizing everything)
The trays are stackable, and can hold up to 19 bottles, each. They consist of 3 parts, the 'holder' the bottom and the optional stiffener. The holder and bottom parts are upside down in the .STLs to make printing easier.
Print as many as needed, glue them together, fill them with bottles and stack them on top of each other. Then slide the cardboard tube down over them.

Endcaps... You need 2. And a cargo strap no to fit in the groove. Note that the caps have an outer diameter of 10mm more than the outer diameter of your tube.. This is the widest object and sets the requirements for yuor buildarea.
There's also the '17ml', which doubles as a paint holder. That one is kind of a long print, though. but you only need one of those, if you decide to use that design.

Also, you CAN store differently-sized bottles, tubes or whatever in this. Just make certain that the 'Bottom' part is sized to fit the item in the layer underneath.

Added files for 2ml, 16mm diameter glass bottles often used for perfume or essential oil samples.
(The holder file is way larger than necessary right now. Still need to clean up some of the code... a lot!)

Started parameterizing the files.
First out is the simple endcap as this is the potentially most useful part. With a pair of it and a strap, any tube can be converted into some sort of transport or storage container.
Still to finish: endcap that doubles as a holder, the 'Bottom' part and the optional stiffener. And any extras I may think of.
Added a 'hex' endcap. Just because I could and because it looks cool...
The file now contains all essential modules:
Simple endcap, hex endcap, and holder endcap
Holder, Bottom plate and the optional Support Plate(to be glued in if you feel it necessary)

1.32... The 'Fix even more stupid mistakes' edition...
1.33. The fix the horrors introduced in 1.32 file' version. Also, drastically speeded up generation of the 'Holder' and the 'Bottom Plate'