DIY Test Tube Safe Storage Box for Open Source Lab

I bought a bulk pack of 12x75mm Pyrex test tubes from eBay, but the plastic bag they were sent in would to nothing to protect them while stored on the shelf in my workshop. So I laser cut this box to hold them and protect them during storage, up to 9 at a time.

There are 3 ways of making this storage box;

Laser Cutting (preferred),

3D Printing (Untested),

By Hand (Probably not recommended - unless you have lots of time and none of the above available).

Required items;

3mm A4 Laser ply / 3mm A4 Acrylic sheet

Wood / Super Glue

12x75mm Pyrex Test Tube with Blue Cap (https://www.ebay.co.uk/itm/181586557634)

This is the method I used to make this box as it is the quickest, easiest and cheapest method.

Using the included .dxf files, laser cut 1x of each file out of the A4 sheet.

Files Required to cut should be;

12mm Storage Rack Vertical x9 Bottom,

12mm Storage Rack Vertical x9 Lid Holding Side,

12mm Storage Rack Vertical x9 Lid Not Holding Side,

12mm Storage Rack Vertical x9 Lid,

12mm Storage Rack Vertical x9 Middle,

12mm Storage Rack Vertical x9 Top.

This step is untested, so take it at your own risk (as every 3D Printer has different tolerances).

The included .3mf files are derived from the laser cutter files with no added tolerances, if the parts are too big then sanding may be a good idea. Alternatively 3D CAD Files will be provided later on so tolerance changes can be added to suit your needs.

These parts can be printed in PLA, ABS, PETG or whatever takes your fancy.

Print 1x of all the files named above (and included below).

For those trying to find the tolerances of your 3D Printer and adjust the CAD files accordingly, I would recommend printing a 20mm XYZ Calibration cube.

For me, I installed the Calibration Shapes Plugin into Cura 4.13.1 from the Marketplace. This provides every calibration print file I may need (Including the calibration Cube!) accessible from the menu.

This small model can then be measured with callipers or any precision measuring device to calculate deviance from the cubes desired size on the X, Y & Z axis. If the cube comes out 20.11mm on X, 20.20mm on Y & 19.95mm on Z, you can deduce that your printer (printing that filament at that certain temperature) was 0.11mm oversized on X, 0.20mm oversized on Y & 0.05mm undersized on Z. This is a pretty good result and allows you to deduce that if you reduce the size of the part on its X Axis by 0.11mm then it will reduce (but probably not eliminate) that oversize.

If your one of the lucky few who gets a calibration cube print within 0.05mm on all axis, then pat yourself on the back as your tuning or filament management is top notch!

Also to note, different filament types and ages *may change this result. I usually always dry my filaments before printing (ABS/PETG) or every month or so (PLA) during the High Humidity Winter, and every new spool I get I run a Calibration cube to test its parameters, make sure the quality is OK and the temperatures are still suitable.

This is not recommended (purely because I am somewhat lazy now I have my Laser Cutter), but if you lack a 3D printer or CNC Laser then you can make these parts by hand.

Included below are the CAD models, as well as a full Solidworks Assembly of the model to aid in your construction of this box. You can use the CAD designs to gather all of the required Dimensions from each of the sides and create your own drawings or notes.

If you do not have a CAD Program then I have 2 great (and Free) options for you in Step 5!

To make this DIY you will need the following tools;

Electric drill (Ideally a drill press),

A small Saw,

A 12mm Drill Bit,

A 8mm Drill Bit,

A 3mm Drill Bit (pilot hole for the slots).

A Dremel (or whatever is suitable for cutting the slots)

The 12mm drill bit will be used in the Top and Middle levels, while the 8mm drill bit will be used in the Bottom level.

To aid you in this project you are going to go a long way if you have a CAD program, but I understand many people don't.

My preference for CAD is Solidworks, I find it intuitive and quite easy to use (after 3 years), but it is paid and has a fairly steep learning curve...

But I said I would have FREE CAD programs to offer, so there are a few Choices that I can recommend;

Choice 1 (For those that want CAD); Autodesk Fusion 360

This is a full featured CAD/CAM software package that is Free for Students/Hobbyists and only requires an account to get started.

After downloading and Installing onto your computer (either PC or MacOS) you can open up the .sldprt or .step files and use the Measure tool to gather the key dimensions of the part. You can also edit dimensions and add on to the existing design of the parts.

Download; https://www.autodesk.com/products/fusion-360/free-trial

Choice 2 (For those that don't want CAD); Solidworks eDrawings

This is more of a CAD Viewer, It is free to download and use (on both Windows and MacOS, it even works on IOS & Android!) and will allow you to import any CAD file (.sldprt, .sldasm, .step, .dxf, etc) and measure key dimensions and view the overall part, as well as export that CAD file to .3mf (3D printer Slicer format). Its a very powerful piece of software just for viewing/inspecting Parts or designs. I use this software in conjunction with Solidworks because of it being lightweight and very quick to use.

Download; https://www.edrawingsviewer.com/download-edrawings

This is a method I had not originally anticipated, but is completely possible if you have the machine.

These files (either the .dxf above or the CAD models above) can be imported to CAM software and cut on a CNC router.

Any Router that will fit can cut them, but the 2 I have and use are the 3018 Pro CNC and the XYZ-Carve (X-Carve derivative).

When cutting these parts on your router however, ensure that whatever bit you use is smaller than the smallest cut diameter, for example each of the slots is 3mm x 30mm, so to ensure proper dimensioning the biggest router bit that could be used is 2mm.

Again, any material that is 3mm thick and suitable can be used to make this box.

I hope this tutorial was helpful for both the design of the box and the many ways in which it can be manufactured.

Please check out my PrusaPrinters page and keep an eye out for more instructables soon :)

https://www.prusaprinters.org/social/233236-nwspitfire/about