Modular sanding disc storage

Background

There are lots of sanding disc storage models out there. The ones I have tried all share one flaw that often slows me down - all discs of the same grit are stored together in the same tray or slot. This leads to two problems:

• When I go to grab a disc, the discs stick together and I end up pulling out all the discs of that grit in one go. This is a particular problem with the net-based discs, such as Mirka's Abranet or 3M's Cubitron.
• Because all the discs are together, when I see that one is looking a bit tired, I become lazy and take the next one, but leave the old one in the stack. Over time, this leads to all the discs of a given grit being used in parallel, and I end up in the situation where it looks like I have a lot of discs, but in reality, none of them are really suitable for the job.

I wanted a storage system not only holds all my discs (I often buy them in ten-packs), but also keeps the “current” disc for a given grit separate from the as-yet-unused ones. The idea being that when I decide the “current” disc is done, I throw it away and load the next unused one from the stack. And when the stack gets low, I know it's time to go order a new pack of that grit.

I couldn't find such a system, so I designed this.

Highlights

• Fully modular sanding disc storage system.
• Parametric - see “Customising” below on how to adjust to suit your needs.
• Holds “current” disc for each grit in a convenient slot - easy to grab when you need it.
• Other discs (from the pack but not “in circulation” yet) are stored in a tray, separate from the active disc and hidden behind a door.
• Components can be stacked together in any order or configuration you like.
• Components snap together with 6x2mm magnets.
• Magnetic grit labels that snap into the front of the disc trays.
• Disc trays have windows in so you can see how may discs are left.
• Finger holes make separating components easy.
• Storage for sander on top.
• Wall-mountable with dovetail mounts (included).

Customising

I have included the F3D model, which is fully customisable and setup to take 125mm discs with 5mm extra diameter (The Mirka Abranet discs I use get close to 130mm), plus 2mm of clearance for good measure.

Pretty much every dimension is customisable, but really you should only need to change a handful of them:

• discDiameter: Diameter of your sanding discs (including extra - I find at least 5mm is a good idea to make getting the stacks of discs in and out of the trays easier).
• outerWidth: Total width of all layers. Must be greater than discDiameter.
• outerDepth: Total depth of all layers. Must be greater than discDiameter.
• lowerDiscStorageHeight: Height of the disc storage trays. I find 27mm is enough to store 10-12 discs, maybe 15 if you squeeze them in.
• pegDiameter and pegDiameterClearance: Tweak these to get the pegs fitting tight enough that the layers don't move, but not so tight that you rip them off when separating the layers! I found 6 and 0.15mm respectively work well.
• upperDiscHorizontalOffset: How much the “current” disc sticks forward relative to the discs in the disc trays. Increase this to make more of your discs stick out. As it currently stands, my ~130mm discs protrude about 10mm, which is enough for me to grab when I'm in a hurry.
• magnetDiameter and labelMagnetHoleDiameter control how large the holes for the respective magnets should be. I find 6.1mm is a nice fit for the 6x2mm magnets I buy from Amazon, but YMMV. By default, labelMagnetHoleDiameter uses magnetDiameter, but you can set it to a specific value if you plan on using different size magnets for the labels.

Tips

• I think v2 of the disc tray is much better than v1, because it allows access to the unused discs without taking the stack apart. I've included v1 as it might be useful to some people, and also because it still respects all relevant parameters and dimensions that you can change.
• You can print the doors for the v2 disc tray “face down”, but I prefer to print them upright (i.e. in the same orientation as they'll be used) for two reasons:
  • This gives them the same look as the disc tray body layers which I think looks a lot nicer.
  • It means you don't need to print supports for the label holes.
• If you do print the doors upright, you'll probably need helper discs / mouse ears to stop the model from detaching from the bed during the print. I know I did! I place my helper discs on the back edge - that way the front remains nice and clean and less de-burring is needed.
• The design is magnet-heavy. Each layer uses up to 14 magnets (4 on top, 4 underneath, 4 for the door snap mechanism and 2 for the label snap mechanism). However you can replace some of these with M3 plain steel nuts without much (if any) loss in functionality:
  • Replace the 4 magnets on either the top or bottom of each layer. Just make sure to be consistent with either top or bottom, or the stack won't stay together in some configurations!
  • Replace either the 2 magnets in the v2 tray door or the 2 magnets that they are paired with in the v2 tray body. Magnets for both is likely overkill.
  • Replace the magnet in the labels - they really don't need much force to hold them in position.
• The labels are designed to be printed with the text in a separate colour. Just add a layer change (M600) where the body of the label finishes, and swap to a filament that contrasts well with the base colour. I really like black text on red, but maybe that's because I play using Team Red Power Tools.
• I've included a pair of sample models for the peg and hole attachment mechanism. I recommend printing a pair of these to check how well the pegs locate. The snugness of the fit will vary based on loads of factors (printer, filament, slicer settings etc etc).
  • If you need to tweak the peg or peg clearance, adjust the dimensions in Fusion's “parameters” window, and then export the Peg Sample - Peg and Peg Sample - Hole bodies to STL and print them.
• Even after tweaking, I still found I needed to finish the peg holes with a 6mm drill in a hand chuck. Even with my MK3S+ fairly well dialled-in, the bottom few layers still squish out and make the holes a tiny bit too small.

Print

• I used Sunlu PLA+, with mouse ears on the corners to reduce warping.
• I find 0.3mm layer height is fine, as it's going in the workshop.
• Don't skimp on perimeters or top / bottom layers too much - if it's too weak the horizontal bases of the “current” disc holders will sag and look bad.