Gridfinity Drop-In Microscope Window Bin, 2 x 1, With Retaining Shim

I've made a few of the print-in place bins found here: 

• https://www.printables.com/model/286354-tapeless-gridfinity-window-divider-bin-windows-pla

But getting them right is fiddly. Moreover, three dividers in a 1 x 2 is too small for many things I want to put into a window bin.   So I was pretty happy to find the slide-in version with no dividers.

I standardize on press-fit bases, so I do what I always do and fed it into the excellent Gridfinity Rebased tool, at https://gridfinity.tools. That version is included here. 

I like that it doesn't involve pausing the print to insert the microscope slide, and carefully fitting a separate little work piece on top with some blu-tack to make a surface for the next layer to print over.  It's great when it comes out perfect, but it's hard to get it perfect. 

I don't like that the front top ends up thin, and the rim only extends around three of the walls.  I don't love having to glue the microscope slide in, either, although that's not such a big deal.

So I busted out OpenSCAD and made a nice little shim which fills in that space.  It's designed to be tight, it should slide in and register with a bit of a clicking sound.  This provides reinforcement for that weak wall (important when trying to press-fit magnets!), and retains the microscope slide. 

There's no need to glue it if you don't care to.  I have been doing so, just for maximum retention and strength, but if your printer is dialed right, neither the slide nor the shim is going anywhere without deliberate action once both are in place.

I recommend the glue shown in the picture without reservation. It's a flexible cyanoacrylate with a metal tube nozzle, and a little needle in the cap which keeps that nozzle clear.  It's workable for a minute or two, and it's set in six (curing takes longer).  It's my go-to glue for both FDM and resin prints at this point, and many other things.  A search engine can serve you better than a link, this being an international site and all, so I won't bother with the latter.

If you have such a glue then gluing the shim is very simple: just squeeze, as shown, and run a little bead along the seam on both sides.  Another reason I like that specific glue is that it is not easy to over-do it here, in fact you're more likely to wonder if glue came out, this is easy to confirm visually.  Then clamp as shown for maximum overkill, give it ten minutes max, and enjoy.

There is no need whatsoever to glue the microscope slide.  It should be firmly retained with nowhere to run.

I'm still dialing in the ideal amount of support, but it's more-or-less as shown: normal, snug, painted.  One layer of interface, ironed. Pops right off, usually need to run a razor along the bottom to de-bump it.  It actually works with no supports at all, at least on my printer, but you get one or two strings instead of a nice solid wall.  However, those are easy to cut away and the resulting bridge is much the same.  I prefer the supports. 

If the shim needs adjustment, this can be done to arbitrary precision with the included OpenSCAD file.  The shim prints horizontally or vertically: the only reason I can think of to do the latter, is that (per the picture) I like to put a color band across the top, and for future batches I can run off a separate run of shims with the top two layers of that color.  This is pure vanity, in order to get a nice even band of the color starting from the rim.  The surface quality is nicer when printed horizontally, although probably I could hide the seam on the side which takes glue and that would no longer be true.