Stands for self-rewinding spool holders

"Well known" self-rewinding spool holders have longer axle than those used by MMU2/S ones (also employed in Lack Enclosure v2 5-spool stand). So we may shorten spool hub (and gave problems with some wider spools), use original stands from self-rewinding spool project and fix them some how, or... invent a wheel once again!

This stands are made up from separate frames, so space between them (axle length) may be freely adjusted. I've used spool hubs from https://www.thingiverse.com/thing:3338467, with 132mm aluminium tube as an axle and 108mm space between frames.
As they no longer fit 5 spools in the row, two stand variants are prepared - one for edge, and one "stand-alone".

Print instructions

Models

There are 4 (+ 1) models in total:
Frame A and A-mirror are "stand-alone" version to be placed on any flat surface. It is in two variants - "ordinary" for 3,5mm screws or "flathead" for 5mm flat head (pan head) screws.

Frame B and B-mirror are intended to be placed on surface edge (i.e. edge of the Lack table or shelf).

A and A-mirror parts as well as B and B-mirror parts are just mirror images of each other, to keep axle slots interleaved.

4 perimeter and additional top and bottom layers would add some strength - in practice PETG with 4 perimeters and 6 layers top/bottom is enough to lift weight of enclosure cover and 3 full spools.

Fifth model - Spacer may be used with with Frame B to make whole spool stand more sturdy and keep spool axle clearance. It may be interchanged with tubing or additional nut and washer (four sets for each intermediate frame). Spacer gives 108mm space between frames, which corresponds to axle length of 132mm

Additional hardware

Apart of printed Frame parts, you will need:

• hub assemblies with axles - I've used 133mm aluminium tube, 8mm diameter for an axle, hub, springs, etc you will find here: https://www.thingiverse.com/thing:3338467
• threaded M5 rod - used as connecting rods
• M5 nuts and preferably washers - at least 4 sets for single rack, but read the rest of description before shopping
• Aluminium (or stiff plastic) tube, with inner diameter of at least 5mm, which will be used as a spacer - once again, more information on it below. 8 mm diameter aluminium pipe (exactly as those in original spool holder...) is perfect.
• screws to fix frames in place

Construction

Frames are intended to be stacked in A - A mirror - A - A mirror... pattern (same for Frame B) - at least one pair of corresponding frames is needed (single spool), the A - A mirror - A pattern gives place for two spools.

There are two horizontal holes (5.5mm diameter) in the bottom part of each frame for connecting rods. To keep distance between frames (spool axle clearance), you will need tubes cut to the length, additional nuts and washers, or (only for B variant) - included Spacers. For 132mm axle use 108mm spacers.

Fitting to the table top

Frames A (flathead variant) are 20mm thick, they are intended to be mounted with 5mm flat head screws (at least 5x30mm for LACK table).
Frames B are 15mm thick and are intended to be mounted with 3.5mm screws (i. e. popular plasterboard ones) - one from the head, and one or two from a top. It is not optimal for thin Lack table top, which is thin and relatively soft - try to screw outer frames into reinforcements on table sides, and use connecting rods to make whole thing strong enough!