MODULAR BOOKSHELVES (PRINT-TABLE #3)

OVERVIEW

This is the third of a series of furniture pieces developed around a “construction kit” philosophy, in which printer-sized components can be simply assembled with minimal experience to create customised furniture pieces.   All it takes to make a real piece of furniture, is some print time and a couple of hours of “Lego”-style fun!  

This version  has fewer components and is even more straight forward to assemble than the BEDSIDE PRINT-TABLE NIGHTSTAND and the END TABLE versions.  They all share the same primary structure, but with individual parts mixed and matched to change the character of the final item.

I think this is close to the maximum volume that can be reliably created using this system and still result in a reasonably sturdy, usable piece of furniture.   Since most bookshelves are much slimmer than the 350mm of this one, I am confident that the system can be successfully used.  in a wide range of situations.    

For sturdy secure shelves I strongly suggest fixing each shelf to the wall with a small angle bracket that you can download separately HERE.  If you do fix the shelves there is no need to build any angle bracing.

Over the coming week I hope to publish a summary of the “kit” parts, with links to parametric versions of each component so that they can be mixed and matched to create different custom furniture pieces.  I that doesn't work for you, I am happy to provide re-dimensioned parts on request.

The shelving in the photos is custom built by me from reclaimed timber, however any standard length of shelving will suit and I have provided files for 250mm and 350mm options.

Assembled with care, the structure is quite rigid, and more than enough for use as a bookshelf - using it beyond the limits of its designed intent may not end well!   I recommend a maximum span between printed frames of around 600mm.    My filament shelves which are not yet complete are at 450mm centres.
 

BEFORE YOU START

May I recommend you print a test piece to check the fit?   Two parts of a LEG, will give you an idea - the parts are printed with zero tolerance to make them a “thump with the palm of your hand” fit, so be warned they may not come apart!

UPDATES
This document is a work in progress at the time of publishing, and will be updated over the coming few weeks, so if you have a question, please ask and it will be addressed. (On completion of final checks this note will be deleted!)
28 April - Added BOTTOM-BRACE_125  to the Printed parts schedule.

DIMENSIONS

Top  as built - 340 x 550 mm

Frame Size as built - 320 mm deep x 250mm  high (13 x 10  inches)  One of four.

TOOLS REQUIRED

3D Printer
Saw (if required to trim the top to size)
Drill/Screwdriver

MATERIALS REQUIRED.

Approximately 0.25 kg of PLA filament of your choice for each frame,  printed with a 0.6mm nozzle and 15% infill.

Shelving to suit.  

10 x grams or so of Cyanoacrilate (Superglue) - I've used both expensive and generic brands and have had no problems with using the cheap “hobby” tubes in this application.

Panhead Screws about 15mm to fix the Top(It's obvious but make sure they are not so long that they go through the table top).
 

25mm long M4 (5/32" will be fine) ( bolts and nuts for the BRACE fixings.)

PRINT SETTINGS 
I’ve printed with a 0.6 nozzle 3.0mm QUALITY mode in Prusa Slicer but if you only have a 0.4mm nozzle 3.0mm DRAFT mode worked well in my test pieces.
 

More infill might add to the rigidity of the structure - I've been happy with the 0.6mm nozzle wall thickness - with the standard number of top and bottom layers.  In use if you remember it's not a ladder or a car engine storage rack, I'm sure it will serve you well.

PRINTED PARTS

The HUBS, POSTS and Rails are made of two identical halves which snap together and are held permanently with a little SuperGlue.

For each frame (minimum two per shelf - for shelves wider than about 600mm (two feet) consider an intermediate. 

POST_250 - 2 required (to make the front and back face of the frame)

INNER_POST_250 - 2required - (joins with the brace beams to provide a rigid structure)

BRACE_BEAM - 2 required (top and bottom - screw to shelf - keep angled flange on the inside)
NOTE 3 lengths of BRACE_BEAM are provided for three different shelf widths - choose one to best suit your shelf.

POST_75 (LEG) - print 8 to make four legs.   If intermediate frames are used, print an extra pair of legs for each.

LEG MOUNTING CLIP- 1 per leg - allows the leg to be screw-fixed under shelf.

FOOT - one per leg (optional - might be nice printed in TPU)

DIAG_BRACE_L /DIAG_BRACE_R - one pair per bay - not required if shelving fixed to wall with angle bracket.

BRACE MOUNTING CLEAT - one per brace.

ASSEMBLY
Now that you have your bench loaded up with a zillion parts, it's time to make a bookshelf!

These parts are designed with minimal tolerances mostly 0.0mm, depending on your printer they will push firmly into place, or may require some very slight processing with a sharp blade to remove any  little printing artefacts. An emery board or light sandpaper will help if you are really stuck.  

My parts at worst need a gentle bump with the palm of my hand to fit - if you need more than that stop and work out what's wrong.   (Maybe a tap with a tiny hammer probably won't hurt if you are SURE everything is in place and really need to use a bit of persuasion - but try to avoid that.)

Use a small amount of CA glue (Super Glue) on each mating surface.   I prefer not to use any accelerator to allow a little working time if necessary.

Hold or clamp the parts for a few minutes until the glue sets to ensure a nice tight connection, you don't need anything fancy here, but if you have spring clamps or rubber bands it will save a bit of “holding” time.
 

All of the posts and legs comprise two identical pieces - a drop of glue on each INNER face of the mounting sockets is all that's required.

Once you have all of the parts joined, lay them out on a bench so you can easily keep track of where you are in the process - make sure that the BRACES are fitted with the mounting flanges on top and bottom faces and so that top and bottoms face the same way.  They should sit square, but it pays to keep an eye on things before the glue sets.

I always label each part to help keep track of the correct orientation.  

Don't sweat if you have small discrepancies, the lines of the finished piece are broken up to make them disappear as if by magic.  When it's completed you'll have a nice shadow recess at each joint which makes the assembly process very forgiving. 

To fit the braces in place you'll need some 25 mm or so long bolts.  Run the bolt through the BRACE CLEAT (like a tee nut) and insert it vertically between the post uprights. (Just as you would a bolt in an aluminium section)  When it is in the ‘cavity’ you can turn it through 90° and using a screwdriver to apply pressure, hold it in place.   Fit a nut into the BRACE end, and tighten.  It's a lot harder to describe than to do.     Use a screw to fix the other end directly to the timber shelf.

Don't tighten the braces just yet, and when you do don't overtighten them - they need surprisingly little tension on the bolts to do their job.

You can choose whether to mount the braces on the inside or outside of the frames - or if you use shelf brackets not at all.

Don't glue the CLEAT (tee nut) in place as you will be able to apply a little tension on the CROSSBRACE if necessary to square the frames, by sliding it along the track in the post. 

NOTE - The flanges on the BRACE_BEAMS face the INSIDE of the shelf. Check the photos below for how the top mounts to them. 
 

Fixing is simple: lie the board on a bench and screw through some or all of the mounting holes in the top flanges.   Drill pilot holes all the way through the centre shelf to ensure the frames are located exactly above one another .

The easiest way to ensure the entire structure is square and that there is no twist in it is to lie it face down on a flat surface (a bench or floor).  Make sure bolts on all the braces are loose.
When you are satisfied that everything is in the right place - tighten the bolts!    DO NOT OVERTIGHTEN - the braces will work well with moderate bolt tension - too much and there is a risk of snapping the fitting.  (Yes, the picture below is a longer unit than the one that features elsewhere!  We are really enjoying having these in our house!)

If you have got this far, I hope all has gone well and you have a piece of furniture of which you can be justly proud.   I am certainly very happy with mine and it's mate which I use for filament storage. 

There is a lot of documentation here, and I'd really appreciate any feedback on anything that's not clear or in need of correction.