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3D Printing Royal Game of Ur – A Great Last Minute Christmas Game

Posted on December 22, 2017  in 3D Printing, Tabletop Gaming

This post is mostly for gamers with a few technical and practical techniques. You’ll need to know your way around a 3D printer and how to mix epoxy glue as well as how to sand and similar skills.

Please note that when printing the demo for this post I discovered my printer had a loose pulley but I didn’t have time to fix it and start the print again so please excuse the wobbly print. It’s not the design it was my printer, it applies to the photos of the bronze-gold coloured board.

Back in May I watched a British Museum YouTube video about a game called the ‘Royal Game of Ur’, an ancient counter-based board game that predates even backgammon. I was instantly hooked by the idea of printing a copy. My mum absolutely loves backgammon and I thought she might get a kick out of playing something similar. I had a quick look on Thingiverse but while I found one, I didn’t like how long it would take to print. It was square-edged and designed to print long edge down which requires a lot of infill, resulting in a very long print. There was a thinner version designed for faster printing but I found that didn’t come out very well and I really wanted a full-sized game with a drawer to contain the counters and pieces. I could have printed the existing design, rotated onto its short end but I wanted one with rounded edges to make it my own. The design I’d found had a non-commercial clause on the license so I decided to go in from scratch and create a 100% new design in Blender.

Using references which I found online for the layout of the board tiles, I set about working on my design. Once it was finished I gave the edges a very large, smooth bevel. I knew this would cause issues with printing due to it having an overhang which was more than 45 degrees so I created some custom supports. For this project I thought I could generate better quality supports that would be easier to remove than auto-generated ones because of the simple nature of the shape.

Finally, I wanted to add some cut-outs to glue rubber pads to the bottom of the board to avoid any possibility of scratching tables because the rougher layer lines would be against the table and any movement might eventually cause small scratches. Because of the vertical nature of the design, I made sure that the tiles and pad cut-outs are as thin as possible so as to require no supports, whilst also giving enough definition.

If you have a 3D printer you can make a great present for someone who loves games like backgammon even with just under a week left until Christmas. Grab your filament (preferably 3-4 different colours) and get to printing!

Thee are three (and a bit) different designs. I’d recommend printing either version 1 or 2, though if you’re up for a challenge versions 2.5 or 3 are there for you if you like the look of them.

Version 1

Version 1 – interlocking board parts

It’s quick to print and ready to play pretty much straight off the printer. It has a drawer for the parts but depending on your print settings, calibration and tolerances you may find this a little snug, requiring a little sanding of the cavity (and maybe the drawer too) to get a smooth fit. The latch that holds the drawer in place eventually wears off though honestly this isn’t too much of an issue most of the time, just don’t leave it face down in your bag.

For reference from now on I will refer to the board part on the left of the above photo the square board and the one on the right the tee board. I know these aren’t 100% accurate descriptions but they’re close enough.

Version 2

Version 2 – inset magnets

The second design is for the more adventurous. It requires a few extra parts and more finishing time. The two board parts and the drawer, all, have cut-outs for small magnets. These need gluing in place and the cut-outs will likely need to be cleaned up a little. The magnets in my original design had a 10mm diameter and were 1mm thick, with a pull of 0.58kg. They weren’t VERY strong. They hold the drawer and board in place, even face down but if you shake the board, the drawer will usually fall out. The two board pieces will be held in place for a play session but can’t really be moved in-place like the first design. As a result, I’ve redesigned the cut-outs to take thicker magnets with a stronger pull. I’ve also made the cut-outs open faced insets rather than slots in the under side of the board.

The slot version is still available but I don’t really recommend you print it unless you want a “magic”/invisible magnetic effect as the clean-up is a little fiddly and the magnet covers are harder to attach. We’ll call this style version 2.5.

Version 2.5 with original side-by-side magic magnet slots

Version 3

Version 3 – no drawer

The final design does away with the drawer, replacing it with a cover that is once again held in by magnets. This is a fancy design but I realised that I actually prefer playing with the drawer as it makes tidying up easier, just put your winning pawns straight back in the drawer and you can just slide it back in at the end of the game. As such I’ve mostly abandoned the design. You can print it if you like the look of the design but I wouldn’t really recommend it as I haven’t tested it properly. One major advantage however is that it can be printed on a single 170 x 170 x 130mm printer bed and takes just under 8 hours at 60mm/s.

In the original design that used magnets I had designed it to use two 10x3mm disc magnets next to each other in all the parts, the thinking being that you’d get a bit more pull and the magnets would have more chance of getting lined up when attaching parts, however I found that this made it quite hard to glue them in place as they kept trying to repel each other out of the slots. You can see this design in the Version 2.5 picture So with this in mind I’ve modified the slots for the two board parts to take thicker 10mm magnets which should result in a stronger pull of all the parts.

Print Settings and Stuff

I recommend printing both parts of the board together if your printer has a large enough build volume. This saves a little time over printing them separately as it reduces set up time but the true benefit is that it allows you to print faster, saving time, and still end up with a high quality print. The single tile-width part of the T shaped board part tends to buckle if printed by itself as the layers don’t have time to cool properly.

Buckled due to insufficient cooling

You can counteract this by lowering your head temperature a few layers before you get there or printing slower but honestly, printing both parts together works much better as it significantly increases the individual layer time thus almost guaranteeing that the layers will have cooled sufficiently by the time the next layer starts.

Recommended Resolution: 0.3mm.

Walls: 2-4 (I usually do 2 but 4 might give you a cleaner drawer cavity.

Top/Bottom Layers: 3-4 (I usually use 3)

Speed: 40-60mm/s – It should print fine at 60 but if you want a more consistent quality you might want to try a lower speed. Print the dice quite slow to keep the first layer stuck to the bed.

Brim: Not necessary but you may have trouble getting the dice to stick without one

Infill: 10% for the boards and drawers 15-25% for the counters, 100% for the dice to give an even weight and add some heft to them.

Supports

Square and Tee Board Parts

I’d recommend turning build-plate-only supports on in your slicing software for versions 1 and 2. This adds almost no print time but just makes sure that the build-plate facing cut-outs are clean and don’t collapse.

You may find it useful to turn on supports everywhere if printing versions 2.5 or 3 as the slots can collapse a little bit without them but it’s not strictly necessary.

Dice and Counters

There’s no need for supports on these items

Drawer

Regarding the drawer itself you can enable supports for the handle overhang, however it’s not strictly necessary.

You may not need supports for the drawer handle.

Colours

I recommend printing the counters in either white and black or some garish colours like fluorescent green and orange. The board looks amazing in chocolate brown or dark grey and if you want to go even more garish why not try the drawer in some other colour that complements the board colour.

The board in chocolate brown (looks nicer without flash)

Great colour combination

Post Processing

Clean up

If you’ve printed well all that should be needed is to use a small, flat screw driver or pliers to pry away the custom supports (and magnet supports), a little medium-grit sand paper can be used to remove any left over support sprue and can be useful for loosening the fit of the drawer cavity. If you really want you can try to go for a glass finish. This will take a lot of time and require pretty much every grit of sandpaper there is. You can see how to do this in the references at the bottom of this post though I think the print looks fine as it comes straight off the printer.

First layer supports

Clean removal of custom supports, gently pulled off by hand.

Little bit of clean up needed.

One more thing you will need to do is to remove the rabbit ears that are built into the drawer files. These help to keep the drawer from warping on the bed. They’re relatively easy to remove, at 0.3mm resolution they should only be a single layer thick, just use a pair of scissors or a sharp knife to cut around the edge of the drawer, this will get rid of the bulk of the ears, you then just need to sand, file or use a deburring tool to remove the rest.

Magnets

Clean up the magnet inset/slot then insert the magnets a little way, try not to push them in all the way (if printing version 2.5-3). You just want to check the polarity, the magnets in the drawer and square should attract and the magnets in the square and tee boards should attract. Once you’ve got this sorted, you’ll need to glue them in place. You can either rough up the surfaces of the magnets with some sandpaper or a file then use some Loctite Precision super glue or try your hand with some 2-part epoxy glue. The epoxy may work better as the magnets don’t stick that well with regular super glue and filing the surfaces can sometimes snap them as they’re quite brittle.

Unglued magnet testing fit and orientation

Add the pads

If you have some 10-12mm rubber pads, stick them to the bottom of the board parts.

Add the Magnet Covers

Hopefully you’ve made sure all your magnets are aligned correctly, now take the magnet covers you printed and apply a small amount of super glue (or expoxy) to the cover and press it into their designated slots. You may find it helpful to use some needle nose pliers to keep your fingers free of glue.

For the inset design (version 2) you want to have two circular covers, these should be placed on top of the tee board and under the square board. If possible try to align them so that the infill pattern matches the infill pattern on the board for a more seamless transition. The magnet covers for versions 1-2 are supplied in their own file. You may find it better to print them at a higher resolution like 0.1mm.

For the magnet slot in the drawer (versions 1-2.5) and on the slotted boards (versions 2.5-3) take the small printed magnet cover sticks and try to fit them in the slot groove. You will see that there is a small lip on which the cover can rest. You may need to trim/sand it a little depending on your tolerances. Once you’re happy that it fits, add a small dab of super glue to the lip of the slot and gently hold the cover in place. If you find you can’t remove the magnet cover but haven’t glued it, just gently add a little dab that fills the gap between the slot and cover.

Test the cover fits in the slot groove. You can see this one doesn’t fit as it’s from a different design.

For version 3 the magnet covers are supplied as part of the cavity cover file (the green item in the picture below), the two longest covers are for the slots in the square board (red in the below image). The middle length covers are for the magnets in the cover (green in the below picture). The final two covers (shortest) are for covering the magnets in the slots underneath the two board pieces.

The longest magnet covers cover the red section

Finishing the Dice

One last thing to do is to accent the pips on the dice. Each die has 2 pips denoted by a slight dent or cut-out. These can be a little unclear at a quick glance. If you have printed them in a light coloured filament you can try marking the dents with a sharpie marker. Otherwise you could use some acrylic paint to paint the pips in.

The dice pips, which I filled in with a Sharpie

Everything should now be done!

Upgrades

If you feel like you want to add your own touch to the finish of the game why not paint the tiles or add some glow in the dark powder to the rosette tiles. The rosettes are the ones that look a little like flowers.

The rosette tile design.

There is one special rosette and four regular rosettes. I’d add some green/blue powder to the regular rosettes and maybe some orange or purple to the special rosette.

Print Time

On my Kossel Mini printer I can get it to print at around 66mm/s, at this speed the whole project takes about 10 hours, though I suspect the drawer cavity would be a little less tight if printed at a slower speed.

Board Parts: 7-8 hours

Dice: 40 min-1 hour

Counters 40 min (per player)

These times assume you have a well calibrated printer and can print each part first time.

Files Needed

You only need to print 14 counters in total, I’d recommend printing 7 of the traditional counters (counter-fingerGrip or counterStandard) in 2 colours OR printing 7 star counters and 7 moon counters.

The star and moon counters are my own interpretation of the counters to make it easier to distinguish between players and make it easier to pick the pieces up, however they may be a bit trickier to print.

Version File Copies Approx Print Time (at 60mm/s) Additional Parts
All Versions D4.stl

counter-fingerGrip.stl

counterStandard.stl

StarCounter.stl

MoonCounter.stl

4

7 (x2)

7

7

45 min

45 min

25 min

25 min

N/A

N/A

N/A

N/A

V.1 (interlocking) SquareBoard.stl

TeeBoard.stl

drawer.stl

1

1

1

4 hours

3 hours

2 hours

1x 10 x 2mm magnet, rubber pads

1x 10 x 2mm magnet, rubber pads

1x 10 x 2mm magnet

V.2 (inset magnets) SquareBoardInset.stl

TeeBoardInset.stl

drawerInset.stl

magnetCovers-inset

1

1

1

1

4 hours

3 hours

2 hours

10 min

1x 10 x 2mm magnet, rubber pads

1x 10 x 2mm magnet, rubber pads

1x 10 x 2mm magnet

N/A

V.2.5 (slot magnets) SquareBoardSlot.stl

TeeBoardSlot.stl

DrawerSlot.stl

1

1

1

4 hours

3 hours

2 hours

1x 10 x 2mm magnet, rubber pads

1x 10 x 2mm magnet, rubber pads

1x 10 x 2mm magnet

V.3 (no drawer) squareBoard-NoDrawer.stl

teeBoard-NoDrawer.stl

SquareBoardCover-noDrawer.stl

1

1

1

4 hours

3 hours

30 min

4x 10 x 2mm magnet, rubber pads

2x 10 x 2mm magnet, rubber pads

2x 10 x 2mm magnet

Downloads

You can download the STL files required for this project on Bitbucket.

Version 1

Version 2

Version 2.5

Version 3

Pieces (Dice and Counters)

Parts Needed

All affiliate links below are provided for convenience and are not recommendations or guarantees that the items will work for you in this project.

All Versions

3D printer, duh – 100 x 100 x 130mm minimum print volume

PLA Filament x 3-4 colours

Colour 1 – both board parts (and either the drawer or cavity cover)

Colour 2 – player 1 counters

Colour 3 – player 2 counters

Colour 4 – D4 dice – I’d recommend a light coloured filament to make adding the pips easier.

Two Part Epoxy Glue

You could probably get away with some super glue but while I’ve had good results gluing PLA to PLA I have my doubts about the longevity of its hold on the magnets.

Super Glue Precision

This is useful for gluing the magnet covers to the boards and drawer (PLA to PLA), the epoxy is probably a bit of overkill for this and harder to work with.

Rubber Bumper Pads

Not strictly necessary but good if you want to take advantage of the foot pad indents.

Sandpaper

Needle nose pliers

Side cutters – Can be useful for cleaning up prints

Safety Goggles – keeps your eyes safe from filings and any errant glue

Vinyl Gloves – keeps your skin safe from the epoxy

Respirator – If you really want to keep yourself safe use these to keep harmful fumes and filing dust out of your lungs

Magnet Versions Only (Versions 2-3)

Use whichever of the two sizes you can get, just try to make sure they have about a 2kg or more pull.

10mm diameter disc magnets 3mm thickness

10mm diameter disc magnets 2mm thickness

OK so this was a bit of a mammoth post but I wanted it all in one place for people to speedily get printing in time for Christmas. I’ll do a follow up post on how to play Royal Game of Ur shortly and if it proves popular, I will try to do a post on how to add glow in the dark powder to the board. I hope you find this project interesing. Please let me know if there are any issues.

Oh! one last thing, here’s the YouTube video that inspired all of this in case you haven’t already rushed off to find it.

References

The British Museum video on the Royal Game of Ur

How to Smooth PLA to a Mirror Finish

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