Does anyone have any suggestions on how to engrave symbols on blank dice? We’re working on prototyping a game that will have custom dice, and have some blank jumbo d12’s. Sadly while I’ve retained membership, I haven’t been to the 'space in forever (actually since I was helping move to the new location!)… so I’m not sure off hand what may be available. I’m wondering if the laser, or the PCB mill, or something else might be suitable (any small CNC dremel-like tools?).
According to Chessex (dice supplier) they’re urea plastic; the laser rules don’t specify anything for that, and googling shows that many folks use laser engraving with decent ventilation without issue - but I’m not sure if that would be permitted at DMS? Any other suggestions?
Depending upon the material your using you could probably use any one of the CNC machines, with the smaller ones probably working better if the laser isn’t appropriate. My choice would be the laser if the material would work with it ( I think the laser is the best tool we have for small engraving).
The major hurdle will be developing a means of fixturing the die, so that you can accurately position the engraving on each of the 12 sides. For one die, you would be talking 12 set-ups that would be needed.
It all starts with how accurate and repeatable you want the process to be. I would be concerned about plastic deforming, but for light engraving it would probably work. You also want to consider how to will be defining your origin point so that you files will CNC properly and in the same location on the die face every time (when engraving die at different times). Of course that depends upon how many your going to make and over what period of time.
If you have just a few, and you can securely hold your 3D printed fixture, you can set-up your origin once, and then just swap faces and dies.
The easiest and most accurate way to make one or two proof of concept dice would be…
stickers.
print 'em
cut 'em with the laser if you really want to, or scissors if you just want it done, and stick 'em on.
This won’t throw off the weight as much as other methods of cutting/engraving as well…
Thanks everyone for the responses so far. Hopefully someone else is a musical theater nerd and got the ‘Shipoopi’ reference in my silly song above
Re: stickers - early playtesting has been occurring with Sharpie’d die; this is just an attempt to get some more professional looking prototypes done (and do some more learning and making!).
So I stopped by and located the Shapeoko, though it had a sign indicating training was required. I asked a few folks around and no one knew how to go about training / who to contact. Any ideas? I’m familiar with the dangers and considerations for bit choice / feed rate / pass depth, etc, I’ve made note of the spindle specs, and would be reviewing my gcode and monitoring the runs carefully - but I’d be happy to get formal training or any other tips/advice from fellow makers.
Also, I think I’ve got a decent design in mind for workholding fixtures - that was certainly part of the plan from the beginning, but I wanted to determine what I’d be using for the engraving first. The laser would be nice since the workholding fixtures could be much simpler, but I’m concerned about fumes from the dice material (turns out ‘urea plastic’ is also known as ‘urea formaldehyde plastic’ - that ‘f’ word doesn’t seem friendly!). So while I’ll need sturdier fixtures for the Shapeoko route, I’m fine giving that a shot first.
Sadly I think I’m stuck waiting on training (or assistance from trained members) for either route though - now that I’ve discovered the Shapeoko requires training. I was certified on the laser cutter in the old 'space, but I know during the move discussions we planned to require re-certification for everyone. Advice appreciated!
I think the laser is your best bet, if the material your using works for that machine.
[statistician hat]
Take care not to make the marks deep, and try to have about the same amount of marking on each face. Even what would seem like relatively minor differences can yield a statistically significant change from the idea of uniform randomness for each face of the die.
One thing I would do, regardless, is perform a chi-square test on the prototypes to obtain some comfort that the are uniformly random. You only need to record 15-20 rolls for each side of the die. So a standard 6 sided die needs 90-120 rolls to get a reasonable confidence that the test is accurate.
[/statistician hat]
Back to normal. For getting the shapeoko training, I would suggest creating a new thread with that title to attract the attention of whomever might know about it!
Maki (@makirules) used to ‘engrave’ dice on the laser at the old 'Space… With air assist, the dice do need to be ‘contained’; but, it was just a matter of cutting out a strip of acrylic, then cutting square holes to hold the dice in place (that was the first round anyway… he may have improved the process…). Maybe he’ll be able to post some examples and/or insight for ya…
Thanks @wandrson - I did split out a separate thread for more specific Shapeoko attention, good suggestion. And I’ll do my best to consider balance in the design, although I’d think it’s not just the amount of material removed from each face, but also where that material is removed from (the ‘center of less mass’? heh), that influences things. I had been planning to do some testing of randomness at the end (thanks for the formal chi-square terminology!) - the fun will be in trying to fix any anomalies.
And thanks to all the laser recommendations, as well as the great info from @LisaSelk and @makirules I now have another thread on training there. I’m cutting myself off from thread-spawning for a bit now
