Wednesday, January 31, 2018

28: Vector Mayhem

Having recently finished the prototype version of all of Space Frontier's Components, I have been able to broaden my prototype creation. No longer do I plan to to go to the printers and then manually cut each game out by hand with a hobby knife. Using the services of The Game Crafter (www.thegamecrafter.com) I am able to print-to-order as many Space Frontier prototypes as I want. I've already used their site for some card printing as well as physical components, but never had a complete prototype ordered from them. I plan to make my first complete order in less than a week.

Part of the reason I've held off this long though is their printing templates are all very specific, so it would require me to make a lot of small custom tweaks to all the pieces to make them fit into their molds. I didn't want to do this until I had all the pieces in a relatively finished state and a complete list of them. Now that the prototype's completion is out of the way, I started editing and uploading all of my components to their site for printing, but there was one problem.

The Game Crafter does not offer a .75 inch x 1.5 inch rectangle shard piece, so printing Cruiser and Harvester tokens for cheap isn't possible. Now what The Game Crafter does offer is a "custom punchout" board that allows you to make any piece shape you want, but it is much more complicated than a regular printed piece of cardstock. For starters, Space Frontier was created primarily on Photoshop and the Custom Punchout requires a vector file.

I downloaded Inkscape (https://inkscape.org/en/) and had some issues learning that program but quickly got everything up and running. I soon had something that looked like this and (thought) I was ready to have it uploaded and made.



Continued after the break:



I thought, foolishly, in my extreme ignorance, that it would be easy. Turns out that in order to tell the laser that cuts the custom Punchout what to cut you need to create a cut line file. However, if you just cut all the pieces out completely they will fall into the machinery, you need a lot of "nicks." A nick is the small piece of cardboard that doesn't get cut in order to keep a punchout in a sheet. So I had 20 pieces with 4 sides a piece, each of them requiring at least 3 nicks. I'll save you the mathematical headache and just let you know that meant 94 individual cuts for my ships. I input all those into Inkscape and was left with this confusing monstrosity.



That's a lot of arrows... And the arrows are wrong. This simply isn't enough to get my punchout finished, not really anyway. The problem is the laser starts cutting a punchout on the top left and follows arrows. However you can quickly see that the arrows eventually lead back upon themselves, which will cause the laser to go to a random location and start cutting again as soon as it can. This leads to huge inefficiencies and The Game Crafter charges a fee based on how far the laser moves, so efficiency and cost are directly linked.

After some fiddling around with Inkscape I figured out how to change the direction of the vector cutting lines, but I still needed to figure out how to get the most efficient cut pattern to lower my cost to the minimum amount. My girlfriend, who is attractive, intelligent, and holds a computer science degree, was a huge help here. With her aid I was able to change the arrows around to make this.


Now at first glance the second vector arrow image is the same as the first one, but there is a key difference. Every cut line of a subsequent vertical or horizontal direction is the opposite of the one preceding it. This way, the laser never gets stuck or wastes movement to retreat to already sliced areas. This alone was not enough however, as I still had to program all 94 cuts for the laser individually, and in the correct order. This took a bit more math and optimization and my girlfriend once again came to the rescue and came up with this diagram.



The way this diagram reads is that the start of the laser is the top left corner. It goes to the right in a straight line all the way across. Once it turns to start going down, it skips the first cut going down and begins cutting left all the way across. It repeats this cutting across right and then left along all the horizontal lines until it reaches the bottom left corner. The laser then goes vertically all the way up and cuts only along the vertical lines, alternating between up and down, ending at the bottom right.

The paper diagram doesn't account for all the of nick cuts, so those had to still be considered. Every single cut had to be placed, 1 at a time, on a separate layer, in order. Making all 94 layers was quite time consuming, but it meant that I was able to cut my costs for this set of ships by more than half.
Optimizing my vector laser cut instructions reduced the cost from $8 to only around $2.50 per sheet, and so was absolutely worth the headache.

If you're ever going to have a board game component cut by a laser, make sure that you understand where the laser begins cutting, how it receives instructions, and the best ways to optimize your components. It could end up saving you a lot of money on prototyping or production.

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