I am trying to print double sized “challenge coins”. I printed side one, without cutting the coins, but instead made two cut guide holes off the the left and right. I then flipped my material and in the GF app, I aligned the other side with the camera and the cut holes. When it printed it was not in alignment. I ran a focus on each side, to minimize issues.
How do you print on both sides and ensure proper alignment?
If I can’t, my thoughts are to make sure that the first side doesn’t need to be as precise as the second and could absorb a slight shifting and still be usable.
I have found the easiest way is to make the design with both sides and the cut circle all on top of each other, like with the same center. Then print and cut one side with the second side set to “Ignore” and you have an instant jig. Just flip the coins over and put them in the same holes and print side 2 with side 1 and cut on “Ignore”. The only trouble you can have that way is if the material is thicker, the shape of the laser may make them where they don’t fit in the holes upside down. But I have always managed to make it work. But I only use “medium” proofgrade, or 1/8".
There is a post that shows you the best way to do this.
Ahh, here we go:
It’s very similar to what @tjones said except for the addition of a surrounding shape to keep everything rotationally aligned. If you use just the simple circle and flip it inside its hole it’ll work but you may inadvertently rotate the coin. This may or may not be a problem, up to you.
There are ways to do this with batches of multiple coins so that you only need to flip it once, basically you make a grid of coins inside your surround shape and then flip the whole set once, cutting the circular coins as the last step.
I use almost the exact same method, but i add a square outside of my coin.
I stack all the artwork (different colors to separate steps). I’ll set one to engrave and the square to cut, ignoring all the rest. I usually pin down my material too because I’m terrible with moving things gently. After i engrave and then cut the square, i flip the material in the square.
I then ignore the first engrave and the square cut, turn on everything else, including my circle cut for the coin, and then let it do its thing. This way i can ensure that my artwork is in the correct orientation each time and not misplaced in some weird angle because i dropped my circle in with the art sideways without realizing it.
Thanks for the clarification and guidance… I had both sides of my image overlayed and I was toggling on ignore and engrave/cut, but I was flipping my entire piece of board, instead of just the cut out coin, so then I was having to try and align it without seeing the coin cut out. Flipping just the cut coin and leaving the base material in place is a lot better!
If I am doing a one-off and rotation matters (i.e. I want the “top” of each side to align) I will cut an enclosing shape on the first pass, then flip and cut the circle after the 2nd engrave.
Variations on that for shapes that are irregular.
If I am doing a batch, I will put them all within a single enclosing shape that surrounds them all, flip that, and cut them individually after the 2nd-side engrave.
