BIG LETTERS alphabet

We wanted our pre-school children to get in touch with letters in a casual way. These big letters are used as decorations in their rooms, but they also play with them. E.g. the O makes for a good hat.

Letter size is optimized for a 21 x 25 cm print plate. While the smaller letters have some space left, the letter W consumes all of it (see discussion of brim, below). The default orientation of the letter models is “face down”, as this gives a nicer front surface. 

I consider following printing parameters to be optimal for PLA:

• 0.45 mm layer height for 0.6 mm nozzle
• 0.3 mm layer height for 0.4 mm nozzle
• 2 vertical perimeters
• 3 top and 4 bottom perimeters
• Adaptive cubic infill, 10%
• Brim > 5 mm
• Skirt off (Skirt loops = 0)

If you use the letters for decoration only (no kids will be playing with them), you could go with a 5% lightning infill and less perimeters.

A brim is required to prevent the corners from lifting off from the plate. With large letters as W and M, you will not find the space for a large enough brim. If you use those letters, consider scaling down all letters slightly to make space for a brim, while having equal letter height.

Letters F and P naturally tip over! This problem is solved through counterbalancing: Both letters have a cavity that should be filled with something dense (sand, steel washers, plaster,  … ). The cavity can be closed using the Lid model and some adhesive. I'd recommend some rather viscous adhesive to get the gaps well filled, especially when using sand.

Styles: I used fuzzy skin and I think it looks great, especially on the blue-ish letters. Another set of letters was printed with fluorescent PLA from azure - They glow in the dark. This has the advantage that it makes the kids go to bed voluntarily; at least one or two times …