Benchy coin + addons

Here is a commemmoration maker coin for good ol' 3D Benchy, as coins are also a staple of the maker culture (although maybe are losing popularity) and I couldn't find a single one on Printables (maybe now there's more than one…).

OVERVIEW

This set includes the Benchy 10-years coin, plus some add-ons.

The coin has several parts (which are available separately for multicolor printing, instead of z-based color change). These are:

•  An outer rim, 2mm thick and 3mm tall (tallest part of the coin), with small texts engraved.
• An inner rim, 5mm thick and 2.7mm tall.
• A set of 10 stars (for Benchy's 10th anniversary) on top of the inner rim. These are 0.3mm tall, so they reach the same height as the outer rim.
• An inner round frame, 1.1mm tall. This holds the Benchy and face texts.
• A set of 2 face texts, reading "2025" on top left and "Benchy" on bottom right, which are thick enough for 2 nice extrusions with a 0.4mm nozzle.
• The Benchy itself, which is 1.6mm tall, fitting in a box of 31mm (W) x 28mm (D).
• A set of texts engraved in the "reverse" of the coin (printing baseplate side), 0.3mm tall, spreading along the outer rim, inner rim and frame.
• In the reverse of the coin, there is also an outline of Benchy's side view, 0.5mm wide and 0.3mm tall.

The add-ons are:

• A set of modifiers to use in the slicer
• The coin in multi-part for multi-part, multi-color printing
• A holder that fits in Benchy's cargo box
• A set of coaster tops to use the coin as a coaster
• A holder for up to 6 coasters.

Very much like Benchy, it has a lot of details and small measured features, which also homage Benchy's sizes:

• Coin is 60mm in diameter, which is Benchy's length.
• The maximum width of the relief Benchy figure is 31mm, same as Benchy's maximum width.
• The rims (outer and inner —or not-so-outer) are 7mm total, which is the same as Benchy's chimney outer diameter.
• Stars measure 3mm from one point to its diametrally opposite (as Benchy's chimney hole diameter). 
• Bridged texts and base features are 0.3mm in height, like Benchy's base text.
• The sides of the coin have six texts which are 0.1mm deep, just like Benchy's plaque text.

PRINTING

To make the most of the coin, you may fine-tune your slicer preparation. After all, Benchy is the "jolly 3D printing torture test", so this allows for some printer torturing. To help you with that, there is a set of modifiers included —as now slicer modifiers are much more feature rich that when Benchy was launched, and they help you add specific tortures or effects. (Notice, for instance, how the Benchy outline in the back of the coin has been printed with concentric infill in the pictures, while the rest of the coin has a monotonic bottom layer infill.)

First of all, for spot-on dimensional accuracy, you need to pay attention to the "Benchy hull line" and the 0.3 heights. The inner frame where Benchy rests is at 1.1mm height. You'll notice this is an odd number —and it's deliberate, to add a bit of trouble at Benchy's hull line, much like happens with the original Benchy. The baseplate texts are 0.3mm tall —so setting everything at 0.15 won't do. You may set your first layer at 0.15, then 0.05, but that will take too long.

Next to pay attention is Benchy herself. (Ships and boats use pronouns "she/her", AFAIK.) It's a highly detailed shape, so the lower layer height the better. And with low layer heights and not-too-big a shape, you can expect quite a lot of stringing —so time to fine-tune retraction settings, and get your wire brush ready. Those of you who do HueForges will know what am I talking about (and BTW, yes, this coin is perfectly HueForge-able; just set the minimum height at 1.1).

I think that the best combination is to mix 0.15 and 0.1 layer heights, using a height range modifier. This will set printing time at about 1 hour, if you use ironing (some 45-ish without) on a Prusa Mini with IS. You may go lower than that layer height with the height range modifiers, but you may need to adjust the slicer settings for your extruder and set the minimum layer height limit at 0.05.

Printing example

Here goes a list of things you can do in your slicer to get a nice result (as I printed the example coin):

• Add a height range modifier with two values: 0.15 layer height from 0 to 0.9, and 0.05 layer height from 1.1 to 2.7. (You may need to modify the values for the extruder layer height range, to allow for a 0.05 layer height; in PrusaSlicer, this is at Printers->Extruder 1.) This will give you a good definition for the Benchy relief, with faster layer for other less detailed parts.
• Set ironing for topmost surface only. This will iron the stars and outer rim.
• Add the Inner rim modifier, and set it to ironing all top layers.
• Add the Back outline modifier, and set it to concentric infill.
• Add the Benchy relief modifier, and set it to 100% infill density. You can play with the fill pattern, too.
• Add the Benchy effigy base modifier, and set it to 100% infill. This will give the Benchy relief a nice solid base. You can also play with the fill pattern and number of solid bottom/top layers.
• Add the Inner frame modifier. Set it to 0 top layers, gyroid infill, in a density and angle that you like for the "waves" that Benchy rides. This could give some trouble on texts, so we'll fix that with modifiers too.
• Add the Face texts modifier and set its infill to 100%. This will give a good base for the texts.

Part-based multicolor printing

I've included the parts to make a multipart object for multicolor printing. Those shouldn't give much trouble, but the Benchy relief part has proven to be quirky. 

All the parts have a non-printable, centering, zeroing fillet to help position them. In PrusaSlicer, you'll usually need only to load them whole as a multipart object, and make sure that every part (especially the Benchy part) are "dropped to bed", using the button at the right of the Z coordinate box (if there is no button, it's already zeroed). In BambuStudio, it seems to work if you load them all as parts, and set the world coordinate of the Benchy relief part at Z=-0.15.

Anyway, just check the print preview before sending it to your machine.

Infill coasters

You can use the solid coaster and its modifier (in the Add-ons folder) to make infill coasters. Just load into your slicer the solid coaster, add the modifier to it, set the top and bottom layers to 0, and adjust the infill type and density as you like.