Makera Z1 CNC: Making a 40mm Brass Maker’s Challenge Coin | Let's Make a Thing Ep. 3 - Makerables
In this episode of Let’s Make a Thing Episode #3, I’m machining a detailed two-sided 40 mm Maker’s Challenge Coin on the Makera Z1 Pro.
The front features THE OBSTACLE IS THE WAY, with a rocky passage and path continuing through the obstacle. The reverse features KEEP GOING, with an upward arrow breaking through layers of stone and debris.
Unlike a simple engraved coin, both sides are full 3D reliefs with raised lettering, rock textures, and fine details.
For this project I’m using a 40 mm diameter × 3 mm thick brass coin blank. Brass or a known machinable zinc alloy can be used, but make sure you know what material your blank is made from. Avoid steel or unknown metal alloys, as they can machine very differently and potentially damage small endmills.
Project Files
Maker’s Challenge Coin:
https://www.makerables.com/project/ma...
40 mm Coin Vise – 2-Sided CNC Milling:
https://www.makerables.com/project/40...
Coin Blanks Used:
https://a.co/d/06DAk1rx
Creating the 3D Reliefs:
I used Makerables AI Craft to create the reliefs for both sides of coin.
After generating the relief, I export the STL and combine it with the 40 mm × 3 mm coin blank model included with the project files. Using the coin blank model ensures the final STL matches the size and geometry of the physical coin being machined.
The completed STL is then imported into Makera Studio with the stock set to: 40 mm × 40 mm × 3 mm
The XY origin is set to the exact center of the workpiece, which is why accurately finding the physical center of the coin before machining is important.
Machining:
Each side uses only two machining operations:
Roughing -
Makera 3.175 mm × 12 mm Single Flute for Metal Endmill
Parallel toolpath
Finishing -
Makera Single Flute Engraving Bit for Metal — 60° × 0.1 mm
Radial/Offset toolpath
The larger endmill removes the bulk of the material first. The 0.1 mm engraving bit is then used for the detailed finishing work, allowing the smaller lettering, rock textures, pathways, debris, and other relief features to come through.
Finding the Coin Center:
I use the Makera 3D XYZ Probe to establish the exact center of the coin.
After homing the machine, installing the 3D Probe, and completing its TLO calibration, I use:
G53 G0 X-103 Y-150
With my 40 mm Coin Vise positioned on the Z1 bed as shown in the video, this moves the probe approximately over the center of the coin.
G53 uses machine coordinates, G0 commands a rapid move, and X-103 Y-150 specifies the machine-coordinate position.
From there I use the 3D Probe to establish the exact X0 Y0 at the center of the coin.
For my 3 mm coin blank, I found a 3D Probe Z value of 0.75 mm worked well. Make sure your probing Z value is less than the amount the coin protrudes above the vise so the probe cannot contact the vise.
Once the coin center and Z have been established with the 3D Probe, do not run the laser probe again before starting the machining job.
Finishing:
After machining each side, I use a wire brush or rotary tool with a wire wheel while the coin is still secured in the vise.
This lightly deburrs the edges, removes machining residue, and gives the surface a cleaner, more uniform finish.
Full Details with written instructions & Files:
https://www.makerables.com/project/ma...
------ My Makerables.com Page
https://www.makerables.com/user/G7273...
------ Free Files on my MakerWorld Page
https://makerworld.com/en/@GabrielMaker
If You Found This Helpful:
👍 Like, comment, and subscribe!
See my other CNC & 3D Printing project videos at:
/ @gabrielmakesthings
If you download and use my files, please leave a positive rating, a like, and a boost if possible.
Thanks for watching, and as always — Let’s Make a Thing.
#Makera #MakeraZ1Pro #CNC #CNCMachining #CNCProjects #Maker #Makers #ChallengeCoin #BrassCoin #CoinMaking #CoinMilling #3DRelief #ReliefCarving #Engraving #Metalworking #Machining #DesktopCNC #MakerProject #LetsMakeAThing #GabrielMakesThings
Music by Daniel William Lawrence from https://pixabay.com/music//?utm_sourc...