Mechanical iris lock box for ring

This is a mechanical iris lock box that I made on my Shapeoko for my fiancee’s ring (Yes, turns out you can use your cnc to get engaged). It consists of two gears, key and lock, LEDs with hidden switch and batteries to illuminate ring when opened, solid walnut box, 22 walnut inlays and of course the iris mechanism. Each joint uses 3mm ID micro bearings so the operation is very smooth.

Raw Materials:
Walnut - home depot
Aluminum (6061) - amazon/ebay

Purchased Products:
M3 bolts
3mm micro bearings
Electrical switch and battery pack

1/4" 2 flute
1/8" TiAlN 2 flute square (primary aluminum cutter 2.5 on Dewalt, .25 mm DOC, .75 mm stepover, 1000 mm/min)
1/8" TiAlN 2 flute ball
1/16" 1 flute (just for marking holes to drill)
30 degree engraver

[The EV-Guide vacuum nozzle did a great job of keeping the aluminum chips out of the tight corners when machining the gears (see below).]

CAD and CAM:

Fusion 360 - Gears generated using Fusions built in application, set backlash to 0.2 mm. I found the best finish on the teeth was achieved by leaving .05 to .1 mm radial stock for a full depth finish pass. The mechanism was also animated in Fusion.


Very Nice Build!


Just WOW… thea most creative and cool ring box I’ve seen in here.
Great looking work!

Crikey, that is cool! Well impressed

Walnut at home depot?? Must be nice lol

Love the work though man, awesome build!

Wow, that’s some impressive work. Good job and congrats!

Damn! I’d marry you if you asked with that! Nice work.


WOW, that should win any contest. Very creative and inspireringly (?SP) displayed.

Thanks for the kind words! @ApolloCrowe @jimidi @grumpa @twforeman @howellusn @Luke

@trichardson hahahaha

Very Impressive. Congrats on a project well done. You should win a prize. You were able to get walnut at your Home Depot? Lucky you.

That is just simply incredible! Very inspirational. What about the key and lock mechanism, did you make that also?

@DJ_Valenski Thank you! Yes, I made the key and lock mechanism. On the backside of the small gear there is a receptacle for a spring loaded ball bearing. The key is made to compress the spring and ball allowing the gear to turn. Very simple, but it works fine.

@drichard Yes, the home depot by me stocks walnut boards. Not necessarily cheap, but convenient!

Incredible work! I’d love to see a walk through on this design/build, starting with fusion. I love that you made it mostly with the Shapeoko at home. This simply wouldn’t have been possibly even 10 years ago without a massive investment of $$$. Thanks for sharing.

Pretty awesome :relaxed:

That is amazing! How long did this take ?!

@J20jeepster It took me about 2.5 months from start of CAD to finished product working a couple of days after work and on weekends.

@wiremonkey Thanks! Is there anything in particular you are interested in seeing? I thought about doing a walk through, but I was in a hurry and didn’t take as many pictures as I would have liked during the process.

I’m interested in the whole process: fusion 360 file-cam-export to g-code. How you chose the type of aluminum, what parts were made via CNC vs by hand, your trials and tribulations, how you installed the light inside, is the lock/key mechanism your creation or did you buy it? Ha! Just very curious overall as it’s the type of project I hope to achieve once I get a CNC router. If there are mistakes you made along the way, those are significant as well… Any or all of that you’re willing to take the time to share. She’s I fortunate gal!

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that rocks!! amazing build and thanks for the photos and details!

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I’ve seen similar projects on the CNC, and am always impressed. Excellent execution here, and love the attention to detail with the bearings.


Boy I’m glad I got married 25+ years ago, some of you guys are setting the bars pretty high.

Amazing work.

Is there any video of the aluminum machining?