Spring Loaded Caliper Case

Here it is the one caliper case to rule them all!

You will need the following tools:
-FFF Printer Capable of printing an object 304mm long.
-Hack Saw or Dremel to cut steel pins
-Sanding implements for rounding edges of pins
-Soldering iron to install heat set inserts
-Resin Printer(may not be necessary if you use small nozzle or maybe a standard 0.4 would work but I used it for the gear set)

You will need the following components for the case:

-M3 x 10 Countersunk Screw qty.1
-M3 x 8 Countersunk Screw qty.1
-M3 x 6 Countersunk Screws qty.2
-M3 x 8 Socket Head Cap Screws qty.2
-Cylinder Shaped Magnets 3x3mm qty.2
-0.5 x 5 x 15mm Compression Spring qty.2
-M3 Heat Set Inserts qty.2
-3mm Steel Stock
-Rotational Damper qty.1
-Music Wire 0.031” Dia.
-Music Wire 0.041” Dia.

Torsion Spring Dimensions:

-Torsion Spring 0.041” Wire Dia. x ~3mm ID x 4 turns x ~180deg.
-Torsion Spring 0.031” Wire Dia. x ~3mm ID x 3 turns x 180deg.
You will need one left hand and one right hand torsion spring for both sets.

Steel Pin Lengths:
300mm qty.2
155 +/- 0.75mm qty.1
18.5 +/- 1mm qty.1

You will need the following components for the torsion spring winding blocks:

-M3 x 20 Socket Head Cap Screws qty.2
-M3 x 12 Countersunk Screws qty.2
-M3 Nut Qty.2

Assembly Instructions:
1. Print all the parts and add heat inserts to the end caps.
2. Install screws onto torsion spring winding blocks and wind the necessary springs. The 0.041” dia. wire is a little tough to wind by hand but it is do-able. You don’t need to keep tension the entire time, just set the spring incrementally making sure the spring is conforming to the screw with each set and push down to keep the spring winds tight. Keeping tension will result in a tighter spring but the clearance should be enough even if tension isn't maintained during the winding. Be patient and wear thick conforming gloves if you can. Music Wire is sharp and can easily cut you if you’re not careful. I left around 20mm lengths to the ends of the springs.
3. Cut the pins to length
4. Install the latch with the compression spring and M3 x 8 Countersunk screw.
5. Add one of the M3 x 8 socket head cap screw to the side closest to the front of the case and make sure that the rotational damper can move into place with the screw in place, this screw will act more as an alignment pin and you won’t be able to tighten it down once the main caliper holder is in place.
6. Install the 0.041”dia. wire torsion springs into the compartments inside the main caliper holder hinge. This may be a little tricky but you can make it easier by bending the spring, but not too much or the spring force will just barely overcome the required torque causing extremely slow movement in the hinge.
7. Install the partial gear onto the main caliper holder using the M3 x 10 Countersunk screw.
8. Slide the caliper holder body onto the spring on the gear side. There is a small pocket that the end of the torsion spring leg fits into. You will need to slide it in slightly but not all the way, only enough for the spring end to stay in the caliper holder body.
9. Slide the other side of the caliper holder body onto the other torsion spring leg. This may be tricky but once you get the ends of the springs in place all you need to do is open and close the part while pushing it in and it should slide into place.
10. Feed the 300mm rod through the hinge.
11. Install the gear of the rotational damper and slide it onto the screw that was installed in step 5. Make sure to slightly close the hinge while you lock the damper into place with the other socket head cap screw.
12. Install the 0.031”dia. wire torsion springs into the pockets for the lid.
13. Similar to step 8-9 slide one side of the lid onto one torsion spring partially then install the other side partially and then shimmy the lid while pushing it into place.
14. Add 300mm pin to the hinge.
15. Feed the 155mm lg. pin into the latch and push, the latch should fit snuggly over the rod.
16.Install the 18.5mm lg. pin onto the button and add a compression spring onto the pin.
17. Place the button pin spring subassembly into the button pocket on the end cap.
18.Install end caps using the M3 x 6 Countersunk screws.
19. You’re DONE!

I have included a Blank Lid STL if you don't want the inlay. I would follow the same steps as in my switch game cartridge case for the inlay lid. I couldn't seem to get the origins to line up so the 1st layer prints will have to be offset from the lid by 0.5mm to get it to come out correct.

Calipers

I printed every at 0.3 layer height with 0.4mm nozzle.
I printed the gear set in resin though you could probably print it with FDM.

The Latch will need supports on for the edge of the hole.