LightsOutIndustries.com 5/19/2019  - Creative Commons 4.0 BY-NC-SA

1)  Print two pieces of the SoldIronFlange.
These models are for clamping onto a handle with a diameter near 24 mm.  If yours is smaller, you may need to build it up with a few layers of electrical tape.

2) Print the large SolderRouterBase.  This is a large print, and will take around 12 hours on a desktop FDM style printer. Be prepared.

3)  Print 4 pieces of the HandleHalf.

For assembly, I like to use a dot of superglue to hold the hextnuts in place in the plastic housing.

The hole through the base that the soldering iron pokes through is sized to be able to be used with a template router bushing.  I matched the dimensions for the one available from Harbor Freight Tools.  https://www.harborfreight.com/9-piece-router-template-guide-set-98361.html?_br_psugg_q=template

I haven't actually tried this technique, but I think it would work pretty well.

This was designed for use with #6 fasteners (I'm in the U.S., so imperial threads are easy to come by).  The hex cutouts are 8mm across the flats.
You'll need at least 11 nuts and 11 bolts.  They should be 1.25" long.  You could substitute shorter screws for holding the two flange halves together, but I layed out the design to use the same screw everywhere.

Remove the tip from the soldering iron and measure it's diameter.  Most are either 4mm or 6mm diameter.  You'll need to either get on a lathe and turn down a tip to work or you can build one up from various bits of brass tubing.  My soldering iron had a 6mm tip, so I had to procure 6mm, 5mm, 4mm, 3mm tubing and 2.5mm rod to make my final cutter.  The 3mm had to be the "thin wall" version which was difficult to source for some reason.  I used 2.5mm solid rod for the last bit.  To hold all of this together, I cut the 2.5mm rod and slid it into a piece of the 3mm thin wall.  I then put these two on a metal surface and hit the tubing with a hammer to crimp the 2.5 mm rod into the tube.  I then just nested the rest together and cross drilled a small hole and put a lock wire through it.  It isn't very hard to do at all, it just sounds complicated when written out.