I was looking for info on setting some brass inserts today (specifically the best temps an iron when using ABS), and found the link below, for a markforged blog post on using heat set inserts.  It has some good tips on designing the pockets for them as well.

https://markforged.com/resources/blog/heat-set-inserts

It was mentioned in the article that using additional re-enforcement around the hole will help.  The way I have done this when designing parts using heat set inserts (or even for through holes intended for use with bolts), is to add some slicer independent thickening of the space around the holes.  To do that, I will add an array of through or almost through holes, with a very small diameter (0.4mm or the nozzle diameter is enough).  These holes are placed at a distance from the hole equal to about 1.5-2x the estimated wall thickness.  So for a wall of 0.4mm x 2 lines (or 0.8mm walls), I'd place the holes around 1.2-1.6mm from the holes.  This way the holes will create an almost solid area around the hole and provide extra strength to the part.  It allows the rest of the part to be printed with lower walls and less infill, since using just 2 walls may not provide enough side support to the insert once it is melted in place.  The holes can be placed so they will not show on the surface, by burying them just below, so the top layers will seamlessly go over them.  This same technique can be used to add internal bolstering to a model, but it should be anchored to a wall or surface so it will not free float in the infill.

​One caveat to using this method is that slicers may ignore the holes depending on settings for things like nozzle diameter and wall thickness.  So it helps to know what nozzle size is planned to be used, and an idea of how many walls and surface layers may be used in printing the part.  If in doubt, making the holes slightly larger should get them to show up in the slicer.​

I made a case for my TS-80 which has been great, but my Pinecil (v1) has been a bit neglected.  The Pinecil works almost as well as my TS80, and is better in some ways (it supports PD where my TS80 only supports QC).  The Pinecil also uses tips which are easier to find (since they are the same as what is used in the TS100).  My TS-80 case has been very handy, so I used it as the basis for a case to hold my Pinecil.  But I designed the TS-80 case with a constraint that it is able to fit into a Stanley case, which limits it somewhat.  For my Pinecil soldering iron, I want to have a case that will contain the following things:

• 100W power bank
• Silicone USB-C cable
• At least one spool of solder
• A Mini-T stand
• A Pinecil with a M2x4mm thumbscrew (used to secure the tips)

I had considered adding a space for a small tin of flux, however I have not found any that are small enough to fit, without making the whole design much larger. 

What I've come up with so far is the result of hacking and stretching my existing case design and adding some features to allow it to be more simply updated for different irons.

I just received the 100W power bank, and need to do some testing with it to make sure it will work, but so far it seems like it will.  The design feels like it is completed, but generally when I think a design is done, it just means I need to print it to find out where I screwed up :D  

Thanks to Daniel Soussi at GrabCAD for the 3D model of the Pinecil iron.  I use the model to help define a slightly larger cavity to set the iron into.  The tray will also accommodate a Pincel with a thumbscrew to hold the tips (M2 x 4mm similar to these).

Update 2/18/2023 - I've printed a couple test parts and they fit, but I have a few more parts to test before I print the whole thing (and then will upload it to Printables if it works).

Update 2/24/2023 - I printed the base to test it out and the battery fits well.  However I decided to get the Pinecil 1M USB cable, since my current silicone USB cable (though really nice) is just a bit too long to fit in the case without some alterations.  I'm gonna wait until the Pinecil gets back in stock on Feb 27 before ordering the cable (it's a good deal for the cable, but the shipping is a bit much for just a cable, unless ordering a few things at the same time).  I plan to design a small spool to hold the cable, which should fit inside the case.