storage tube cap (1" PVC pipe)

Caps to make 1" PVC pipe (nominal, US size) into storage tubes.  As published, the caps will work ONLY with SDR-21/Class 200 pipe ("sprinkler pipe").  They will NOT work with schedule 40 (different inside diameter).  These are NOT air, water, or dust tight, but they should do a good job keeping dust out under "normal conditions".  

I tuned the sizes to get a good fit on my crappy Ender 3, but I've tried to make it so they can be scaled or manually adjusted to fit without too much work.

The fixed side is easy--there's a decent amount of variation here where it will still work.  It just needs to fit tight and stay in.  Scale up or down as needed and if it requires a fair amount of force you're good (e.g. put the cap on a sturdy table and pushing the pipe down over it with ~30 lbs of force is reasonable).

For the removable cap, scale it up if it's too loose.  If it's too tight, the interference fit is just from the three raised ribs so lightly file on those until the friction fit is where you want it.  No need to sand the entire outside diameter.  

There is nothing stopping you from using the removable cap on both ends of the tube if that's what you want.  If you don't care about access from either end, the fixed cap takes less time to print and uses less material.  

Scaling for other pipe sizes should work within the same class (e.g. scale to fit 2" SDR-21 pipe). Other classes of pipe have a different ratio of inside to outside diameter, so if you scale to where the inside diameter fits, the part that sticks out of the tube will be larger or smaller than the outside diameter of the pipe.  

Step files are included if you need something different (my first time making anything even sort of complicated so if the model is weird I'm sorry).  

These will fit an AR-platform recoil spring perfectly, just cut the PVC to the appropriate length for your recoil system.  

Printing:

30% infill worked well for me.   No supports.  Use a brim if you need it.  This design is pretty tolerant parameter-wise.