Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:3382926.
While setting up my Thrustmaster Warthog for playing Elite:Dangerous I realized how dependent I was on my old HOTAS center detent for dropping the ships to zero throttle reliably. In looking around, I couldn't find a good, free throttle insert piece to give me this so I could use the Warthog as a full-range throttle (-100% to 100% thrust) so I grabbed my calipers and modeled one up based on others I'd seen on Thingiverse.
This one has one detent at 0% throttle, and a second one at 75% throttle (for supercruise flight time optimization). Both are fairly light detents, with the 0% most effective when approaching from negative thrust and the 75% most effective when approaching from full thrust.
I printed this is PLA, but I don't know how durable it will ultimately be. If I have issues with it I'll either just print another (if it lasts long enough to be worth it) or start trying other materials with higher durability like ABS or PETg. I recommend printing this at 0.1mm or smaller layer height on it's side (using supports and a brim for adhesion) to maximize the smoothness of the surface over which the throttle has to slide.
Revision: Added a 0% only detent version. Also, I recommend setting the zero band to about 3 in the TARGET software to allow for a bit of slop in the print/model.