The small gap at the back of the arms has been fixed in "Battery Adapter.R.5.1.stl" and "Battery Adapter.L.5.1.stl". Please use those files if you want to print the flat bottom ends. I've also added "Battery Adapter.R.6.1.stl" and "Battery Adapter.L.6.1.stl" which has a more rounded end. The gap is fixed on these as well. They will need to be printed upside down, as in the cura screenshot image, and with supports inside.
I've added 2 new files called "Battery Adapter.R.5.0_ActualSize.stl" and "Battery Adapter.L.5.0_ActualSize.stl". These are the same as the originals but scaled down to 10% to match the actual printed size as I usually design at 10x the size in Sketchup and the original files were still at that scale.
Want to use 18650 batteries in your Frsky Taranis X-Lite? These 2 prints will replace the controller ends that came with the X-Lite and allow you to use the longer 18650 batteries instead of the hard to get 18500 size.
You will need to print the left "L" and right "R" controller ends, scale them down to 10%. I used 0.1mm layers to get enough detail on the sliding lock for it to be solid enough, and a 30% infil. 1.2mm walls and 0.8mm top and bottom. I also played with the supports in Cura so that they were only generated in the little sliding hole and so they were only 1 line wide, just supporting the end bit of the "shelf" above the groove. Other settings may work fine but that's what worked for me.
Once the print is done remove the few supports that are there and gather 2 18650 (or other) batter holders, some double sided tape, and some sort of conductive tape (I used copper tape from Aliexpress).
Cut the spring side out of the battery holders and add a piece of double sided tape then stick them on the bottom of the inside of the printed items. Make sure to run the wire along the groove in the print and leave a small exposed section on the lip at the top of the battery hole.
Cut some conductive tape and loop it around the inside of the top lip, making sure the exposed piece of wire is held in place and in contact with the tape. Then trim the tape so it doesn't stick out over the edge. You can also use a craft knife and some tweezers to cut and push the tape into the sliding "lock" groove on the print.
That's it, add 2 18650 batteries and screw the ends onto the X-Lite and turn on.