Thanks to @Cornely_Cool for posting the SolidWorks files, so I didn't have to reinvent the wheel!
Just updated 1-9-19 the "Universal 2mm shorter Tevo X Tensioner body.stl" will work on all machines with either center threaded piece and nut. It will fit the Ender 3/Pro screw loosely (metal screw in the T-slot on front), but the belt pressure holds the piece in place. The screw is just an alignment tool/helping hand.
I hate confusing posts, so here: these 3 files will fit universally with as much clearance as possible:
- Universal 2mm shorter Tevo X Tensioner body.stl
The Ender 3 Pro and My Tevo Tornado both have the X carriage bracket slightly past the rail on the right. This is properly clearanced (and currently in-use) on my printers. It has a slim adjustment knob, open-ended.
2 versions of the slider/sled/puller - one with a too-sexy "landing bay" for your shuttle craft (nerded-out there!) and a plain, solid slider.
Added shorter-belt main bodies (-1mm & -2mm) in case you have clearance issues (STL only). Do not remove your belt: place the bearing into the loop and push in from the top slot.
My Ender likes -0.07 Horizontal Expansion (Cura) for accurate parts, but clearances should be good on any decent setup printer. Like my Y-axis tensioner, the threads are clearanced a little.
It should print upright without supports - I use MG Chemicals PETG.
For my Ender 3 Pro Y Belt Tensioner https://www.thingiverse.com/thing:3268192
STL and STEP files are included on both
MG Chemicals PETG
I print at 240, 40% fan, .2
The stock belt length is close, tight on mine, but I was afraid to make the frame any shorter.
If anyone needs a little more clearance it would be easy to clip 1mm from the area contacting the end of the extruded aluminum. I will upload that labeled "shorter"
Also, the screw that goes into the T Nut doesn't make stress on the part, oversized intentionally: it's just keeping the part in place until tension pulls it tight to the frame.