An accurate and repeatable way to measure belt deflection and thus determine the tension in your printer belts.
This project grew out of a mistake I made purchasing a "belt tensioner" from AliExpress for $20, which turned out to be just a cheap digital tire tread depth gauge and some (very poorly) printed parts with a few hair elastics as the "spring"... Suffice it to say, it was hot garbage as sold, but I was intent on making it useful.
Fast forward 3 weeks of design, I reverse engineered the main clip on part for the foot of the gauge, the rear slide clip and added some features:
Now snap fits onto your gauge and has optional thru holes for permanent mounting with screws. Uses a compression spring for better reliability, repeatability. Rear slide clip has retention pin and screw for better mounting. Has a proper "normal" pin spacing of 50mm. (was 62.5 previously ?!?) Included STEP files for anyone who has a different fitting gauge and wants to make changes.Hardware required is simple:
M3x20 Socket Head Cap Screw (1) M3x10 SHCS (1) (+2 for optional permanent mounting) M3 hex nuts (as required) M5x20 steel pins (2) Compression spring (I used what I had, OD 14.25, 70mm long, 0.7mm wire, 14 turns) from an old medical device.The trick is to find a spring that is just right; not too strong so as to damage the belts and still strong enough to return the slide reliably back to start consistantly.
BTW I printed my parts in ABS and the design accommodates for some material shrink, so if you are using PLA be advised. (I don't do PLA, ever!! )