This model was made to help reinforce the idler pulley of the flsun sr delta gantry. We be swapping two of the components: Idler → 20T pulley | 25mm Screw M5 → 30mm Screw M5

The printed stabiliser should be printed solid (mostly walls). I printed using Nylon-CF but you may use ABS, ASA, or PETG if you must. DO NOT USE PLA due to deformation and loss of rigity over time from heat and strain. 

New Hardware List:

30mm M5 Screw - The original screw was a bit short for my design. Can be found anywhere but here's what I used (Amazon Affiliate Link - I earn a commision at no cost to you if you used this link): https://amzn.to/47971Yr

(Highly Recommended) - GATES gt2 10mm wide belts (4 Meter length) - MAKE SURE TO GET AT LEAST 4 METERS OF BELT!!!! Cut each to 1250 millimeters long x3. Should match length of original belts):

 https://www.aliexpress.us/item/2251832667244886.html?spm=a2g0o.order_list.order_list_main.23.21ef1802L7NqOv&gatewayAdapt=glo2usa 

20T GT2 Pulley 10mm wide (6mm BORE REQUIRED) - This is the hardest to find part but here's a link of the part that worked for me:

 https://www.aliexpress.us/item/3256807224244003.html?spm=a2g0o.order_list.order_list_main.11.21ef1802L7NqOv&gatewayAdapt=glo2usa 

INSTRUCTIONS: 

1. Install new belts first if you got the belts. You can follow this tutorial: 

but it does not require full disassembly of each slider rail, but if it helps, you can try removing one to help learn how it works. Also might as well clean and relubricate linear rails if needed).

2. After the new belts have been placed, follow the images in the preview along with the instructions below:

- The first 7 images preview how the assembly goes together (we replace the screw and pulley with our new ones and use the new printed part (Follow next images to see how to start).

- Remove the 2 screws on the rail holding the idler and unscrew tensioner (yellow thing) to completely take it out.

- Now following the preview, assemble just the screw, bushing, sleeve and 20T idler

- Take your printed part and slot in the nut that the original came with

- Now wrap the belt around and close it in with the stabilizer. Tighten screw and make sue everything lines up

- It should fully slot into the rails and line up perfectly with little or no slack.

- Now use a toothpick or something thin to push up the T-nuts that are still in the nail and screw back in the screws you removed (Do not tighten) as well as start screwing in your tensioner from below (Do not tighten just yet) 

- Repeat above for all three sides

- Follow this tutorial on tentioning belt (you use your phone to meansure 60 Hz on your belt) and then you can finally tighten everything and check frequency of strumming the belt again to verify it's around 60Hz. https://www.facebook.com/groups/336951057403890/posts/398154937950168/ 

Your printer should be good to go! Rerun bed leveling and whatever other things like input shaper if you have those mods. Good luck on your future endeavors!

If you made it this far and ran into issues with the printed part having issues, here is a link to my cad files so you may make a copy or adjust the file tolerances:

 https://cad.onshape.com/documents/8767f0376dc0b8e6951b0b59/w/6b4372be98e56e315648a4f0/e/3773b5c379c5b1bbe79e919f?renderMode=0&uiState=688e07d7e8f89e631d61352c 

It contains very reliable dimensions for the rails using a 3D scan as well as many caliper measurements to verify accuracy of the inner well. The actual outer dimensions are also relatively accurate (Slight inconsistency of the extrusion slots compared to irl but they are the right width and locations)! There are two variants of the SR rails but I believe it sohuld work for both