Pella Screen Door Trolley

I have a Pella sliding screen door that one of the trolleys shattered.  The part is no longer made, but hey, it's just plastic.  Why not print it myself. :)

I printed with Inland ASA for durability with 100% infill so I can tap the threads.  I typically use the “0.20mm Quality” Print settings in PrusaSlicer for tensile strength with the 0.4mm nozzle.  It requires a little post processing to get the clip to grab at just the right tension.  I used a 10-24 x 7/8" FHMS and thin nylock for the axle.  I replaced the 3" screw that held the screen door to the trolly with a machine screw because it's easier to tap machine threads in the new trolly vs wood screw threads.  (Though the wood screw did work okay in my prototype.)

I decided to cut the threads in the bottom and side holes with a tap, instead of printing them.  Printing 100% infill makes it very easy cut sturdy threads.

If you can't print these yourself, I don't sell parts, but there are plenty of online companies that do. I've had good experiences with Shapeways, Xometry, and Protolabs.

Update-July 2025: V4 is still going strong, but people have asked for an update.  V5-2 has a more flexible clip, so there is little to no need to fine tune it after printing.  Please see the pictures with the blue filament for assembly.

1. Print the body upside down to minimize supports. I added them unde the clip, next to the spring hook, and inside Wheel B. (The void for the hex nut.)

2. Machine screw and nylock become the axle.

3. Tap the 2 holes.

4. Insert longer machine screw into the back and cut off the head.  This inserts into the aluminum spacer inside the track between the 2 trolleys. I lightly crimped the spacer until it pinched the machine screw threads.

FWIW, this is the machine screw and locking nut that I used.

https://www.mcmaster.com/product/90273A422 - Axle 

https://www.mcmaster.com/product/90633A011 - nylon insert nut

https://www.mcmaster.com/90272A368/ - Machine screw used to hang the screen door