Required parts

• M2.5 x 6mm countersunk screws
  • Metric screws are not ideal for this purpose, but they are working really well here. 
    If you have suitable self-tapping screws, use those.
• Cheap 5/16" and ½" round stock
  • Mild steel, nothing fancy
  • Cut to the length of your rail
• Spring (Wire 0.3mm, OD: 4mm, Length=20mm)
  • Maybe 0.4mm wire would be better… 0.3 works well. It's not very forceful though, so you might need to do a little bit of filing to get the silders moving very smoothly.

Printing

• I used a textured bed. It's glorious.
• .25mm layers, 0.5mm first layer.
• .6 nozzle