Through Shelf Filament Guide for 1/4" OD PTFE Tube

thingiverse

Another Filament Guide passes your filament through a shelf up to 5/8 inches thick. You could probably scale the Z-axis to make it further. Using ideas from other designs, I added a funnel on the spool side to make loading filament easier and made sure my new 1/4-inch OD PTFE tube fits snugly into the bottom and stays there during printing. Then, I added a retaining ring on the bottom to keep things aligned, just in case the hole I drilled in the shelf was a little sloppy and might allow some movement. To cap it off, there's a hot end adapter since my new tube is slightly larger than the stock tube that came with the printer.