Bell 205/UH-1/212 42º & 90º Gearbox Sight Glass Puller

A puller tool used to remove the oil sight glass from the 42º or 90º gearbox on a Bell 205, UH-1, or 212 helicopter. The puller has two different size spacers (one thin, one thick) which may or may not need to be used depending on the sight glass (the one I tested the puller on needed no spacers).

Necessary Hardware for Assembly:

• 1x — M5x40mm socket head cap screw (this is the shortest screw you should use; longer is okay).
• 2x — M5 hex nut.

Print Recommendations:

• PLA or another material with good rigidity.
• 0.6mm nozzle recommended for increased strength.
• 0.2-0.3mm layer height.
• 3 perimeters.
• 25% infill with 100% infill on the top of the puller body (split portion) and the puller cap (removable piece).

Note: The nut pocket on the puller body is not designed to be a complete press fit, but you may need to use the “nut pulling technique” depending on your printer/tuning. Secure the M5 screw with a fair amount of torque, but excessive torque will probably deform or crack the part (it really only needs to be slightly tighter than what you can accomplish tightening the thumb nut with your fingers). The nut pocket in the thumb nut is a press fit design and should require some force to seat the nut. I accomplished this by threading the nut part-way onto the M5 screw and then aligned the nut pocket in the thumb nut with the M5 nut and pressed it in against a flat surface (in my case, the edge of my desktop). Whew… That was a lot of nuts!

Change Log:

• 30MAR2024 — Updated model and print files with a revised version to correct a recently-discovered fitment issue on the newer-style sight glasses. Special thanks to user @MAE_1822999 for discovering this issue and helping me resolve it.