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+-- Thread: Goodell Pratt eggbeater rehab, Part III (/showthread.php?tid=7298674)
Goodell Pratt eggbeater rehab, Part III - JimReed@Tallahassee - 06-11-2016
Continuing with the saga of the GP eggbeater. I need to name these pieces so you can follow:
The big piece is the chuck bell housing. It is where all of the goodies reside. The sides are sloped in order to force the lobes together. The bottom piece that screws into the bell housing is the collar. It is removable so you can service the internal components. Inside we have three lobes, three springs, and a floating bottom. The lobes and the floating bottom are hardened and polished so much that metal tools just slide right off. This is why it is hard to repair a chuck without taking it apart. The lobes are too slick and slippery to grab from the outside.
The three lobes are assembled into a single component that is held together by three springs. The springs fit into holes at the bottom of each lobe. This whole assembly is inserted into the bell housing and the collar is tightened. As the chuck moves down the threaded post of the drill, the pointed part of the floating bottom is engaged by the tip of the post and it pushes the three lobes in unison. At the same time, the bell housing sloped sides force the lobes together. It is important that they stay in sync so they all engage the bit at the same location. If one or more of the springs fail, the lobe might not move or might move later than the other lobes. That can make the bit off center or can even allow the lobe to get stuck between the bell housing and the floating bottom.
Dirt and gunk can restrict easy movement of the lobes. Everything inside the bell housing needs to be CLEAN.
The inner parts of this chuck are a lot more delicate than I originally thought. They need to be in good nick, clean, and lubricated. My guess is that many become frustrated with these tools because the chuck needs attention. I spent time cleaning and polishing the inside of the bell housing. All of the other pieces were brushed and wiped. I will lubricate with graphite after assembly. Here is the completed lobe assembly.
Here are the lobes inserted into the bell housing. Note that the floating bottom has been inserted into the collar. Now for the tricky part--assembly. You have to screw the collar into the bell housing without the lobes falling apart and without the floating bottom falling out. I got lucky on the first try by turning it sideways and holding my breath. I felt like a bomb tech unscrewing a fuse to defuse a 500 pounder. And don't forget to use your walnut spanner wrench to tighten the collar. The dot you see inside is the pointed end of the floating bottom.
Here is a shot of the lobes in action. So far, so good. All are advancing in unison.
WooHoo! Back in action. I love the moment when a tool goes back to work. On this Goodell Pratt, everything works well. The action is smooth. The bit has no runout. Chips fly. After this experience, I will appreciate my eggbeater chucks more and will treat them with gentle hands. Hope you enjoyed the posts.
Re: Goodell Pratt eggbeater rehab, Part III - Window Guy - 06-11-2016
Jim, great post and explanations, thanks for sharing.
Steve
Re: Goodell Pratt eggbeater rehab, Part III - Alan S - 06-11-2016
Thanks. This is a good tutorial that will likely be responsible for a bunch of these being brought back into service. I hope you put it somewhere more permanent than here -- it deserves to survive.
Re: Goodell Pratt eggbeater rehab, Part III - GNP - 06-12-2016
