Prop Cylinder/New Spinner Support

[bill.hutchison]

Right now, I'm still mulling it over but I'm going to chalk this one up to "unintended consequences."

I sent my prop for a clean/reseal + ECI (has the 100 hour AD) since the blades are still in excellent condition and a full overhaul wasn't necessary. Shop agreed, but noticed that the anodizing inside the cylinder on the dome part was gone and there was some scoring - they deemed this part condemned and required a replacement.

The cylinder threads onto the hub, and unfortunately, they didn't re-orient the new cylinder the same way the old one was - I don't know enough to know if this was something they could control, but the end result is that when my forward spinner support was re-installed, the holes for the spinner at the mid-line no longer line up. The guy who built the prop back up told me that the dis-assemblers didn't mark/index it and this is what caused the problem. I don't know enough about props to know if there is a way to correct that, but....<shrug>

This is annoying, but not particularly difficult to deal with. I could simply drill new holes and install nut plates in the spinner support, but I don't like the idea of extra holes. It's probably not a big deal, it just doesn't sit right with me. Whatever. I'm weird that way.

So I ordered a new spinner support from Vans and I'll just re-do that one to match with the spinner. It's a slightly bitter irony that I sold all my riveting stuff on this site just a week ago, so I'm gonna borrow some stuff when I get back from my trip next week. It's gonna add a few hours to the re-install, but at least I have the rivets and nut plates in the shop. I think.

 

[Ironflight]

Unfortunately, that’s the way it works with a Hartzell prop - the black “dome” never goes back on with the same exact clocking (I don’t know how the prop shop thinks they could have done it….). What you hope for is that it will be far enough off that you cane reuse the forward bulkhead by just drilling new holes and putting on new nut-plates. What’s frustrating is when it’s just a degree or two off, and the holes for new and old interfere….

 

[tthrew]

Slot the bolt holes

Just had mine resealed this spring. My alignment was changed, but not by much. I just took a file and slotted the 4 bolt holes. If you do a search, you should come up with a thread on VAF discussing this. (Perhaps your alignment is too far off for slotting and new holes would need to be drilled.)

 

[RV7A Flyer]

Just had mine resealed this spring. My alignment was changed, but not by much. I just took a file and slotted the 4 bolt holes. If you do a search, you should come up with a thread on VAF discussing this. (Perhaps your alignment is too far off for slotting and new holes would need to be drilled.)

I have no experience with this, but so many do that it makes me wonder why the original forward bulkhead doesn't come already slotted. Seems it would be any easy thing for a supplier to do...especially since *everyone* should eventually run into this after an overhaul (unless, like me, you did the "screwless spinner" ).

 

[pilotkms]

Just got mine back from the prop shop. 6 year service. Looks brand new. Was aware that the holes would need to be “adjusted”. Prop shop isn’t going to be concerned about those holes lining up with your spinner. Their concern is proper torque on reassembly, so I’m told. And seems much more important.
Friend with a milling(?) machine offered to do the relocating of the holes to exactly fit. Bout half an hour. Bought him lunch. Good to have talented friends.
Tim’s file method, above, would work. But this is a little more precise.

 

[cajunwings]

Spinner bulkhead.

This one is pretty easy. Prop shop has to torque the dome on and it ends up where it ends up. Usually it’s a little more righty-tighty from where it was before. If off by a little I slot the holes, if a lot just move the nutplates. Nothing wrong with installing a new bulkhead, but it’s not necessary. Way back when I was a shop rat maintaining Pipers new Hartzell bulkheads came with big slots so we never had to do any modifying. Don’t forget how shallow the threaded holes in the dome are and use care to not bottom out with the bulkhead bolts.

Don Broussard
RV9 Rebuild in Progress
57 Pacer