mfleming

mfleming

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At a 100 hrs my Hartzell CS prop had to go into the prop shop to be resealed due to slinging grease. Now the front spinner bulkhead screw holes don't line up.
The prop shop said the front dome gets torqued on and never lands exactly on the same spot as before the disassembly. They say all the new certified prop bulkheads come slotted to compensate for this.

My question for those that have run into this:
What are you doing to make the front bulkhead fit?
 
I've heard it said that new holes and nutplates can be installed, if you get lucky enough that the new orientation is offset enough. If not, you might get stuck building a new front bulkhead.
 
mfleming said:
At a 100 hrs my Hartzell CS prop had to go into the prop shop to be resealed due to slinging grease. Now the front spinner bulkhead screw holes don't line up.
The prop shop said the front dome gets torqued on and never lands exactly on the same spot as before the disassembly. They say all the new certified prop bulkheads come slotted to compensate for this.

My question for those that have run into this:
What are you doing to make the front bulkhead fit?
Click to expand...
Buy a new bulkhead, redrill and install new nutplates.
 
rocketbob said:
Buy a new bulkhead, redrill and install new nutplates.
Click to expand...
If they are not too far off, you can slot the front four bulkhead screws hokes, the screws that attach it to the hub. A good example is in Vic Syracuse “how to set CS low pitch stop” video. The Hartzell prop example shows up there.
Mine were off about a quarter inch. Got the old divider out and drew an arc between the bulkhead mounting screws, drilled new holes, and took a round file to clean up the slot. It may only be good until the next rebuild, then I might be doing what Bob suggests. Also, if you’re too far off, remake that bulkhead as recommended by Bob.
 
bjdecker said:
Slot the 4 holes. There was a kitplanes article a couple of months back on how to do this.
Click to expand...
And here you go….

www.kitplanes.com

Spinner Bulkhead Clocking - KITPLANES

Spinner woes were the topic of midsummer musings on Van’s Air Force this year. Specifically, Bill from Virginia commented how, after getting his Hartzell prop hub back from an eddy current inspection (ECI) and installation of new seals, the spinner mounting holes on the S-603 forward bulkhead no...
www.kitplanes.com www.kitplanes.com
 
georgemohr said:
I've heard it said that new holes and nutplates can be installed, if you get lucky enough that the new orientation is offset enough. If not, you might get stuck building a new front bulkhead.
Click to expand...
The four holes that hold the spinner on don't have nut plates and I'm off about a half of inch.
Ironflight said:
And here you go….

www.kitplanes.com

Spinner Bulkhead Clocking - KITPLANES

Spinner woes were the topic of midsummer musings on Van’s Air Force this year. Specifically, Bill from Virginia commented how, after getting his Hartzell prop hub back from an eddy current inspection (ECI) and installation of new seals, the spinner mounting holes on the S-603 forward bulkhead no...
www.kitplanes.com www.kitplanes.com
Click to expand...

That's a great article but I don't have access to a milling machine and I'm not a machinist.
EDIT: After re-reading, my response, it sounded a little abrupt. I appreciated the link and ended up using this info to guide my local machine shop!


My holes are about ½" off. I think I can just drill new holes for mounting to the prop dome ( leave the outer edge holes with the nut plates alone) but haven't figured out how to precisely locate the new hole location. I could cleco the forward bulkhead to the spinner and then install the spinner but then how to mark the new hole location. Maybe if I had something to paint on the dome so the it would leave a mark on the forward backplate!? Not sure if that would be precise enough.

Any suggestions are welcome.
 
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georgemohr said:
I've heard it said that new holes and nutplates can be installed, if you get lucky enough that the new orientation is offset enough. If not, you might get stuck building a new front bulkhead.
Click to expand...
S-603 bulkheads are predrilled for the dome mounting holes as well as the spinner holes. So it would require a new spinner, not a new bulkhead.
 
You don't need to stay in a Holiday Inn to do this.

Remove front bulkhead from dome
Use a circle template to mark two circles one on the inside of the 4 holes, the other on the outside.
Determine which way you need to rotate the front bulkhead
(optional) Do a little trig to determine the location of existing holes that the new holes need to be.
(optional) Eyeball & guess where a new set of holes should be, for 1/2" I'd swag that the new holes are going to be 1/8" - 3/16 away.
Mark 4 center lines for the new holes, on the bulkhead, 90° apart, centered on the low pitch bolt/nut hole.
Mark 4 new holes in between the two circles
Drill new holes to #21, Check Alignment within the two circles
Drill holes to #12.
Dremel out the materiel between the new holes and the original holes and stay in between the two circles marked in step 1
Deburr new holes and slots
Install two bolts, washers - just tight enough to hold the bulkhead in place but allow it to be rotated.
Install spinner and adjust front bulkhead position using an awl, or pick.
Remove spinner
Install remaining two bolts and washers
Tighten all 4 bolts
Safety wire all 4 bolts
Install Spinner
Go Fly

Use a drill press to keep the holes square and true to the bulkhead, and hopefully round -- assuming your DP has as little run-out as possible; unlike your Ryobi/Dewalt/Makita drill...
 
Just to finalize what happened with the forward spinner bulkhead. The machine shop slotted the bolt holes. I then installed the bulkhead approximately where I thought the machine screws would line up. I did that a couple times until I could use an awl to center the screw hole. Then I carefully removed the spinner without disturbing the forward bulkhead, tightened the 4 bulkhead hold down bolts, double checked nothing moved, then torqued and safety wired them. 10 hours later, all is well.
 
On mine the orientation was so far off that slots wouldn't get it done. So I moved the bulkhead to the position where the holes were farthest from original position, and drilled new holes. Moved the nutplates to the new positions and all is good. I added another spinner bulkhead to my next Vans order because I might end up with slots next time, or I might just want to throw in a new one.
 
I am told, but have not asked a shop directly, that if you tell the shop,
they can mark and keep the holes relatively close to the original location. Anybody have experience with that?
 
JonJay said:
I am told, but have not asked a shop directly, that if you tell the shop,
they can mark and keep the holes relatively close to the original location. Anybody have experience with that?
Click to expand...
My prop shop told me that the dome is set by a torque value, hence the inability to keep the bolt holes clocked as the original. My prop shop also said that the certified spinners are slotted just for this reason.
 
A: Screwless spinner. Or at least the method applied to the forward bulkhead (formed-in-place "gasket" using Pro-Seal).
 
JonJay said:
I am told, but have not asked a shop directly, that if you tell the shop,
they can mark and keep the holes relatively close to the original location. Anybody have experience with that?
Click to expand...
Tried that when I dropped my prop off at Hartzell. "Sure, no problem, it'll all line up when we're done." Complete and total fabrication. Holes were so far off I did what others have done. Removed the nutplates and reinstalled at new locations. Last order from Vans I got a spare spinner plate for next time.
 
Thanks guys. Just hold to “don’t believe anything you hear and only half of what you see”.
 
mfleming said:
Just to finalize what happened with the forward spinner bulkhead. The machine shop slotted the bolt holes. I then installed the bulkhead approximately where I thought the machine screws would line up. I did that a couple times until I could use an awl to center the screw hole. Then I carefully removed the spinner without disturbing the forward bulkhead, tightened the 4 bulkhead hold down bolts, double checked nothing moved, then torqued and safety wired them. 10 hours later, all is well.
Click to expand...
Did that 10 hours include the machine shop work?
 
I misread that, sorry :) glad it worked out. Maybe (suggestion for future product enhancements) Van’s could slot those holes…
 
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