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GRNDP51
09-16-2015, 01:30 PM
Don't know the specifics, but gear problems sound like it. Down safely, not sure why they took her up today..? :dunno:

Desertdawg
09-16-2015, 01:33 PM
Thanks for posting that, I was wondering if there was landing gear issue, especially when Strega flew over couple times for a close look.


Glad Stu got her down safely.

Fence Sence
09-16-2015, 02:54 PM
I was surprised they went up as well. I didn't hear a mayday call but it looked like something was going on.

GRNDP51
09-16-2015, 03:18 PM
I was surprised they went up as well. I didn't hear a mayday call but it looked like something was going on.

Guess she took off too fast and the wheels didn't enjoy being pulled into the gear well at that speed..

knot4u
09-16-2015, 03:35 PM
The gears that move the pocket doors have been and probably will continue to be an ongoing issue on that airplane. I remember going through a box of spares and not having much luck finding any good ones. It would be an expensive part to make due to how complex it is, internal female spline precisely clocked to an external segmented gear. Not impossible, but very expensive, but there is such a small market for these parts that no one is willing to even tool up to do it.

Desertdawg
09-16-2015, 03:42 PM
The gears that move the pocket doors have been and probably will continue to be an ongoing issue on that airplane. I remember going through a box of spares and not having much luck finding any good ones. It would be an expensive part to make due to how complex it is, internal female spline precisely clocked to an external segmented gear. Not impossible, but very expensive, but there is such a small market for these parts that no one is willing to even tool up to do it.

This is exactly why AAFO HangerTalk is so special - the knowledge present here is second to none.

A simple thread or question can turn into some interesting feedback/knowledge.

Thanks for sharing.

:beerchug::beerchug::beerchug:

440_Magnum
09-16-2015, 03:43 PM
Guess she took off too fast and the wheels didn't enjoy being pulled into the gear well at that speed..

I guess at least the problem of the extended gear/open wells fouling up air flow through the oil coolers so that flying too long with the gear down starts cooking things is no longer an issue... Boil-off wins on that one. ;-)

ChrisMX105
09-16-2015, 04:11 PM
Boil-off wins on that one. ;-)

Boil-off wins period.

The fluid capacity is such that the available fluid exceeds fuel, So you would run out of gas long before the cooler would go dry.
Add the drag reduction and there is nothing not to like.
Also in the case of RB having a midwing the entire system is gravity fed via a float so not even any pumps or electric valve.

Race5
09-16-2015, 04:14 PM
Thanks for posting that, I was wondering if there was landing gear issue, especially when Strega flew over couple times for a close look.


Glad Stu got her down safely.

That wasn't Strega it was whoever was flying cover. Lady Alice I think.

hm66sk
09-16-2015, 04:38 PM
The gears that move the pocket doors have been and probably will continue to be an ongoing issue on that airplane. I remember going through a box of spares and not having much luck finding any good ones. It would be an expensive part to make due to how complex it is, internal female spline precisely clocked to an external segmented gear. Not impossible, but very expensive, but there is such a small market for these parts that no one is willing to even tool up to do it.

Hmmm. 3D print out of some unobtainium?

knot4u
09-16-2015, 04:55 PM
Hmmm. 3D print out of some unobtainium?
I doubt it. The structural integrity of that part would be suspect, which has already been a problem and the parts that aren't available were made during a time when the entire industrial might of our nation were building stuff not for profit but for a much more important reason. Sadly these airplanes will all be grounded someday due to the lack of available spares, unless someone decides to start redesigning and making these seemingly small parts that are are critical to safe flying.

GRNDP51
09-16-2015, 05:13 PM
That wasn't Strega it was whoever was flying cover. Lady Alice I think.

Probably Wee willy, they look the same for the most part lol :p

GRNDP51
09-16-2015, 05:17 PM
I doubt it. The structural integrity of that part would be suspect, which has already been a problem and the parts that aren't available were made during a time when the entire industrial might of our nation were building stuff not for profit but for a much more important reason. Sadly these airplanes will all be grounded someday due to the lack of available spares, unless someone decides to start redesigning and making these seemingly small parts that are are critical to safe flying.

I feel like ACE, the company that made some parts for PM and the team is going to be the one help make the parts for the warbirds. Their mission seems to be just that..

Some of you have probably read this post

http://www.ace-performance.com/ace-builds-custom-parts-for-precious-metal-griffon-engine/

knot4u
09-16-2015, 05:39 PM
I feel like ACE, the company that made some parts for PM and the team is going to be the one help make the parts for the warbirds. Their mission seems to be just that..

Some of you have probably read this post

http://www.ace-performance.com/ace-builds-custom-parts-for-precious-metal-griffon-engine/

I'm glad to see a company building parts for these airplanes. The pocket door segment gears on the Rare Bear are already overstressed, the market is one airplane that would require two parts. Engineering an improved version and making two parts without the backing of a huge company like Grumman (imagine ingots, forges and massive metalworking machines) is not impossible, but replicating and improving on the original will be exceedingly difficult, and not just financially.

hm66sk
09-16-2015, 08:40 PM
Does anyone have a pic or a link to a pic/drawing of the pocket door mechanism?

SkyvanDelta
09-16-2015, 09:08 PM
I'm glad to see a company building parts for these airplanes. The pocket door segment gears on the Rare Bear are already overstressed, the market is one airplane that would require two parts. Engineering an improved version and making two parts without the backing of a huge company like Grumman (imagine ingots, forges and massive metalworking machines) is not impossible, but replicating and improving on the original will be exceedingly difficult, and not just financially.

Has the computer, attached to the machines changed this so parts can be easily made by programming the original specifications into the computer and allowing it to make original or better than new parts?

GRNDP51
09-16-2015, 09:13 PM
Has the computer, attached to the machines changed this so parts can be easily made by programming the original specifications into the computer and allowing it to make original or better than new parts?

I was thinking the same thing, technology has come such a long way we should be able to 3D print 4360's by now!! Lol, I don't see how ANY mechanism no matter how complicated couldn't be made in today's world :confused:

Ebehne
09-16-2015, 10:57 PM
The gears that move the pocket doors have been and probably will continue to be an ongoing issue on that airplane. I remember going through a box of spares and not having much luck finding any good ones. It would be an expensive part to make due to how complex it is, internal female spline precisely clocked to an external segmented gear. Not impossible, but very expensive, but there is such a small market for these parts that no one is willing to even tool up to do it.


I don't have a totally clear understanding of what these parts look like, but based upon the above description it sounds like someone could wire EDM them. Not really any tooling required, used all the time to make prototypes. It's pretty expensive, but I think it's likely reasonable for such a valuable and unique part. Considering that the landing gear issue is a recurring theme and potentially really dangerous for the plane/pilot, seems like the cost would be justifiable.

toldjaso
09-17-2015, 05:05 AM
I was thinking the same thing, technology has come such a long way we should be able to 3D print 4360's by now!! Lol, I don't see how ANY mechanism no matter how complicated couldn't be made in today's world :confused:


3D printing a part won't give you a forged part, I would guess?
Most of these type parts are forged, where they hammered them under great pressures to tighten up the grain structure.
(In my opinion, don't have the print that has the specs for these gears).
Anybody out there agree or disagree, and why?

ChrisMX105
09-17-2015, 07:00 AM
I would imagine that forgings would still be needed. The stresses of being opened and closed at 100+mph has to be insane.

440_Magnum
09-17-2015, 01:20 PM
Boil-off wins period.


Oh, I agree. I was poking a somewhat blunt stick at all the hoopla made over whether closing the oil cooler inlets and moving the air intake was a net win. Its the air intake part that's not a certain win or loss (well, there are people who are absolutely CERTAIN... on both sides!).

440_Magnum
09-17-2015, 01:26 PM
I would imagine that forgings would still be needed. The stresses of being opened and closed at 100+mph has to be insane.

I've never seen the parts, but from what you've said it sounds like something that couldn't be NC machined from a blank of forged material. That would be the obvious way to have the strength of a forging without the tooling costs- but if its a shape with a blind internal void (or any number of other constraints) then I could see where it would be impossible with current NC equipment.

Metal "printing" is on a faster curve than NC tools at the moment, maybe eventually forged-equivalent strengths will be possible. Not holding my breath, though.

BellCobraIV
09-17-2015, 02:25 PM
In 1973 Lyle's uncle Floyd Ledbetter had two sets of these gears and the segment gears made at an oil field machine shop in Kermit Texas. We just didn't have the budget to have more made. The parts are just stock F8F-2, I believe that Rod was able to acquire spares from Whittington.

hm66sk
09-17-2015, 02:30 PM
Yes, there is gonna be a strength difference between forged and machined from billet. I'm guessing the old ones have been welded and remachined a few times already?

Desertdawg
09-17-2015, 02:38 PM
In 1973 Lyle's uncle Floyd Ledbetter had two sets of these gears and the segment gears made at an oil field machine shop in Kermit Texas. We just didn't have the budget to have more made. The parts are just stock F8F-2, I believe that Rod was able to acquire spares from Whittington.

John,

Thanks for sharing that bit of history. Sharing your knowledge/memory about such simple things like "Lyle's uncle Floyd Ledbetter ....." is just so special. What more can I say - this is AAFO HangerTalk.

Thank you.

Hans

knot4u
09-17-2015, 03:03 PM
In 1973 Lyle's uncle Floyd Ledbetter had two sets of these gears and the segment gears made at an oil field machine shop in Kermit Texas. We just didn't have the budget to have more made. The parts are just stock F8F-2, I believe that Rod was able to acquire spares from Whittington.
John, I hope you understand my comments weren't meant as a jab to the current owner or crew, I was just pointing that some of the parts to keep flying are very difficult to obtain, much less improve. Your mod to the T-33 brakes are a good example of this, parts were becoming scarce and the airplane needed better brakes.

BellCobraIV
09-17-2015, 03:40 PM
John, I hope you understand my comments weren't meant as a jab to the current owner or crew, I was just pointing that some of the parts to keep flying are very difficult to obtain, much less improve. Your mod to the T-33 brakes are a good example of this, parts were becoming scarce and the airplane needed better brakes.

Not at all, I know you better than that. I was just filling in a little backstory for everyone else. Life is too short for all the hate, I don't go to the races anymore because if I went there I would have nothing to do. I'm a racer and that's just how I feel. I admire all these guys that still get up early, stay up late, work all year, to fight the fight. I was 6 when I started and 39 when I finally took a tip from Dwight and then Lyle. Now I'm a Hawks fan. This will be a tough Sunday against the Pack.
Go Voodoo! Go Hawks!

knot4u
09-17-2015, 04:00 PM
Not at all, I know you better than that. I was just filling in a little backstory for everyone else. Life is too short for all the hate, I don't go to the races anymore because if I went there I would have nothing to do. I'm a racer and that's just how I feel. I admire all these guys that still get up early, stay up late, work all year, to fight the fight. I was 6 when I started and 39 when I finally took a tip from Dwight and then Lyle. Now I'm a Hawks fan. This will be a tough Sunday against the Pack.
Go Voodoo! Go Hawks!

Wish there was a like button on this forum, glad to hear it sounds like things are going well. As far as racing airplanes is concerned, I always seem to get a little antsy this time of year. But I'm in my mid forties now and the price of admission required to participate is not one that I'm willing to pay, I have to admit those were some of the greatest years of my life. I suppose time washes away all the negative memories and the ones that remain are mostly positive.