Looking for a up lock and down lock block for CNC owner produced

[Guest]

On 1/12/2020 at 1:22 PM, cliffy said:

Just a thought Has anyone tried a repair by sleeving the hole and welding the slot? 

Or welding the damaged area, then machining the hole back to spec.  It seems to me that if a crankcase can be weld repaired this part can as well.

Clarence

[CWM20f]

Money sent.  That goal was meet fast!

 

[G spot]

Looking forward to the drawings and a producer.  This a great!  

[Sabremech]

Parts headed to the machine shop for drawings. 
David

[Anders J]

15 hours ago, hammdo said:

This may help decide:

https://www.twmetals.com/products/plate/aluminum/7050.html
 

looks like the way to go...

 

-Don

 

Been chatting with a couple of friends that works for a local military aircraft manufacturer, and it is being recommended to me we rent a Thermo Niton XRF Analyzer to determine the Zn level.  Have dropped an email to find out what cost to rent one for one day.  Next I spoke with a client with a university in MO, who does metal sciences, and he recommended a ICP analysis.  Found a company that ICP tests, and have asked them for a quote.  More to come.

 

Anders J

Edited January 24, 2020 by Anders J

[rbridges]

Just asking a couple of dumb questions. They'll be able to compensate for the wear on the used blocks when they're designing new ones?   Also, they use aluminum to minimize wear on the Johnson bar itself?

[RLCarter]

47 minutes ago, Sabremech said:

Parts headed to the machine shop for drawings. 
David

Never really looked at the block on the floor, looks the same minus a few steps and the mounting holes are 90°. Which will make the machining easier 

[hammdo]

This is gonna kick butt when done! 

-Don 

[cliffy]

8 hours ago, M20Doc said:

Or welding the damaged area, then machining the hole back to spec.  It seems to me that if a crankcase can be weld repaired this part can as well.

Clarence

I don't see any reason why it couldn't be done as just a repair.  Weld the hole, clamp to a fixture, eyeball the hole with an end mill and plunge it down Same with the slope- weld and file it if you had too. You could probably file the hole also.  Nothing complicated here. This is not a structural piece of airframe. 

[Sabremech]

11 minutes ago, cliffy said:

I don't see any reason why it couldn't be done as just a repair.  Weld the hole, clamp to a fixture, eyeball the hole with an end mill and plunge it down Same with the slope- weld and file it if you had too. You could probably file the hole also.  Nothing complicated here. This is not a structural piece of airframe. 

Definitely would be a simple repair process, but is it legal to do as an owner part? How would the repair be signed off? I personally would not want the responsibility of signing the repair as it is a very important piece of the landing gear system. It’s not a structural piece of the airframe but is for the landing gear. 

Without a repair from Mooney or a repair station license with this type of repair listed on the repair station, how could this repair legally be done? I did think of this the other day, but found no easy way to get it back in the airplane with a legal sign off. 

 

[RLCarter]

An old one could be repaired, but I think it would take more labor than just cutting a new one. Also think some are overthinking the alloy needed, the original is cast and junky at that

[Sabremech]

11 minutes ago, RLCarter said:

An old one could be repaired, but I think it would take more labor than just cutting a new one. Also think some are overthinking the alloy needed, the original is cast and junky at that

Definitely not overthinking the alloy. This part must be the equivalent of the original. We can’t guess at the alloy to comply with the rules. I have had to use a lab near me to determine the alloy in the past and can do the same with this part. 
David

[N201MKTurbo]

While the gears in the Dukes actuator are critical, you could probably make these blocks out of oak and be in pretty good shape. Not to mention it gets inspected every time you use it. When doing a failure analysis, detection of failure is important, with it right in front of you, detection of failure is very high.

[Hector]

Definitely not overthinking the alloy. This part must be the equivalent of the original. We can’t guess at the alloy to comply with the rules. I have had to use a lab near me to determine the alloy in the past and can do the same with this part. 
David

Agree David. Need to figure out what it is made of. If it’s an aluminum casting I can almost guarantee that 7050 will be superior but the drawing will need to specify the grain orientation as the the properties of this machined part can vary depending which axis you pick (anisotropic material).


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[cliffy]

Why would this be any different than "repaired buy welding" on a muffler? 

Yes it is part of the landing gear system but what is the failure mode if done wrong? What can be done wrong? 

I think it can be done by any A&P by welding. We weld airframe parts don't we? Tube structures. We weld engine mounts don't we?  And they are structural.  Its just aluminum welding. Oxy/hydrogen or TIG would suffice. The only wear surface is what you are replacing. Inspection in the future is no different than original. One may have to determine the material type to choose the correct welding rod. 

Granted it would be nice to have new part but to think that is the only way to fix something may not be true. 

Also as Sabermech stated above  - you just can't guess at the material on any OPP'

You can't just do what ever you want on an OPP!  It has to comply with all the legs of the reg as req'd!

For those who think different, I suggest you go read the requirements to qualify as an OPP. 

AC 20-62   P. 4b2

https://www.faa.gov/documentlibrary/media/advisory_circular/ac 20-62e.pdf

You gotta have some kind of approved data to build to

 

[MooneyMitch]

“Yes it is part of the landing gear system but what is the failure mode if done wrong? What can be done wrong?”

 

Not necessarily for the up gear up floor block, but for the gear down top block, from first hand knowledge...... a failure of that block can result in gear collapse. 

[Hector]

Most aluminum casting alloys can be welded, but welding aluminum takes some skill. Do I want to take the chance the mechanic who is doing the welding has the required training/certification? Frankly, I rather have a new part machined from a superior alloy. The first one lasted 50 years. The new updated part using a superior alloy will be the last one I will buy with little risk and piece of mind.

 

 

Sent from my iPhone using Tapatalk

 

[hammdo]

Well, this thread has produced some real chatter! From the looks of the block — appears to be a cast. 
 

from the FAA ac. Note 7075 is an accepted material:

 

 

we need equal or superior to original part. My guess this and the other material I linked to will (7050) suffice.

-Don

Edited January 25, 2020 by hammdo

[hammdo]

5 hours ago, Sabremech said:

Definitely would be a simple repair process, but is it legal to do as an owner part? How would the repair be signed off? I personally would not want the responsibility of signing the repair as it is a very important piece of the landing gear system. It’s not a structural piece of the airframe but is for the landing gear. 

Without a repair from Mooney or a repair station license with this type of repair listed on the repair station, how could this repair legally be done? I did think of this the other day, but found no easy way to get it back in the airplane with a legal sign off. 

 

See highlight: pretty much no can do...

 

 

[hammdo]

A bit more info on aluminum:

 

[Guest]

7 minutes ago, hammdo said:

See highlight: pretty much no can do...

 

 

Based on this, there will be a large number of engine crankcase and cylinder repair shops surprised to be out of business if they can weld engine parts.
S & B Industries in Utah welds quite a number of aluminum gear parts used in Piper landing gear.  
 

Clarence

[rbridges]

Just now, M20Doc said:

Based on this, there will be a large number of engine crankcase and cylinder repair shops surprised to be out of business if they can weld engine parts.
S & B Industries in Utah welds quite a number of aluminum gear parts used in Piper landing gear.  
 

Clarence

I'm just asking out of ignorance.  Maybe those repairs are approved by the manufacturer?

[Guest]

26 minutes ago, rbridges said:

I'm just asking out of ignorance.  Maybe those repairs are approved by the manufacturer?

I’m sure they all process some form of FAA approval for their welding process.  
 

Clarence

[EricJ]

While ACs are accepted data, and AC 43.13 is approved data in the circumstances outlined on page 1, they are not regulatory.   Manufacturer's manuals or even SBs or SIs, can easily be used to trump AC 43.13.   Manufacturer's data almost always has priority.

[hammdo]

Yeah, my point was if we don’t have procedures acceptable for repairing the down/up locks (Manufactures or FAA), then we’d have to go for approval ourselves. 
 

That seemed like more work vs owner produced parts...
 

-Don

Edited January 25, 2020 by hammdo