If you need/want the OEM 40:1 Gear Set

[Matthew P]

On 10/8/2024 at 5:41 PM, MikeOH said:

Glad to hear it!

So, is this the same company (http://www.avongear.com/products/worms.html) that I found and pointed you to in a PM two days ago, or a different one?

Yes, they produce the same gear set however, they reached out to the company that they produce them for and the company said that they were NOT interested in speaking with me in regards to us ordering the gears from them, nor would they tell me who the company was....Avon also said, since they make the identical gear sets for an existing company that they could not use the drawings I have to build gears for us nor could they recommend anyone.

I'm really surprised, that whatever Company it is, wouldn't be interested in selling 100 gear sets...just wish I could find out who the company is.

[cliffy]

The South African way works for OPP just like dealing with McFarland on engine controls.

I didn't read all 6 pages but was any mention made of hiring a DER to get an approved design for the gears? Once approved by a DER any decent gear maker could make them up to the spec required by the DER.  Seems just right for a group project. 

If anyone hasn't disassembled the actuator and inspected it as required its only a matter of time before the airplane is a hood ornament awaiting parts. 

My right arm is still pretty strong!

. 

[Matthew P]

7 hours ago, cliffy said:

The South African way works for OPP just like dealing with McFarland on engine controls.

I didn't read all 6 pages but was any mention made of hiring a DER to get an approved design for the gears? Once approved by a DER any decent gear maker could make them up to the spec required by the DER.  Seems just right for a group project. 

If anyone hasn't disassembled the actuator and inspected it as required its only a matter of time before the airplane is a hood ornament awaiting parts. 

My right arm is still pretty strong!

. 

So, involving the DER is premature at this point until I am able to determine the material and heat treatment (if any) that is used, once I have that information and can show that the parts will meet/exceed OEM then I can get the DER to review/approve. Unfortunately, the process isn't as easy as one would think, I haven't been in contact with a single gear manufacturer that is interested in dealing with an individual, they only want to deal with a "company." I've texted Mooney's CEO" ...crickets....but I'm still working the issue...I DID find a company that is willing to do a Rockwell Hardness Test and determine what material and whether they used a heat treatment on the gears, so once I get that report we will have the CAD Drawings and Materials Specification...just a reminder that I only had access to a 20:1 gear set, I'm sure someone knowledgeable could take the CAD files and render a 40:1 drawing as i would prefer the 40:1 if possible.

If anyone has any personal contacts in the gear manufacturing business, please let me know..

[MikeOH]

@Matthew P

I, too, am surprised none of the manufacturers want to take your (our) money!

FYI, looking into the design of worm gear systems a critical parameter is the distance between the centerlines of the two gears; it's not sufficient to just have the diameters of the two gears.  This distance needs to be accurate to within only a couple of thousandths.  I think a careful measurement of the gear housing would be required.

[cliffy]

1 hour ago, Matthew P said:

So, involving the DER is premature at this point until I am able to determine the material and heat treatment (if any) that is used, once I have that information and can show that the parts will meet/exceed OEM then I can get the DER to review/approve. Unfortunately, the process isn't as easy as one would think, I haven't been in contact with a single gear manufacturer that is interested in dealing with an individual, they only want to deal with a "company." I've texted Mooney's CEO" ...crickets....but I'm still working the issue...I DID find a company that is willing to do a Rockwell Hardness Test and determine what material and whether they used a heat treatment on the gears, so once I get that report we will have the CAD Drawings and Materials Specification...just a reminder that I only had access to a 20:1 gear set, I'm sure someone knowledgeable could take the CAD files and render a 40:1 drawing as i would prefer the 40:1 if possible.

If anyone has any personal contacts in the gear manufacturing business, please let me know..

Well maybe $10  for 500 business cards and a local business license would a swage their fears? 

[PT20J]

If you get a drawing and material specs, perhaps the best solution is a smallish machine shop. It sounds like the specialty gear manufactures are not interested in making a small run of parts once.

[Matthew P]

Some good news.

I heard back from the FAA this morning, they have agreed to assign my (our) request to an FAA Aerospace Engineer to look into and assist with a solution, I made them aware that there is a company that states that they are making that gear set but that their "customer" isn't interested in making those parts available, so maybe they can persuade the "customer" to make the parts available to us or provide the original drawings and metallurgy report needed to verify that the gearsets we are wanting to have produced under OPP meet/exceed OEM.

[Yetti]

Talked to the Cessna guys.   They believe that the 182 172 flap actuator was made by ITT.   We looked at one in the parts catalog and the motor was oriented at a 90 degree angle where the Mooney is inline.    I would see about finding a 1975 or so Cessna 182 flap actuator and seeing what the gear ratio is.   Cessna is probably the "other" company that Avon Gear is talking about.

[EricJ]

I recall somebody saying somewhere along the way that they're also similar to Cessna flap actuators for one or more Citation models.    There are so many of those that that might be tough to track down, though.

[1980Mooney]

On 10/16/2024 at 1:44 PM, cliffy said:

Well maybe $10  for 500 business cards and a local business license would a swage their fears? 

 

On 10/18/2024 at 3:42 PM, Yetti said:

Talked to the Cessna guys.   They believe that the 182 172 flap actuator was made by ITT.   We looked at one in the parts catalog and the motor was oriented at a 90 degree angle where the Mooney is inline.    I would see about finding a 1975 or so Cessna 182 flap actuator and seeing what the gear ratio is.   Cessna is probably the "other" company that Avon Gear is talking about.

If the specs are owned by ITT or Cessna/Textron then they are not going to give you squat.  All they get is liability in return.  When a large corporation licenses IP/technology/drawings to another entity, they expect to get an indemnification from the receiving company to hold them harmless and reimburse for any lawsuits arising due to a failure with the new product/new licensing company.  Lawsuits go after the deep pockets.  An indemnification from an individual or a hollow shell of a company is worthless.

[cliffy]

What would be the cost to hire a DER to approve a gear design?

That's all that's needed Then you could go OPP

[Matthew P]

The FAA has assigned a case manager (engineer) to our request, awaiting word back from him/her. To answer your question, probably more than I'm willing to spend as an individual.

Edited October 21 by Matthew P
Additional comment

[Yetti]

10 hours ago, 1980Mooney said:

 

If the specs are owned by ITT or Cessna/Textron then they are not going to give you squat.  All they get is liability in return.  When a large corporation licenses IP/technology/drawings to another entity, they expect to get an indemnification from the receiving company to hold them harmless and reimburse for any lawsuits arising due to a failure with the new product/new licensing company.  Lawsuits go after the deep pockets.  An indemnification from an individual or a hollow shell of a company is worthless.

That's one way to look at it.   The other way would be to open up a ITT flap actuator unit and see if the gears are 40:1.    If they are then the solution has been found.  ITT still has an Aerospace Division that makes actuators.   In theory they are advocating their responsibility for not supporting their products.    Their liability is the same either way.

 

Here are some pictures of the 182 flap actuator.     https://baspartsales.com/c301002-0310-cessna-182q-flap-motor-and-actuator-assembly-28v/

[PT20J]

2 hours ago, Yetti said:

Here are some pictures of the 182 flap actuator.     https://baspartsales.com/c301002-0310-cessna-182q-flap-motor-and-actuator-assembly-28v/

That looks a more like a Mooney electric flap actuator than a Dukes landing gear actuator.

[KSMooniac]

38 minutes ago, PT20J said:

That looks a more like a Mooney electric flap actuator than a Dukes landing gear actuator.

You're absolutely correct

[PT20J]

Interesting background article on Maxwell's website. Note the last paragraph. Might be worth considering removing the inner doors if you have a M20J or modified F with the Dukes actuator -- especially if it has 20:1 gears.

https://www.donmaxwell.com/ad-75-23-04-sb-m20-190

[Echo]

My Dukes system was installed in 1965. I think it is pretty damn robust. It has functioned for nearly 60 years…20:1.

[Matthew P]

1 hour ago, Echo said:

My Dukes system was installed in 1965. I think it is pretty damn robust. It has functioned for nearly 60 years…20:1.

Well, you are lucky thus far, but gears and motors don't last forever

[Echo]

23 minutes ago, Matthew P said:

Well, you are lucky thus far, but gears and motors don't last forever

I am on the list…

[cliffy]

I will venture a guess that the airplanes that have worn gears or suffer an actual gear collapse have not been maintained properly for years. If the gears have been cleaned and regreased with the proper grease on schedule they will, in all, probability last as long as the airplane does. 

Running them dry is what causes the wear we see. 

[MikeOH]

^^^ THIS ^^^

I check and grease mine religiously and am counting on the same 'ventured guess' for as long as I own my Mooney.

[Matthew P]

And yet, when you buy a used aircraft you assume that the ones doing the maintenace...do the maintenance and don't pencilwhip it, but we know that's not the case, I bought a plane last year that had come out of a $10K annual from one of the best known MSCs, and it is amazing what was missed on that annual....so I'm a little skeptical and concerned.

[Yetti]

20 hours ago, PT20J said:

That looks a more like a Mooney electric flap actuator than a Dukes landing gear actuator.

And what is the ratio of gears in it?

[Echo]

3 hours ago, Matthew P said:

And yet, when you buy a used aircraft you assume that the ones doing the maintenace...do the maintenance and don't pencilwhip it, but we know that's not the case, I bought a plane last year that had come out of a $10K annual from one of the best known MSCs, and it is amazing what was missed on that annual....so I'm a little skeptical and concerned.

You shouldn’t need to assume?  The logs will show if the gear cleaning and re-greasing has been completed.  You can tell from logs when a plane sat and received a minimal “inspection “ vs. pro-active extensive annual. My previous comment regarding gear robustness was based on Maxwells call out of fragile in the article. It is a single failure point and will likely result in a gear up and potential total loss so maintenance and inspection of the gear/dukes system is critical for sure. I would love to have a spare. 

[MikeOH]

3 hours ago, Matthew P said:

And yet, when you buy a used aircraft you assume that the ones doing the maintenace...do the maintenance and don't pencilwhip it, but we know that's not the case, I bought a plane last year that had come out of a $10K annual from one of the best known MSCs, and it is amazing what was missed on that annual....so I'm a little skeptical and concerned.

Your concern is very understandable.  And, you are right, you really don't know the quality of maintenance before your ownership.

It's the main reason why my first criteria was recent and continuous use by the PO.  In my case, the PO flew around 100 hours/year for 13 years; I attribute the relative lack of issues I've had to that fact.  If usage history shows continuous use it serves as a pretty good indicator that the plane is well maintained; the owner has been successfully relying on it.