R.May

Landing Gear Shock Disks Source?

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Hi all,

i am looking for new shock disks.  I have called LASAR and they are sending a retrofit kit to be able to use newer disks they sell.  We will see what the looks like.  I will report back.  

If you know of a source or where I could go to do a run of them, let me know.  

Rich

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I did the LASAR kit, a lot cheaper than Mooney. If your not pressed for time I would clean and paint the gear while your there (wish I would have)

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13 minutes ago, RLCarter said:

I did the LASAR kit, a lot cheaper than Mooney. If your not pressed for time I would clean and paint the gear while your there (wish I would have)

Great idea! I think I will replace my main gear donuts at my next annual...

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So, wait.  The parts person from LASAR got back to me and said the afformentioned kit was not for the M18.  Gents, this IS the M18 Mite forum...  Is what you got for the M20 perhaps?  Got me all excited for a second.

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So, I have a call into Don Maxwell- Waiting

Emailed Boyd Maddox and Paul Workman- they do not have any leads.  They are making it sound like I need to find the spec and make some.  Anyone have a lead on the spec for these things?

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15 minutes ago, R.May said:

So, wait.  The parts person from LASAR got back to me and said the afformentioned kit was not for the M18.  Gents, this IS the M18 Mite forum...  Is what you got for the M20 perhaps?  Got me all excited for a second.

Ooppps!! not use to the M18's yet...my apologies 

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There are plenty of companies that can mold rubber parts. You are going to pay some tooling costs. You can probably get a bunch made for a little bit more money after you pay the tooling. Might want to get a bunch of mite guys together. For owner produced parts.

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The folks at Lord are pretty easy to talk with... they were at KOSH this past year...

Their expertise is in rubber bits...

They make both the rubber donuts for landing gear and rubber mounts for engines....

Chances are they have the details for all the Mooneys...

https://www.lord.com/products-and-solutions/vibration-and-motion-control/aerospace-and-defense/fixed-wing/general-aviation-mounts

 

Of course I could only find the dynafocal mount part of their site... not the donuts I was hoping for...  but, their phone number will work...

Best regards,

-a-

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41 minutes ago, R.May said:

.  Gents, this IS the M18 Mite forum...

R.M,

This is MooneySpace... :)

And you have reached the section of MS that is welcoming all Mite owners and pilots....

As you know... The Mite forum, collapsed... Before that happened, their members were invited to join us here... initiated by one Mite member that is also an MSer.

 

Bare with us for a bit...

some MSer read all the posts regardless of what section they are posted in... It takes a lot of memory for everyone to read all the details of what section they are in...  It happens to the Bravo owners as well...

In some cases you might get help from somebody that has the answer you are looking for, even though they aren’t specifically visiting the Mite section...  they might just know a ton about rubber donuts....   :)  are you only accepting answers from the Mite guys, or are you open to receiving helpful answers from anyone?

See what I mean?

Best regards,

-a-

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No worries, sorry.  Newbee coming off too flip here.  I was ribbin' when I don't even know folks yet...bad form.

Good to hear about LORD.  They were on my list to contact.  I was going to try to put together a spec for them before approaching.  May have to take an old disc and pull measurements from it.  I fully intend to make a large set of these things if that is what it comes to. 

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We have this :) and a few other emoji in the event your typing might be mis-understood...

We have people from around the planet here... it is extra easy to be mis-understood...

 

Any idea how old your donuts are on the Mite?  Standard ones have the molding date on their sides...

Compression and cold flow are the death of rubber donuts... high weight and hot temps both add to the cold flow.... the rubber spreads out slowly...

Short body Mooneys get a decade plus out of their eleven donuts...

Long body Mooneys get about 6 years...

Wondering how long a Mite can get out of how many donuts?

The stock price of a Mooney donut is about $100 each... for the standard size...

We also have a really knowledgeable mechanic shop owner that has a Mite in his hangar... See if he is around here as well...

Best regards,

-a-

 

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On 1/7/2019 at 12:42 AM, bluehighwayflyer said:

If you haven’t already, you might want to call Mack Trucks, Inc. before you delve too far into the owner-produced option.  I wouldn’t tell them you want to install their parts on an airplane, though.

From page 15 of the below-referenced issue of The Mooney Flyer ...

“Bill Wheat, former Mooney test pilot and Designated Engineering Representative (DER), recalls that Al Mooney discovered Mack Truck engine mounts would work perfectly for the rubber shock discs on the Mite.”

Jim 

2015-JulTMF.pdf#page15

That’s a story I had never heard before.  I too have to find shock discs for my Mite restoration.

Clarence

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All the parts came from some other machine wherever possible...

some examples in newer Mooneys included

The glass bowl fuel separator that got modified to be safety wired...  (John Deere?)

The AC Delco generators... (standard Chevy of its day?)

The landing gear donuts and truck engine mounts aren’t very similar in one way... but then again... Lord makes both the rubber donuts and the engine mounts on my M20R...

Interesting machine challenges that come up in the design phase...and again 60 years later...

Best regards,

-a-

Also look up...   Lord, Barry, VIP...

 

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The donuts age on my Mite?  See photo of the data I pulled from the donut.  Looks to be 1984 per what you say.  Pretty tired I would say.

IMG_5420.JPG

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I am reaching out to vintage Mack folks.  We will see what happens. 

Also, talking to someone in Boeing and another in Pratt who are familiar with reverse engineering to see what they may be able to do. 

Mooney has been quiet.  I will have to pick up the phone and rattle them a little for data.

IMG_5411.JPG

IMG_5417.JPG

IMG_5416.JPG

IMG_5402.JPG

IMG_5406.JPG

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Looks like a part number and a date code!

They were probably cylindrical in shape, originally...

If you have the plane’s logs, somebody probably put an entry in the log regarding swapping out the donuts...

Best regards,

-a-

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I’ve considered the discs from an Ercoupe from Univair as a source, or taking one from a current Mooney and seeing if it could be machined to fit the Mite.

Clarence

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Machining rubber has been done before... probably requires some interesting technique and cutting tools... keep it frozen (freezing/hardening temperature of rubber) while milling/lathing?

@GEE-BEE has recently demonstrated a method of die cutting rubber sheets...  die cutting rubber parts down to size is an interesting possibility.  The press and the cutting tools may have some strength limitations...

The molding of rubber typically uses a mold that gets filled with liquid monomer, a chemical reaction takes place under heat and pressure, after the reaction is finished, the mold is cooled and the part removed... date codes are put in the edge of the mold so they show up in the finished part...

So it is also possible to find a rubber molder to turn out a few bisucuits as well.  A few phone calls to see what they have for molds that may be close...

Selecting the proper rubber may be a challenge that rubber part suppliers will be familiar with... lab test will probably include...

  • Chemistry, rubber type
  • hardness
  • elasticity
  • % filler, and type
  • % carbon black

Makes an interesting user supplied part situation... there is definitely a need, and no commercial supply available... 

Ohio used to be the center of rubber manufacturing...in the US.

Seeing if any of this spurs any ideas... :)

Best regards,

-a-

 

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Those are easy to do,  i will need a sample

 

I suggest epdm rubber

70 shore

 

 

Molding has mold cost , etc

 

min run 100/250/500

Iam doing a batch of flurosilicone fuel caps now / 40 duro

Early beech

Edited by GEE-BEE

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Gee-bee,

Do you have access to a testing lab service... to send a rubber sample to get a ‘finger print’,  essentially determine the existing chemistry, % cross-linking, hardness/durometer, %filler, and other things....?

It would be nice to know if the M18 donuts are made from the same dough as the M20 donuts...

 

It would be best to find something close, that is commercially available, at a low cost...

than, to have to build a mold and make them yourself... costs could get away quickly... quality challenges may be hard to control.

 

If paying for a mold for an existing supplier like Lord.... they would have the strengths in all departments... paying for a mold might not be that bad...

 

Die Cutting new donuts out of commercially available rubber sheet would be an interesting solution...

 

Fortunately... the commercial rubber chemistry wasn’t very complex in the 50’s and 60’s...

 

PP thoughts only, not a donut maker...

Best regards,

-a-

 

 

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Clarence,

Do you know if the M18 donuts are cylindrical in shape when installed similar to the M20... or do they start out conic in shape as they look in the drawing you posted here?

Some rubber can withstand being one shape, and being compressed into the other.... other rubber compounds may generate a split over time...

Best regards,

-a-

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I’m not really sure, but I believe that they were flat when new and become tapered over time.  The set from my Mite are hard and tapered as well.

Here is what I thought I’d try from Univair in Colorado.

Clarence

 

5A9C202B-BC85-4FA1-A6B5-847F24EC1B1E.jpeg

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This post got a little out of order.....

The Aircoupe catalog is also the M10 Cadet catalog.

https://www.univair.com/content/ercoupe_catalog.pdf

I left them a request for info.   See if they get back to me...

 

03CBF1CC-A275-4FC4-8462-A55EA824B3AE.thumb.png.1541c6d01e30618caafee8d899bef6b9.png

 

 

Univair gave us the Rosetta Stone of dimensions... they included a ruler so we can infer the dimension of the ID and OD...  next to the related rubber donut....

 

71DAC69E-47DD-453B-8BA2-797C705A82E0.jpeg

3E605FD0-AFFE-4D9A-AB87-7D575BAB3F92.jpeg

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