Re: COZY: engine mounts [6 Attachments]


These holes should always be welded up as a final step.
Holes and even welded up holes are another opportunity for failure.
We do not drill holes in our mounts, we always leave a small gap on one end of each tube in our welds in a safe spot until the entire mount is completed, then we weld up these "vents".

-----Original Message-----
From: Drieux Gilbert
To: Dale Martin ; vance atkinson
Cc: Cozy Builders ; canard-aviators
Sent: Mon, Apr 28, 2014 8:41 am
Subject: Re: [c-a] Re: COZY: engine mounts [6 Attachments]


I have a Brook engine mount for my VE Lyc O-235.
I experienced 2 (TWO...) mount cracks.....  (July 2006, and July 2009).
Each oh them ALWAYS throught the little hole drilled for welding requirement (warm air must escape from tubing during welding process).
I repare them and apply reinforcements.
I obstruct all "holes" with a welding point as show in picture 09-07-25 (5).jpg
And made a mark close to the location each hole was;  So it is easyer to check the right places at any visual inspection.
(I beg your pardon; my pictures are not better than my english partice...   ;->).
----- Original Message -----
Sent: Monday, April 28, 2014 2:12 PM
Subject: Re: [c-a] Re: COZY: engine mounts


Maybe I should of said, it was under designed.

The Tubing he used was considerable thicker.  As for the shape, it is different but not radically.

As for my qualifications on designing engine mounts ...zilch !  I am not an engineer, but I slept in a Holiday Inn last night.

As for the original 0235 mount vs the original mount using a Lyc 0320 on it ...I can only take Weldtechs word on it and my observations of NO cracks or failures of these mounts.

And finally, I didn't mention the aluminum angle mounts as that is a whole other story and yes I have the heavier extrusions.

If you find those drawings of Weldtech a builder named Jack Wolf would like to see them.


On 4/27/2014 5:34 PM, Dale Martin wrote:

I disagree the mount is designed wrong.  It was meant to hold a 235L2C over 12 G's using a 3 inch extension.  I know because it was part of my structures assignment when attending college.
If however your saying it was not designed to hold a 320 as designed, you would be correct.  Although to add two additional braces to the top of the mount which distributes the torque load much more evenly is not difficult and the tubing used for the braces should be 5/8" .058 wall.  In addition, the aluminum extrusions should be increased in size to handle larger weights with longer prop extensions and for some, heavier props.

IF and I say IF making a new mount today I would start with a dynafocal ring from Snowline and proceed from there using thicker wall tubing (.058 on the 5/8", 3/4" and 7/8" tubing when using the 320 or the 360.

In a file somewhere I have the specs for the Weldtech mount.  I only wish I had the time to going looking for them..  maybe in couple of months for I can talk my son into doing some snooping!  (fat chance)...  :)


On Sun, Apr 27, 2014 at 5:58 AM, vance atkinson <nostromo56@...> wrote:

After reading Marcs article on his cracked Brock engine mount I'd like to say something about the OTHER mfg of cozy engine mounts. Cozy 3 aircraft that is.

I was one of the first ones to NOT use the recommended Lyc 0235 for power.  I chose the Lyc 0320. And knowing it was heavier I contacted a company out of Washington (weldtech I believe) to make a heavier and shorter mount.

They said sure, send us the plans.  I did.  They wrote back and said, "this mount is miss-designed, what do you want to do?"  I told them to re-design it and let me know price and time frame.

Cutting to main point, Nat had a fit that I, and several others at that point,  were going to be using an unapproved mount. 

They made the tubing thicker and the overall design was slightly different.   After 28 years and 2800 cracks, so rest easy if you have one of these mounts looks like they will go the distance ...but don't stop checking.

Vance Atkinson

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