Chapter 17 – Pitch Trim Spring

After 5+ years of looking, I found ’em! Thanks Mike!

One system in the Long-EZ that is not well-covered out there in the building community ether is the pitch trim system. That is, if you’re not going with the original stock springs and mechanical lever.

For electrical pitch trim the overarching style in use on the Long-EZ seems to be the Davenport style, where a composite paddle is secured to the elevator torque tube and then connected to typically the same size actuator as used for the Landing Brake. Reportedly this works fine and I had planned on going in that direction, but fairly quickly realized that with the shear amount of stuff I had packed into the panel –not to mention my odd-duck Triparagon– that the Davenport style was not going to work for me.

My seemingly-elusive search culminated in my choosing an Electric Pitch Trim system that was designed by Cozy IV builder Vance Atkinson. Most canardians know Vance since he makes & sells the spiffy fuel site gauges. Well, after a discussion in January 2014 regarding his pitch trim system, I decided to use his design in my Long-EZ.

One issue I spoke with Vance about was where to secure the springs he identified on his system overview page. He called out an Ace/True Value Hardware spring #196 that had dimensions of 6.25″ long x 5/16″ diameter. Well, as hard as I and Marco looked for these darn things, we never found them. Even contacting the Ace main office to see if they carried them anymore, to which they replied that they were not in their system any longer.

A few months ago Mike Beasley contacted me to discuss his pitch trim system. He had noted that I was not using my Davenport Leaf Spring + Firgelli Actuator system and wanted to buy it from me. I sent it off to him and wished him luck.

Well, unknown to me until Rough River, Mike had gone down virtually the same decision matrix I had with his own final realization that the Davenport style took up a bit too much real estate and wasn’t going to work for him neither. In fact, Mike, Marco and I had a fairly in-depth brain-storming session on the Atkinson pitch trim system, the result of which was Mike leaning strongly toward it.

Ok, so today I get a text from Mike that he found the ever elusive #196 springs at his local Ace Hardware store! I was flabbergasted since I had looked in at least 15 stores over the past few years, just in case they still had some by any off chance.

Curiosity got the best of me and I went to two local Ace Hardware stores, and wouldn’t you know it –in somewhat of irony– the store a mile from the airport had a bunch of them! I grabbed 4 of them to ensure I had extras, and will probably grab a few more.

Amazing, but here is photographic proof! ha!

Crazy adventure this airplane building. Strange how things work out and how patience truly does pay off sometimes!

One big side note: During the first half of 2014, while Marco was machining my Atkinson pitch trim spring housing, I bought close to $200 worth of springs looking for a 6.25″ x 5/16″ diameter spring. As grateful as I am to Vance for sharing his electric pitch trim system design, after actually getting these #196 springs in hand, I realized he had inadvertently/mistakenly sent me on a wild goose chase. Yes, these springs are 6.25″ long, but they ARE NOT 5/16″ in diameter, ID nor OD. These fit inside the 0.75″ tube and are close to 5/8″ diameter. Might have been a typo on Vance’s diagram, but it definitely made my life an adventure for quite some time trying out springs –based on those specs– that were simply to small to work in the spring tube.

2 thoughts on “Chapter 17 – Pitch Trim Spring

  1. Just looking at the #196 spring, I went ACE and bought 2, I took some measurements and found that the springs I got were 6.5 inches long. What was the wire size of the springs you got, The wire size on the one’s I bought are .075.

    Thanks Bill

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