Self Centering Nose Strut Upgrade

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SHANE O'DAY
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Joined: Wed Feb 08, 2023 4:41 am
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For those that don't know, the early Esco nose struts vary widely in configuration. One big change Lancair made was the introduction of a self-centering feature in the mid 90's. Early struts without this feature use a hoop attached to the fork to ensure that the wheel doesn't jack-knife against the fuselage when being retracted. The addition of self-centering eliminated the need for this hoop as the strut automatically centers itself when it is near full extension (weight off the gear). Since this introduction most all variations and adaptations of the Lancair nose strut feature self-centering of some form.

The Esco strut on my 360 was one of the early ones, it was non-self centering and didn't have the latest shimmy damper upgrades found on the later 360 struts. A few years ago I upgraded it to self-centering and changed some things to improve the shimmy performance. There were a few parts I needed to make and some I had to modify.

• New centering cam
• Modified existing bushing housing to interlock with centering cam.
• New Guide Key & retainer set w/o-rings and countersunk screws (my original was only Loctite sealed w/ counterbored holes)
• Modified existing rotation sleeve with the two extra o-ring grooves and shortened
• Modified my rotation key to add a second groove
• Modified original flange with slots
• New flange shim
• New strut collar

Would I do it again? I'm not sure, there are a few things about the design of the Esco I don't like so I think I would prefer to build a new strut. The mod is certainly not something anyone can do, even overhauling these struts requires a number of custom tools, usually owners don't understand this until the strut is half disassembled on the bench.

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Rotation Sleeve Mod.PNG
Rotation Key Mod.PNG
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Shane O'Day
O'Day Design LLC
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SHANE O'DAY
Posts: 32
Joined: Wed Feb 08, 2023 4:41 am
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To give a better idea of how the esco strut self-centers near the full extended position:

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Shane O'Day
O'Day Design LLC
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SHANE O'DAY
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Joined: Wed Feb 08, 2023 4:41 am
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I've had a number of owners ask for me to overhaul or upgrade their nose strut or for me to instruct them what they need to do themselves. The nose struts require a number of tools and fixtures in addition to the seals. These really require machine shop equipment to produce so its not something the average mechanic, builder, or owner should take on. Most owners don't realize this and assume its as simple as changing some o-rings. While I have all these tools doing repairs really isn't my thing so I almost always recommend they talk to Chris Z. Chris is well setup to work on these even stocking new replacement pieces.

Legacy Main struts are a completely different story, these are quite easily rebuildable on the aircraft, I wrote an entire instruction manual and created a seal kit to help owners complete this:

https://odaydesign.com/product/700-0065/

While I don't recommend you overhaul your own nose strut I do offer an Esco nose strut seal kit now as so many owners were trying to use the Legacy Kit to rebuild their nose struts, I figured it was better that they at least have the right parts.

https://odaydesign.com/product/700-0066/

This is just a sampling of the tools required to do the basic overhaul on an Esco nose strut:

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Shane O'Day
O'Day Design LLC
Chris Zavatson
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Joined: Fri Aug 25, 2023 5:48 am
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For the last several years I have been doing a presentation at the LOBO Landings titled "ESCO Deep Dive". It covers a combination of design evolution (most changes were good, some had unintended consequences), functionality and maintenance.
The design has proven to be rather tolerant of less than ideal maintenance practices. Typically owners simply don't know what to check. If ignored too long, it will eventually fail - and shimmy can make for a really bad day.
I posted an annual check list previously. reposted here.
Attachments
Annual Esco Checklist Items.pdf
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Chris Zavatson
www.N91CZ.com
YouTube: N91CZ
Tom Sullivan
Posts: 105
Joined: Mon Nov 28, 2022 2:33 pm

Just a quick shout out to several of our newly active members, adding great value to our Lancair Live Forum with interesting and informative posts lately!!

Tom
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