Gear Strut differences

[Farmboy]

Okay, so I got some ends to make up airfoil covers for the bungees, and while they looked small, I compared them to a loose strut and they fit.

Then I was out at the hangar and took a photo of the actual units on the -11, and it appears that mine is different.

The loose -18 strut seems to have a shorter lower cross tube, so the bungees would stack on top of each other, and the upper cross tube is longer, allowing the bungees to lay flat.
My -11 strut seems to have the same size cross tube upper and lower, making an airfoil cover not be able to fit over the lower cross tube.

Is this typical? It works obviously, but the parts breakdown and such do not seem to reflect this?

On the PA-11:


Loose strut for an -18:


Help?


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[cubdriver2]

Looks like a J3 strut, not the more streamlined 11 strut?

Glenn

[Farmboy]

Is the J3 strut built that way Glenn, with both cross tubes tall?


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[bob turner]

Yes, but they are all interchangeable through early PA-18. I am not sure if new parts follow the later streamlined idea, but they should. The newer struts look better even with leather boots.

My airplane came in 1962 with one of each.

And by the way, new gear legs for all Cubs are PA-18 style, which fits the Grove parts better.

[Farmboy]

Bob, not trying to interchange them, I am trying to get covers to go over them. Seems my streamlined covers are too small.


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[RaisedByWolves]

We found out that the J-3 shock struts are different from the -11 and -18
http://www.univair.com/winter-sale/p...trut-assembly/
http://www.univair.com/piper/piper-p...trut-assembly/

It appears that the lower end of the shock strut on the -11 and -18 is narrower and the bungees stack up instead of sit next to each other like on the J-3

[Farmboy]

Arrgh... so Tom and I spent time on the phone comparing Univairs and Pipers drawings and figured it out.

I have J3 struts. The J3 struts are the only ones with wide top and bottom bungee mounts, which is what I have, and the bungees sit side by side. The -11, -18 and -18A all use a different strut (non-hydrasorb) with wide top and narrow bottom mount, so the bungees stack on the bottom mount.

Of course I didn’t expect to have J3 struts, so my now primed airfoils won’t fit as they are too small for the J3 lower mount.


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[Farmboy]

Tom’s faster on the keyboard and beat me to it.


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[cubdriver2]

Arrgh... so Tom and I spent time on the phone comparing Univairs and Pipers drawings and figured it out.

I have J3 struts. The J3 struts are the only ones with wide top and bottom bungee mounts, which is what I have, and the bungees sit side by side. The -11, -18 and -18A all use a different strut (non-hydrasorb) with wide top and narrow bottom mount, so the bungees stack on the bottom mount.

Of course I didn’t expect to have J3 struts, so my now primed airfoils won’t fit as they are too small for the J3 lower mount.


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Wow, you guys are good!

Glenn

[Farmboy]

Wow, you guys are good!

Glenn

Yup! You were right! You just didn’t get back to me on the follow up question.


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[mike mcs repair]

easy to make new bigger cover plate ends, if you want to know how?

[Farmboy]

Mike thanks, I can do it or get a set, but it would make the foil quite a bit thicker/bigger.... not sure I want to do that either.


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[Scouter]

Your hands are too clean and your LL Bean slippers are untied, can only mean one thing:
you are messing with an airplane after dinner instead of spending time with the girl of the house

Atta boy

Jim

[Farmboy]

Your hands are too clean and your LL Bean slippers are untied, can only mean one thing:
you are messing with an airplane after dinner instead of spending time with the girl of the house

Atta boy

Jim

Ha! Blame the loafers on the local duffer Mr. Doody. I haven't figured out how to wear those yet.

Pb


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[Steve Pierce]

Ain't Experimental fun. Get some vinyl bags and put aluminum in them.

[Farmboy]

Ain't Experimental fun. Get some vinyl bags and put aluminum in them.

Aluminum in the vinyl bag?


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[Steve Pierce]

Aluminum in the vinyl bag?


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http://www.supercub.org/forum/showth...e-Covers/page3

[SteveE]

Or just put some carpet pad inside vinyl covers.




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[Farmboy]

Steve, pad inside the bag just so that it was a smooth round tube?


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[Steve Pierce]

Yes, the th r ad I linked shows my shredded bags.

[Farmboy]

Ah. Got it.

I'm with Zinks comments in the other thread about losing speed. In my case every little bit helps as I'm the slowest (aside from Douten maybe), and I don't have much brush or ground cover here to whack, tear or affect the bags or covers. So streamlined covers made perfect sense until I found the J3 struts.

If I could reuse the bungees I'd cut off the end cap and weld it back on at the pa-18 width, and use the small airfoil endcaps. But replacement struts are $$$$ and so not much of an option.
With the J3 struts, I'm not sure that the larger hydrasorb covers would even fit.

Might have to keep running bags.

Pb


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[cubdriver2]

Peter is chasing the mythical top end speed that he thinks a Cub should have. You might get a half mph out of those alum covers.

Glenn

[Farmboy]

That said, if anyone want end caps, with a little persuading Don Jones will still send some your way.


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[Farmboy]

It's not a mythical thing Glenn, and I don't have any expectations as to what it "should have".
What I have is a desire to make it better than it is, and every little bit helps, or if it doesn't, I look for alternatives. Pretty hard to find a mousetrap that can't be improved upon.

Someone once said to count the ounces and you'll find pounds.

Pb


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[RaisedByWolves]

Hey peter
90hp j3 level flight




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[Farmboy]

lol. I saw you showing off that photo on Facebook Tom Ford. You should take that and go fly with John Fleurent, in his "slow" J3...

[BC12D-4-85]

I used large soft cold weather fabric shock covers and put pieces of round foam water pipe insulation in front and back of the bungees. Tapered the covers some front to back and gained whatever that did for speed. Actually the main reason was to absorb or deflect grass and brush hits in winter on skis landing on dry snow covered spots to set traps. By day's end the rest of the ski gear would eventually get covered with debris and any water from overflow froze to the vegetation but not the covers. They may have flexed like deice boots but didn't overthink the why.

Gary