Q on tail post sleeve for pa-22/20

[Steve Pierce]

I am not sure about how much play but if you look at the fuselage drawing it will give you the tube size of the tail post and the fin drawing will give that tube size which will give you the interference.

[Steve Pierce]

Now that Ive gotten the fin out of the tailpost and examined it--- (and cleaned it some) the fin post slides down in there much easier than it did.
I can wiggle it a little bit now-- where I couldnt before. How much slack there is permissible ? I am tossing around the idea of putting in a new tailpost
--- partly so I can sleeve it to my liking--- but I will keep this one if it doesnt look too bad inside-
I thought I could put a 12 ga. shotgun brish in the drill and run it down in there to clean the inner surface to better make a fair judgement of the interior condition. Looks like putting in a new tailpost would be a pretty good chunk of delicate work -- but I could do it ….

How much "wiggle" is tollerable in the fin at the rear socket--- ?

Tim

Tim, I moved this new thread to your thread on the stuck vertical stab. I figured they go hand in hand and would be easier for someone to find all this information in one place. One of my goals here is to make subjects easily searchable for generations to come so that the can benifit from the knowledge shared here.

[violinmaker]

Gotcga ya-- thanks----
Do you mean the piper drawings CD ? For some reason I didnt think to look there.

I had an idea/observation I will throw out later today about how to do a top-down fin post sleeve job. (throw out for opinions/feedback)
Thought I might describe it to clyde smith and also see if he thinks it would be good. (assuming I don't do a "full amputate" mine.... )
Tim

[violinmaker]

Noticed that my 22/20 has a short sleeve at the bottom-- comes up just a little above the old spring hole (which never got patched-)
Not sure if that was put in during the conversion or was a 22 leftover.

Just thinking-- if I was to simply drive a sleeve inside the existing post- it would bottom out against that short sleeve. And that junction would be
very close to where they crack across the hole. Seems like this geometry would force all the movement from the tailwheel stress to work the outer
tube at that junction - which would seem to only make the problem worse by forcing all the action to that small confined area.

Im thinking a better idea would be to use the same general type of inner sleeve-- but insert into the end of that sleeve a shorter sleeve which would
fit snugly inside the short bushing at the bottom of the tail post. That piece could run all the way to the bottom and even stick out of the short


bushing that is there now. That way when the tail post is flexed from the leaf spring-- it cant distort at the junction between my long sleeve and the
short pre-existing short sleeve. (the short one may be there to beef up the cross hole for the Paa-22 skid ????)

I can see some weld melt through at the upper longerons that I will have to smooth /grind out in order that a sleeve will go all the way down. May be
able to clear that up using a 3/4 inch stone on a long stem.

Thought I's throw this out for engineering type comments and feedback...

If I can measure the ID of that short bottom sleeve- I could make my sleeve out of the same material so that the ID's of both would match-
and the internal connector would fit both snugly.

Tim

[violinmaker]

can someone tell me how to "delete" ??

The "edit" button says "edit/delete" when you hover over it--- but after you click it--- I cant find a delete button …… can you give me a hint ?

[Jim]

Hi Tim,

Might be dependent on what you have, but here I click on edit then along the bottom right in that box there are several options. Steve could help out if you don't have Save, Go Advanced, Delete, Cancel where you can option their use.

[Steve Pierce]

I merged them.

[Marc Davis]

I believe that "short sleeve" at the bottom is the piece of the original tie down hook that someone cut off during the conversion. Probably could not get it out of the tail post so they just cut it off. Mine has the same small sleeve and the cross hole was also drilled in it. If it was me (and it was me , and given how many of these have cracked, I would do what you need to do to get that old sleeve out and install a proper sleeve. That probably means installing a new tail post and spring perch. That also give you a chance to look inside the lower longerons for rust. Mine were in good shape which gave me more confidence in the overall fuselage.

I just finished up my tailpost last night. The job took me 10 days of spare time from cutting off the old fabric to spraying the last coat of finish color on the new. I'm going to test fly it today.

[violinmaker]

Marc----
After you cut the old post off--- what method did you use to remove the curved disks (post remnants) remaining on the other tubes---- the disks would be the leftover part of the
tailpost and the weld fillet around it---- that would have to be ground (?) away so the new post is in the exact same position as the old one was........

Did you grind/drill through the center of the circular piece ---- then work the hole outward to the ID of the tube and then grind down the outer edge containing the old fillet
till about flush with the tube OD ? The shorten the tube by had about .030 inch ?

Dont want to jump into water over my head till I know what lies below

Tim

[Steve Pierce]

I cut the tube being replaced away and then grind the part left with a cutoff wheel. You can see when the tube disappears, then the new tube will fit perfectly. Works on tail post, longerons or any other tube being replaced in a cluster.