Thorp Air Command - T18.net

Supporting Owners, Builders and Pilots of the Thorp T-18 and its variants.
It is currently Thu Mar 28, 2024 10:58 am

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 23 posts ]  Go to page 1, 2  Next
Author Message
BobMoe
 Post subject: Folding Wing Pins
PostPosted: Thu Apr 14, 2011 4:47 pm 
Full Member
Full Member

Joined: Fri Oct 23, 2009 7:33 pm
Posts: 145
Images: 4
Location: USA-Daytona Beach, FL
Has anyone made their own 9/16" pins per the drawing 231 ?
What procedure did you use to harden the pins?
Did you Cad plate?
I thought I saw a Quick pins number listed somewhere.

I have some Avibank 17984-916 pins and AN9 bolts that I test fitted to my reamer with good results. (Reamed a test block)

Any feedback is appreciated.

Thanks,
Bob MO


Last edited by BobMoe on Thu Apr 14, 2011 4:47 pm, edited 1 time in total.

Top
 Profile Personal album  
 
admin
 Post subject: Folding Wing Pins
PostPosted: Thu Apr 14, 2011 5:09 pm 
Administrator
Administrator

Joined: Tue Oct 20, 2009 2:21 pm
Posts: 176
Location: USA
Years ago while building my S-18, I had a machime shop make some out of titanium, don't know what happened to them. I bought from Phil Tucker a set of his pins that were cad plated. Since I've only folded my wing twice in 17 years I have installed AN9 bolts. It takes 10 minutes to take the wings off for transport.

*** admin posted for William Williams ***

_________________
Forum Administrator


Last edited by admin on Thu Apr 14, 2011 5:09 pm, edited 1 time in total.

Top
 Profile  
 
jrevens
 Post subject: Folding Wing Pins
PostPosted: Thu Apr 14, 2011 5:18 pm 
Sr. Member
Sr. Member
User avatar

Joined: Thu Oct 22, 2009 10:13 pm
Posts: 789
Location: USA
Bob,
I started out making the folding wings, then reverted back to the originals, after building spars, fittings, etc. I did make my own pins, 30+ years ago. I was corresponding with Lu Sunderland quite a bit at that time, & I got the wild (stupid?) idea to make mine out of stainless steel. I made them out of 431 stainless, had them heat treated to 195,000 psi, and then ground to dimension. I figured I'd lightly lube them, and no plating necessary. Lu thought they were just fine. A lot of screwing around for some simple pins, when I'd probably have ended up just bolting everything together like a lot of the guys do. If you make them out of 4130 chrome-moly, you heat treat to 150,000 psi, and cad plate.

John Evens N71JE
Arvada, CO

_________________
John Evens
Arvada, Colorado

T-18 N71JE (sold)
Kitfox 7 SS N27JE


Last edited by admin on Thu Apr 14, 2011 5:18 pm, edited 1 time in total.

Top
 Profile  
 
Rich Brazell
 Post subject: Folding Wing Pins
PostPosted: Thu Apr 14, 2011 8:31 pm 
Hero Member
Hero Member

Joined: Wed Oct 21, 2009 12:33 pm
Posts: 3095
Images: 64
Location: Jamul, CA (San Diego area)
Bob: There is a number listed for the rear spar "Quick Release" pins on a drawing, I'll look for the drawing # in the AM. Good luck finding "that" pin. I've spent many hours researching the plans called for pin and could not find it. There are outfits that can "Special Order" the pin, but I imagine the cost would be "Special Order" also. I found some double acting pins (surplus and I think I got the last 4) that are slightly longer than the plans pins and so far they are working just fine. Let me get the number off them.

RB


Last edited by admin on Thu Apr 14, 2011 8:31 pm, edited 1 time in total.

Top
 Profile Personal album  
 
BobMoe
 Post subject: Folding Wing Pins
PostPosted: Fri Apr 15, 2011 3:54 am 
Full Member
Full Member

Joined: Fri Oct 23, 2009 7:33 pm
Posts: 145
Images: 4
Location: USA-Daytona Beach, FL
Thanks for the positive response's. I spent 2hours searching for the avdell or avibank or avi??? Numbers. Rich, your probably right. They were probably for the rear spar.
The pins are made from 4340 and I want to play with my new lathe, if I can get the specs for the tailspring. I think they are made from the same. ACSpruce has the 150,000 temp listed, but I was hoping for:
Heat cherry red and quench, heat to 325degrees and bake for 3 hours or something along that process.
I will probably make several pins and have them plated.
I did not know what was being used and thought I would ask.
I do have some extra 5/16, 3/8 & 9/16 Avibank Ball-lock pins if anyone is interested.
Thanks,
BobMO


Last edited by admin on Fri Apr 15, 2011 3:54 am, edited 1 time in total.

Top
 Profile Personal album  
 
Rich Brazell
 Post subject: Folding Wing Pins
PostPosted: Fri Apr 15, 2011 6:47 am 
Hero Member
Hero Member

Joined: Wed Oct 21, 2009 12:33 pm
Posts: 3095
Images: 64
Location: Jamul, CA (San Diego area)
Bob: Drawing #102R MS 17999C404. I spent weeks looking for them and finally came to the conclusion they were "surplus" and available at the time. Even sent a copy of the drawing to B & B Surplus (think it is B & B) in Kansas and he didn't have them. The A/C is at the airport and I keep the spare rear pins with the A/C, including spare mains pins. I'll get the number for the rear pins I used tom. AM. They are slightly longer and I believe they are "off the shelf" available. I also devised a way to easily insert and remove them. I'll take a pic of my Inserto tool (patent pending).

RB


Last edited by admin on Fri Apr 15, 2011 6:47 am, edited 1 time in total.

Top
 Profile Personal album  
 
jrevens
 Post subject: Folding Wing Pins
PostPosted: Fri Apr 15, 2011 11:13 am 
Sr. Member
Sr. Member
User avatar

Joined: Thu Oct 22, 2009 10:13 pm
Posts: 789
Location: USA
Bob,
I assumed you were talking about the main pins (9/16"), & that appears to be the case. I don't know how the other pins came up. If you machine your own out of 4130, I would highly recommend having them heat treated by someone who does precision/mil-spec heat treating. This isn't something that you want to do yourself, unless you have a very accurate oven, possibly with inert gas atmosphere, etc. Also, when they are plated, make sure the shop knows how to properly bake them for hydrogen embrittlement, and does it within the accepted time period after plating - again, a shop that does aircraft-spec stuff. Are you sure you don't just want to buy a set from Mike Archer (if available)?... the voice of experience. Some may disagree.

John Evens N71JE
Arvada, CO

_________________
John Evens
Arvada, Colorado

T-18 N71JE (sold)
Kitfox 7 SS N27JE


Last edited by admin on Fri Apr 15, 2011 11:13 am, edited 1 time in total.

Top
 Profile  
 
BobMoe
 Post subject: Folding Wing Pins
PostPosted: Sun Apr 17, 2011 5:55 am 
Full Member
Full Member

Joined: Fri Oct 23, 2009 7:33 pm
Posts: 145
Images: 4
Location: USA-Daytona Beach, FL
John & Rich,

You are both correct. I was just wanting to see what others have done. I

Thanks


Last edited by admin on Sun Apr 17, 2011 5:55 am, edited 1 time in total.

Top
 Profile Personal album  
 
Rich Brazell
 Post subject: Folding Wing Pins
PostPosted: Sun Apr 17, 2011 4:06 pm 
Hero Member
Hero Member

Joined: Wed Oct 21, 2009 12:33 pm
Posts: 3095
Images: 64
Location: Jamul, CA (San Diego area)
Bob: Here be the number for the pins I use on the rear spar.

Avdel NAS 1354DS7S05 Push/Pull BLS4R05D. Pretty sure I copied the numbers right ? You might be able to get them off E-Bay ? Although some knuckleheads charge WAY too much for even one ! Try that place in Kansas...B & B Surplus ?

Got another 2.0 today on NX115RX. Re-rigged one aileron, big difference. Shortened the links on the servo tabs...big difference. Not so HEAVY on the controls ! [;)] If I didn't have the "eyeball vents" in the dash, it would have been brutal. 90 + here the last 2 days. [}:)] 15.0 hours to date and other than the rig problems, no problems. Using almost no oil at this point...a good thing. [:D]

Faster and Farther

RB
NX115RX


Last edited by admin on Sun Apr 17, 2011 4:06 pm, edited 1 time in total.

Top
 Profile Personal album  
 
ljkrume
 Post subject: Re: Folding Wing Pins
PostPosted: Mon Oct 14, 2013 8:00 pm 
Sr. Member
Sr. Member

Joined: Mon Oct 26, 2009 1:33 pm
Posts: 232
Images: 213
Location: USA
Hey guys,

Seems it's been a while since pins for folding wings has been a subject. I checked with Mike Archer just a week or so ago and he's out. Thought I'd ask first if anyone has a set (#231) to sell before I go to make my own. And here's a curious thing: I can't figure out what the narrow finger is for on the lock that holds it in place (same drawing). Really thought I'd be flying in by now to some of the events this summer, but work gets in the way. Anyway, it won't be long!

Thanks, Les Krumel,
Albuquerque


Top
 Profile Personal album  
 
Hagle347
 Post subject: Re: Folding Wing Pins
PostPosted: Mon Oct 14, 2013 8:05 pm 
Sr. Member
Sr. Member
User avatar

Joined: Tue Oct 26, 2010 3:42 pm
Posts: 566
Images: 19
Location: USA
Hi Les, I must have got the last set he had. After they arrived I checked the holes - yup bolt size. I kept them instead of sending them back.

Get with me and I'll get them coming your way.

Terry
850-974-5608 cell


Top
 Profile Personal album  
 
bfinney
 Post subject: Re: Folding Wing Pins
PostPosted: Mon Oct 14, 2013 11:07 pm 
Sr. Member
Sr. Member
User avatar

Joined: Thu Oct 22, 2009 2:24 pm
Posts: 501
Images: 6
Location: Yelm, WA USA
Les,
If you note the side view of the 231L-1 lock, there is a small bend at the end of the narrow finger. Also note drawing 230L shows the -1 lock installed with mating #12 holes in the 215 fitting that match the end of the narrow finger. I would say that it is a "locking" method to keep the -1 lock in place. That said, my aircraft does not have the narrow finger on the -1 lock or the #12 holes in the 215 fitting and this wing was installed on the aircraft in 1978.

_________________
Bruce Finney
N18JF T-18C #262
Yelm, WA USA


Top
 Profile Personal album  
 
Jim Mantyla
 Post subject: Re: Folding Wing Pins
PostPosted: Tue Oct 15, 2013 2:04 am 
Sr. Member
Sr. Member

Joined: Wed Oct 21, 2009 6:57 pm
Posts: 227
Location: Barrie, Ontario,Canada
Guys,

How about using hardened and nitrided "ejector pins"? They are common in the injection molding industry and come in 1/64" diameter increments and start ar 6" in length.

Jim Mantyla


Top
 Profile  
 
Rich Brazell
 Post subject: Re: Folding Wing Pins
PostPosted: Tue Oct 15, 2013 7:29 pm 
Hero Member
Hero Member

Joined: Wed Oct 21, 2009 12:33 pm
Posts: 3095
Images: 64
Location: Jamul, CA (San Diego area)
I got all my folding wing parts from CSA . My -1 lock does not have the "little finger ? " I am saving my "Big Finger" for future political events ! The -1 lock is held in place by the gap cover . ;)

RB O:-)


Top
 Profile Personal album  
 
dickwolff
 Post subject: Re: Folding Wing Pins
PostPosted: Wed Oct 16, 2013 7:13 am 
Sr. Member
Sr. Member

Joined: Tue Nov 24, 2009 7:40 pm
Posts: 498
Images: 6
Location: Canada
Bob - Just throwing this idea out there: If it's not too late, consider AN386 tapered pins, or a custom version if necessary. http://www.aircraftspruce.com/catalog/h ... perpin.php

The main feature of this type of pin is the threaded portion at the small end. The advantage is that you can draw the pin snug into the tapered hole... thus always eliminating play. The pin is retained by the nut. Note that there are special washers for AN386 pins.)

This method has been used on many types of glider wings with great reliability. Gliders are typically assembled and dissassembled every flying day, and wear is simply not a problem.

Of course, do the reasearch to make sure the AN pins are equivelent in shear strength.

D


Top
 Profile Personal album  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 23 posts ]  Go to page 1, 2  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron

[ Time : 0.199s | 12 Queries | GZIP : On ]