Strut fork
- Thread starter Ron B.
- Start date
Crash
GONE WEST
Nikiski Alaska
I wouldn't be counting threads on the forks to get the dihedral right.
Stretch a piece of Spectra (spyder line, jet line etc.) fishing line from one wing tip light to the other and move it for and aft until it lies over the front spar. With the top wing root fairings off, measure from the line down to the front spar fuselage attachment fitting. It should be 3" + / - 1/8", on both sides, EQUALLY. You can't rig anything right until this is "dead nuts" on the money first. Take care. Crash
Stretch a piece of Spectra (spyder line, jet line etc.) fishing line from one wing tip light to the other and move it for and aft until it lies over the front spar. With the top wing root fairings off, measure from the line down to the front spar fuselage attachment fitting. It should be 3" + / - 1/8", on both sides, EQUALLY. You can't rig anything right until this is "dead nuts" on the money first. Take care. Crash
strut threads.
1. It might be rigged incorrectly.
2. More likely, it took that differential to partially make up for a crooked airframe. I say partially, because, in my newly reinforced and growing experience, most airframes that are tweaked some can be rigged to almost compensate for the ills of the airframe, but nothing will come out better than a jigged true airframe, well rigged.
My 12, when I got it, had lots of thread differential, and when I got the fabric off, I had a lot better idea why.
(always participate in your own prepurchase due dilligence)......
1. It might be rigged incorrectly.
2. More likely, it took that differential to partially make up for a crooked airframe. I say partially, because, in my newly reinforced and growing experience, most airframes that are tweaked some can be rigged to almost compensate for the ills of the airframe, but nothing will come out better than a jigged true airframe, well rigged.
My 12, when I got it, had lots of thread differential, and when I got the fabric off, I had a lot better idea why.
(always participate in your own prepurchase due dilligence)......
RCharles
Registered User
Atlanta, Ga
strut forks .
Hyrdflyr , This was something I have heard but this airframe was built for me by Jim Soares at Rocky mountain Airframe when he still owned it .Not saying it is not possible but I feel it's unlikely .I'm going to check the Dyhedryl very carefully .Can always find something to mess with! ...Thanks ...RC
Hyrdflyr , This was something I have heard but this airframe was built for me by Jim Soares at Rocky mountain Airframe when he still owned it .Not saying it is not possible but I feel it's unlikely .I'm going to check the Dyhedryl very carefully .Can always find something to mess with! ...Thanks ...RC
Longwinglover
Registered User
Charlotte, NC
dlg,
I do believe the recommendation is no more than 15 threads showing.
If you're not a troll yanking our chain, I suggest you consult with your A&P/IA before you fly again.
The rigging proceedure can be found here (page 16): http://www.j3-cub.com/data/j3c65_owners_manual.pdf
John Scott
PS If you're a troll, GO AWAY!
I do believe the recommendation is no more than 15 threads showing.
If you're not a troll yanking our chain, I suggest you consult with your A&P/IA before you fly again.
The rigging proceedure can be found here (page 16): http://www.j3-cub.com/data/j3c65_owners_manual.pdf
John Scott
PS If you're a troll, GO AWAY!
Longwinglover
Registered User
Charlotte, NC
dlg,
Then accept my sincire apology! The situation you discribe seems so extreme it seemed to be chain yankn'!
I still think you should have the rigging checked. If I saw adjustments that extreme on a Cub I would assume something was out of whack. A complete rigging check and adjustment of the wings and tail should take a competent Cub mechanic less than half a day.
You don't list your location, so I can't suggest a mechanic. How much experience does the mechanic that signed off the annual have with Cubs? Maybe if you tell us where you are, we can suggest competent Cub help. 8)
And IF you think the Cub flies great, maybe a "seat of the pants" adjustment is in order too!
John Scott
Then accept my sincire apology!
The situation you discribe seems so extreme it seemed to be chain yankn'!I still think you should have the rigging checked. If I saw adjustments that extreme on a Cub I would assume something was out of whack. A complete rigging check and adjustment of the wings and tail should take a competent Cub mechanic less than half a day.
You don't list your location, so I can't suggest a mechanic. How much experience does the mechanic that signed off the annual have with Cubs? Maybe if you tell us where you are, we can suggest competent Cub help. 8)
And IF you think the Cub flies great, maybe a "seat of the pants" adjustment is in order too!
John Scott
RCharles
Registered User
Atlanta, Ga
forks
T.J. I measured the struts and they are right on. They were purchased from Univair - ordered from piper as factory new sealed ,ETC years ago . Going to check the dihedryl at the wing attach pionts .Could be that the dihedryl is correct but one wing is lower-heck! I don't know ? It does fly good though ,thanks ...RC
T.J. I measured the struts and they are right on. They were purchased from Univair - ordered from piper as factory new sealed ,ETC years ago . Going to check the dihedryl at the wing attach pionts .Could be that the dihedryl is correct but one wing is lower-heck! I don't know ? It does fly good though ,thanks ...RC
How long....
Guys,
Ok, 15 threads maximum. What are the lengths of the large and small PA-18 lift struts? I have one strut fork that has 17 threads showing. They are about twice the size of my old J3's forks, and I wonder if two threads is anything to worry about. My SC flys fine, as is.
Mike
Guys,
Ok, 15 threads maximum. What are the lengths of the large and small PA-18 lift struts? I have one strut fork that has 17 threads showing. They are about twice the size of my old J3's forks, and I wonder if two threads is anything to worry about. My SC flys fine, as is.
Mike
