Patrol spar arrangement

[sjt]

THIRD PASS,
The consensus is that it is generally safer to leave them full length and then cut to fit.
This is the safest approach.

However, if someone wants to take the chance, here is my best "guess" for the PATROL


I need to make 15 nose ribs per wing, some reverse flange:
9 must be 1/4 short, but the one at the web splice needs a notch cut in it
3 must be 1/8 short
3 must be 0 short

I need to make 13 center rib blanks for 12 total ribs per wing -- some must be reverse flange:
8 must be 1/4 short , but the one at the web splice needs a notch cut in it
3 must be 1/8 short
2 must be 0 short

stan
Austin Tx
P284

[DRLPatrol]

I am glad you asked that because when I get there I was going to ask for a double check also. I think you have it right but we will see what others say.
Doug

[N3UW]

This might help. This is what I put together so that I could better visulize the cap strips. This drawing is looking down at the top of the spar. The right side is the tip and the left is the fuselage. The upper drawing is the top of the spar and the lower drawing are the cap strips on the bottom of the spar. You are correct in that the wing attach plate buts up against the cpap strip you show.

[SC Patrol 253]

John,
I am a month or so behind you. Thanks for posting the sheet. I was in the process of creating the same sort of diagram when I found yours.

Todd Ramsey

[Chewie]

At quick glance, your diagram looks correct. Front and rear sides are shown in the same view, which is what threw me off at first. But you stare at it long enough and it'll make sense.

Use the section views to confirm.

[geraldmorrissey]

Be very careful cutting ribs. If you cut too short you will regret it. The ribs can be cut at any time. Wait until you need then then cut to actual length which may differ from your calculations due to tolerance stack. It's easy to wait, a pain in the ass to fix if you cut to short. I don't know why everyone is so eager to cut the ribs when they do not know what ACTUAL length is needed until it's time to install the parts.
Just saying.
Cheers
Gerry
Patrol #30 WIngs

[Collin Campbell]

Good advice Gerry! I found it best to cut and fit the ribs as you go. Much less chance of making a mistake as you say. No need to do all the calculating, keeping track of them etc. But then, that's just how I did it.

Collin Campbell, Patrol N180PB, N370CC, 4-place
Bolivar, MO

[Chewie]

I found it best to cut and fit the ribs as you go.

I like this way of thinking. Only thought I had is how do you juggle the final trimming with priming? Trim and then prime (would require keeping track) or prime and then trim (exposing an untreated edge)?

[Collin Campbell]

Mark,

I primered the ribs before I trimmed them. I didn't consider the raw untreated edge to be a big deal. But you could just apply a bit of touch up primer to the edge when trimming and assembling them.

Collin

[geraldmorrissey]

I bought a set of factory formed ribs from another builder who cut them to net and so far he cut 5 center ribs 1/8" short. Now I'm short edge distance between the rib and the attach angle. S#$(#($#$)!!!!!!. Got to call Bob and find out the fix. I'll bet I'm not the first to call about this. I'm a bit passionate about this subject of cutting ribs because I'm living with the consequences of not getting it right.
Cheers
Gerry
Patrol #30