Ribs

The last few nights with some help from Leah and Matt G we've started to put ribs back in the right wing.  I ordered some more wood from Aircraft Spruce to re-do the trailing edge and to rebuild the area around the airbrake as well as add all the necessary stiffeners to the ribs.  I need to work on the profiles of the ribs now and will need to get the last two false ribs built up to the right shape so they can be removed and used as templates.  Previously they were way undersized which lead to the leading edge skin separating from them, especially on the lower surface.

We moved the fuselage for YYY into the garage today and I did some sanding work on Leah's cedar rowing shell.  We had a really nice day here today with light winds and t-shirt weather in the afternoon.

Here is the current state of the right wing. The two false ribs on the right side are the ones that still need to be replaced.  The rib on the right where the plywood ends is the one that I broke the bottom off aft of the aft spar.  Will scarf in a new piece to replace that rather than completely replacing the rib.

Sawdust

Not a lot to report lately so there haven't been many updates.  Matt G and I did cut out a few ribs after making templates from a set of ribs that I found online.  Used the router I got over thanksgiving and learned that I really needed a router table to do a semi-quality job.  So I very slowly gathered the wood I needed to make a router table and ended up with a pretty nice 4 foot long by 1 foot wide table that the router mounts to.  Tonight I finally got it all finished up and put it to work.  I had two full size ribs that I needed to re-do so I nailed the first one to the new plywood and started cutting. It went great until almost the end when the template became detached and the new piece was ruined. Drats!  I had almost exactly enough plywood to just do the two pieces and no more so I had to make sure to do it right.  Thankfully with some luck (or my incredible skill) I managed to not screw up the pieces and I now have two very nice new ribs to install on the glider.

Plan is to work the next few days on getting the new ribs in place and then I'll finish tweaking the profile of the two false ribs that need replaced.  I have enough scraps large enough to make those I think.  Then I will have all the ribs replaced and can start working on putting the airbrake box back together and then eventually new skin.  I am starting to see the light at the end of this repair!

Neutral Progress

Matt G has been a great help lately and we've gotten a little work done and moved backwards in a few ways too.  Late last year I got a full set of ribs in the mail which have come in very handy during this process of rebuilding this section of the wing.  I've used the old ribs to fit onto 53T's wing, tweak to the right profile, and then use them as a template for new ribs.  Matt and I were able to use my new router to make new ribs for the two that I broke a few weeks ago.

Last week I spent some time working on the rib that goes through the middle of the airbrake.  Long story short I ended up removing pretty much all of the "box" that surrounds the airbrake and one of the cross members that tie the spars together.  However last night we cut a new rib for that location.  We also started cutting the last rib but weren't happy with how it was going.  So, this weekend, I hope to build a router table like I should've done to begin with.

Also, after some more inspection I decided to remove the last 8 inches of skin on the leading edge as the false ribs were a bit undersize and the skin had become detached on the bottom of the wing.  I glopped a bunch of super-fil on those ribs so we can get them profiled to the right shape and then use those as templates for new ones.  So that little hold that started a few months ago has grown to basically replacing everything but the spars from the inboard edge of the airbrake to the inboard edge of the aileron.  4 feet.  I'm going to have to make another order of wood here pretty soon, might need a bigger sheet of plywood for the leading edge and will probably need more plywood for ribs.

In other news, I learned that a Cherokee II has been donated to the Antique Airplane Association in Blakesburg, IA. I'm looking forward to learning more about it and what their plans are for the glider.

Back to Work

Leah and I had a nice Christmas break which included plenty of traveling.  Didn't get out in the garage much last week but last weekend our friend Matt came down to visit.  He started a welcome crusade against clutter in the garage and by the time he left on Tuesday morning the place was totally cleaned and organized. Thanks Matt!

Can't remember if I put anything up here but Matt G and I (ok...it was me) managed to break the existing rib that goes through the middle of the airbrake area before Christmas.  Additionally, while walking around the garage on Sunday I managed to bump into the exposed ribs on the right wing and broke two.  One was a new false rib and the other was an original full size rib (which I wasn't planning on replacing)

Last night Matt G came over to help and we worked on further destruction to get the newly broken stuff removed.  With some careful chisel work we managed to get everything removed and preserve it all pretty well so hopefully we can use them for patterns for the new pieces.

Fleet update

First off I took some time to update the roll call post.  Some information has changed and I added a few more pictures that have come in in the last 6 months or so.  Check it out: http://cherokeesailplanes.blogspot.com/2009/11/cherokee-ii-roll-call.html

N98P, the first Cherokee II to fly, has recently been sold and is heading to its new home in Idaho next week.  I'm excited that it is going to a new home and am looking forward to seeing it get back in the air. 98P was built by Frank Kerns and was ready to fly before Stan Hall's own Cherokee, N63P.

While talking to the new owner he asked about the paint scheme. All the pictures I had ever seen of 98P from its first flights were black and white. However, longtime SSA member Bertha Ryan was mentioned in the article Stan wrote about his first flight in 98P.  She was flying her kit built 1-26 on the same day.  By the way Ross Briegleb was up that day in his BG-12.  Quite a day for homebuilt soaring!  Bertha had some old slides showing 98P and sent them to me.  The first two show Stan (in the hat) and others after the first flight of 98P.

The following slide from Bertha was taken after Stan finished his first 5 hour flight in his own Cherokee, N63P.  Very cool and thanks Bertha!

We did get some more work done on 53T on Sunday.  I worked with the plane for a while getting the new trailing edge trimmed down to shape. It is looking good now.  Bad news was that I managed to break a couple ribs in the process.  Good news is that one of them was the new big rib which will be easy to replace.  Not to mention it was a little oversized anyway.  Also the existing rib that broke was the worst offender as far as being twisted from the airbrake return spring and now it will be much easier to get a nice looking straight rib in that location :)  So now I know what will be waiting for me after the holidays.

Excellent Progress

Yesterday a 5 ft long piece of Spruce arrived on the front porch.  Perfect timing since today was going to be in the mid 50's. Not bad for December!  I got to work this afternoon, starting with finishing the cuts in the existing trailing edge.  Finishing the inboard side went alright and cutting the outboard side was a breeze. Here is the trailing edge pieces cut:

Then I cut the new piece of spruce to length and laid out the scarfs for it.  With a nice sharp blade on the plane it took very little time to get the scarfs cut for the new piece.  Helps when the piece is just clamped to the bench and not flopping around on the glider with ribs in the way.

Next I started thinking about ways to get the ribs straightened out.  I also knew I was going to need to get the ribs out of the way in order to glue in the new trailing edge.  I notched some 1x2's with the table saw to act as a sort of jig for the ribs to force them into a straight-ish orientation.  It actually worked out pretty well and I think when the time comes will work alright for getting things lined up.  I also removed the vertical stiffeners and cut the trailing edges of the existing ribs in order to get them to move out of the way for the trailing edge.  Here is the jigs in place:

With the ribs able to move now I had to go get some supplies for epoxying. Namely, dixie cups and paint brushes.  Then I clamped the aluminum angle firmly in place.  It worked as a nice guide in my attempt to keep the trailing edge square and straight.  Worked out a clamping scheme and mixed up the epoxy and put everything in its place.  Then for grins I glued in the remaining bits of the false ribs so I'll have plenty of clamps to remove in the morning.

Installing Ribs

Not a lot of work done on 53T lately but Matt and I did do some work this week on insulating the attic.  Only 2 or 3 rafter widths left on that job and hopefully we will do that tomorrow!  We did do some work on 53T today though.  I bought a piece of stiff aluminum angle at The Yard Store this morning and am using it to jig together the two ends of the trailing edge on either side of the piece that I cut out.  I started cutting the scarf on one side of that gap today.  Matt worked on getting the ribs ready to glue in place with some last minute touch up.  We ran a taught line to establish where we wanted the leading edge and made sure that we had a 1.5 mm gap between the rib for the skin.

We finished up the afternoon by mixing up epoxy and gluing and clamping the 6 false ribs to the forward spar.  I have some more work to do around the airbrake before I'm ready to epoxy the real rib in place.  We will also need to glue 4 of the false ribs to the rear spar.  However our monthly glider club meeting interfered which was quite interesting.  It featured the designer of the Belite Ultralight, www.beliteaircraft.com.  He spoke at length about the recent feature of his plane on Mythbusters and the design of the craft. Very cool.

I also made it out to Harry's shop this afternoon and picked up a 4 foot square piece of 1.5 mm plywood which will be used for the new skin.  Slowly but surely I can see this repair coming to an end!