Flap repairs continue. With the tightness of the skin and short bend radius, making the skins align squarely across the spar and ribs is a challenge. Careful application of ratchet straps helps, but doesn't leave a lot of room for drilling and clecos.
I took a couple of nights off and when I came back, Ron had striped the paint on the 701 wing, the original parts of the inboard flaperon and the entirety of the outboard section.
Went back to the shop this afternoon. Ron was away so I thought I'd tackle some of my parts. We plan on building our new slats and flaperons together, taking advantage of common assembly jigs. In order to do this, I need to get the balance of my flap and slat ribs done.
Due to the tight radii of the nose section, I was concerned how the aluminum would bend. It took some finesse, but I got them done. Happy with how they turned out!
A big part of this project is going to be taken up by drilling, clecos, drilling again, deburring clecos, rivets..... more to come.... stay tuned.
For quite some time now I've been helping Ron rebuild the wings on a 701 - using this as a learning experience towards building my 750.
In an attempt to ramp up our progress on the repair so we can get back to building new airplanes, we've been working hard at the flap extension.
It's become a huge quagmire. NOTHING that the original builder matches the plans. We could forgive a little tolerances here and there - IF THE TOLERANCES WE EVEN CLOSE TO WHAT THEY SHOULD BE! Even worse, it seems to have been a real terminal case of TLAR.... "That Looks About Right".
We've been building any new parts for the repair and extension exactly as the plans call for. However when we add those as components of the flap extension, they seem to create more problems because the "good parts" of the original builder are not "good parts" after all. Assumptions...
For example, we've had to add 3 rear ribs and a couple of nose ribs. Perfectly sized parts according to the plans. But the originals are several millimeters bigger than the plans, so the new extension skin doesn't fit right, it won't wrap tightly down to the new ribs, nor will it remain straight (leading and trailing edges). There is no way to predict this as none of the "changes" the original builder made are to scale (nothing is larger or smaller by the same amount). Assumptions...
What does this mean for us? Hours of thinking and rethinking on how to get the job done. I know the extension is our idea, but really that should be just more materials - if the dimensions were right (or at least close) on the original, we wouldn't be fighting at each and every step of the build.... sigh.
We'll keep working on it and I'm certainly learning where to watch tolerances. So far the pieces I've made for my 750 are real accurate to what is shown in my plans, so I'm happy. Guess I'll have to wait and see how they go together in assembly but I have much more confidence than I do with this 701.
Speaking of assembly, someone on the Zenair builders website was kind enough to email me a copy of the latest revisions to my 750 STOL plans. I have "Edition 3" plans, but with any design they are updates and additions made by the Zenair factory. Most of these are small changes made to make things incrementally better and of those most come from builders suggestions.
Having a look a the 20 or so pages of updates he sent me initially made my mind spin:
After pondering these and truly wondering what the hell I was thinking when I decided to scratch build this airplane, I decided the best way was to set aside some time at the dining room table and make notes on my plans of the updates:
The entire exercise took me most of a Sunday morning with breaks here and there for food, water (and sanity), but I think I have a good handle on what is important and what isn't. I probably have more freedom to decide what changes I want to incorporate as I am still early in my build and I'm making my own parts so unchanged parts can be modified to match up with the new designed parts easily.
A lot of the changes are simply cosmetic and make the 750 STOL have more part commonality with the more recently introduced 750 Cruzer model.
Onwards fellow builders and thanks for continuing to follow along.
Not a huge update, but a few things to mention this week.
Ron and I got further along on the 701 wing repair the last two weeks. We are being really challenged by the mistakes of the previous builder's measurements and decisions on what was "good enough". We've compounded that by adding the wind extention, but we are getting it figured out.
The flap extension to match the new wing length is coming together nicely. Because this is an add on, wrapping the short flap skin is certainly fun...
Once we get the flaps skinned we can fix the spacing of the flap brackets. As most things on this repair, nothing is consistent, even between both wings. Having the flaps apart allows us to adjust where they meet the flap brackets. Make it right has been the goal all along.
The days lately have kinda blurred together with my new position at work, but I'm certainly not missing the shift work that's for sure. It has made it somewhat difficult to focus on my project, but things will improve soon as I adapt to my new job and this Monday to Friday schedule. What hasn't changed is the feeling I'm doing something great when I do get to the shop, even if Ron and I spend the hours just jawing about airplanes and flying.
I've long been following the online musings of William Wynne, the Corvair expert I've mentioned before. He wrote the following quote on his blog the other day and it really struck a chord with me:
“Hours in the shop working with your own hands cleanses the part of your sanity which modern life soils”
Indeed William.... indeed :)
Husband, father and 911 dispatcher. Long time pilot with a licence that burns a hole in my pocket where my student loan money used to be. First time aircraft builder. Looking to fly my own airplane.