Adam's Sopwith Pup

3/23/08 17:00

Two steps forward, one step back...

After feeling that I'd made a lot of progress, last weekend ended in disappointment as I realised that I'd been working to incorrect information. The "full size wing rib" diagram on the plans was not in fact full size. It meaured 58 inches, when the chord is supposed to be 61.5 inches. There must have been some shrinkage in the plans copying process. It was (in hindsight) a stupid error not to have measured it before launching into my work...but, lesson learned. Apart from the capstrip, everything else I've made went into the scrap bin.

I was a bit depressed at first about throwing away so much work, but after a while it was a relief to think that I found the error as early as I did. Also, a lot of my work wasn't wasted - a lot of it is "thinking & working things out", that won't need to be repeated.

Played with the large plans copier at Kinkos and after some trial and error discovered that increasing the size to 102.2% got all the dimensions right. Spent most of Saturday making patterns for the front, middle & rear plywood sections. Shaping and sanding the lightening holes is no less laborious the second time around. But everything seemed to go a lot faster, and was helped by having a second copy of the full size wing rib that I could cut out and use.

Started making my wing rib jig today, and made quite a lot of progress with it. Next step will be to glue up my first rib. One of the EAA "Hints for Homebuilders" videos was really helpful in giving me an idea to use locking cams in the jig. These will work perfectly (I think).

Experimented with soaking and pre-bending my capstrip, also I have glued up a couple of sample pieces to start getting a feel for gluing (those discarded pieces in the scrap bin coming in useful...) Ordered a load more wood from Aircraft Spruce.

Paul Poberezny and Chuck Parnall stopped by this afternoon. Paul seemed satisfied with the quality of my work, which was comforting to hear. This week Paul put me in touch with a guy called Joe Hauk here in Wisconsin who is about 5 years into a Pup project. He sent me some photos and has done great work. Look forward to catching up with him at some point.