Sunday, December 29, 2013

Gluing cap stips to rib nose pieces

I made a simple jig to glue the cap strips to the nose ribs. The clamps are nothing more than a Oak rod cut up in to pieces on a chop saw. I then drilled a hole off center so it act like a cam.

The jig surface is a cheap shelf purchased at Home Depot. I waxed it so the assembly doesn't stick. Glued and clamped it. The jig allows 2 ribs to be glued at once.


Nose rib cut out

Unfortunately I don't have a photo of the jig but it's really pretty simple. I cut out a notch in a piece of scrap plywood and centered the nose rib on it. Then I nailed down pieces around the rib template to secure the part. Once I took the template off I smoothed out the notch and the pattern was ready to go.

I took each nose rib and put it on the router template, penciled the shape, took it off, rough cut it, put it back on, and routered it out.

They turned out flawless!

Once that was completed the next step, according to the plans and builders manual, is to glue up cap strip to the upper and lower portion of the nose rib. This is very unusual compared to most airplanes, usually all the cap strip is glues up in one step.

So I pretty much drove around with them on service calls thinking and planning my next move.

Nose rib stringers - Upper and Lower notches

With the nose notch complete the next step is to build a jig to cut the upper and lower notches. Similar to the front notch these stringers are for structural support to hold the aluminum leading edge except the notches are very thin.

Once the nose rib is mounted securely I ran it through the table saw.

Nose tip notch

The leading edge of the rib nose has a notch for a stringer to be glued in. I decided to build a jig that holds each piece inverted over a table saw. I them mounted a Dado blade in and cut each notch making sure the jig was well made so each notch lines up accurately with the others.



Nose rib template for the wing rib jig

I started the project by making a nose rib template. The material is phenolic and its very hard, this allows me to have a perfect pattern to use on a table router.

I cut up a sheet of 1/4" aircraft grade plywood into squares. Bolted the pattern up, market it with a knife/pencil, took it apart, rough cut it on a bandsaw, bolted it back together, then routed it out.
 Here is a side view.

A router bit is round and the pattern has a sharp notch in it that needs to be cut out free hand. I simply left the part clamped to the pattern and took a razor knife and cut it out using the pattern as a guide.




This is the starting point of the nose ribs. Each one is perfectly matched to the other because a router follows the pattern.

















Little Scrapper - The Baby Great Lakes biplane built from scrap

This blog is a story about an adventure in building a biplane; the Oldfield Baby Great Lakes.

The basic idea is to build the biplane from scratch using no out of pocket money. The money to fund the project comes from finding scrap metal and recycling it for cash.

I own a small plumbing business so I have a constant supply of copper and brass scraps but it's not really enough to build a biplane. I have to go out in the community and gather junk thrown by the curb as garbage and take it in to be recycled.

Besides recycling I'm also taking other builders scraps and using them as well. Fortunately, the Baby Great Lakes is such a small biplane that it doesn't require much material.

Why the Baby Great Lakes?

Well, it's small. The wings can be built in 4 separate panels so it can be built cheap and in a small space. The engine is the lowest cost of just about any other option. The biplane can fly well with a C-65 engine and that is what I will use.