OX-5 #1

In my last post, I said I was going to start on an aileron.  The one for the lower RH wing I'm building now is about 90% done, but thought I would wait until it was completely finished before uploading pictures - maybe next week.  I also finished installing all the capstrips and will post pictures of those as well.

Engine number on airframe data tag.

In the meantime, I started some work on the OX-5.  I couldn't wait to get my hands into this engine.  In my very early posts, I mentioned the history of this airplane and the very low time on both the engine and airframe.  This particular OX-5 is also original to the airframe - a numbers matching airframe and engine after 86 years!  I'll be numbering the OX-5 posts like I'm doing with the wings - this one being #1.

Engine number on engine data tag. 

Engine number on crankcase.

Engine number on oil sump.

The first thing necessary was cleaning off all the corrosion after sitting for so many years.  In the A&P classes I teach, I don't recommend bead blasting engines.  It is difficult to remove all the media from the nooks, crannies and oil galley's.  If you're very careful, though, it can be done.  The OX-5 does not have a lot of places to trap media, and only 5 oil galley's - a straight bore from the cam bearing to main bearing.  I also removed all the studs.  They were rusty, and it will allow me to apply new black oxide coating like originally done.

Crankcase and sump prior to cleaning

I blasted the inside of the crankcase with walnut shells to avoid damaging the bearing surfaces, and then blasted the outside of the both the sump and crankcase with the finest glass bead media I could find.  This worked great - it removed the corrosion and brightened the aluminum without pitting the metal.  I then scrubbed everything with an acid etch and treated it with clear Alodine for protection.  I love the clear Alodine for stuff like this.  It protects the aluminum from oxidation while still giving it a natural aluminum look.

Finished sump and water pump housing

Finished crankcase

Crankcase mounted to overhaul stand

My long-time friend Mark also made me this great overhaul stand.  It is beautifully made and will work great for the OX-5 assembly.

My main focus is still the wings, but I'll occasionally do work on the OX-5 and will create posts as work is completed.  Next will be water pump work, cleaning/polishing the crankshaft and checking fit in the main bearings.

Wings #7

Fixturing used to hold ribs straight

More wing work this past week.  In my last post, I showed the fixture I used to form the capstrips.  I got them installed on the top half of the wing.  Went well, but I went to great lengths to make sure the ribs were straight before gluing them on - do not like the look of wavy or curved ribs thru the covering!!

Installed capstrips on top half of wing

Detail of capstrips

A #2 brass screw was added to the end of the
capstrip to hold it down tight while the glue dried

Andy and Dennis also got all the aileron ribs made.  Can't say enough how much I appreciate these guys help.  They are saving me a bunch of time, and their work is impeccable!
The ribs are made from basswood like the main wing ribs.  A comment about the basswood:  I've never worked with it before this project, but that's what was originally used.  It makes a nice rib - lightweight, tight grain (although the grain can sometimes be a little stringy when cutting), and decent strength.  Plus, it's way cheaper than spruce!  I wouldn't hesitate using it again if the need arose.


With the ribs and spars now complete, I can start assembling the aileron.  That's what I'll be working on this next week.

Wings #6

Completed front and rear aileron spars, originals
on left.

Most of my work the past couple of weeks was focused on the ailerons.  This involved a lot of cutting and planing the Sitka Spruce for the front and rear spars.  The front spar is also routed to reduce weight.  Andy made a nice router fixture that made the process go very fast and easy.

Routing on front spars

The front spar was then temporarily mounted on the wing to check spacing and determine the length of the ribs for the ailerons.  This would insure the trailing edge of the aileron would line up exactly with the trailing edge of the wing.

Detail of aileron hinge

Aileron spar mounted to wing

I also did work on the capstrips for the ribs.  I wanted these installed before I finished tramming the wing to prevent the ribs from bowing under the load of the drag and anti-drag wires.  The capstrips are made from 5/8" wide by 3/16" thick spruce.  This material is too thick to wrap over the nose ribs, so I made a tube to soak them in water and then put them in a forming fixture until dry.  When removed, the shape of the rib remains.  Some make a  steaming apparatus to soften the spruce, but I've found soaking them in water works as well unless the curve is very severe.

PVC tube to soak spruce strips and forming fixture