Category Archives: Empennage

Pietenpol Build. First elevator frame completed.

To construct a single elevator piece (two are required), twenty two spruce parts must be cut, milled, and glued together. That’s 44 custom wood parts for the elevators. And then sanding. Lots of sanding…. No wonder it takes some people ten plus years to finish one of these babies.

It’s finally starting to look like an aircraft part! I used gravity to hold the joints together as T-88 likes minimal clamping pressure. I used tape for clamping pressure around the spars to hold them against the trailing edge.

I have also glued on the 1/8″ backing plates for the hinges.

You may have noticed that there are only gussets on one side of the leading edge. If you are building your own Piet, it is crucial that the hinges are installed before putting the gussets on the other side. Otherwise you will not be able to properly torque the hinge bolts.

 

Pietenpol Air Camper: Elevator Construction Part 2 – Fitting and Glueing

After a long break I am back to work on the Air Camper. First elevator piece is being assembled. I used T-88 Epoxy and held everything in place with a jig.
Now I am waiting for hinge bolts from Aircraft Spruce. Looks like I will need to fully install the hinges before putting the gussets on the other side.

If you look closely at the next pic you can see that the hinge nuts and plate will be between the gussets and nearly inaccessible. Next step will be to get the plywood hinge back-plates built and glued in. Hopefully I will have enough time to get the other elevator piece finished before the bolts get here. Building the second identical elevator piece should go much quicker now that I have all the jigs built and the technique down.As you can see the joints are held together via the jig so there is no excessive clamping force starving the joints of adhesive.Please check back often as I will post updates as I build. If you would like to support my build you can subscribe to my YouTube channel, click on some ads or support me on Patreon. Thanks!

Pietenpol Air Camper: Elevator Construction Part 1 – The Plan

My first spruce shipment came in last Friday! I decided to build some of the smaller parts first so I ordered the vertical stabilizer kit and the elevator kit. I already have the space to build these parts and I figured it would be an easy place to start. I was slightly mistaken about the easy. This “mistake” is actually working in my favor. It has given me time to perfect my mental build of the craft, see how the build process will be best accomplished, and is getting me mentally prepared for the meticulous nature of this undertaking.

Layout of elevator parts before milling.

The plans and instructions on building the empennage aren’t entirely clear and must be studied thoroughly. Much googling and reading of forums revealed that I was not the only one that found these pages of the plans “left to interpretation”.

Elevator as pictured on the plans.

There are no definitive dimensions for the gussets. They are numbered with a note that says “These numbers correspond to parts in the kit.” The “kit” from aircraft spruce just contains a peice of 1/8 plywood for the gussets to be cut from. I could not find patterns or dimensions anywhere. Also the dimensions for the center beam seem to be only for the stabilizer and the correct dimensions for the center beam on the elevator must be deduced. The solution ended up being quite simple, I made a full scale drawing of the elevator. Once this was done, figuring out dimensions and designing the gussets was actually quite simple.

Caliper, straight edge, rulers and swoop stencil

I began by constructing a simple build surface that I could screw wood to to form a jig for the elevator. I used some scrap particle board and made some 2.5″ spars with my table saw. I spaced these out on the floor, put a bunch of wood glue on the upward facing surface and then set my build surface (3/4″ particle board) on that. I weighed down the top with¬† heavy things and let it dry overnight.

Spars for underside of build surface
surface glued to spars weighted down overnight

The next morning I screwed the “table” to my sawhorses with two 6″ screws. I put one screw down from the top and through the middle spar into each sawhorse. Then I used shims under the other spars to make the surface flat in all directions.

build surface attached to sawhorses and shimmed to perfect flatness

Once my surface was ready, I covered it with kraft paper and meticulously translated the elevator blueprint to full size on my build surface. I then came up with what seemed like the correct dimensions for the gussets and used the pictured swoop stencil thingy to do the rounded corners.

Stencils, rulers, a square, and some really sharp pencils.
Translating blueprint to full size.

When it comes to holding gussets in place while glue dries, if you ask 5 builders you will get 10 suggestions on the best way to do this. The original plans call for cement covered flat head nails. It has been recommended by some to use a pneumatic nail gun to staple or nail them into place. Some say pull the fasteners, some say leave them in… Some say use weights, some say light clamps. Goodness… what to do? Well, after drawing up the full size plan, I’ve decided that building with a jig and just using small weights to hold the gussets while the epoxy dries is going to be the method for me. Both elevator pieces should be identical, so building everything in a jig makes the most sense. This also will allow me to miter and assemble the entire unit without having to glue anything until it is perfect.

I will be posting a YouTube video explaining this more thoroughly. I am also intending to come up with full size patterns for the gussets which I will make available on this website.

Stay tuned!