ZNLine Factory Enigma Build by Mark Novack

Well, it's Thursday. I was very tired last night after working all of these 18 hour days, but lets get right back to work now. The wing is on and dry, we have previously made the holes in the fuselage for the stab tube and incidence pin, the stab is completed up to the root rib, and not yet faced so now is the time to fit and mount our stab. All we have to do is slide it onto the tube, align it with the wing, and glue the socket and pin into place. The pin will be waxed, however, so that it may be removed/replaced as needed. The pin socket will be the epoxy/micro balloon mixture we lay around it. We will place some clear sticky back plastic onto the fuselage to prevent any possibility of the stab sticking in place. Here is a photo of our sticky stuff on the fuselage with tube and pin in place.

Here we slide the stab onto the tube. We make the usual measurement between stab tips and wingtips. If the holes where drilled well then stab being fitted against the fuselage side will bring it into perfect alignment with the wing and the fuselage axis. (SIDE NOTE: although building an F3A airplane is an endeavor in alignment and very careful procedures, an accurately cut airplane can make it very easy to align. However, one should always check and double check alignments every time. It's wonderful to find out that no adjustments are needed before gluing; it's terrible to find out that there were adjustments needed after the glue dries) In this case, no adjustments where necessary.

Take a seat a couple of meters behind the airplane, that is, and check wing stab alignment for parallelism in the horizontal plane. If any adjustments are needed, now is the time to file the holes. File a tiny amount of material at a time, replacing and checking often. Take your time. If you are feeling shaky after a bad day in the office, then return the next day on this step. This is one of the times for absolute perfection. Here is our aligned stab.

The stab is on and aligned. We mix up our 24 hour epoxy with some micro balloon, cut some 49 gram strips of fiberglass (about 3" long by fin width wide) and start gluing. We put epoxy around the stab tube and pin, working it between the support plate and the tube. Then we lay our strip of glass cloth neatly over the tube, glassing it onto the support plate. We make a small fillet around the tube where it meets the fuselage and ensure that the waxed pin is nicely encapsulated in epoxy mix.

After the glue is in place, we place the rudder cap temporarily into position and again, check alignment. In an hour, I'll take a Coke Cola break and again, sit behind and check alignment. We will not touch the assembly for two days. I will periodically check alignment until the glue sets up or I go home for the night.

Well, it will be a couple of days before I continue on as I get the other airplanes up to the same stage. Soon we shall face the stabs, cut free the control surfaces and face and hinge. We will finish up the fin interior with the antenna tube and vertical former and close it up with the rudder post. After that comes engine time. Here is a photo series from four angles of what we have up to this point.

And a side view.

And a rear quarter view.

I posted this so you could get a feel for the side area of this fuselage. This is a whale. This airplane was specifically designed for the upcoming FAI schedules that include lots of knife edge and rolling loop maneuvers. When we flew our first Enigma last summer, we could not believe the ease with which it flew knife edge loops. The one roll loop from the top is no problem for this airplane and the DZ hauls it back topside like nobody's business. Incredible combination. The weight at this stage is 3.4 pounds. Expected finished weight is 9.6 pounds. 

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