The Drawings

Many people find the Skyote Drawings to be difficult to interpret. I would guess that Dwg.# 100200 causes the most difficulty due to the high density of information packed into it. In my opinion, this particular drawing is a designer's layout drawing and not really a builder's drawing. It contains many dimensions which are not pertinent to fabrication but are there as part of the design process. An example is the dimensions which locate the center of the bolt holes in the lugs which fasten the drag and anti-drag wires to the spars. These were required to calculate the dimensions of the drag and anti-drag wires. Otherwise they are not relevant to the builder.

The 7.2 degree sweep of the wings creates the opportunity for confusion in several areas. The rib locations along the spars (Dwg. # 100202) are given two different dimensions for each location. The larger number is the "Station" dimension and is measured from the longitudinal centerline of the airplane and perpendicular to that centerline. The smaller number is the actual measurement from the onboard or "zero" end of the spar and is measured along the axis of the swept-back spar. This is not readily apparent in first reading the drawing.

The swept wings also contribute to the possibility of small errors in the fittings which attach the interplane struts to the vertical surfaces of the spars. The dimensions on the drawings are correct for the center plane of the pair of fittings. The fittings don't actually reside in the center plane but are separated by 0.080". This separation causes the inboard fitting to move "forward" and the outboard fitting to move "rearward" resulting in a mismatch of about 0.030". This falls in "small stuff" catagory, but since everything is calculated to three decimal places, it seems a shame to ignore it.

I have found a few small errors so far.

Constructing Fuselage Jig/Welding Table

Almost completed the fuselage jig/welding table today.

I doubled up on the middle set of legs so that the table can be cut in half making two tables when the fuse is finished. Of course, it can always be screwed back together for that next project!

As you can see from the final photo, I added a lower level using MDF. It makes a great place to store tools and materials.

VR3 Fuselage Tube Kit

The VR3 profiled tube kit for the fuselage arrived today. The kit includes 124 profiled tubes plus a bag of scrap ends for welding practice. It came in a carton about 8"x8"x48" and a tube about 6"x60". Total weight is 42#. The kit includes every tube included in Skyote Dwg. #100400 EXCEPT the streamline tubes which anchor the flying wires and the upper end of the landing gear strut, and the two round tubes which brace the streamline tubes to the fuse.

The kit also includes 1/4 scale CAD drawings, both 3-view and perspective of the assembled fuselage with every tube listed and numbered. Also each tube is labeled with its number and spec.

Introduction

This blog is a build record of Skyote #88. All my building experience is limited to Van's RV's so I have no experience with building tube & fabric or "plans building". I have much to learn so take everything I write with a grain of salt and reasonable skepticisim.

I do not intend to follow a "traditional" path for the construction of #88. I intend to employ low level technology and $ to reduce the construction time and difficulty where possible and practical. By low level technology I am referring to CAD, laser, waterjet, CNC. For example:

• I have purchased a complete wing spar kit from Jerry Kerr.
• A rib kit from Mr. Bartoe.
• Brunton Flying Wires and Drag wires from Harvey Swack.
• A CNC profiled fuselage kit from VR3.

In addition I have converted all of the wing fittings, brackets, links, lugs etc. to CAD and had them cut by water jet. I have designed a laser cut wing spar drill template/jig which positions the five spar components so that all of the holes can be drilled in a complete spar as an assembly. I plan to continue converting as many parts as I can to CAD so that I can reduce the "hand-made" components to a minimum. While it takes a little time, converting the design to CAD is a great way to truly understand the drawings.
The Skyote is uniquely suited for conversion to CAD in that a "computer" was used in it's original design. I have read that Mr. Bartoe used a HP calculator to "compute" the design and dimensions of the Skyote. The plans show all of the critical dimensions to three decimal places for X,Y and Z axes.

Amazingly, when I put the design into CAD the results agree out to Mr. Bartoe's third decimal place about 99.9% of the time. I have found a few small discrepancies but usually less than 0.030"! Some of these may be due to my erroneous interpretation of the drawings!

If you want to build your Skyote as cheaply as possible, or if you enjoy handcrafting the same parts over and over again then my approach to building is not for you!

 If you want to build your Skyote in the minimum possible time with highly accurate parts then this approach may be the answer. I personally get a lot of satisfaction out of organizing the project so that it can be produced  accurately. Hopefully some of this work will prove useful to others.