*****Skyote #88 gets Bronze Lindy for "Airventure-Oshkosh 2016 Plans Built Champion"******

October, 2007

Welcome to "Skyotelog", the build record of Skyote #88. I assume that you are familar with the Skyote biplane. If not, you should visit http://www.skyote.org/ for a complete introduction to this unique but elusive biplane.

The posts are presented in reverse chronological order (newest first). Or you can click on one of the "Labels" to see all of the posts concerning a specific topic. Click on any photo for a larger image.

All my building experience is limited to Van's RV's so I have no experience with building tube and 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.
  • CNC profiled tube kits for the fuselage, tail feathers and landing gear 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.

Note: As of June 2015 I have over 100 CAD files which provide 600+ water jet cut parts for the Skyote.

While it takes a little time, converting the design to CAD is a great way to truly understand the drawings. plus a huge amount of information has been extracted from the rather complex drawings. This can be a great help to others in understanding and interpreting the design.

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 resulting 3D models agree with Mr. Bartoe's thee decimal place dimensions about 99.9% of the time. I have found one discrepancy but less than 0.030"!

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 in the future.

Comments are welcome. I will respond as time permits

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Thursday, February 28, 2008

Installing Motor Mount Bushings

The following photos show the use of a fixture made to hold the motor mount bushings and washers in the correct position for welding. The appropriate hole pattern was carefully laid out and drilled in a piece of 3/4" MDF. It serves three purposes, first as a fixture for the motor mount bushings, second as a mount for the "rotisserie" forward pivot shaft, and third it will be used later to align the motor mount weldment when it is fabricated. This will assure a good match of the hole patterns if the welding distortion is not too great.

The last two photos show a small mod we made to the motormount bushing attachmment. We used rectangular tubing with one side cut away to make 45 degree gussets to reinforce the attachment. Again, a few ounces of added weight but it is in the area where the Jab engine saves 25 plus pounds so a little give back here won't hurt.

Friday, February 22, 2008

Aligning Landing Gear & Wing Attach Parts

The alignment of the landing gear and especially the wing attach fittings is critical. The plans call for 1.9 degrees of incidence for the lower wing and this is set by the position of the attach fittings relative to the lower longeron. The magic of CAD reveals the correct dimension of each of the four side plates which make up the two attach box fittings on each side. The fittings in the photos were cut by waterjet complete with the attachment bolt holes correctly offset in each part to achive the 1.9 degree incidence.

One method of ensuring the proper alignment uses threaded rod, tubing and spacers of the correct length to make an "assembly" which can be positioned correctly before welding. The following photos show the fitting assemblies for both the landing gear attach and lower wing attach components. The fuselage is upside-down in these photos.

Note that the wing attach fittings establish a 1.9 degree angle of incidence.

Tuesday, February 19, 2008

EAA SportAir Fabric Workshop

Tom and I attended the SportAir fabric covering workshop in Lakeland over the past weekend. We were very pleased and impressed with the experience. Lynn Zaro, the workshop leader, was fantastic. Not only is she a world class fabric expert but also a great teacher. This was a very helpful workshop. We both came away with complete confidence that we can do a very good job covering the Skyote. Wish I could have left the TIG welding workshop with the same degree of confidence!

Thursday, February 14, 2008

Wing & Gear Attach Fittings

Made the first run of fittings with the new waterjet source today. Due to limited time available today we only cut the 0.080" wing and landing gear attach fittings. We will cut the remainder of the order next week when I return from the SportAir Fabric covering workshop in Lakeland, FL.
Everything went well. The quality of the work is excellent.

Monday, February 11, 2008

More Parts in CAD

Today I managed to convert all of the more demanding fuselage attachments to CAD. This includes the wing attach boxes, the landing gear attach plates, motor mount plates, etc.. I also did the elevator and aileron bellcranks and horns. Hope to get them all cut by waterjet later this week.

New Waterjet Source

I met with a possible new source for waterjet services this week. The owner is very interested in learning to fly as his wife and her father and brothers are all pilots and airplane owners. He was very interested in the homebuilt market as a possible outlet for his services. Better yet, he is excited about the possibility of building a Skyote for himself! He is totally agreeable to helping set up standard "batch files" (my terminology) for fitting kits and might be willing to serve as the source for fittings. The prices quoted are much better than my initial supplier. This could work out to be a very good arrangement for Skyote builders as well as other homebuilders. I will be taking metal and DXF files to have fuselage attachments cut later this week.

Saturday, February 2, 2008

RV rudder Pedals for the Skyote?

Some quick measurements reveal that Van's RV-8 rudder pedals will fit nicely in the Skyote. I don't plan to use the adjustable pedals although they would easily fit. The whole assembly works very well on our RV-8. Everything including brake cylinders is included in the package. Up to 1 1/2" can easily be removed from the width of the assembly. If this works out, it will be another time saver.

A half-set of pedals from the 7A would also work if you wanted to stay with the overhead pivot. However it looks like RV8 pedals would make a cleaner installation.

Or maybe best yet, RV4 rudder pedals!