*****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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Friday, November 30, 2007

Spar Drill/Assembly Jigs

I got the spar drill/assembly jigs from the laser cutter yesterday. They will allow all of the holes to be drilled in all five spar components as an assembly. No layout of individual holes will be required. Maybe I will have time to give them a trial run over the weekend. There are approxomately 134 holes in each spar assembly. Multiply that by eight spars and that's a lot of holes!

The spar jigs were laser cut while the wing fittings were cut by waterjet yet the holes match perfectly.

I built a flat table using MDF. It has a spline to hold spar flat. All of the hole locations for ribs and fittings are in the jig. No layout necessary!

Wednesday, November 28, 2007

Radius Bender

A while back I sketched up a precision radius bender. I based it on some Thompson Linear Ball Bushings which were surplus from some project long past.

My friend and fellow RV builder, Les Kanna, finished building the radius bender today. I decided to bend a few fittings and I am happy to say it works great!

The bender features a micrometer adjustable stop which precisely sets the bend centerline under the radius bar. The distance from the bend center to the edge of the part is given by the CAD program. I am using a 20 ton hydraulic press from Harbor Freight.

It produces a nice smooth bend of the correct radius. The bender is currently set up for a 0.125" bend radius

Thursday, November 22, 2007

Fittings Cut by Waterjet

I received the first batch of wing fittings about two weeks ago.
The quality is excellent.

VR3 Kit Assembly Completed

I was able to complete the test assembly of Skyote VR3 kit #001 yesterday (Nov. 21). The tubes all assembled as advertised with no visible gaps. VR3 will be replacing the longeron tubes and the firewall perimeter tubes so that the longeron/firewall joint will better conform to Bartoe's drawing. The change in the joint arrangement will allow the fittings for landing gear struts and flying wires to interface with the longeron tubes as originally intended.

The VR3 Kit is an incredible time saver. I'm not sure that I would ever be able to fit the tubes in the traditional manner. I know that I could never match the quality of the work!

New style Assembly Jig

I decided to redesign the assembly jig for better accuracy and better access to the tubes. The new jig is an internal structure as opposed to the external structure of the previous jig. The stability and accuracy is much better as well as better access to the tubes. Each tubular crossmember is supported by a pedestal which locates it in the correct dimension in all dimensions. The longerons are added next followed by the diagonals. The VR3 tubes don't actually need this much jigging for welding, but my intent here is two-fold. I want to confirm that the tubes conform to Bartoe's drawings as well as confirm that the fit each other properly.

Saturday, November 10, 2007

Fuselage Progress

I was able to put in about 7 hours during the past week. The progress is apparent in the photos. The fit of the tubes is excellent. There is really no "fitting" to do at all. All of my time is spent building the assembly jig to hold the tubes in the correct position. Absolutely no grinding or cutting tubes required.

I am not satisfied with the stability of the jig. The tall 2x4 posts are relatively easy to deflect at the top end. If I add gusset bracing it will obstruct access to the tubes.

Wednesday, November 7, 2007

Trial Fitting Fuselage Tubes

I decided to purchase a CNC profiled tubing kit from VR3 in Canada. Since this was to be the first Skyote kit produced by VR3 there was some design time involved. I placed the order on 9/09/07 and received the complete kit around 10/27/07. Subsequent kits should have a shorter delivery time. As purchaser of Skyote Kit #001 it falls to me to perform the initial check-out of the tubes to confirm that they all fit well and conform to Mr. Bartoe's drawings. The tubes will need to be assembled in 3-D without welding as some of them may need to be modified. This means that the assembly jig will likely be a little more elaborate than what will be required to assemble and weld subsequent tube kits.

The Fuselage Assembly Table was completed on the afternoon of Nov. 2 so we took a shot at assembling a few tubes starting at the firewall. The tubes all fit perfectly. Unfortunately the design of the joint between the firewall tubes and the longerons does not agree with the Skyote Drawings. As supplied, the longeron tubes butt into the firewall tubes which are mitered to each other. The Skyote drawings call for the longerons to extend through and be flush with the forward surface of the firewall tubes. This allows the firewall tubes to butt into the longerons. I spoke to Don VanRaay of VR3 about this discrepancy and he readily agreed to supply replacement tubes per the drawings. We agreed to wait until all of the remaining tubes have been fitted before replacing the tubes in question so that all of the tubes can be corrected at once.