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.

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.

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!

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.

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.

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!

The Fuselage is Tack Welded

The fuselage is out of the jig! Dale Doane tacked welded the main portion of the fuse yesterday. After I fab the finger plates and other fuselage attachments, I will take the fuse to Dale's shop in Newnan, GA to complete the welding. I continue to be impressed by the VR3 tubing kit. The tube which extends rearward from the bottom center of the firewall looks crooked because it is! This is where we ran out of Argon and that particular tube is still loose.

Just so happens that Glenn Bridges got his VR3 fuse tack welded and out of the jig the same day!

Prepping Fuselage for Welding

I disassembled the fuselage and polished all of the weld areas this week. Acetone was used to clean the weld areas inside and out to remove oil contamination. I am a little concerned that oil contamination may migrate from the interior of some of the tubes, especially the ones in vertical orientation.

I have arranged with Dale Doane, an A&P who works for Delta to weld my fuselage. Dale plans to fly his Cessena from Atlanta and tack weld the fuse here in my shop. I will then take the fuse in my truck to his shop in Atlanta for finish welding. We had hoped to get started this week but now it looks like the weather isn't going to cooperate.

Glenn Bridges has his VR3 fuse all jigged and polished and started tack welding today. looks like he will be ahead of me for a while!

Center Section Spacers

Made a couple of sets of spacers for the center section today. The .115" and .300" spacers were too short to easily make from the purchased spacers so I made them from scratch using bar stock. The .250" long spacers were purchased from www.aluminum-spacers.com.

Next will be the 1"x 1" x 1/8" "C" channel fittings for the ends of the compression struts.

Rib to Leading Edge Clips

Made 70 angle clips to attach the ribs to the
leading edge tubes today. I taped 7 or 8 clips together and
"gang" bent them as a group to save time. The bender is so accurate I was able to adjust for the added thickness of the tape so the bends would come out exactly right.






I had to push the holes outward toward the ends of the
angle legs a little. As drawn, there is not sufficient room for
a rivet puller to operate. The drawing
references " 4 number 3 rivets". The rivets which go in
the tube must of course be pulled rivets.

Compression Strut Bushings

Tom and I made two sets of bushings for the ends of the compression struts last week. We started with 3/4"x 3/4" x 5/16"ID spacers from http://www.aluminum-spacers.com/. We made a mandrel for the lathe so we could turn down the barrel of the spacer to 0.652" leaving a 0.060" flange at one end

The bushings fit nicely in the 3/4"x 0.058 wall x 6061 tubes. The "hammered" effect on the ends of the bushings is from tumbling the parts after the spacers were made.

Priming the Spars

We had some nice weather (70 degrees) earlier this week so Tom helped me prime the spars for one wing. First we pulled all of the spar caps and webs over a 3-M wheel to polish all the edges smooth Then we scuffed every thing good with Scotch-Brite and cleand with a degreasing cleaner.

We are using RM brand DE15 epoxy primer and it seems to work very well. I used PPG DP40LF on my RV7A but that paint store closed. (Edit: See updated post as I have reverted to DP40LF)

The three cans in the picture......$335.45 +tax Ouch!

P.S. The funky looking parts near Tom's left hand are wing root strakes for our RV-8. They are reported to lower the stall speed significantly and eliminate a strong tail buffet which occurs near stall speed.

Bending Rib-to-spar clips

Bent the rib-to-spar clips for one wing today.

The following pictures show a clip in the process of being bent.

The first in the sequence shows part in position.

The second shows the ram just touching the part which is "zero".

The third shows the part at 0.210" ram travel after zero. This will result in a part with 82.8 degrees included angle.

The fourth is the finished set for one wing.

Teardrop Aluminum Strut Material

I found a source for teardrop aluminum strut material. It is:

David Gordon
AED Motorsport Products 5373 West 86th Street Indianapolis, Indiana 46268 USA Phone: 317-334-0569 / US Toll-free 888-413-0233 Fax: 317-879-9397

email: dave@aedmotorsport.com

or web site: www.aedmotorsports.com

They offer teardrop tubing made fro 1.5" x 0.058" wall 6061-T6 per the Skyote plans. They custom make this to order so they only deal in 12' lengths. The best deal is to order three 12' lengths which will make struts for two airplanes with one strut to spare.

Drilling First Main Spar

Tom and I drilled the first spar last Friday the 14th. We proceeded with extra care as it was the first spar to be drilled using the laser cut spar drill/assembly jig. We drilled all of the holes for the ribs and fittings in about 50 minutes. We did not drill any holes in the tapered section of the tip.

Everything worked as planned. We will drill an aft spar next. We plan to complete the rib/fitting/spar assembly for one wing before drilling the remaining spars. Better safe than sorry.

Excellent Fuselage Construction Book

As a neophyte fuselage builder, I have found the book "Construction of Tubular Steel Fuselages" by David Russo to be very helpful. Much of the information in this book directly transfers to the building of a VR3 fuselage. The book can be found here: http://www.actechbooks.com/construction_tubular_steel.htm

VR3 Final Report

I am happy to report that the final version of the VR3 Skyote fuselage tube kit has been assembled and checked. I received the replacement longeron and firewall tubes last week but just got around to assembling them yesterday. These tubes have a different arrangement for the joint between the longerons and the firewall tubes. The new joint arrangement provides the same type of interface with the landing gear and flying wire fittings as called for on the plans. The original joint design from VR3 was not wrong, just different.
The new joint design provides the same "perch" for the fittings, but eliminates the need for plugging the end of the longeron tube by mitering it to the vertical firewall tube. Since a picture is worth a thousand words, just take a look at the latest posting in the VR3 photo album. Others may take issue, but I am satisfied that the new joint is structurally equivalent to Pete's design while being easier and more accurate to build.
I am very happy with the VR3 kit. I have had a couple of experienced tube fuse builders look at it and they said that it would not be possible for them to duplicate the accuracy and fit quality using the traditional manual profiling methods.
The VR3 kit is about the same cost as Pete Bartoe's rib kit. In my opinion, the VR3 is at least, if not more of a time saver, than the rib kit. I think I could eventually hammer out the ribs if I had to. I'm not sure that I would ever get the fuse hand fitted to a point that would make me happy.
In my book, there are only two valid reasons not to go with the VR3 kit:
(1) You WANT to fit the tubes yourself.
(2) You can't justify the $$.
If you are not burdened by either of the above "problems" then VR3 is the way to go.
In conclusion, I have no connection with VR3, financial or otherwise.

Aluminum Spacers

I just received the first aluminum wing fitting spacers.

I got them from http://www.aluminum-spacers.com/ . In a quantity of 500 they were only $0.17 each. These are 1/2"dia. x 5/16"bore x 3/8" long. I wil make the shorter spacers by cutting down some of these.

The spacers are a perfect fit with the 5/16" 4130 tubing which will be used to make the bushings that fit inside.

The actual company name is Daven Screw Machine Co.. They are a small family run business and were very easy to deal with. If you don't see what you need on the web site, give them a call as some standard sizes are not listed as was the case for the above spacers.