Throttle Quadrant Refinements

The throttle/mixture quadrant has continued to undergo minor refinements. Specifically, all of the phenolic friction washers now have anti-rotation tabs. Also, the anti-rotation pin through the shoulder bolt has been replaced by a stainless steel tab welded to the head of the shoulder bolt. This makes assembly and disassembly much easier,

Rather than welding the assembly mount to the fuse diagonal, the assembly is now held in place by a two-piece clamp collar. This allows some adjustment of the position and makes removal for maintenance or modification more convenient.

Throttle/Mixture Quadrant Completed

Eventually you have to quit designing and cut some metal! I decided I had reached that point with the throttle/mixture quadrant so I machined up the latest version this weekend. I haven't drilled the attach holes for the throttle and mixture cables yet as I want to confirm the correct position with everything in the airplane. The paper pattern is still on the back side of the levers and shows the likely position of the attachment holes for the control cable ball ends. Also, black and red spherical knobs will be pressed into the ends of the handles when they arrive.

This design works on the same principle as Pete's design using bellville washers but has been modified to include the mixture control as well as forward stops for both throttle and mixture. I will likely add a small lever to the friction adjust knob when I can determine the correct location so that the lever will wind up in the correct position for easy adjustment.

The action is good and smooth with the friction adjustment being fairly linear through about 1/4 turn of the friction adjust knob. Each of the controls is isolated so that movement of one control does not affect the other control or the friction setting.

Cowling Progress

Dale has continued to pound metal and as a result the cowling is really taking shape. Forming the "eyebrow" cooling ducts has been quite a challenge but they are almost finished. We used a fiberglass cooling duct supplied by Jabiru as a model but the duct we used has been replaced by a later model which gives "better cooling". Hopefully this design will work okay for the Skyote.

Throttle Quadrant Re-Do

I built a model of the previously proposed "pony brake" style throttle quadrant which was less than satisfying in relation to the smoothness of the action. As a result I have gone back to a design much closer to Pete's original design. It uses a stack of Bellville washers to develop the friction when compressed by the knurled knob. A mock-up of this arrangement gave very smooth action so this will likely be the final design.


This part is made from 1/4" 4130 and welds to to the diagonal fuselage tube in the appropriate position. It provides the basic mount for the quadrant and provides the anti-rotational anchor for the shoulder bolt which serves as the pivot for the throttle and mixture levers. The shoulder bolt and the bellville washers came from www.mscdirect.com and the 1/8" phenolic for the friction washers came from Aircraft Spruce. The levers are fabricated from 0.070" titanium and the knobs from 6061-T6.

Nose Bowl--One More Try

The nose bowl is getting close. This shape seems to work better.

Engine Cowling/Nose Bowl

Here's the first stab at the cowling/nose bowl. We are now trying to reshape things to let the cowling and nose bowl flow together with out the bump at the junction. Cowling a "first time" engine is lots of fun. Looks like it will take about four attempts to get it right.

I had originally intended to use the same nose bowl/spinner as Pete Bartoe did on his airplane. Unfortunately, it just did not work out well with the Jab engine. Also the spinner combined with the 6 cylinder engine was starting to make the nose look a little long. A rounded nose bowl with a "skull cap" spinner will help keep the nose in proportion

Hanging the Engine

We hung the engine on the firewall Saturday afternoon. Now begins the process of finding a home for everything. Unfortunately, it looks like the Jabiru exhaust system is going to require significant modification.

The nose bowl ala Pete Bartoe also has some difficulties jiving with the Jab engine. We may revert to a round style nose bowl like Hawkeye/Dave Novak.

Sheet Metal Progress

Some progress has been made in finshing the boot cowl and cockpit surround. These pictures were made 5/30/09. Everything is pretty well fitted and fastened so it is time to move on to the challenge of the firewall forward.

Boot Cowl

The boot cowl is beginning to take shape. We plan to use flush riveted hidden hinges to attach the cowl and eliminate most visible fasteners.

Wing Tank Fuel Gauge

The fuel gauge for the wing tank was made by cutting off a "Stearman" style gauge from Aircraft Spruce.

Throttle Quadrant

If you have ever set in the cockpit of a Skyote you know that space is at a premium. In some Skyotes the throttle/mixture controls become knee knockers. I originally considered using panel mounted push/pull controls to keep them out of the way. I finally decided that panel space was too valuable to devote to throttle/mixture so I decided to use quadrant controls but minimize the intrusion into the cockpit. I came up with a compact quadrant design that works on the "pony brake" principle to provide friction adjustment.




In operation the adjustment knob squeezes the split tube down on the cylindrical bodies of the two flanged bushings ( blue and orange parts). A 1/4" flat head through bolt holds it all together but it is not shown as I am just too lazy to do it! The ends of the bushings are machined to receive the flat stock throttle and mixture handles. Moving the handles causes the bushings to independtly rotate against the friction of the split tube. The split tube will be welded to the diagonal fuse tube near the pilot's left hand. The throttle control cable will actually be outside the fuselage tubes in the area provided by the stringers. This will hold the cockpit intrusion to a minimum.



A version with handles rather than knobs.

Turtle Deck Progress

The turtle deck is beginning to shape up. We made the forward deck skin somewhat longer than the plans to accommodate an extended headrest ala Hawkeye's Skyote. I also plan to install the windscreen in the aft position per Hawkeye's recommendations. Dale Doane is responsible for the beautiful woodwork!

Pete's Original Nose Bowl Tooling

This is Pete's original forming block used to form the nose bowl on his personal airplane. Glenn Bridges talked Pete into letting us borrow the tool to form our nose bowls.



Pete included this test part when he sent the tool.



Checking the fit of the spinner backplate with the formed nose bowl. Looks like a good fit.



Time to start making airplane noises!

Interplane Struts Riveted

The interplane struts are riveted. Still have to trim the angles on the ends to clear the brace wires.

Interplane Struts and Drill Fixture

It's time to tackle the interplane struts. This will be another deviation from the plans since we will be using aluminum streamline tubing rather than the squeezed round tubing specified in the plans. The tubing is 6061 and has the same overall dimensions called for in the plans. The streamline shape requires that the aluminum spacer blocks be shaped to compensate for the teardrop shape. We designed and made a precision jig to hold all of the parts for drilling. The tubes were cut to length using a milling machine to achieve the final overall length. The jig is aligned with each end of the tube for match drilling the components.

Panel Layout Update

Installing a foam mock-up of the floor mounted console showed that location to be less than satisfactory. After taking careful measurements, we were surprised to find that there was room to include the Comm and Transponder in the lower center of the main panel. I had assumed that there would be a conflict with the top of the stick but this is not a problem. This may be the final version.

Engine/Cowling Model

I refined the engine/cowling model a little. I still need to add the cooling ram air ducts and some simulation of the 6 into 2 exhaust system. Pete Bartoe is lending us the forming blocks he used to form his nose bowl. The orange part is the battery which needs to go up front to help with the CG. The battery will be supported by a subframe off the engine mount. It looks like most of the exhaust and ram air ducts will be outside the cowling.