February 19, 2013

2013 Annual Inspection

Well, it’s that time again. Time for the annual condition inspection! The good news is that there was nothing to fix this year. Just run the compression tests, open all the access panels, lube the pivots and put it back together and return to service. The only new change I made, was to remove the zip tie seat mounting and replace it with a screw mount from the seat pan to the tube structure behind the seat. This will make it easy to get behind the seat for maintenance and inspections without always having to cutoff the zip ties and then replace them with new ones. I also extended the mounting tabs a bit with some fiberglass and carbon to get more material on the bolt locations where the seat screws to the floor boards. The original installation was cut too close to the hole edges and broke out over the years.


August 30, 2012

Alaska Bushwheel Tailwheel

I thought I would share some info about my new tailwheel install. In searching around the net and on the Kitfox forum I was not able to find much concise information about how to do the finer points of setup etc. So here’s what I learned…

First up, I needed to replace my tailwheel spring as the one I had did not have enough angle bent in it. My old one was about 35 degrees, and it needed to be 45. Thanks to John M for pointing it out while sitting in his booth at Arlington this year. Of course not having enough bend was the cause of my castering shimmy…

The new spring from Kitfox comes as 3 bent steel springs. I have had great service from a product called [URL=”http://www.por15.com”]POR15[/URL] which really binds to the steel and keeps it rust free over the years.

Kitfox supplies a great kit with the new spring, the Alaska Bushwheel tailwheel and ALL the parts and pieces needed to get it all setup. Highly recommended to save having to scrounge around for that one part you needed to finish the job.

With the new spring in place the pivot point of the tailwheel is nicely canted rearward and it’s smooth sailing at 30mph taxing down the runway.

A key point of setup is the length of the chains and springs for the steering. My old matco setup was very tight with all the tension pulled out of it. What I found is this contributed to a very stiff breakout force to swivel the tailwheel.

As you can see the chains are a bit loose here. The key is to jack up the tail so the wheel is off the ground. Turn the rudder to full deflection. Then turn the tailwheel to just the point where you can feel the breakout detent. Now adjust the chains to as little slack as you can on the opposite side that you turned the wheel. So if you turned left, then adjust the right side. Now repeat for the other side. You will end up with some slack in the chains when pointed straight ahead, but that’s ok. Now with this setup it effortlessly kicks out when the tailwheel hits the detent and works just great at all speeds.

As you can see from the pictures I used two quick links to attach the chains. One on the rudder horn, one on the tailwheel arm. Then two links of chain to attach to the Maule compression tailwheel springs.

The Alaska Bushwheel tailwheel could not be easier to maintain with grease fittings on all bearings and replaceable parts to maintain any wear points in years to come.

Overall this upgrade is highly recommended and makes for a great flying plane.

It also raised the tail by a few inches compared to my old spring and wheel setup. With the 850×6 tires on the front the stance is a bit more level and you can see over and around a bit better. 3 point landings are fine as well.

January 1, 2012

Strut finishing

One of the projects that never got done originally was to finish the air-foiled strut coverings. They are made from ABS plastic and snap over the steel struts. Then they need to be finished to look good.

This process is a bit involved.

  • First up removing the struts from the wings, building wing stands to hold the wing in place while the strut is off.
  • Sanding down the struts with 80 girt on a power sander. This is to remove all of the tooling marks and get a nice smooth airfoil shape.
  • Filling and shaping the section where the two struts join together is a major project itself. I used spray foam to fill in the empty space, then cut that level and filled the area with epoxy filler. This was sanded and filled until smooth and shaped properly.
  • Lastly I covered the area with polyfiber fabric and filled and sanded until everything was smooth.
  • I painted the entire struts with polyspray to give the ABS some UV protection before final paint.
  • Final paint was white polytone to match the other parts on the plane.

October 30, 2011

Electric trim installation

One of the big problems with the Kitfox Series 7 was the fact that this was the only year that the elevator had dual servo tabs installed. The benefit was greatly reduced elevator stick forces, the down side was a lack of elevator authority at slow speed and stall. There just wasn’t enough up elevator to get the job done with those tabs tipped down every time you pull back on the stick. Lucky for me all of the proper attach points for the electric stab trim were already installed in the fuselage, just unused. Kitfox Aircraft had a nice upgrade kit with all the parts needed. It included the trim motor (a kind of jack screw that attached to the stab leading edge) and all the wires, switches, bolts and nuts needed to install the system.

The only thing that had to be free fabricated was to fill in the old trim tab location on the elevators. I ended up using some aluminum tube (from aircraft spruce) and hysol along with some plywood to reinforce the opening and fill in the space. Then I just covered over it with some polyfiber fabric and painted it up to match.

Of course after finishing up the fabric work, I needed to build a paint booth to spray the layers of the polyfiber process. I used some heavy construction plastic and built a booth that I could paint the parts in, along with other parts of the plane that I also needed to paint.

June 13, 2011

Rotax Soft Start Module

This last weekend I installed the Soft Start module for my Rotax 912S. Thought I would give a quick report and a couple of pictures. The main module install was fairly easy as it’s a plug and play setup with matching connectors for your ignition module and a single wire you hookup to the starter solenoid. The only hard part of the install is that you need to disable one ignition while the other is starting the engine with the soft start module. In my case I have a key switch with start so it does not have the option on it’s own to shut off one ignition for start. I simply installed a Y into one of my ignition kill leads and put a second switch that would ground out the second module for start. So the procedure is flip the switch to the start position, hit the key switch, once it starts, flip the switch to the run position which enables the second ignition module.

The Soft Start module really does smooth out the initial start. Before I was getting periodic kickback or at least what seemed like kickback that the starter would power through. I have a new battery and good cables and grounds. So it does seem to work.