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Archive for August, 2010

Alignment and a Honda Hitch

At the suggestion of a friend, I checked with one of the local alignment shops for some throw-away shims. It’s my understanding that they use these shims to adjust the castor on old, solid axle vehicles and trailers. These are much more heavy duty than aircraft shims, but hey, 2 degrees is 2 degrees, right? I cut them down to size using my band saw.

This is my right landing gear leg and I’ve inserted 2-2 degree shims which tipped the top of the tire outboard. The picture is somewhat confusing because the tire has already been flipped and is showing wear on the outside of the tire instead of the inside. Trust me, it was the inside of the tire that was wearing–excessively, I might add.

This is the left landing gear leg. I’ve only inserted one 2 degree shim because while this tire was also wearing on the inside edge, it wasn’t wearing nearly as much as the right tire.

In the process of removing and replacing all the various tire, wheel and axle components, I discovered that my brakes were dragging excessively. I found that the shim between the caliper halves was slightly too thin for my brand new brake discs. When I tightened the caliper bolts down, the pads pinched the disc and caused some pretty good drag. I fabricated an additional shim out of some .032″ material. I’m happy to say the solution worked very well. My takeoff roll was shortened by at least 800′. I tease people and tell them that it also added 3 knots to my top speed!

I also installed this Curt Class III hitch on my CR-V today. I mention this because I credit my aircraft refurbishment experience with giving me the confidence to do this sort of thing. The local trailer place wanted $300 for this hitch and wiring harness plus another $150 to install it. I bought the same exact hitch and wiring harness on Amazon for a total of $185 including shipping and installed everything in less than 45 minutes. If I was married, I would try to spin this story into justification for owning $7500 worth of aircraft tools! But since I’m not, I’ll just give the manly, Tim-the-Tool-Man-Taylor grunt and keep moving…


Landing Gear Alignment

As this picture suggests, I have an issue with the camber on my landing gear. I’ve decided to try to shim the axles to adjust the camber. I’ll also flip this tire around to wear out the other side.

The left side gear leg is also splayed outward a bit, but not as much as the right side. I also rotated this tire in hopes of maximizing its useful life.

Looking at the front of the airplane, the landing gear camber issues are pretty obvious.

I decided to remeasure my landing gear toe and camber. The first step in this process was bringing the airframe to a level flight attitude. A friend of mine owns this taildragger tail lifting apparatus. He loaned it to me for the afternoon. Gotta get me one of these buggers. It sure makes leveling the plane a simple and quick task.

I used my Smart Level on the fuselage longeron to determine level flight attitude. This setup works very well. I set the Smart Level to beep when it reaches 0.0 degrees and then simply crank the tail lifting jack until I hear the thing beep.

I dropped a plumb bob from the center of the firewall and from the tailwheel spring attach bolt to determine the fuselage centerline. I then taped a length of unwaxed dental floss to the floor between the two centerline points. The dental floss is near the black carpenter’s square in this picture. The line in the foreground is just an expansion joint in the cement.

I clamped a straightedge to the outside of the wheel and then measured from the straightedge to the centerline. If the toe-in/out was set perfectly at zero,the measurement from the straightedge to the fuselage centerline would remain constant over the entire length of the straightedge.

I jotted down my measurements directly on the concrete floor with a fine-tipped Sharpie marker.

I drew out a simple line drawing and copied all my measurements to the whiteboard. Armed with all this information, it was a simple matter of looking up a few trig formulas to derive a number of degrees of toe in/out.


Battery Charger

Today I installed this Hella receptacle for my battery charger. I’m not sure exactly what the real name for this style of receptacle is, but everyone refers to them as “Hella.” BMW motorcycles use them as power ports for accessories and heated clothing.

I liked the plug because it’s got a spring-loaded cap and it’s rated for up to 15 amps DC. It’s sort of like an undersized cigarette lighter plug, but it kind of snaps into place in the last 1/4″ of insertion, too, so it stays put–unlike cigarette lighter plugs that always seem to back out.

This is my whiz-bang Odyssey battery charger/conditioner/maintainer. I figured that since I had an Odyssey battery, the Odyssey folks probably know how to make an appropriate battery charger. The nice thing about this one is that it’s got a quick charge capability, but it’s also “smart” in that it reduces the charge as necessary to a variable maintenance level to prevent over charging if you leave it plugged in forever. The downside to this is it’s pretty big and it’s got a fan that runs constantly whenever it’s plugged in. I’ll probably invest in a different, smaller charger for traveling.

Storm clouds near the airport this evening. It was a funky weather day around KFNL today. For a few minutes this evening I thought we might be watching for funnel clouds.

I laid-up this oil cooler diffuser box for a friend today. He’s got a Sidewinder and has been very helpful to me in my Midget Mustang project. It was the least I could do for him. The more I think about it, I think I’ll probably re-do the diffuser box for my oil cooler. The tubing size is just a little too big for my tastes.


FNL-PUB-LMO-FNL Breakfast

It’s been quite some time since I’ve posted anything on this website, but I finally have something to share.

There’s a group of pilots based in the Denver area who make it a habit to fly somewhere for breakfast on Saturday mornings. One of the guys invited me to tag along this week. We ended up having 11 people and 10 different airplanes show up for breakfast in Pueblo, Colorado (KPUB) this morning. I flew down with a friend from KFNL. He has a Sidewinder that he built himself and first flew in 1981.
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The route is displayed to the left. I avoided the Denver and Colorado Springs airspace to the east on our way down to Pueblo and to the west on the way back home. We also stopped in Longmont (KLMO) for cheap fuel at $3.78 per gallon.
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As of the end of today’s flight I now have 20.9 hours on my Midget Mustang. There are a few squawks, but nothing major. The fuel burn is a little higher than I had hoped, but I’m not leaning aggressively and I’ve been flying around at relatively low altitudes and at full power to help the engine break-in. The airplane is not nearly as fast as I would have hoped, either with a top speed of about 175 mph at 8,000′. My friend with an IO-320 powered Sidewinder could pull away from me with 18″ of manifold pressure and 2300 rpm. I’m hoping the wheel pants and a few other aerodynamic clean-up mods will provide a few more mph.

Airborne near Hudson, Colorado. Photo by Allyson Schauer. Photo ship: Mike Schauer, RV-6.

Gotta love the silhouette photos and our beautiful blue Colorado sky.