I just ran across this ebay add for a Kitfox muffler. Maybe the pictures will show what you need to see. Or maybe someone wants it and buys it.... JImChuk https://www.ebay.com/itm/Kitfox-SS-912-Exhaust-System/264081402236?hash=item3d7c7a697c:g:qrUAAOSwEp5cDaqJ:rk:4:pf:0
Finally got my wings finished up thru the filler coat, or course a lot of time was spent installing new tanks and a couple of ribs and working part time. Will wait till I finish covering everything prior to painting which only messes up the shop once. I really like the Stewart System better than Poly Fiber cause now I can actually walk in a straight line from the shop to the house. Well, straight for someone in their 60's.
Oh, BTW, and returning to the original theme, I pulled the plane out of the garage for a little testing and, after almost 2 months of inactivity, the engine wouldn't start. Pulled the plugs and, you guessed it, the electrodes of even the extended-tip plugs were covered in oil! Gotta fly more often! Working on a cabin heater, among other things.
Testing can reveal important physics. I have prior experence with surface tension effects, so not suprisingly my intuition was correct. Once a paper filter is saturated with fuel or oil, any water coming along cannot saturate the paper, and becomes trapped. Once the amount of accumulated water is such that it becomes able to cover all of the paper media, the pressure drop required to force that water through goes way up. That is calculable once the pore size is known. Good thing, Leni, that your fuel pump was strong enough! In the pic below, I first saturated the filter in fuel, then added water on the upstream side. The horizontal line visible in the picture is the water surface. That water is trapped. Accordingly, I have removed my inline paper fuel filter from behind the seat, then installed a fine screen filter (larger pore size), but placed downstream of the "header tank" gascolator, where it is protected from water. The little screen filter was sized for smaller engines, but inline testing at full throttle showed its pressure drop to be negligible. My oversize paper oil filter is located where it is easily inspected and replaced, but I really expect little or no atmospheric water to thermal-cycle-pump its way into my oil tank, thus ultimately piling up against my oil filter. By-the-way, I also flow-tested that filter in oil, and it passed. So Leni & Vance: I hear you, my friends! No offense intended. It's just a matter of how I process information. As an old airplane engineer, you can trust that I beat the holy schidt out of the problem, per well-established tradition! I too am very keen on my prop not stopping unexpectedly!
Hi Larry! There is no question changing castor angle can affect shimmy, and it is possible in some cases (maybe a lot of cases i don't know) to greatly reduce/eliminate shimmy by changing castor angle. However it didn't work for me when I tried a very large tailwheel tire. The particular tailwheel I was using did not incorporate any resistive damping by design. When I went to the large tire the shimmy began. Trying to solve the problem, the designer built me various tailspring sockets to change castor angle. i was using a stinger type spring which made changing castor angle relatively easy by changing the spring socket angle. I tried various castor angles from negative to neutral to positive. The effect on my tailwheel of changing castor angle was that with negative castor angle it would shimmy continuously. With positive castor angle it would shimmy violently but would then suddenly track without shimmy. But it still shimmied and was violent. The large tailwheel would ALWAYS shimmy under one condition or another until we applied resistive damping. He finally modified the design of the tailwheel to add resistive damping and that eliminated the shimmy. And with adequate resistive damping, It did not matter what the castor angle was. it did not shimmy I think that is why at least one newer manufacturer of really big tail wheels has eliminated steering springs altogether and uses tons of resistive damping in much the same form as Vans does using belleville washers to eliminate shimmy on their nose wheels. Vans specifies something like 10lb of force required to move their nose wheels back and forth. This resistance critically dampens any resonant frequency in the system. i think we have to look at tailwheels the same way.
Any good sled shop can reseal it for you. I have done 4 or 5 582's myself. The rebuild manual is on this site and the dvd "deep inside your rotax" pretty much walks you through it. Buckchop on here is in Fairbanks and has a shop he used that resealed his engine. I don't know anything on the other shops up there.
Skypics is right. I about ground looped my plane once when my foot slipped in behind that center bar while trying to get a landing straightened out. That was a bad design. I am going to put a fence on the peddle to give my foot an edge to set against so it wont slip off.
Now might be a good time to figure out how to get more foot room on the pedals. That lower crossbar on the firewall frame will interfere with how much of your foot can fit on the brake pedal. I wear a size 9 and I can oly get my tip toes on the top of the brake pedal. If I could get the ball of my foot up om the top of the pedal I could get better braking. Also it is possible to get ypur toe between the top of the brake pedal and that cross bar. Avid MK4 John M
Hello all, Just a short update here. The Skytrax gearbox has been doing great during flight testing with only a few refinements that will be added to the production boxes like a sight level gauge snd slightly larger sump area. IF you didnt follow the Stol drag a few months back Steve Henry posted the second fastest time behind the 680hp turbine powered plane they call draco. In parrelel to Steves testing Thomas Hauklien of edge performance in Norway will start Dyno testing with a Turbo charged Apex. The goal is to get some 300hp sustained runs with and without the clutch and tear it down as nd measure and inspect parts.
Well, thank you very much friends. This is something pushing this forum forward - sharing ideas and experience. My tail wheel is pretty COTS but I don't exactly know about tail spring and setup//geometry of this part. There is U-strap as well (No. 6 on my picture) where is free space (real clearance about 10 mm/0.4") in between fuselage and tail spring. It seems not correct for me, I would expect sort seal (sort of rubber? or elastic material ) there as spacer to damp vibrations. One more observation is that there is only one fix point of tail spring - bolt (pin) and U-strap without sort of spacer is leaving free motion up and down for spring. I will check caster angle definitely anyway.
Caster is usually the number one culprit.Another useful item (which may not work on Jenki's setup) is to replace the tension springs with compression springs.Maybe the internal friction or the higher spring rate somehow dampens the shimmy?