Thanks, Nick. Good info.
Thanks, Nick. Good info.
Steve Wilson
Huntsville, UT
Kitfox 85DD
912A / 3 Blade Taper Tip Warp Drive
Convertible Nosewheel & Tailwheel
SkySteve's SPOT Page
SkySteve's You Tube Videos
Hey there, av8rps. Watch who you're calling O-L-D!! I've set my VNE at 100 mph and may have exceeded that a few times. No flutter, but I wouldn't want to push it past that. But you are right, ol' 85DD is a cruisin' maniac!!
Steve Wilson
Huntsville, UT
Kitfox 85DD
912A / 3 Blade Taper Tip Warp Drive
Convertible Nosewheel & Tailwheel
SkySteve's SPOT Page
SkySteve's You Tube Videos
Something for Steve- just in case you hadn't seen it before. That Warp prop would work nicely on this rig.
85DD on floats.jpg
DesertFox4
Admin.
7 Super Sport912 ULS Tri-gear
DF4, Now that's a good areoplane! Some lucky guy has probably hung a tapper tip warp drive on it by now! And, no, I haven't seen that. Thanks!!
Steve Wilson
Huntsville, UT
Kitfox 85DD
912A / 3 Blade Taper Tip Warp Drive
Convertible Nosewheel & Tailwheel
SkySteve's SPOT Page
SkySteve's You Tube Videos
Thought you might like that Steve. That little airplane sold a ton of kits.
It think it would look good with some Aerocet 1100 amphibs. Just a thought.
DesertFox4
Admin.
7 Super Sport912 ULS Tri-gear
Steve Wilson
Huntsville, UT
Kitfox 85DD
912A / 3 Blade Taper Tip Warp Drive
Convertible Nosewheel & Tailwheel
SkySteve's SPOT Page
SkySteve's You Tube Videos
I was able to fly the new Warp Drive Taper Tip propeller today. I installed it at 11 degrees measured at the blade tip, same as with the square tip. On the ground run up, the rpms increased 300 rpm, from 4850 to 5150. My plan was to do several stop and goes but there was just too much traffic today, so I did several T&G's then some straight and level flight away from and back to the airport. Take off was very smooth and seemed to be shorter than normal but I was only able to make one take off from a stop. During several T&G's I noticed it was difficult to slow the plane down on final. I usually come over the fence about 50 mph with a touch down speed between 38-40 mph. Today I had a hard time slowing down over the fence much below 60-70 mph, resulting in float at the threshold where I normally touch down. When I left the airport the wind picked up a bit and was choppy, but I did notice that with a little power added, the prop spooled up quickly, taking me over 100 mph in just a moment. Much faster spool up than with the square tip. I finally found some smooth air to test cruise speed (just me on board and 1/2 tanks of fuel [about 6 gals]). I normally like to cruise at 5300 rpm which gives me 93-95 mph with a 3.5-3.7gph fuel burn. With the square tip I can get 98-100 mph at 5400-5500 rpm at 4.2-4.5 gph fuel burn. Today I also cruised at 5300 rpm which gave a 98 mph cruise speed on the Airspeed Indicator and GPS. Fuel burn was 3.7 gph. All in all I'm pretty happy with the results. I'll try again tomorrow or the next day to get more data.
Steve Wilson
Huntsville, UT
Kitfox 85DD
912A / 3 Blade Taper Tip Warp Drive
Convertible Nosewheel & Tailwheel
SkySteve's SPOT Page
SkySteve's You Tube Videos
Steve,
Sounds like a great first experience with your re-configured prop.
Early on I had a similar deal with the plane's reluctance to slow down on short final. Diddling with the pitch changes that but not necessarily in agreement with optimum climb or cruise. Originally I the set the idle speed at 1800 on the ground - that gave me approx 2300 rpm with the throttle closed & gliding @ 65 mph. I set back the ground idle 200 RPM and that resulted in 2100 rpm @ 65 mph glide with the throttle closed and allowed the plane to slow down over the threshold more easily. I then adjust the throttle on rollout so the RPM ends up @ 1800 when I stop.
Thinking what this has to do with is if the speed is low (like 65) the prop is still either 1) making some thrust at a "normal" idle speed for a particular prop pitch or 2) not producing enough drag at a "normal" idle speed for a particular prop pitch. By reducing the RPM some of the thrust goes away or the drag increases. I have thought about coming up with some sort of measurement system to determine what the "zero thrust" @ RPM & MPH would be for a particular pitch; but, haven't figured out any novel way to measure that yet.
Sincerely,
Dave S
KF7 Trigear
912ULS Warp Drive Tapered
Dave,
Good thoughts. I have my idle set slow, also. I can't remember right now what it is set at, but I think i set it all the way back to 1100 rpm. Of course, I only use that on final to slow down. I normally idle at 1700-1800 rpm on the ground. I'm thinking the propeller mass has been reduced enough that I'm not as draggy as I used to be on final. On final I use the stick (attitude) to control speed and the throttle to control rate of descent, adjusting throttle on the glide slope to hit my predetermined touch down spot. I'm thinking my hand muscle memory may be over-riding my brain! I'll work on it within the next couple of days and see what I can do. Thanks for your input. It caused me to think again.
Steve Wilson
Huntsville, UT
Kitfox 85DD
912A / 3 Blade Taper Tip Warp Drive
Convertible Nosewheel & Tailwheel
SkySteve's SPOT Page
SkySteve's You Tube Videos