Kitfox Series 7 Super Sport - Show Me Fox

[alexM]

I have been looking at the Sensenich 3 Blade Ground Adjustable Props. I was wondering if anyone had any experience with them?

After speaking with the rep today I understand they are furnished with 6 indexing pins. To set the prop pitch you simply turn the blade to full fine insert the index in of your choice then turn the prop blade to engage the index pin.

Basically there are 6 positions you can set the prop and the index pins provide a quick and repeatable way to adjust the prop without protractors. Each pin will adjust the pitch by approximately 1 degree or 3” of pitch.

I may be posting a used Whirlwind Prop and Spinner for sale in the near future if all this checks out. I will be visiting their booth at AirVenture in the coming weeks.

I have the Sensenich two blade on my plane right now. Can't say as I've flown behind it but I have installed it and set the pitch using the pins you mention. It's a very cool concept. Not quite as fancy as the Duc prop with the single Allen Wrench hole in the middle but still pretty awesome. Quality of the prop is outstanding. The blades are beautifully made. I checked tracking on mine just last week and the blades track less than 1/16" apart.

If you search the web you'll read where people caution you to still use a protractor to check the blade pitch when you set it with the pins.

RE: Rivnuts
I've a very vocal Rivnut hater based on my career with the big airplane company. All it takes is one spun rivnut to ruin your entire afternoon. There are locations where you don't have a choice. When that occurs: ALWAYS use "keyed" Rivnuts, DO use something to help secure them like the Loctite that Gary uses, DO run a screw through them several times to make sure the threads are clear before you put parts together, DO NOT ever let some knuckle dragger anywhere near them once installed.

[Jason Murphy]

First work session following AirVenture

Ordered a Tannis Heater for the Rotax engine at AirVenture.

Applied a coat of Tung Oil to my floor boards.

I have been looking at various options for fabric covering systems. I have decided I am going to use the Stewart Systems waterborne system.

I will benefit from this system because it will allow me to continue my work at home. I spoke with Marty at Stewart Systems. He advised their system is approved for use with all types of fabric. I clarified to ensure I am in compliance with their STC and instructions for use. I will be able to use the Poly Fiber Fabric (or any manufacturers) and Tapes with Stewart Systems adhesives, sealants and top coats and be in compliance with their STC.

In addition the Stewart System does not require the PPE required by other systems. Marty advised I would even be able to spray their top coats with a simple respirator. Essentially I will be able to complete all of my work at home using their system which is huge a huge windfall.

I requested reviews from people who have used the Stewart System and received positive feedback. A friend of mine advised they had trouble in Alaska with bonding and delamination. I discussed this with Marty he advised those issues came from the permeability of EkoFill and moist conditions there. Stewart Systems changed their their process to use the EkoBond as a sealant. EkoBond will make the surface impermeable to water. Essentially the EkoFill will be encapsulated by the EkoBond as the base layer and the topcoat preventing moisture from getting in from the outside.

I have been reading their manual and watching the instructional videos posted on their website.

I can continue to work in my basement without risk of fire or explosion all through the winter.

I also did some sanding on the existing SuperFil in preparation for fabric.

I have been in touch with Sensenich and it appears my 11.3” spinner will be compatible with their 3YO or 3BO prop per their President whom I spoke with at AirVenture and received his contact information.

I apologize about the poor organization of this entry.

[Jason Murphy]

I have the Sensenich two blade on my plane right now. Can't say as I've flown behind it but I have installed it and set the pitch using the pins you mention. It's a very cool concept. Not quite as fancy as the Duc prop with the single Allen Wrench hole in the middle but still pretty awesome. Quality of the prop is outstanding. The blades are beautifully made. I checked tracking on mine just last week and the blades track less than 1/16" apart.

If you search the web you'll read where people caution you to still use a protractor to check the blade pitch when you set it with the pins.

RE: Rivnuts
I've a very vocal Rivnut hater based on my career with the big airplane company. All it takes is one spun rivnut to ruin your entire afternoon. There are locations where you don't have a choice. When that occurs: ALWAYS use "keyed" Rivnuts, DO use something to help secure them like the Loctite that Gary uses, DO run a screw through them several times to make sure the threads are clear before you put parts together, DO NOT ever let some knuckle dragger anywhere near them once installed.

Thanks Alex,

After speaking with the Sensenich President Steve at AirVenture he advised me of a new prop they released specifically optimized for the Rotax 912 iS and the Vans RV12.


It is the 3YO it’s been out for a few years. It is not on their website. I spoke with Phil from Lockwood aviation and he said that is the prop they are using on their AirCam and he is very pleased with it. I emailed photos of the 3YO to Steve and he reported the 3YO and the Whirlwind Spinnner I have are compatible.

The trade I will make for this setup is the 3YO does not have an adjustment pin. It is similar to yhe Whirlwind where the blades are simply clamped in the prop hub and lined up with a protractor.

Another piece of advice I received from Phil was I should set the pitch to achieve a certain RPM and power setting and stop messing with it. There’s probably a lot of truth to that advice.

[Jason Murphy]

I have decided to use Stewart Systems for covering. This will allow me to use a lot of my existing materials I.e. fabric and tapes with my their chemicals and remain within the guidelines of their manual and STC. I will be able to use the poly fiber epoxy varnish and primer on the wood and metal also. I will also be able to paint at home instead of 65 miles away at a friends hangar / paint booth. I have been watching videos on their website and reviewing their application manual to familiarize myself with their system.

Fabricated and installed bracing for Rib No 10.

Found 4.5” 7/16 diameter bolts at the farm store. Borrowed an engine hoist and placed the engine on an engine stand. FWF components are placed in a tote for storage until they are ready to install. Covered engine with plastic bag to protect against contamination.

Tannis Heater arrived today. It was placed in parts cabinet.

All the work which remains on the left wing is to fabricate a plate for my pitot mast and bond reinforcements for the No 1 rib. Then this wing will be ready for covering.

I will be installing my Magnetometer in my right wing to avoid interference from the wiring I will be running for pitot heat. It will require 10g wire to handle the 10A of current which will run to it.

[Kitfox Pilot]

RE: Rivnuts
I've a very vocal Rivnut hater based on my career with the big airplane company. All it takes is one spun rivnut to ruin your entire afternoon. There are locations where you don't have a choice. When that occurs: ALWAYS use "keyed" Rivnuts, DO use something to help secure them like the Loctite that Gary uses, DO run a screw through them several times to make sure the threads are clear before you put parts together, DO NOT ever let some knuckle dragger anywhere near them once installed.[/QUOTE]


Haha, finally someone who agrees with me about rivnuts!

[alexM]

Wow, look at all that cheap labor! Great that your family members help out.

I'm a big fan of water based stuff (like Stewart Systems)where ever possible. The people who don't like it are generally people who ignored the instructions and applied techniques from legacy systems and got crabby at the results. Stewart Systems used to be in Washington (not too far from Geek), and attended Arlington every year. The planes they brought to show in their booth were beautifully covered.

If I were to build another Kitfox I would put the magnetometer in the right wing too. My left rear spar is a bit busy with pitot/AoA tubing, CANBUS and power for the magnetometer and wires for the WAT tip lights. It all fits but spreading the love would be better.

[Billiken]

Nice airplane factory Jason! I’ve been tossing around the idea of switching to a 912is to save weight and add endurance. I’ll be watching your build closely going forward. Sorry I missed you at the BBQ. I’ve been working on my garage in preparation for starting my build next year maybe. Keep the posts coming! -Jay

[Av8r_Sed]

I will be installing my Magnetometer in my right wing to avoid interference from the wiring I will be running for pitot heat. It will require 10g wire to handle the 10A of current which will run to it.

10 ga is overkill for the pitot heat. You will probably have difficulty terminating that large of a wire. I think 14 ga is commonly used with a 15 A fuse or breaker.

[Eric Page]

10 ga is overkill for the pitot heat.

Agree. 10ft of 14AWG will have ~0.025Ω of resistance. At the full 10A, you'll see 0.25V drop at the pitot tube. Insignificant.

10ft of 10AWG will have ~0.01Ω of resistance and 0.1V drop at 10A. It will weigh about 2.5 times as much as 14AWG.

[Geek]

Haha, finally someone who agrees with me about rivnuts!

Yeah yeah yeah. They've always worked well for me as long as I don't ask them to do something they weren't designed for. Just kidding with you Harlan

Wow, look at all that cheap labor! Great that your family members help out.

I'm a big fan of water based stuff (like Stewart Systems)where ever possible. The people who don't like it are generally people who ignored the instructions and applied techniques from legacy systems and got crabby at the results. Stewart Systems used to be in Washington (not too far from Geek), and attended Arlington every year. The planes they brought to show in their booth were beautifully covered.

Yup. The Stewart brothers who started the company still live close by. Really good guys who are willing to share their experiences.

10 ga is overkill for the pitot heat. You will probably have difficulty terminating that large of a wire. I think 14 ga is commonly used with a 15 A fuse or breaker.

Agree. 10ft of 14AWG will have ~0.025Ω of resistance. At the full 10A, you'll see 0.25V drop at the pitot tube. Insignificant.

10ft of 10AWG will have ~0.01Ω of resistance and 0.1V drop at 10A. It will weigh about 2.5 times as much as 14AWG.

These comments are right on Jason. I used 14ga on mine and it works perfectly as far as I can tell. I say that because the controller varies how much current actually goes to the heater based on OAT. I'd be really surprised to ever see the system ask for full current but even if it did, 14ga is good. While I don't expect to fly mine in that kind of cold where I need a lot of heat, my training was that if you flew into rain - turn on the pitot heat. Doesn't take a lot of heat to deal with the rain but still helps keep water out of the system.

Like Alex, I love how your kids are involved in the build. The time spent now are the memories you have later. Those are priceless.

Geek