Kitfox Series 7 Super Sport - Show Me Fox

[Jason Murphy]

If you have been following this thread you would have read where I suspect I may need to relocate a rib on my right wing. I have started the process to determine if this concern will be valid.

The flaperons were removed from their crate. I used my tie down straps that are secured to the floor joists with C Clamps to suspend them from the ceiling and protect them from falling.

I need to ream the existing holes in the flaperon hinges. I ordered a new 3/16 (0.187”) reamer my old one was not cutting to my satisfaction anymore. It will arrive tomorrow and I can continue work.

I plan to ream all the brackets and hinges connect them with the supplied hardware and check the fit of the flaperons to each wing to ensure all of the ribs have been properly bonded in place before I proceed any further. This will confirm or refute the theory my right wing will need minor correction on the outboard ribs. The left wing appears to be correct without any deviation from specifications.

Dressed the edges of the baggage sack floorboards. Will apply a third and final coat of varnish to protect the edges and make a final decision on how I would like to finish the floorboards.

After tomorrow when I get my reamer I will have a better idea of what my next steps will be.

I emailed seeking clarification about the best technique to install solid flush rivets in the trailing edge of the flaperon. I purchased a squeezer with this task in mind. It is my current plan that I will drill, debur, dimple, then squeeze the rivet. I emailed to make sure this process will not damage the flaperon with how the trailing edge has been bonded.

I also contacted a fellow builder and made arrangements to exchange the wingtips for the Hoerner style wingtips. Allegedly I will receive some additional aerodynamic benefits and I feel they are more pleasing to look at. This will bring about a new challenge of modifying these wingtips to accept position lights and landing lights. I have the position light adapters. I plan to use John McBeans plane as an example to complete this task.

[Jason Murphy]

See https://eaabuilderslog.org/?s=KitfoxS7SS for more details entries

Tow Hitch Adapter and Brian Bush Door Handles

Follow up: The tow adapter was a SkyStar product. Shipping cost on the item was cost prohibitive and there is no longer tooling available to produce it.

1/10/23

Once again excellent service delivered by Heather and Brandon at Kitfox.

Received instructions for the fitting procedures for the Hoerner Style wingtip. These were specific to the Series 5 and 6 but applicable to the Series 7.



Received clarification of instructions and tips on fitting flaperons. After having several head scratching moments wondering how if the trailing edges of the wing only had 1/16” deviation why nothing was lining up.

During the cooling process the brackets would pull to one side or the other they just needed tweaking.

Flaperons were once again dry fit and using a set of Knipex pliers to create uniform pressure attachment points were tweaked and they fit perfectly into place.

Removed old hysol from right wing trailing edge with a flap wheel. When I bond the trailing edge material to the left wing I will use some of the excess hysol to build up the trailing edge of the right wing to replace some of the material that had been sanded down to achieve a distance from the spar of 11 3/8”

Reinstalled main landing gear.

1/8/23

Continue to cleanup around the shop.

Packed cabane spring gear to deliver to a potential buyer in Iowa.

Put tires and axels back onto the grove spring gear.

Searched for the inside break pad for about 3 hours while cleaning and organizing workspace. Had a head slapping moment when I realized that I put one caliper back together when I removed it and the missing part had been bolted into the caliper. I had the part in hand the whole time.

1/1/23

Put tail wheel back on.

Cleaned up the workspace made preparations to reinstall main landing gear. Gear have been brought to a high polish with Flitz.

Packed up the jigs for the next user.

Recheck sweep after installing the wing spar reinforcement bracket. Sweep has not changed.

Awaiting call from factory for clarification of instructions for flaperon trailing edge and fitting.

[alexM]

I just went and looked at your tow hitch adapter pictures. It took me about 10 seconds to realize how it works. It also explains those cross tubes on my series 5 fuselage which have until now not had any reason to be there (other than to be annoying when you're covering the fuselage).

Do the current production planes even have those cross tubes? Curious about that. If they don't, that hitch adapter wouldn't have a way to attach to the plane.

Either way, "tooling no longer available" would not be an issue. Pretty much any local welder/fabricator in your area could make one if they had the fuselage in front of them and some idea of how long long that tongue has to be. Downside is that you'd be towing the plane on its main gear. I could just imagine the abuse a pair of air streaks would take on a single trip to the airport. May as well chuck $100 bills out the window as you drive.

Hoerner was an aerodynamics engineer for the Germans in WW II. Assuming they conform to his design they increase effective span without the increase in drag that would come from longer wings, and they cancel out wing tip vortices. Probably nothing dramatic but they are efficient. I actually didn't like the way they looked until I saw completed Kitoxes with them. They just look like they belong there.

[Jason Murphy]

Hey Alex,

Yes, the Series 7 fuselages still have those cross tubes in the tail section fit the tow bar. I know a few tool and die makers who could probably help me out with that venture.

I won’t be using Airstreaks. I opted for the 8.50x6 aka poor man’s airstreak. I also have some 6.00x6 that were pulled off an old flying club plane that I am curious to find out the amount of airspeed I will be giving up for the larger tire I probably wouldn’t routinely use.

Yeah, I really like the look of the Hoerner style tips. I am fumbling around with how I will mount a set of landing lights. John McBean cut out the leading edge and used micro suns. Looking at the numbers I would like to have something that put out a little more light. At the price of AeroLED and WAT I am feeling an off-road truck light May be a good option to start with. Once again my plans for night flight would be occasional at best.




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[Jason Murphy]

Took a road trip between shifts met with a fellow builder. Received some feedback on current build steps.

Sold Cabane Spring Gear, will use the funds to obtain the remaining avionics items required for the project.

Exchanged the upgraded wing tips with landing light provision for Hoerner Style wing tips. Received guidance on methods to create a provision for landing lights in the Hoerner Tip and how to fit and finish the Hoerner tips and install nav / position light provision.

Needing to start coming up with ideas for a paint scheme because that step will be coming in the near future.

[bbs428]

Agreed on how the Hoerner wingtips look. They take a lot of work, more if you want to add taxi/wing lights. I added some led lights and made a custom aluminum bracket to house them. My wingtip nav light standoffs are made from balsa as the fiberglass ones were a bit clumsy looking and heavy, imho.
I have quite a few build pics on my Hoerner tips to spur your creative juices, yours for the asking. I'll refrain from posting my pics on your build thread, lol.
Let us know the colors you're considering for your paint scheme! It's an enjoyable process to bring the vision of your thoughts to paper and then to the plane.

Keep up the great work!

[Jason Murphy]

Yes, I would be interested in checking out what you did with your wingtips. I will delve into your build threads.

I struggle with creativity… I have thought about a paint scheme similar to an L5 with invasion stripes or one of the WWII warbirds. The checkerboard pattern on the tail is really appealing. On the other hand I have seen one that looked a lot like the factory STI except the body was white and the stripes were grey. I feel like that would match the polished landing gear the best or the WWII Warbird scheme

[Jason Murphy]

Placed Hoerner style wing tips in a safe place.

Prepped trailing edge material with denatured alcohol and scotch brite.

Bonded trailing edge reinforcement material in place.

Cut a piece of left over stringer material to create a short piece of trailing edge reinforcement material for wing bay no 9.

Prepped and bonded reinforcement material in place.

Wondering if I were to fill the small gap at the trailing edge of the rib with SuperFil if that would provide better protection against moisture.

Bonded short piece of trailing edge material and the next adjacent piece of trailing edge material to ribs 10, 9, 8, and 7.

Cleaned up excess Hysol.

[Jason Murphy]

Finished fitting and bonding trailing edge to left wing.

Clean up and relabel trailing edge pieces which were removed from right wing. Remove old Hysol. Clean with alcohol.

Installed trailing edge reinforcements.

Bonded to right wing. Used tongue depressors to extend the top of the cap strips to ensure the trailing edge material fit flush with capstrips.

Masking take worked well as a barrier to prevent clamps from being bonded to wing.

[Jason Murphy]

Returning home from a week at work I return where I left off.

Still concerned about how the flaperons fit to the wing I took a better look at each wing and compared each using measurements taken from the wing and flaperon.

Measured the distance between ribs 3, 5, 7, and 9 on each wing.

Measured the distance between the centerline of each pre cut slot in the flaperons.

Compared the distances on each wing to find there is only 1/16” variation between the flaperon and the ribs.

Used a speed square to assess if the flaperon hinges are perpendicular to the surface of the flaperon. I found that none of the flaperon hinges were perpendicular.

Using a speed square I trued each hinge where it was perpendicular to the surface of the flaperon. When I dry fit the flaperon to the wing they were almost a perfect match. They required just a little loving and each hinge is centered with their corresponding slot in the flaperon and the brackets run parallel with the ribs.

Sent Brandon an email for clarification of the directions awaiting a response. How I read the instructions you need to use a carpenters square to extend a line down from an AN washer that is used to bolt the flaperon bracket to the flaperon hinge. The line should be 1/8 inch aft of the trailing edge material (see photo).

The other way I could interpret the photo in the manual is to allow 1/8” clearance of the flaperon bracket to the trailing edge (also see photo).

Regardless today was productive and the only deviation found between the two parts was 1/16” which is well within the general tolerance specified in the build manual.

I plan to place an order for parts tomorrow, I managed to crush a finger screen using a pair of Knipex pliers. Mental note only use a socket to wrench on those brass fittings.