Project 5 build thread

[alexM]

A few pictures going in to the weekend and hopefully some more along the way. I have the balsa pieces glued on to the ends of the horizontal stab and elevator, rough sanded, filled with Super Fill and sanded some more. I've decided to wait until I pull the stab/elevator off the plane to finish shaping the tips because access will be so much easier.

Before that
My plan is to measure and mark the rudder cables (I may cut and swage them as suggested in the tips section and just get it over with), and I still have to set my center hinge bearing on the rudder. Really looking forward to that step. I've also got to fix the rudder over travel issue because the PO trimmed too much off the horns. I've read of some elegant solutions here on the forum, so thanks to whoever screwed this part up before me.

I'm also going to follow the rigging instructions to set up the horizontal stab and elevator to make sure there are no issues with that. I have already determined that the two welded tabs at the very back (not used with the speedster tail) do not interfere with the elevator travel at the extremes of stab trim. It's that kind of stuff that I'll be looking for by following the rigging instructions, but it should also allow me to lock down some of the push rod adjustments and not have to mess with them later. I'm not going to celebrate with torque seal on them just yet though.

Engine mount
Since I'm going with the weirdo engine I'll need to obtain an engine mount. The US distributor that I'm working with suggested I design my own, and sent me some pictures to use as inspiration. I've never designed an engine mount before but I have designed airplane parts most of my career so I decided to give it a try. I measured up my fuselage attachment locations, spent a lot of time staring at/measuring the 912 mount I have, looking at/measuring the mount on my Citabria and then looking at a whole lot of pictures of radial engine mounts. I also had a nice long conversation with Ted Myers who is installing a nine cylinder Verner on a Kitfox 7.

Back the truck up a sec
I have to walk back a statement I have probably made a few places, and that is in regards to the plane Ted is working on. I was under the mistaken impression that the plane Ted is doing the work on was a previous factory demonstrator plane. Though the paint schemes are similar, it is not the same aircraft. The plane Ted is working on is one some of you might have seen on Barnstormers a year or so ago, a plane that was in the Rotec booth at Oshkosh 2019 (assuming I finally have my story straight).

Moving on
I now have a fully parametric model of a ring-type mount which can be adjusted any way I need it to. I've done 3D CAD since the late 80s so this kind of stuff is what I do. I own an older (legal) seat of Solidworks but it's on an old laptop that is weak in the knees. So I downloaded the EAA Solidworks 2020 onto my new laptop and gave it a spin.
Scarlett 7U mount.jpg
This is one of those objects that is difficult to view from a single angle and have it look right. As modeled I can shift the engine forward or back, raise it up, add some thrust angles, change tubing diameter/wall thickness and recalculate the whole thing in seconds.
I used the "Weldment" function in Solidworks which is pretty amazing, and I did some finite element analysis which showed the mount could shrug off +6G with a 1.5 factor of safety. Not an exhaustive evaluation but at least it is a start.

The Verner uses the same Lord mounts as the Rotax 912 and some Continental O-200 installations, and I just happen to own four of the mounts already.

A couple of days ago I sent the CAD model to the same welder Eric used on his Barn Find recently. Not only is his welding a thing of beauty, the guy welds most/all of the engine mounts for Van's so he probably knows a thing or two. He's going to review my design and sling dirt at it until I get it right.

Getting my hands dirty again
All that computer stuff is fine if you have the stomach for it, but we're here to build airplanes. I've been itching to get this next task done for a while. My fiberglass seat pan has never been a thing of beauty. Back when I was spending time at my local body shop to clean up my fuselage after welding and powder coat repairs I picked up a can of two-part bed liner. Of course I waited until the temperatures dropped to try it out right? I had my son sand the white gelcoat until it was paper thin, and I ran out and bought a space heater for my garage. My seat pan has the optional storage trays already mounted so I masked them off and cleaned the whole thing very carefully with alcohol. Out of excuses, I hosed on the bed liner last night.
PXL_20201107_002550360.jpg
Before
PXL_20201107_005645842.jpg
After
And no, I didn't paint it sitting there. In that second image it is still very wet and flashing off. There were a lot of acetone fumes so I got the heat going and left it alone. The wet clumpy look calmed down considerably and I'm pretty happy with way it turned out. The stuff I used cures in one hour but it takes three days before you can really give it the business. I'm going to weigh it today and see how much the bed liner cost me in useful load.

Window and door trim
With the seat about ready to bolt in I turned my attention to the aluminum pieces around the door frames and the window. These were actually the very first pieces I did anything with when I first got my project. I can recall being a bit overwhelmed at how they were supposed to fit and not really happy with their condition. They had been installed by the first builder and removed by the second builder. They were not perfect when installed and removing them didn't improve them at all.
PXL_20201107_013430108.jpg
Some of the pieces actually fit very well and some are way off. After messing with them for a few hours the other night I decided to order all new pieces from Kitfox, and emailed in my RFQ yesterday. The pieces that are in good shape will serve as patterns for the new pieces, and the bad pieces will serve as a guide on what not to do.

I made a discovery last night that I was not stoked about. A couple of weeks ago I brought home my side stringers and cleco'd them in place. There was tape around the ends and they still needed to have the old structural adhesive cleaned up. Well last night I pulled the tape off and found that whoever cut those side stringers screwed up the right side and cut the tube too short. They cobbled together some kind of fix involving a short aluminum inner sleeve, a piece of wood dowel and a wad of Hysol.

I figure shipping a couple of 9' long pieces of aluminum tube from Idaho will cost more than the tubing, so I've sent a request for quote to Metal Supermarkets about 20 miles away, who I have done plenty of business with in the past. I can just drive there and get the pieces and be back in business quickly.

I'm still resolving my landing gear situation (I need some more inches to clear a big prop) and I have started looking at what I'm going to do for my panel. With any luck I'll be taking the fuselage to my hangar soon and starting my wings by Thanksgiving.