Slender Delta
1.) All pics of process and finished product in attachments.
2.Informational link here
https://en.wikipedia.org/wiki/Concorde#Slender_deltas. No plans yet, but here's something very similar that's awesome and I highly recommend. This can be built with the nice curved delta wing shown, with a regular slender delta wing, or simply used as a reference for custom builds.
https://forum.flitetest.com/index.php?threads/plans-for-the-kolibri-high-alpha-flyer.56915/
3.)Reasons for choosing this plane: This was a plane I have wanted to build since I first started learning/trying to build rc planes. At very first, the idea came to me simply because the sharp, slender triangle shape looks cool and works well with traditional paper airplanes, which are basically little slender delta gliders. I did some research from there on real delta planes of high sweep and low aspect, and it got me a lot more excited about building and flying this type of plane. I learned about the hp-115, the most acutely swept delta ever flown, and how it flew well with only a top speed under like 300 MPH for low speed research, and how this super-sonic looking shape could fly well at both low and high speeds and high angles of attack. I also learned about vortex lift generated by the shape. Neil Armstrong got to fly this plane in 1970 and enjoyed the experience. One of the main minds behind the hp-115's development and slender delta theory was a woman named Johanna Weber, a German born British mathematician and aerodynamicist who chose engineering over teaching because teaching at the time required her to be a member of the Nazi party, which she refused. After the city she worked in was liberated she went straight to work for the allies. Definitely an interesting history.
I love unconventional planes, especially mid-twentieth century jet age planes including a lot of prototypes with cool, retro-futuristic looking designs. The slender delta is sort of a signature plane for me, something I really want to master and be able to share with others. I would like to see a lot more people try their own takes on this general concept like
@Dr. Looping Looie did with the Kolibri Flyer.
4.) Build log:
5.) Build difficulty: 1/5, Simple
Total time invested: Build: about 7 hours; Rebuild: about 5 hours
Build progress update:1) 2/4/19 Drew up a more streamlined fuselage design for 5" props. Took about 15 minutes. This is a rough draft.
Build update 2/12/19: starting slender delta: Wing blank with cut lines drawn on bottom. I'm using a modified FT swappable motor mount to mount my graupner 2806. Final draft hard cut fuselage template is ready. I used the template and a straight edge to draw up this simple A-fold fuselage. I am still sloppy at this.
Build log update 2/13/19: airframe pieces built and painted but no glued and no electronics yet. I built a cool top over from poster board but haven't added toothpicks yet. I should have used white FB to make my fuselage because my yellow paint faded to green on the black. It still looks cool but not originally intended.
Build update 2/15/19: installed electronics and linkages, but could not get proper function. elevons were sloppy. I will replace the elevons and try to link with my best two rods, if not, I will order some more rods. Build update 2/16/19:Build finished. I replaced the elevons successfully but my linkages are a bit sloppy and the elevons don't have much downward travel.I need to order more servo extension cables so I can use shorter push rods on future rebuilds.
Build update: 2/26/19: Last night and today, I rebuilt the whole plane slightly differently. The rebuild needs a top hatch and then is good to go, I'll take a pic when it is done. Thrust angle is feeling a lot better in hand, cg feels good, and less control slop than the previous build. The A fold fuselage is still a bit uneven, and mounted just a hair unevenly to the wing, which is very slightly warped like the last one. I do not expect these minor imperfections to be detrimental to basic flight. I cranked this one out in about 4-5 hours total time.
6.)See pics
7.) no maiden
8.)Fly Rating: 3/5, moderate
9.)Reflective Statement: I really wish I would have had more success with this one, as it is a huge milestone and personal scratch building goal that I really want to achieve. Also, it is a cool flying experience I wish to have. There are so many little factors with this one that I still have to perfect. Thrust angle can be difficult with high mounted pushers, and durability concerns for both your wing and prop arise when making this a prop in slot build. One thing that gives me hope is, I heard a podcast about Josh Bixler's approach to scratch building. Basically something along the lines of; "Start with picturing the end goal, what type of plane do you want, and how do you want it to fly and handle? Then build it as basic and crude as possible, launch it, crash it, learn, repeat. Keep at this and keep making adjustments, and your plane is pretty much guaranteed to turn out good." Well that's the approach I have been taking with this plane all along, and will continue taking, not to mention all the help and input I receive here on the forum.