Mini Tailsitter VTOL by Lob0426

Last crawled date: 3 years ago

this is a work in progress
This is a non-scale drawing of a design by a Flite Test Forum member slembcke. He was making a very small VTOL tail sitter plane (fixed wing)
https://forum.flitetest.com/index.php?threads/mini-tail-sitter-vtol-wing.36637/#post-369841
I made a few changes as it is not to scale anyway. It is a KF2 step Airfoil design (Kline-Fogelman). It is made with Dollar Tree Foam Board. Also known as Adams Readi-board. This drawing is 400mm X 280mm tall, when standing on its tail. The rudders are fixed and rudder is by differential motor control, while in plane mode. In VTOL mode the Yaw axis is by Elevons.
He originally powered it with 1304 brushless motors in front of the wings. He eventually moved to 1806 motors midline in the wing. He used a custom programmed Seriously DoDo controller from RMRC.
I plan on following up his work. Not being a programmer I will be using a KK2.1.5 Mini Flight Controller which is 36X36mm form factor. The stock firmware has been replaced with OpenAero2VTOL firmware. I am also planning on using 1806 2280K motors with 5X4 propeller's.
He was using a very small battery in his and had relatively short flight times. I think the design needs to be sized up some to get better flight times with heavier batteries. But I would like to start where he is right now. I hope he will return to the project. He was making good progress. This is my first drawing that has so much work into it. Still some to learn about SketchUp (2016). I first tried Fusion 360 but was getting nowhere with it. I will have to try it again.
Again this work was not began by me so make sure you attribute the work fairly if you try it out!
Ver 2 files; lengthened the KF step to add strength, fixed some mismatches. This thing will need some sort of spar if you plan to build it. the best place would be under the KF Step and above the wing sheet. I would put a groove in both the step and the wing sheet and hot glue the spar inside them both.
I am considering redoing this for 3D printing.
NOTES;
Version 3 has all the changes listed below. It will still accept a battery over 100mm long inside the fuselage. Additional changes. Cleaned up all hidden geometry. Internal fuselage front pod properly formed now. More than enough room for a FPV Camera and Transmitter. Limited to 5" (127mm) props. This thing is about ready for a build out of Readi-Board. Worried the pod may be to far out front now. have to build it to find out!

The upper compartment of the fuselage pod is meant to house the Flight Controller and the Receiver. The Lower compartment is for the Flight Battery. The Battery compartment is really large. I think the battery for this is going to be a 4S 1P 1300ma. The Battery compartment can hold 2 of these batteries side by side. And it is 100mm deep where the Batteries are only around 69mm to 75mm in length. In other words the Fuselage pod is on the large side. It needs to be reduced some to save weight. A little more height in the electronics bay would be nice as it is only 16mm tall. You could use a 2200ma in the battery bay. But the amount of wing on this will not carry the weight


I think you can use hard wood dowels from the local hardware store for spars. I would use two almost full width. As stated above I would score the KF step and the Wing sheet and imbed the spars between them.


The motor mounts will most likely be mid chord. This means cutting slots that are about 5.25" (133.33mm) on each side of the centerline. This may cause strength issues in the trailing edge.


All of the tail surfaces are touching the ground. This is a no no in a VTOL aircraft. At the very least the control surfaces have to be clear the ground so they can move freely. Plus there needs to be some pass through space except for the pieces that are keeping the plane vertical.

Recommend 5" X 4.5" Bullnose Propeller's.
Foot Note; for those of you that wonder why these things get done in stages and versions. At this point I have probably 10 hours into computer time drawing this up. There is probably another couple of hours into research like battery sizes and motor weights. Then getting any changes into the next version. And some more research for propeller sizes and pitch for maximum thrust. Not to mention probably an hour or so posting all of this into Thingiverse with my slow typing! LOL!
Build comments: Most major parts now cut out of Black colored Readi-board. Need to find my compass to draw half circles on pod sides. Forgot how easy the Flitetest Speed Build kits are. It has been a couple years, or so, since I scratch built an Armin/Experimental Airlines style plane. Cutting this out will remind you. LOL! I would say beginner/intermediate level build. The KF2 style wing makes it easier.
Still need to cut the motor/prop holes in main wing. A Flite Test Power Pack A has everything except the flight controller. I am using the KK 2.1.5 Mini. It is 36 X 36mm. These flight controllers have been hard to come by lately. The pod is not wide enough to fit the full size board 52 X 52mm. It may fit up in the front of the fuselage pod on one side or another. I will check this out when I get further along. The pod may get changed to allow the KK 2.1.5 and the KK 2.1HC. The hard case version is pretty heavy for such a small format. More expensive FC's like the Pixhawk mini should fit easily.
After I get this test flown I will make some plans, if it goes well. Most of this is going to be "butt" glued in place. There are a few places where adding glue tabs would improve strength and make it more accurate to assemble. I also think the pod will need to be shortened for better balance.
So far it is going well. Stay tuned, I know I am slow bare with me!
5/31/18:
Airframe mostly assembled, no electronics as yet. Some adjustments made in scratch build. Pod widened to 60mm. This should allow a full size KK board. My scratch building skills are not back up to par as yet, struggling, but it is getting done. Not pretty but pretty solid so far. Unintended design consequence seen. LOL! When set horizontal the pod and vertical stabs align almost level. I need to add 6 to 8mm to the underside of the pod or remove from the bottom of the stabilizers. I will make sure that makes it into the final drawings.