Start UP! - a FREE 3D printable airplane

LitterBug

Troll Spammer
Egads... simple adjustment turns into replacing two fans and an extruder tube fitting. But the good news is, printer is back online and printing good as it ever has. May give a go at a few of these parts in the next few days. Not ready to start back up on the eclipson stuff till I find out if Wifey, er, um, Mrs. Claus got me some LW-PLA...

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Dr. Looping Looie

Elite member
The last few days were extremely busy. Lots of printing and test fitting, but I am very happy so far. This is by far the most complex plane I ever did, it consumed hundreds of hours of CAD design and I even spend two evenings running vortex lattice simulations to calculate the optimal CG and angles of attack. So of course I have extremely high hopes, and Im very excited. Tomorrow I need to print the landing gear and install the electronics.

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LitterBug

Troll Spammer
Hmmm. Trying to use profiles/slicers i've used for other planes, but not having much luck. Care to share what slicer and settings you are using?
 

Dr. Looping Looie

Elite member
Hmmm. Trying to use profiles/slicers i've used for other planes, but not having much luck. Care to share what slicer and settings you are using?
The parts are not normal 3D objects, they are just a bunch of surfaces with a thickness of 0. I chose this route because it allows me full control and single wall prints. Unfortunately, the only slicer that can understand these files is Ultimaker Cura. You need to activate surface mode. More information is in the how to guide, which you should find in the attachment browser of this thread.
 

Dr. Looping Looie

Elite member
Update.
Over the weekend, I did multiple attempts trying to get it to fly. Spoiler alert: Up to this point it did not have one successful flight. Right after takeoff, it starts violently rocking around its longitudinal axis, until it crashes. Its completely unstable in the roll axis, which should not be considering the low CG and lots of dihedral.
What I think is most likely is an instability in yaw expressing itself in the rolling motion because of the dihedral.
To gather additional information, I quickly smashed together a cardboard replica of the 3D printed plane with all the same dimensions, and it flew equally as bad, indicating that it is in fact a stability issue.
To fix this, I will have to enlarge the stabelizer and move it further back. I will have to redo everything in CAD, which means another week of work.
But no matter what happens, I will not give up until it flies good.

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FlamingRCAirplanes

Elite member
Update.
Over the weekend, I did multiple attempts trying to get it to fly. Spoiler alert: Up to this point it did not have one successful flight. Right after takeoff, it starts violently rocking around its longitudinal axis, until it crashes. Its completely unstable in the roll axis, which should not be considering the low CG and lots of dihedral.
What I think is most likely is an instability in yaw expressing itself in the rolling motion because of the dihedral.
To gather additional information, I quickly smashed together a cardboard replica of the 3D printed plane with all the same dimensions, and it flew equally as bad, indicating that it is in fact a stability issue.
To fix this, I will have to enlarge the stabelizer and move it further back. I will have to redo everything in CAD, which means another week of work.
But no matter what happens, I will not give up until it flies good.

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Keep it up man!! When it is done I hope to make one! 👍
 

Dr. Looping Looie

Elite member
Update!

Lots of stuff happened. First of all, it flew finally! I printed the straight wing with ailerons, and this time, it was able to take to the skies! Overall, I am very happy with it, but its not without its problems. The good things are that it can get a lot of flighttime (10-15 min. with a 3S 1200mAh LiPo) and it also glides very good. But I could also feel the instability. It was very easy to get it to spin. At this point, it is definitely not great for beginners, but the next version will be much better.



Speaking of the next version, I finished updating the "outer shape" of the plane. I moved the V-Tail 100mm further back, increased its area by 20% and cleaned the T-spline bodys up. Sadly, I have to redo all the inner structure, which takes a majority of the time. But I can use the knowlege gained from the first prototype to make the next one even better!
Some of the upgrades include:

-Optimized control horns, so that all the servo throw can be used.
-Removable shock absorber at the tail to keep the fuselage from braking
-Removable motor pod to make it much easier to take the motor out

Here is a little comparison of the two side by side:

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And last but not least, I made foamboard plans!

It is similar to the updated version in every dimension except airfoil of course. Sadly, here in Germany foamboard is very hard to come by these days, so I would really appreciate if you guys would try it out and tell me about your experience so it can be improved even more.

I hope that I can get this thing done before chrismas, but I want to make sure that I have a plane that lives up to the expectations before releasing the files.
 

Attachments

  • Start UP foamboard 1.pdf
    1.4 MB · Views: 0
  • Start UP foamboard 2.pdf
    1.4 MB · Views: 0

Dr. Looping Looie

Elite member
Version 2 is done! It printed very well and all the surfaces are super smooth and its just epic! First flight will be tomorrow, and if it is sucsessful, I will upload the STL files.

It came in heavyer than I expected, at 550 gramms with a 3S 1200 battery and fully loaded. This leads to a wing loading of around 40 gramms / dm².

Lets hope for the best for tomorrows flight.

Enjoy the pictures!


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Dr. Looping Looie

Elite member
It finally flew good! Video will follow soon.

The latest and last upgrade is complete. The servos in the wings are now screwed in and accessible behind a hatch. This means that you can install and take out all electronics after the plane is finished. Previously, the Servos were glued in the wing in a way that you would have to break the wing open to get the servo out. That is now fixed.

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I will release all the files today!
 

Dr. Looping Looie

Elite member
Can't seem to download anything??

:unsure::unsure::unsure::unsure::unsure::unsure:
Click on the button and then on the shopping cart and proceed as if you would buy something online. Since the price is 0$, you don't have to pay anything. After checkout, a page with the download link should appear.

I'm still figuring out the whole website online shop stuff.
 

Scotto

Elite member
That's amazing! Very well done. I love how the parts are removable. Thanks for sharing this. I need to get my printer set up and figured out.

Do you think some Dornier style water-wings could go in the landing gear sockets?
 

Dr. Looping Looie

Elite member
That's amazing! Very well done. I love how the parts are removable. Thanks for sharing this. I need to get my printer set up and figured out.

Do you think some Dornier style water-wings could go in the landing gear sockets?
Yes, that is very doable, but it would need to be one big float because the fusalage has no step and is not designed for water.