Projects            

A 3D Printed Hobby   -   Printed Cessna

September 2017

As most of you already know I’ve been printing my own graphics for some time now. Then it hit me, “Lets Print a Plane”!

Moments after that thought, I purchased an ANET A8 3D Printer. For starters I thought I had better start small so I printed a cowl for my Calmato. Turned out well. The orders came flooding in. Everyone can certainly use a cowl. Great practice. (Alex Zattelman, nice cowl on your Calmato)

Now time to get serious. 

After chatting with John Scott about my idea to design a Pipistrel Panthera, he suggested I take a look at 3DLabPrint and perhaps purchase one of their designs to see how they do it? Great idea John, a bit of recon, I like your thinking J

Same night I purchased the Cessna 152 files and champing at the bit, got to work. My first print of two of the wing components was well let’s say, “Less than a confidence boost”.

Wow this is not going to be as simple as I first thought.

Part after part with different mistakes. Some parts printing out quite well. Working in IT I’m looking for logic, a pattern, a formula that will produce consistent components. (Still looking for that so if anyone finds it, let me know J).

OK *Doctor Frankenstein so we have different components all of different qualities. Do I lower my standards for a perfect model or do I outlay more money for a few more rolls of printer filament?

Easy argument as my wife said I’ve already spent a lot of money on the hobby so let’s work with what I have. Happy wife, happy life apparently J

Some of the issues I’ve found so far.

If the Extruder (the part that heats up the plastic filament) is too hot, it leaves spider webs and other unsightly additives both inside and out.

If the Hot Bed is too hot, the lower parts can warp.

If the Extruder is too cold, the layers won’t stick properly to each other.

If the Hot Bed is too cold, the lower parts lift up at the edges creating a convex join.

Goldie Locks is coming to mind. It really is a balancing act that takes many test prints and many hours.

OK, let’s put this baby together.

- (A messy work bench is a happy work bench) …. so I keep telling myself.

Haven’t worked much with CA glue and a can of Accelerator but I now have to say, “How have I ever survived life without it?” For someone who is lacking in patience, this is the next best thing since a cross your heart bra. <- (my wife wanted to be a part of this for enduring my hobby and 2 weeks of absolute sound torture.) Personally I prefer the sports variety but that’s for another 60 minutes J

Now I’m thinking, “Is this really going to work?” After gluing a few pieces I learnt one valuable lesson, (Don’t glue your fingers to the components). It is actually quite hard to align the components (each averaging 150mm in length) ready for the accelerator without getting your fingers wet. I found a great use for Nail Polish remover. Shhh don’t tell my wife as I commandeered a bottle or two J

So now the plane is completely assembled. Time for the electronics. The designer was good enough to think of everything needed in the main design. Servo holders and access points.

I designed and printed the ESC holder as I did for my Calmato. For convenience but mainly to keep a potentially warm ESC away from a very thin PLA Plastic wall.

After 2 weeks of trials and errors, waisted filament, hours upon hours of X,Y,Z mechanical motor movements and almost enough time for the skin to grow back on my finger I thought………..

“IT’S ALIVE” (* refer Doctor Frankenstein comment above)…….. made me laugh J

OK time to get really serious. After putting the whole plane together I was eager to show everyone at the club and get some valuable advice from the other members. (This is where I love being part of such a great club)

Trying to paint some parts of the model I found the layered surface was bleeding the paint at the edges due to the uneven layers that a 3D printer generates. Graham Evans suggested Pin Stripe tape to finish and clean up the edges. Great idea.

Michael Best took out his Microscope and went from nose to tail. Pointed out some structural concerns that I also shared. Michael also sent me the document of Victor Lai's build for some wing load testing ideas which I completely took on board. You’re a genius Victor.

We also had some betting odds on the flying weight. Jose Morel and Alex Zattelman made it a fun moment. Juris Briedis did the honours and it came in at 2.2kg. I think Jose won that one as he had bets either way J Alex stuck to the odds on favourite.

Load testing the wings the Victor Victorski way. (Kind of)

Initial wing loading test. 5.5KG bucket of water test. 

A few concerning crack noises heard and some more CA and Accelerator…… 

5.478kg. Total loading = 10.956kg.

 

Over 3kg brick on other side for counter balance.

And the other side.

Neetly added Carbon strip. J I’ll cover that with some red tape.

Looking at this photo I feel I’m being stared at? Here’s looking at you kid J

 

Maiden flight with Michael Best.

A little twitchy as I forgot to add rates and test for correct control throws.

After adding those Michael took it up for a second time. Much better. He even felt comfortable enough for inverted flight, rolls and loops. Yay.

 

All dressed up with over 5G’s load testing and we’re ready to go again.

 

By Drew Buckley

PDF version here

 

*** 22 September, 2017 08:25 AM +1000 ***

Last updated 22 September, 2017

Home  |  About |  Print |  Feedback  |  Contact Us  |  Site Map  |  Disclaimer  |  © 2002-2017