Designing for 3D printers

greggl1962

New member
I'd love to see an article or get some guidance on designing planes for print on 3D printers. Even to just design parts for existing planes. What are people using? What are the pitfalls of free compared to 'for purchase' software? What about learning curves? Ease of use? (this list can probably go on and on....)

Thanks for your thoughts!

Gregg
 

mrjdstewart

Legendary member
what are you wanting to do?

do you want to design whole airplanes or just parts?

i personally use Tinkercad for my design. it is a free CAD program that allows you to do almost everything you need. it is not the most advanced by any means but a simple way to begin the design process. the more you use it the better you get and the easier it is to take your idea from thought to design. there is a learning curve like anything but it's not that hard.

good luck,

me :cool:
 

JasonK

Participation Award Recipient
I use blender for 3D modeling, Cura for slicing. Works great.
From what I have seen for Tinkercad, it seems like a good choice also.

Regarding anything special for 3D printing.. the things that are 'special' about 3D printing are roughly has follows:
  • 3D printers have a nozzle diameter and layer height, so there is a limits to minimum dimensions of various parts
  • Depending on the printer, you may or may not get 100% dimensional accuracy, for example, I have found that I need to make my holes slightly bigger then I want them, as my printer tends to 'over fill' into holes slightly
  • things are printed in layers, and each layer has to rest on the layer below it, this means either making sure your angles allow support all the way up or printing with support, or some combination
  • depending on the printed material, temp, speed, etc, layer to layer adhesion is typically lower then the general material strength, meaning that your end result will have stronger and weaker tensile strength directions.
  • there is a limit to the print bed size (different printers more so then others)
that is everything I can think of off the top of my head that would impact your modeling considerations (there are more things when you get down to the parts about actually printing your object, some of which might be addressable in the modeling).
 

Merv

Site Moderator
Staff member
I'm a newbie at 3D printing, got mine a week ago. I went with the Ender3 Pro, I'm using the free version of SketchUp & Cura. My Y & Z dimensions are spot on, my X is short by 2%. I've not taken the time to fix this.

My first designed project was a servo like arm for a small stepper motor with a shaft that is not round, it has 2 flat sides. I elated to a get press on fit on my 3rd attempt. I agree with @JasonK, my holes are undersized. I use the printed hole as a marker to drill a precise hole, works great.

It's very quick & easy to design and print a project. I'm very happy with the results, wish I took the plunge a long time ago.
 

quorneng

Master member
Perhaps the most important consideration for 'printing' a complete plane is that the print material is heavy, at least 10 times that of balsa, so much of the structure has to very thin to compensate. The very thin elements are tricky to print and even more so to design.
On the other hand printing parts that would normally be a solid plastic works very well. In addition you have the ability to make it exactly the size and shape you want and as many as you like. The only thing required is time.
As an example the cowling on the AN2 in my avatar is a 3D printed component made to the exact scale the plane. Such a cowling would normally be some sort of plastic moulding so there is little or no weight penalty in it being 3D printed.
 

LitterBug

Techno Nut
Moderator
There are tricks to making 3D printed planes light yet rigid. There are several different schools on how to do it, most use a single layer shell. There is also a new lightweight "foaming" PLA that weighs 60% less. You might want to print some of the "test planes" from thingiverse to get an idea of what people have done. This Eclipson "free" plane comes to mind. https://www.thingiverse.com/thing:3302937

Cheers!
LitterBug
 

greggl1962

New member
I'm already printing a Cessna 152 model from 3dLabprint. They are using that 'single-layer' light and rigid shell. For now, I'm interested in printing spare parts (like a cowl - for example) for other planes I have. I'm also interested in converting plans for a balsa model into a 3D printed project ( Sikorsky S39) by printing parts in a similar thin-walled fashion and maybe print wing ribs and spars and still cover wing in a traditional manner. There are a lot of possibilities that I wish to explore.
 

LitterBug

Techno Nut
Moderator
I'm already printing a Cessna 152 model from 3dLabprint. They are using that 'single-layer' light and rigid shell. For now, I'm interested in printing spare parts (like a cowl - for example) for other planes I have. I'm also interested in converting plans for a balsa model into a 3D printed project ( Sikorsky S39) by printing parts in a similar thin-walled fashion and maybe print wing ribs and spars and still cover wing in a traditional manner. There are a lot of possibilities that I wish to explore.
I'm thinking about turning one of my older 3D printers into a light duty CNC. You can't beat Balsa for strength and weight.
 

OliverW

Legendary member
There are tricks to making 3D printed planes light yet rigid. There are several different schools on how to do it, most use a single layer shell. There is also a new lightweight "foaming" PLA that weighs 60% less. You might want to print some of the "test planes" from thingiverse to get an idea of what people have done. This Eclipson "free" plane comes to mind. https://www.thingiverse.com/thing:3302937

Cheers!
LitterBug
I wouldn't try that one.. mine disintegrated
 

greggl1962

New member
I wouldn't try that one.. mine disintegrated
After looking at the Eclipson Model T, (sea plane version) I decided to buy the files rather than do the free version. The first part I printed (part of the fuselage) was brittle and did just as you described - I ended up doing what I have done on other thin-wall prints... Turn Up the Heat!

The PLA I use is a brand sold by Microcenter computer stores (microcenter.com) called Inland. I use their PLA plus and the printing temp range is between 205 and 225c. I turn it up to 240 because at lower temps it doesn't 'laminate' to the previous layer well. At 240c I get great lamination giving me a flexible yet strong part that won't turn to a pile of PLA string
 

OliverW

Legendary member
After looking at the Eclipson Model T, (sea plane version) I decided to buy the files rather than do the free version. The first part I printed (part of the fuselage) was brittle and did just as you described - I ended up doing what I have done on other thin-wall prints... Turn Up the Heat!

The PLA I use is a brand sold by Microcenter computer stores (microcenter.com) called Inland. I use their PLA plus and the printing temp range is between 205 and 225c. I turn it up to 240 because at lower temps it doesn't 'laminate' to the previous layer well. At 240c I get great lamination giving me a flexible yet strong part that won't turn to a pile of PLA string
Mine was printed at 230°. It really blew apart! I wasn't mad because it was so spectacular
 

mrjdstewart

Legendary member
my first 3DPrint Lab plane had almost 1 flight and failed in a very spectacular fashion as well. printed another due to stubbornness and still have it but only fly it on "special" occasions. i worry if i blow on it too hard it may break. i have the BF-109 printed as well but have ZERO confidence it will last so haven't even assembled the parts.

regrettably, the 3D printing is cool and getting better by the hour but for planes it still has something to be desired...

good luck,

me :cool:
 

Boberticus

Active member
Im thinking that hybrid builds are going to eventually start to take over. plastic ribs/offsets with skins made out of lighter materials like shrink film or foam skin with custom printed parts that are more complex for control surfaces, electronic mountings, and scale details and whatnot. I mean, right now the last thing listed on the resources page is a mild form of just that, parts to make your P38 look awesome. a few fuselage and wing cutouts out of plastic and you got yourself a hybrid, with offsets you didnt have to cut out...

Think of the literally thousands of free plans available online that are simply a bunch flat pieces of balsa cut to shape and glued to each other. I have always heard that working with balsa is tedious, is it still tedious if you dont have to cut the pieces, they always fit each other perfectly with no sanding, if you break something you can just print another off in a few minutes, and can use superglue on the joints?

look at almost anything "fully" 3d printed. either they are going to extreme lengths to make something crappy that is only plastic, or they are using 3d printed parts in conjunction with metal inserts and rubber wheels and belts and other non printed items to make something that works.

We already have a really nice ways to skin wings, tail, fuselage, (foamboard, monocoat, tissue paper), but lack in repeatable complex shapes,(airfoils, curved nosecones, fuselage shapes, landing gear, canopies, ect.) and the ability to be rigid or to attach to rigid structural components like spars without compromising aesthetics or strength.

Imaging a 3d printed wing that is just a arrow spar and offsets that you then glue together and skin. way simpler to print, can be done in parts and glued together, and a huge aircraft can potentially be done on a relatively tiny build plate. whats more if you plan it right it would be just as rigid, if not stronger than as a balsa build. and you can have custom parts that piece together say like a removable wings, gun pods, motor mounts, magnetic battery trays, landing gear doors and other details that you wouldn't be able to do in flat balsa by hand, or with foam
 

bracesport

Legendary member
I am currently making a curvaceous glider fuse that is thin skin printed (completely hollow) and is being covered with a carbon fibre woven sock - as a sloper, weight is not critical and the carbon will bring up the strength - Tail is fully 3D printed - we shall see! :)
 

greggl1962

New member
One of the features I like about the 3dLabPrint planes would be the structured support work inside of the parts. There seems to be enough rigidity to help the plane maintain its form as well as having additional gluing surfaces between the printed parts.
The one thing I'd probably like to see more of would have to be additional tabs to help line up the pieces while gluing.

I also agree as Bob is pointing out that there's definitely a place for more hybrid builds... whether it be in spare and/or add-on parts or main components like wings. We already see some forms of that with balsa or fiberglass fuselages and foam wings sheeted with balsa.

The possibilities and combinations could be endless. I've also been reading more and more about balsa shortages. 3d printing is definitely another way, as foamies have become, to help keep us flying!