A few final things to do before we are ready to mirror the left side of the model. First, since there will be a servo in each wing for the ailerons, I have made a cutout so that they can be inserted into the wing. To do this I have cut the wing at a suitable point for printing, but more on that later. I have used a calibrated canvas to get the correct dimensions. I have also made a channel through the wing for the aileron servo wires. This is easily done with an extrude cut, an operation that would be much harder had we already put the dihedral in, as would the aileron and hinge - see, I promised patience would pay off.
After all that, the mirrored model gives us a first look at all our hard work. I think it looks great!
As it stands though, we can't 3D print it. It's time to start thinking about a few things. All of which will have an effect on how we section and hollow out the aircraft.
- Access: How are we going to get in to the aircraft for the battery?
- Modular: Is the wing going to remain in place all the time? It has a wing span of 1.4m so that is perhaps not practical. If the wing is removable, how is it held on? This particular model has the added complication that the tail is attached to the wings.
- Print Bed: We are going to need to section the aircraft in order to print the components. What is the maximum size we can print? Ideally the bigger the better. Remember when I was talking about sectioning the wing for the aileron cutout? From experience I know that most common printers have maximum z-component of 250cm so I made sure not to make the outboard section of the wing bigger than that. We want to make sections required by 3D Printing serve a purpose if possible.
- Where are we flying? Does the aircraft need a landing gear? This is a whole other topic which I'll cover another day, but it's worth having a think about.
- How is it to be assembled? Do we need control runs built in to the model? Cutouts for carbon rod wing spars?
Those familiar with 3D printing will know that it has limitations, there are things you can do and things you can't, and other things that you can but probably shouldn't, unless you want to wait for hours whilst your supply of filament disappears into a support structure that needn't have been there had the model been designed differently.
Hopefully as we progress I will show some of these printing pitfalls and how I answer these questions. I would love to hear from you out there about your solutions.