# 3D Design / 3D Scanning / 3D Modeling > 3D Printing Gallery >  3D Print Nano Drone that Takes Selfies and Combines Virtual Reality

## kathyhacks

Hi everybody, I'd like to share something about the 3D software design of the ELF VRdrone, which you can get an overview by clicking here. 



It's based on FDM printers, generally using ABS or PLA as filaments. 

*Modular design: split complex parts into a few simple parts, assemble them after printing.*

If we noticed, we’ll find that by splitting the motor housing into 2  parts, the structure of “large upper part, small lower part” we  mentioned at the beginning will not appear, and the success rate is  greatly enhanced. Thus, for more complex designs, and those “large upper  part, small lower part” unavoidable, consider about dismantling the  model into several parts.

Take the ELF WIFICAM housing as an example, before we secure it to the  drone, we part it into 2 parts: the shell and the hook. With the WIFICAM  firstly mounted into the shell, we can then fix it on the drone using  the hook.



As you can see from the above design, every part can be guaranteed  without any support or post-processing. We apply the same trick on the  ELF battery case design.



Last comes the ELF overall body. The “dismantling rule” also works. In a  word, for a larger overall framework, you need to work extremely  intensively on every little bit to avoid collapse and pay extra efforts  on the support as well as post-processing only to get a fairly humble  print. The utilization of “modular design” is really important.

After printing all the parts, people will probably think about how to  assemble them into an integrated robot. In the following parts, we are  going to talk about some points important to pay attention.

*Important points of modular design*

Traditional assembly design requires up to 0.1 mm difference in size  between the parts. However, due to the nozzle head diameter of FDM, the  final prints have some discrepancy compared to the 3D models. Take the  nozzle of 0.4 mm diameter as an instance, to print a 10x10x10 (mm), but  it will result in 10×10.4×10.4 (mm) cube. Why is that?



The above picture shows that it is because the nozzle head diameter is  0.4 mm, the print length and width are both 10.4 mm, while the height  remains 10 mm. If it is a single object, such errors can be ignored; but  if it is several parts which will be assembled into something new, then  still using the “0.1 mm difference” like we normally do will be a  problem. Taking into account the mutual engagement of the two parts will  eventually be more than 0.4 mm error as the design size, we come to the  conclusion that the two parts must have 0.9 mm difference in size. If  you need to fit them tight, narrow that difference to 0.8 mm.

*Design the most efficient print how-tos.*

Try to leave out support, which consumes much time outside of the useful print part and requires removal.

Use hollowed design if necessary since this saves time and filaments.

*Choose the proper filaments.*

FMD mainly uses two filaments: ABS and PLA, each with its own  characteristics. We need to choose the proper type under different  circumstances.

PLA with lower melting point, has better adhesive properties, emits no  odor during the printing process-which is the biggest advantage.

ABS is better known for its low density, light weight, good toughness and certain flexibility.

If you need to print a craft, having nothing strict requirement on the  weight and the toughness, then PLA is the best choice. But if you want  the model lighter with some hooks or buckles, and toughness, ABS must be  better. The ELF is printed by using ABS.






All the 3D print models mentioned above can be found on MakerbotThingiverse. If you want a 3D print nano drone, welcome to check out on our Indiegogo campaign page.

----------

