Good morning Engineers and 3D printing enthusiasts!

As you have already read in the article on the presentation of polyDlab, and in the first episode where we told you about Valerio and his bladeless fan, PolyD-Lab is the MJF 3d printing technical lab. PolyD has created this lab to create, with your contribution, extreme and complex components and parts on projects submitted by our followers. The initiative is called 'polyDlab Contest'.

PolyDlab tests the limits of Multi Jet Fusion 3D printing and provides the technologies, skills and experience of PolyD's technicians.

PolyD electric Skateboard

PolyD, electric scooter and skateboard

The Contest

At polyDlab we print your prototypes and industrial and professional parts. If you would also like to participate in the online 3D printing contest of your project, send us your file to

Our team of experts will select one every month. The piece will be 3d printed and sent to the designer free of charge. For each piece, we will make a video explaining its special features in detail, with the collaboration of the selected customer or follower.

In the PolyD lab we therefore print and analyse projects of parts, prototypes and components, based on 5 simple criteria:

  • Resolution quality of the Stl file;
  • Degree of optimisation of the 3D print;
  • Aesthetics and Details;
  • Printability;
  • Usefulness of the part.

At the end of the video we give an overall grade to the project. Each month the ranking is updated, so you can find all the pieces rated episode by episode!

3D Printing of Scooter and Skateboard Parts

This month, the piece selected by our experts is that of Marco Sarracino; the main motivation behind the selection is ease of use.

Marco is passionate about 3D printing and electrical systems. For his skateboard, he needed a prototype gear that could sustain high performance even at high temperatures. Almost all the materials he tried had performance difficulties. For Marco, we moulded

a pulley in Nylon PA12 and the performance was fully comparable to 1 metal;
a plate to house the motor on the plastic plate. Here the mechanical stress is minimal, but temperature still plays a key role. The PolyD-moulded piece in Nylon PA12 fulfils the function perfectly.

PolyD skateboard parts

As mentioned above, the parts are moulded in Nylon PA12, then sandblasted and finally coloured in UV-resistant black.

The evaluation team, having listened to the problems submitted by Marco and studied the design, decided on the following scores:


The quality of the STL file received is undoubtedly very good and without burrs.
Rated 5/5


Looking at the files, one does not get the impression that the parts were designed solely for 3D printing, but rather that they may appear to be designed for CNC machining. How can we tell? There are no obvious optimisations such as emptying some internal parts of the pulley to lighten the part. We suggest Marco use less material and consequently make the part more economical, while still guaranteeing the same mechanical characteristics.
Rated 2/5


We have a real obsession with gears, pulleys and bearings; however, to be impartial, we admit that Marco's design has nothing we haven't seen before.
Rated 2/5


As for the quality of the STL file, there are no problems to report. The print as you can see came out very well indeed.
Rated 5/5


The parts are undoubtedly functional and useful; our follower Marco showed us this through his video. Marco went from using a very expensive steel part to using MJF 3D printing, which saved him time and money.  
Rated 5/5 


PolyD electric skateboard pars scoring
We summarise the grades awarded to the project:

  • File quality 5/5
  • 3D printing optimisation 2/5
  • Aesthetics and details 2/5
  • Printability 5/5
  • Finally usefulness 5/5

The final grade, obtained by adding up all the scores and dividing them by the number of criteria, i.e. 5, is 3.8. The design of the skateboard gears takes second place in the ranking.

First place still remains firmly in the hands of Valerio's bladeless fan.

Thanks to Marco for participating in our MJF 3D Printing Workshop!

Follower Marco Sarracino



PolyD is the MJF 3d printing service. Rapid prototyping and professional and industrial 3d printing are our business: we print on different materials such as 3d nylon printing. You can find out more at the links Materials and Finishes.

Estimate your part now online and enjoy 3D printing!