MOSQUITO OPEN BETA 1

It was discovered that using a textured build plate on certain FDM 3D printers, such as the Prusa MK3S, could produce a surface finish far more visually appealing than typical layer lines, even closely resembling professional surface finishes. Therefore, it became a mission to integrate it into the MOSQUITO, as no other 3D printed model design had done this before on a full scale.

Each main component had to be redesigned to be split into two halves so that their exterior surfaces faced the build plate. However, printing on the textured sheet alone did not fully eliminate layer lines. Extreme lengths beyond regular hobbyist printing were required to achieve ideal results.

Through extensive experimentation, an optimised method was developed. The nozzle height must be intentionally lowered to an unusually small offset, bringing it extremely close to the build surface. This compresses the first layer of the molten material further into the grainy texture of the build plate, making layer lines almost invisible. This process requires very precise bed calibration to ensure near perfect flatness across the print area.

The illustration drawn then shows the additional steps required. Due to the compression, printing a regular object will cause a large "elephant's foot" effect at the base of the object. This can be partially mitigated by printing external perimeters first, as the material stabilises from the outside inwards. Then, the remaining deformation must be offset by modifying the original CAD geometry itself at the edges to predict and compensate for the expected bulge. This became a very unique process, not previously seen before during the MOSQUITO development, by treating the deformation as a design parameter rather than a flaw to post-process later.

For more reading, this method is further detailed in the Open Beta 1 handbook part 1, starting on page 9, and in the Open Beta 2 handbook, starting on page 35.

Stacked Bridges: Bridging in 3D printing is a process where a horizontal platform can be made between two points, and in mid-air, without the use of support material. This can happen due to the viscosity of the molten material that still binds to the nozzle as it extrudes and moves along, combined with air cooling to partially solidify it mid-air. Normally, the outer barrel model shown would require support material for the internal cavity when oriented upwards, as shown. However, by strategically placing bridges on top of each other in order, starting from the edges, the entire underside can be formed without the use of any support material.

Seamline Realignment: Back in 2022, when slicer sofware were less advanced, an observation noted during the MOSQUITO development was that the straightness of seamlines was highly dependent on the refinement of the triangulated mesh. Extensive experimentation was therefore carried out on STL export settings. In short, a denser mesh produced straighter seamlines. However, excessively dense meshes had adverse results in both seamline straightness and file size. As such, a balance was found by carefully tuning surface and normal deviation values in Fusion 360 during STL export.

Realigning Shifted Patterns: The Open Beta 1 model had two versions: one optimised for a 0.4mm printer nozzle, and another for a 0.6mm nozzle. As several components that were split into two halves had repeating patterns, such as the gearbox and battery grip, a unique problem emerged with the 0.6mm nozzle: when assembling the two halves, the repeating patterns were out of phase. This led to prolonged confusion as there was no clear initial answer. After careful observation of the printing process, it was found that a larger nozzle diameter exhibited directional material shifting, where the extruded material was slightly dragged along in the direction of the tool head. When printing the two halves, the tool head would move in opposing directions, resulting in the pattern phase shift. This was alleviated by first measuring the distance of the pattern misalignment and compensating directly in the CAD model, offsetting one side of the pattern by the same amount.

The Open Beta 1 model was released in April 2022 on the Printables platform, where it quickly became one of the most popular 3D printed airsoft models and gained attention across social media. This exposure led to a rapid increase in users joining the HYBRID ARMORY Discord server, and the community began expanding significantly. Soon, users from around the world were creating their own builds and bringing them to airsoft skirmish sites such as Action Airsoft Club (UK), Airsoft Arena (US), Arena 149 (New Zealand), Killhouse (Belgium), and Lauterback (Germany).

To gather structured feedback, a user survey for the Open Beta 1 test was published on Discord in December 2023. The survey received 19 responses, fewer than anticipated, likely because a large portion of users were not active on the Discord server itself. Responses primarily came from the United States and European regions. Overall, the feedback received was highly positive. The majority of respondents found it easy to 3D print and assemble with the provided instructions. There are also a lot of comments praising the design for being lightweight, compact, and enjoyable to use in skirmish games, and attracting significant attention from other players.

There was some constructive feedback received, noting that some components were difficult to source, in particular, the clevis pins. The internal wiring process was also fiddly for some. Some also reported that the 5mm clevis pins would loosen and fall out by themselves over time.

Despite some shortcommings, all respondents would recommend the MOSQUITO to other airsoft players. Overall, the Open Beta 1 proved to be successful and significantly increased visibility for the MOSQUITO platform and the HYBRID ARMORY community.