April 2024, the season is just around the corner and we are ready to launch 4 very important technical and mechanical upgrades on Keelcrab brand drones with the aim of improving the mechanical capabilities of drones due to an increasing need for hull maintenance in warmer and warmer seasons.

The updates will involve 4 aspects

  1. motorized brush carriage
  2. machine control software upgrade
  3. hydrostatic trim
  4. brushing discs

1) Motorized brush chassis: what have we improved?

The motorized brush chassis arrives at its first restyling presenting itself today as an increasingly “industrial” accessory with higher performance and resistance. Thanks to a painstaking “painstaking” work of studying interaxes, it minimizes the waste of system current while significantly increasing efficiency.


More power: The brush-handling motor has been increased to 24 volts with 100 effective rpm at the brush

Motor torque management is via custom firmware designed to preserve the motor from current spikes and ensure mechanical integrity in case of accidental blockage

More efficiency: the new transmission by toothed belt gives more cleaning efficiency

In the first motorized brush release, polyurethane round belts were used to achieve counter rotation of the discs (a smart system and still used today on some vehicles in industry). The polyurethane round belts, while providing high strength, needed to work at a high tension to ensure sufficient drive torque and avoid slippage; however, these tensions increase the system discharge current (that amount of current needed to move the entire brush body “on the bench”).

Downstream of this new engineering based on XL pitch round belts and mechanical referrals, there has been an increase in efficiency of more than 27.8 percent; this energy and power is now all available to the brush disc for cleaning and brushing tasks. In addition, the rated torque of the motor is exactly the resultant at the bristle tip (as there are no losses due to slippage).

New transmission shafts in stainless steel-316

In the first brush release also the stainless steel shafts (like the carriage) was made sintered (glass filled) system excellent for freedom of construction and strength but obviously not comparable to the mechanical properties of the definitely stronger, long-lived 316 stainless steel that especially in the threaded sections guarantees an unlimited number of assembly/disassembly of the brush body.

2) Machine control software upgrade: better thrust!

Increasing the efficiency of the motorized brush was the focus of the design of the new machine control software. The design reasoning led us to increase the average function (of all machine parameters) pushing us in the direction of wall efficiency, in fact the energy “saved” by the new brush system was then made available mainly for the suction pump that gains a 7.4% absolute thrust in terms of the robot’s resultant force against the hull surface (all by NOT varying the overall system current).

The new firmware also was designed with the prerogative of current control of all motors that are now punctually measured in performance hundreds of times per second (by special additional electronics components on the machine control board) and managed according to a prudential logic whereby power is cut (prudentially) in the event of any current spikes (positive or negative). This generational shift toward more effective and efficient system electronics can be likened to the advent of ESP in the automotive industry and will allow for a drastic reduction in possible failures and breakdowns (estimated to be in the range of 88.5 percent) in favor of an increasingly high customer experience that is increasingly the focus of our drone development.

3) Improved end user experience with new hydrostatic trim set-up

New mechanical components on the motorized brush (motors and shafts), pump thrust efficiencies, cross-over in the automotive field what would an increase (for example) in weight of some components of an engine suppose front (or rear) and a relative change in power entail?

Certainly a revision of the grounding of the vehicle through a new study of the barycenters and metacenters and its relative trim; exactly what happens to our keelcrabs i.e., mechanical upgrades and changes in barycenter always go through a tuning of the overall hydrostatic trim, an element sometimes underestimated but of extreme importance as the real beating heart of the user experience. What if, once the robot is put in the water and the pump is turned on, the robot is unable to be reasonably directed toward the waterline (even through the help of the power cord..)? What if, upon reaching the surface in the hull, the “forward motion” command was followed by an obvious translational motion (e.g., toward the boat’s waterline)?

In these cases (and many others not mentioned), it is evident that the user experience would diminish to such an extent as to make the use of the robots tedious or almost irritating; for these reasons, all the man-hours necessary were invested in carrying out the maniacal study of the new machine barycenters and metacenters and related and endless machine adjustment (in fresh and saltwater) in order to find maximum efficiency (again, paretian) with the purpose of optimizing the user experience at the end user.

4) Variety brush discs, important news coming soon:

In order to cope to the fullest with a season that, along the lines of summer 2023, promises to be even “hotter” (in terms of average measured temperatures of the waters of our seas) for motorized brushes as well, we have introduced important innovations in order to increase the plafond of possible brushings to increasingly allow for the most correct work by maximizing the fouling removal/anti-fouling compliance relationship.

Below are the 3 types of motorized brush discs available for keelcrab PRO 2024 restyling (available from April 2024)

SOFT nylon : High-density, high-strength sintered polypropylene brush disc inset nylon diameter 0.8 mm height 40 mm. These soft brushes (accompanied by long excursion spring, supplied) allow maximum adaptability and gentleness of brushing your hull by acting only on the first layers of fouling and algae bringing the antifouling back into direct contact with the water and causing a restart effect to the proliferation process. Suitable on average between the first and third month (from last pre-season antifouling painting).

MEDIUM nylon : High-density, high-strength sintered polypropylene brush disc inset nylon diameter 1 mm height 38 mm. These medium brushes (accompanied by long excursion spring, supplied) allow excellent adaptability and medium abrasive capacity for brushing your hull by acting on the layers of fouling, algae and fouling principles bringing the antifouling back into direct contact with the water and causing a restart effect to the proliferation process. Suitable on average between the third and ninth month (from last pre-season antifouling painting)

HARD inoxHigh-density, high-strength sintered polypropylene brush disc inset stainless diameter 0.30 mm height 34 mm. These hard brushes (accompanied by short excursion spring, supplied) allow good adaptability and high abrasive capacity for brushing your hull by acting on formed fouling layers, algae and advanced fouling principles. Suitable on average between the ninth and fifteenth month (from last pre-season antifouling painting)

New double-bristle brushes !

The experience gained and the many tests carried out to implement the 3 types of brush discs (soft-medium-hard) prompted us to try producing 2 more experimental double-bristle nylon & stainless steel discs (0.10-very soft) with truly AMAZING results.

Doubling the bristle density (while maintaining the overall weight of the brush disc in water) by playing with lengths, diameters and materials of the individual bristle allowed us to discover new horizons of brushing efficiency. These brushes turn out to be highly suitable for polishing, for example, a pre-rubbed boat hull to a mirror finish (nylon) or removing principles of coralline and fouling (stainless) increasing cleaning efficiency but perfectly respecting the physical integrity of antifouling product layers. Already orderable (with 4 weeks delivery time) and ready for catalog inclusion by Q3 2024.

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