Hovercraft - Div B Submit a question about this topic Questions may be submitted to the FAQ system when it opens on September 16. Prior to that time, please re-read the rules which might help answer your question. Leave this field blank Reveal Questions A student came across a problem while making the hovercraft. The brushless fan he is trying to use needs an integrated circuit and the rules say that we can’t use an integrated circuit unless it’s an integral part of the motor. Rule 3.f. We c... 12v batteries sold at shop and online with 12v labelled are actually higher than 12v when charged (10 cells * 1.2=12v since each cell is 1.2v nominal, but often 1.4-1.5v when charged). Commercially labelled 12v nimh packs are allowed right in this... 3.b line 3 said inflated skirt must continuously contact with the base surface. Does this mean a inflated skirt is required for a hovercraft. 4.c states "...8 minutes to adjust and repair their vehicle and make test runs. Practice runs are not allowed." Could you please clarify what is considered a test run (allowed) vs. a practice run (not allowed)? 5.a states that a “smooth” surface is required for a competition setup. Does that mean that any sort of start/end line demarcation that would make the surface unlevel (such as masking tape) would be prohibited for competitions? Are supervisors intended to post Target Times and Bonus Target Times at impound? Are they allowed to, if they wish? Or are the times required to be kept secret? Are teams allowed to clean the track using either dry or wet towels? Are tools with integrated circuits, such as multimeters or voltmeters, that are connected to the hovercraft's circuitry during the 8-minute testing period, but removed before a run permitted? Are transistors allowed? Are we allowed to start our hovercraft against the side of the track as long as we show levitation and aren't using the wall as support, and instead use it because our hovercraft veers to the side, or are we forced to start in the middle of the tr... Are you allowed to touch your hovercraft when giving the 3, 2, 1 countdown and then let go when you say go? As long as I'm within the size parameters, can I put free-spinning wheels on the corners of my hovercraft to reduce friction along the wall(s)? Can a hovercraft use the side rails to propel itself (as long as it only contacts the inner portion)? Can a student bring multiple batteries to impound as long as the hovercraft runs under 12V? Can a student slightly lift the vehicle during initial inflation of skirting, so long as the vehicle remains levitated afterward with no additional assistance? Can a team hold their hovercraft at the top of the ramp until it is launched or does the team have to let it rest against the foam pad at the start line held by the event supervisor? Can students switch thrust fan to improve the timing. For example one fan for 6 second target and another fan for 20 second target? Event Parameters - 2.b states that teams can bring spare parts and supplies. Can passive components like resistors be switched with spare parts after TT or BTT is announced. For lift fans or blowers, is a thin plastic sheet covering the entire vehicle bottom (such as skirting) considered sufficient for the dowel test, or must there be additional "hard" guarding as there would be without the plastic sheet? Given switches that are mechanically activated by a motor, and electromechanical DPDT relays, what determines a "manually-operated" switch? I know circuit boards are not allowed, but for connection purposes would a solderable breadboard be allowed for making wiring connections? If I am not using a skirt does the bottom of the part have to be covered so the dowel can't touch it or just from the top being that is getting protected by the floor or is it being tested in the air. If I spin a flywheel before the start of the run, release a pendulum before the run start, or use a mousetrap, does the energy from said flywheel, pendulum swing, or mousetrap count as outside energy sources? If a digital multimeter is mounted on the device but placed in series with a manual switch that is turns it off before the run, may the voltmeter tack the trip down the track as part of the weight of the device? Is a rheostat an allowed electrical component? A rheostat is basically a potentiometer for higher voltage and current and, as it was described in a question to me from a clinic participant, a potentiometer would not be safe with this amount of vol... Is continuous or near-continuous contact permitted between the ground and a portion of a non-inflated skirt? For example, if one corner or side of the craft is dragging or frequently touching the ground. Is it permissible to use battery placeholders ("dummy" batteries) to adjust the voltage on astring of batteries? They have the same form factor as standard batteries (inour case AA cell) and works as a conductor. We are using these to adjust t... Is it permitted to use a motorized wheel for propulsion on our hovercraft instead of two fans? Specifically, can we use one lift fan for hover and a motor-driven wheel that constantly contacts and pushes against the inside wall of the track to mov... Is it still a manually operated switch if it is mechanically triggered later on in a run, without a human hand directly touching it the moment it is triggered? This is assuming you set up the switch with manual operation prior to it triggering/swi... Is the starting block always placed flush to the start line? Ex: a team wants the block placed further back to start their vehicle at the top of the ramp, and the block be placed right below their vehicle. Or they want the block at an angle. Is there a minimum amount of rise required for the levitation test? Some crafts may rise sub-mm -- is that acceptable? It says we can use a brushless motor, but it doesn't explicitly address the ESC (Electric Speed Controller), nor PWM (Pulse-width modulation) control. Please confirm if we can use ESC and PWM control. It says wires are allowed but is it OK if alligator clips are on the wires and used to connect them to motors? May a hovercraft have multiple circuits that are separate from each other and under 12 volts, even if the combined voltage of all batteries is over 12 volts? Nothing in the rules prohibits someone following their hovercraft down the track and placing their hand or some other object behind the driving fan, such that they are not touching it but still changing the airflow around it to allow for more thru... Rule 3.f. lists the permitted electrical components but does not mention fusing. Can an inline 12V fuse (such as an automotive fuse) be used without penalty? Rule 4.n makes reference to restrictions on the Bonus Target Time being those of listed in 5.d. However 5.d describes the photogates. Rule 4.d seems a more appropriate reference. Can you clarify if (a) this is a typo or (b) how we should interpret... The rule states ‘if a team has 3 incomplete runs their testing period is over’. Same is stated in the Team Checklist - 2026; then why is there a column for 4th Run in the Team Checklist ? This is leading to illegal 4th run during competitions. The students use manual switches, but the switches can be activated by the air pressure of the fan. Is this allowed?Thanks,Man The text mentions “continuous contact of the inflated skirt” is allowed, but does not state that an inflated skirt is mandated or not. Can a rigid or non-inflated foam skirt be used as long as the vehicle levitates when pushed down and rises, ... Under Electrical components stated manually-operated switches is allow. Is a PWM motor speed controller allow? Is a light dimmer allow? Would banana jack ports (for connecting a multimeter during calibration/setup) be an allowed component? ‹ Physics A student came across a problem while making the hovercraft. The brushless fan he is trying to use needs an integrated circuit and the rules say that we can’t use an integrated circuit unless it’s an integral part of the motor. Rule 3.f. We c... ›
