All donations are securely managed through PayPal. Amounts donated are not published online.
Many thanks for your kind support.
Model Boats Website Team
December 2018: 4 people November 2018: 11 people October 2018: 9 people September 2018: 13 people August 2018: 5 people July 2018: 8 people June 2018: 8 people May 2018: 7 people April 2018: 24 people March 2018: 11 people
switching off and on via the ESC switch does NOT disconnect the battery from the ESC just stops the ESC passing current. Power is still being used. The only way to end all current flow is to disconnect the batter by either opening the pos or neg lead from the battery. Mounting the magnet on the end of a screw and having that fit into a threaded hole should deal with the problem of keeping it in place while running.
I do not know how much knowledge of electronics your friend has but I need to point out that a hall effect sensor is not like a relay. While they do act like a switch ( sort of) they need to be powered and have a hall effect voltage to switch. This would mean in the use intended there would be a current drain on the sensor and if the power supply ( battery?) voltage fell to far it would not function. The effect you want could be replaced by a reed relay cheap and simple to use. However reed relays can only pass low currents so would need to be cascaded with a higher rated relay before switching the main battery supply on and off. https://www.ebay.co.uk/itm/10-Pcs-2-5X14mm-3-Pin-4W-Glass-Re... these reed relays have both normally open and normally closed contacts and at a couple of quid for 10 worth buying so he can experiment.
as a first thought if you have a spare channel on your transmitter use it to drive a servo to close a shut off valve it could also function as a valve to prevent accidental gas leakage when connecting everything up. Trying to do it auto is fraught with danger since even if your out of water your still going to have pressure. If on the other hand your wanting to stop the gas if your pressure falls to low why?
first question which no one seems to have mentioned is :- did you have the transmitter switched on BEFORE you powered up the receiver/ esc ? If not de power the receiver and try switching on the transmitter . Most of these systems have an interlock to prevent the motor running if there is no transmitter.
the short answer is YES! however it may be a little more difficult than your willing to undertake I guess you want to allow some one to select full throttle but have limited speed. Depending on your transmitter you may be able to have dual rates on throttle. if not read this article its a walk through on retro fitting dual rates on throttle. https://www.instructables.com/id/Add-dual-rates-to-a-channel...
https://www.ebay.co.uk/bhp/laser-decal-paper My point was and is using an inkjet requires you to seal the printed item before water slide since inkjet ink tends to be water soluble while laser printer ink is not so its one step saved. obviously once in place on a model it needs to have a protective layer of something.
depending upon the type of motor cooling it can be a problem. Most brushless motors are out runners so the case rotates! In runners are usually for higher speed applications (or driving a gearbox). If you have an idea as to the size of IC engine the boat was intended to have then this list may be a help .049 or .051 = 100 watts 0.10 = 200 watts 0.15 = 300 watts 0.25 = 500 watts 0.32 = 640 watts 0.40 = 800 watts 0.45 = 900 watts 0.51 = 1020 watts 0.61 = 1220 watts 0.75 = 1500 watts 0.91 = 1820 watts Since Watts are Volts * Amps ( I know this is not accurate for a reactive load like an electric motor but its a rule of thumb) This gives you a ball park next point is the KV ( revs per volt) of a motor. The higher the KV the smaller the prop. Finally buy a Watt meter they are not expensive and give you a chance to " fine tune" a setup. https://www.ebay.co.uk/itm/FT08-RC-150A-Hight-Precision-Watt... Car ESCs ( usually) have a reverse function while the airplane versions do not. They are generally cheaper than boat specific ESCs.
you could consider using some of the modern tech and fitting active stabilizers there are a lot of cheap solid state gyros and if your receiver does not have enough free inputs and outputs an arduino mini could handle the logic.
I recently tried 2 ESC(s) into one battery connection then into 2 channels of the radio. Received wisdom said that one of the red leads to the radio should be disconnected. This I tried and one ESC ceased to function. So to prevent unwanted feeding on the positive lead from one ESC to another I fitted a diode to each of the ESCs. If you were to do the same I think your setup would work. However if your TX has mixing capability then why not use that ability to mix rudder with the 2 outboard motors so you have the added steering of the 2 outer motors? Any how fit the diodes please this should prevent the ESCs damaging each other its a simple job https://www.ebay.co.uk/itm/20x-1N4007-rectifier-diodes-DO41-... 20 diodes for £1 the silver band is positive so goes towards receiver plug.
Do you NEED insurance to fly a model airplane no. Should you have it YES. Its not very long ago a teenager was killed in Dartford. https://www.telegraph.co.uk/news/uknews/1447013/Girl-14-kill... You may take the position that this was a large(ish) model yours will be smaller. While I cannot locate a reff. I have a memory of a story relating to a child killed by a .049 powered model. This was many years ago. Your idea of a foamy probably being to light to do much harm sounds good until you consider how much mass it holds in ballast. Remember the energy of a moving object is given by 1/2 MV^2. If you have a flying site which is remote from other people and privately owned so there are no members of the public around then again your probably good to go. If however there are chances of other members of the public around then its foolish to take a risk which is not needed.
I know people build real jets I look at them and DROOOOOOOOOL. However at my age and short pockets looking is about all I can afford. When it comes to stabilising I have a pixhawk in my quadcopter and that is an amazing beast. It is capable of autonomous flight following GPS waypoints then auto landing.
reading the rc advisor I found one point VERY strange he states in runners still have brushes ???? All together children " OH no they don't" I had forgotten the ducted fan use however yes ducted fans with a need for high RPM and less torque in runners are the obvious choice.
in runners get used in the model car crowd other than that they are used in FAST boats. As with most things its a trade off in runners lower torque but more revs ( for any given wattage ) match the prop to the motor and your going faster with an in runner. https://www.youtube.com/watch?v=I4hU7Rv7X2w one example!