Hi JJ. Just a word of warning, your Mtronics esc will not work with brushless motors, also 20amps is close to its limit with twin motors and fairly large props, performance wise, brushless is the way to go, but will need 2 esc's, wont run with one, if your dropping hints to the elves, spec your motors at about 700 watts and 600-700kva great torque with good revs at 7.2v even better at 12v Mark
Thanks again Will give that a try first and then perhaps see if Santa brings me some brushless motors 😁 Cheers J.J PS At the moment using a single ESC( 20A Mtronics) but would probably go for two if I move to brushless.
I have no idea of the size of your boat, but I have used the Mtronics sound board (choices of engine type) together with a pair of Dayton Exciters/transducers ( EX25VT 4 Ohms) which are 2” in diameter. My boat is a Tug only 21” long with 8” beam. Volume is fine and exciters easy to accommodate. All the best. NPJ
Hi Ian Looking at the pics it would appear to sit correctly and certainly planes well. If your ballast is forrard it will mean it has to be lifted to plane, at the cost of increased power. If you are still using the Mtronics 600 motor the prop is about right. The specs say 6-12v so running at 7.2 v will probably account for the heating problem. A higher voltage will allow the motor to run at its optimum design speed and cooler. The stall current is 48 amps! I am assuming you have a good a free running prop shaft and tube and the motor and coupling are aligned? Can you post a pic of your prop? Dave
I have an original Aerokits Solent powered by two Torpedo 800 brushed motors controlled by two Mtronics 25 amp brushed speed controllers. I normally use two 8.4 volt 5000 mah NiMh batteries, although I have also used two 11.i volt Lipo's. The shafts are fitted with 50mm three bladed brass propellers. The boat performs nicely on the water. My stanchions are home made from 3mm brass rod with holes drilled to take 2mm chain. The stanchions are 70mm in lenght above the deck with approx 10mm below the deck, the base of the stanchion has a suitable sized brass washer fitted where it passes into the hull, the top of the stanchion is filed to a ronded profile. Shaun
Hi Just had a quick Google as I was not sure of the size. There was the very same item on our For Sale section 5 years ago: "Deans Marine 1/24th Scale British Power Boat Co. Seaplane Tender Includes JP Power 400 Motor, Deans (MTronics) ESC, 5Cell NiMh Battery." That being the case any small brushless 28XX size with a Kv of around 1000 and 30 amp esc and 30 -35 mm 3 blade brass prop should suffice. I have similar in my 34" Fireboat and use an 11.1v Lipo. If you are new to LiPo you do need a dedicated LiPo charger and be aware that unlike other battery technology they pack a very heavy punch. You must follow the charging regime to the letter and make sure you do not overdischarge when running the model. There are some rather frightening U-tube videos of what happens if you ignore the rules! That said I have been using LiPos for several years now without any major problem, but I am always aware of the risks and make sure I don't take any unnecessary risks Good luck Dave
Here's mine I built as per plan about 4 years ago. Name: "Merlin" Specs NiMH (7.2v) 4 Amp/h MTronics Viper Marine 15A Constant Motor: High speed Low drain 545 Type: Brushed Drive: Direct Drive Props: Single Propellor Type: 2 Blade X Type Size: 35mm Built from a Traplet plan In 2013. All wood construction, 545 direct drive motor water cooled with 2 blade prop. 2x 3.7amp 7.2 volt NiMhd batteries and a Mtronics Viper Marine 15amp speed controller.
Hi Dave I am using Mtronics Viper Marine 20s- (I did order 15s but Howes sent these by mistake). I am using 3cell 30-40c 5000mah in the Perkasa - batteries are overkill I suspect? A 7.4 2 cell lipo seems a good bet then? Steve
Hi Steve Yes I did look at the Masterblaster but it appears to be an on/off devise the Mtronics sound is portional to the motor speed I.E. From a tick over it increases as you throttle up or down to relate to the motor speed, it picks the motor speed up from a sensor that is joined into any two of the three motor wires and must say the installation is very simple with the pre made and plugged wiring harness. Hope this helps Peter
Thanks for that. Mine is already fitted with twin shafts and a friend has suggested that I use two 900kv outrunners with 60amp esc's. I notice that you are using an Mtronics sound system, I assume for the motor sounds. What sound do you use as I understand that these boats were fitted with gas turbine engines?
I have two ESC's (mtronics Viper Marine 15)and a P40 mixer from Action Electronics. Because of this the motors have their own batteries, 7.2volts, and the receiver has it's own 6volt supply. Neither of the ESCs provides power to the receiver, although they are obviously connected to it, the central wire is removed from the connector and taped back, out of the way, so could I use one to supply the power for the sound unit? The mtronics spec for this BEC unit is 1.2A but the voltage is not mentioned. Chris
HI Biggles I believe Haverlock's suggestion should prove suitable and Mtronics are very good at designing escs for model boats. Their Esc is also suitable for LiPo use as it will cut off piowerr if the cell voltage drops too low. The motor is a 1000kv which is the shaft speed you will likely get for each volt of your battery. You will not need big props otherwise you will overload the motor and three bladed brass possibly 35mm would be my starting point. The power available however with two motors will be far greater than required for a 28" boat so you will need to reduce the throttle control on your Tx. My 34" crash tender has one 28 size brushless and with 11.1v Lipo (2200mA) is quite uncontrollable without this. I use a Futaba 6Ex Tx which allows me to adjust the throttle stick output to about 45% in my case and I also have a differential set up on the rudder controlled by a switch as full rudder at high speed is dangerous. There are other sets available that offer the same functionality but my Planet 5 channel was unsuitable. LiPos are high tech and become very unstable if overcharged or discharged below a set voltage (about 3.3v). They are fragile compared to NiMh and should never be dropped and need discarding if they sustain damage. The internal chemical processes are stable at the nominal cell voltage 3.7v but become increasingly less stable above and below this voltage. Unlike other technologies the chemicals can not be restored once a parameter has been exceeded and and in the worst case scenario a chain reaction takes place. You will also need a LiPo charger. Do follow the instruction to the letter and never leave the battery on charge unattended. I have a charge bag and use the metal bench in my garage when charging LiPos. Good luck and please ask if you need more help Dave
Any advice re the wiring arrangements for my Aerokits Solent would be much appreciated, specifically in the BEC area. The boat is fitted with twin MFA Torpedo 800s each controlled by its own MTronics Viper 25 speed controller and powered by individual 8.4v 5000mAh NiMH batteries Each speed controller has its own on/off switch, however I have noticed I only need to switch one on to get the set up to work. I want to make these switches more accessible so I don't have to remove the superstructure to turn the system on and off. Can I do away with one of the switches? this would make the relocation so much easier. Cheers Shaun