Good Morning Doug, Just a couple of more clarifications.
Of which material i need to use the thrust washer between the prop and the tube? Copper? Brass?
Please can you indicate me where to find on the web a Low Battery Alarm Buzzer for 6V battery Lead? because i can find only for LiPo batteries.
Which one is the different between LED at 6 Volts and the lights at 6Volts?
Because i can find LED and Lamps with the same shape of the LEDS. The question is generated becausee if i utilize the lamps i do not need to utilize the resistors as on the LED. Thanks

Doug here i attach the picture of what i mentioned in the previous mail
The Switch to connect to the RX and the group of Leds, in this case i need to switch of this one for one gruop of leds and the second for the second group of leds. Moreover i attach the picture of the ESC that i founded in order to utilize the PB battery. This esc works with NiCd batteries and i suppose can works with Pb. Thanks and i hope in your help and also that the informations are enough to make you a clear picture of my project.Ciao

Dear Doug, thanks for replay but i become your nightmare because now i need to finalize all the information on the realization of the project.
I attach here 2 pages where i resume the situation. On page 1 i rappresent the total situation related with all the equipments to be utilize on my Krabbe 12Ton Graupner. On the Page 1 i rappresent also the location and the number of Leds that i would like to utilize on the boat. On the page 2 i show the Leds and the relative Resistors to utilize according the color.
I would like to ask you to check if the Resistors mentioned by me are corrects according the Led Color. Moreover always on page 2 i ask in which way to connect the LEds if in Series or Parralel or one by one and in this case each of them with one Resistor that is suppose is the best way. Moreover i would like to switch on in the same time by the same switch the 2 white leds on the Mast Plus the 2 White leds *one infrom of the cabin and 1 on the back of cabin. Moreover by a second channel i would like to switch on by the same switch the Red ] Green Led and the Led inside the cabin. Now what i really do not know is how to power this 2 groups of Leds. I would like to use the same battery that i use for the main motor ( Pb 6V with 4200 mA/h) but how to switch on the to groups indipendently on from the other? I need to utilize to Switch to connect in 2 different channels of the RX for example channel 5 and 6? But can i use a switch connected with RX to switch for example the 4 white leds all in one time? what i need to jont the 4 wires (-) and the 4 wires () of the leds to joint the switch? please see page 3 of the attached document. and in the same way i can use a secontd switch to connect to an other channel of the RX where i joint 1 led white1 led red+1 led green? Morever the main battery can support motor plus leds. Of course i do not keep the leds ON for all time just for example 10 minutes considering that such battery for my 280 Speed motor can supply power for at least 60 minutes (only for motor). Thanks

Hi Fulvio,
"Can I use it with Pb battery?"
Yes you can, but you have to 'fool' the ESC Cut Off circuit😉
IF possible (DIP switch or jumper plug) set the ESC to NiMH battery.
The ESC should then assume a 5 cell NiMH if you use a 6V Pb battery, or 10 cells for a 12V battery. If possible by programming (easiest with a programming card if available) set the number of cells manually to 5 or 10 as appropriate.
Cheers, Doug 😎

Thanks Doug for your complete explanation. I will follow your concepts for sure. One more topic the ESC 10 amperes normally for brushes motor is suggested for Lipo and NiMh battery. Can I use it with Pb battery? I suppose yes. Thanks and happy Xmas to you and your family. Ciao

Hi Fulvio,
One more topic ... or two?😉
1. Shaft and blade - I assume you are referring to the propeller.
"The blade is assembled by thread?"
If it is there should be a locknut screwed tight up to propeller hub.
If there is no thread a short locking screw (grub screw) should be visible on the side of the propeller hub.
If the propeller is fixed firmly to the shaft I would leave it alone and make any adjustments needed at the inboard (motor) end. Grease the shaft and the tube and insert the shaft with a thrust washer between the prop and the tube.
Inboard adjust the motor mount and shaft coupling for as straight alignment as possible.
I also fit a thrust washer and a collet (ring with locking screw) to the shaft just in front of the tube, and adjust it to give about 5/1000 (approx 0.125mm) movement of the shaft in the tube. The collet stops the shaft sliding out of the boat if the coupling becomes loose on the shaft.

2. Motor driven by the BEC.
Sorry to disappoint you again Fulvio but that can't work.
Firstly; the BEC is only designed to provide 1, 2, or 5Amps depending on the type.
Second; there is no way to switch the BEC output to the motor. Unless you build an external relay or FET switch. Even if you did that you would have no control over from the TX. It would simply be On or OFF, with no speed control or reverse if it worked at all.
Not sure what would happen (I'm not going to try it😉), you may even destroy the ESC by connecting the BEC to the motor wiring💥

A better solution is to fit a Low Battery Alarm (a few Euros on Ebay/Amazon etc).
They can be wired to set off an audible and/or visual alarm (e.g. siren or flashing lamp).
This gives you a chance to bring the boat back before the motor stops.

Even better is an ESC that reduces power to the motor when the battery is low.
You can then bring the boat slowly back before the ESC switches off completely.
Hope this helps,
Cheers, Doug 😎
Buon Natale🎁

Doug thanks for your clarifications that as usual are exhaustive. One more topic. I have the motor Speed 280 with gear 2:1 already assembled but also the blade is already assembled on the main shaft. The blade is assembled by thread? the question is because i need to remove the blade and assembly the shaft inside the boat and i do not know how is the assembly system. Also one question more about the ESC. The ESC has the BEC and in this case as you know if the level of battery go down the ESC stop the motor, but in this case as i can back to me the boat if for example the motor by the BEC in the middle of the lake?. Thanks

Hi Fulvio,
Strictly speaking a brushed motor should not affect a quality 2.4GHz receiver, especially if it is mounted as far as possible away from the motor and motor supply wires.
It has been reported that brushed motor interference may also affect some ESCs and even servos! Especially with 'cheapo' ESCs and Servos and if their signal wiring is run close to the 'dirty' motor wiring.

BUT! Some of us (especially submarine drivers) still use 40MHz sets which can be badly affected by brushed motor interference. Reason is that 2.4GHz is not effective underwater🤔
So as a precaution and courtesy to other users nearby suppression capacitors should be fitted.
Click on the pic in the article to enlarge it and you can then read the values.
They are 1 x 0.047µF and 2 x 0.1µF (microFarad).
Principle is the 0.047 between the terminals collects the spark energy from the brushes (like spurts of water into a bucket) and the two 0.1 caps bleed the energy away to ground. Like two leaks in the bucket
In this respect it helps if the motor case is connected to the negative side of the battery supply (ground) and even better if this negative ground is also connected to the propshaft tube which can contact the water.
The capacitors should be of the flat ceramic type, NOT tantalum types as they are polarised (+/-) and will pop when you reverse the motor💥☹️

Most model shops sell suppression kits of the three capacitors.
Krick here in Germany for example -
https://www.krickshop.de/Electronics-Motors/Engines-Electric-Motors/Electric-Motors/Accessories/Electric-Motors-interference-set.htm?shop=krick_e&SessionId=&a=article&ProdNr=42128&p=357
Cheers, Doug 😎

Doug thanks but i need to understand one thing. Do I need to utilize the capacitors also if my radio is 2.4Mhz?
Moreover from the attached document i can not read the value of the capacitor to be utilized. Can you tell me the capacitors specifications? in a old Speed 500 motor by graupner i utilized just one capacitor. I did not know is better to utilize 3. Thanks

Hi Fulvio,
It's not resistor that you need but a capacitor!
In fact 3 capacitors😉
This 'How to' article on this site shows the values of the capacitors and how to wire them to the motor, keeping the leads as short as possible.
Cheers, Doug 😎
https://model-boats.com/wiki/38741

Good Morning to All of You.
I back to ask if one of you knows which electric resistor has to be assembled on a Graupner Speed 280 brush motor because i know that normally have to be install a resistor between + and - of the motor but i do not know how to calculate the value of the resistor. Thanks

Thanks Doug and Roy, now is much more clear for me. I will buy a new ESC in order to have problems. Do you know whay i make you such questions? because i done only air models for more than 20 yesrs and now i would like to start with boats models and i like fishing models. Thanks for now and Happy Xmas fro Italy to All of You. Ciao
P.S. if you have any type of suggest in terms of eletronical aspect of the boat you are welcome because i need to learn almost all aspects.

Hi Roy,
Absolutely no reason for you to apologise.
Fulvio had us all going 'up the garden path' there for a while.
(Small aside: I like the rather quaint German equivalent, 'auf den Holzweg zu leiten', transliterated = to lead on the wood way 😁)

In the meantime I have found the instructions for the Power Switch that Fulvio has - see attached pic. Only in German I'm afraid, but after living in Munich for 30+ years I can read that as well as English😉
From this I deduce that the device is a main power switch for both motor and receiver supply. I.e. the small slide switch shown in the pic and Fulvio's photo activates an internal relay to switch on the main power to the motor, via an ESC!!! and the RX power.
When the battery voltage drops to 5.5V power to the motor is switched off but the receiver supply is maintained. Abschaltung: Makes sense in an aircraft where, given enough height, the plane can still be controlled and be brought in to a safe landing. A bit more difficult with bringing a boat home though!🤔

There does appear to be a switch function that can be set to operate at a user preset position of a control stick (via a push button on the unit case?) but it's not clear what that's supposed to do🤔 Maybe to switch off the motor in an aircraft as I mentioned before?
Or to switch ON a motor in a power assisted glider?
Whatever, I see only limited use in a ground or 'sea' model where 20A capacity for auxiliaries is hardly needed. E.g. LED circuits only need mA (milliAmps - 1/1000A).
Hope this has cleared the fog a little.
If not we're all up the creek without a paddle😭
All the best to All,
Cheers, Doug😎

Sorry all I thought we were talking about an old Graupner esc, which I have 2 off working well. Sorry for the duff Gen.
Roy

Sorry Fulvio but that won't work!
That switch (which is NOT a Profi 20) is a power switch rated for 7,2 - 8.4V at max 20Amps.
It also seems to supply 5.5V 2A for the receiver.

Also; Abschaltung as shown on the switch case means 'Switch Off' or 'Cut Off', i.e. indicates that when the battery voltage drops to 5.5V everything stops🤔.
So may not work reliably (if at all) at 6V.
If you use a 7,2V battery (6 cell NiMH) you could then use it to supply 2 or 3 LEDs in series.
Or several single LEDs in parallel if you drop the voltage to 2 to 3V. Try it on 2.5V which should work for most LED types.
Haven't found the User Manual for it yet so not sure how it is intended to operate; manual or radio controlled🤔 Maybe in a plane it could be used to switch off the motor and glide to save battery power? I can't see how it could regulate the motor speed, other than digitally; all or nothing!
I suspect it is a manually controlled main power ON/OFF switch.
You must have had some other ESC in your plane.
For the ESC (speed regulator) for low amps to the motor, you mention 3Amps, I can recommend from experience an MTroniks Viper Marine 10 (Max 10Amps).
Cheer, Doug 😎

Maybe i can use for the LED light at 6V and i can take power always from the main battery Pb 6V the same that i use for power the motor. I can make a "Y" connection from battery and one connection to a Regulator for the motor and the other connection to the Speed Profi 20 to on/off the LED lights. At least i can re utilize the Regulator. Thanks

Doug and All of You
you are right my Profi 20 is just a switch on/off. I can not use for the motor regulation. I need in this case utilize a different Rgulator. Sorry

Doug sorry in this case is my mistake because what i have and what i used time ago for an Air-model from graupner was the device in the picture attached. In that time i utilized it for control a motor Speed 500 BB Graupner that today i do not use any more and become. In this case come in my mind to utilize the Speed Profi 20 for a small Boat model Graupner Krabbe Ton 12. But at that time i utilize it with stick channel 1 all down motor was stop and that gradually stick up i got the maximum of the motor. Now if i would like to ustilize in a Boat i need put the stick channel 1 in the middle ad this is neutral position of course i need to set fordward and reverse but i do not know if is possible eith this Profi 20.

Hi Fulvio,
The device in your photo is NOT a speed controller!
It is a simple ON/OFF power switch.
Can you post a photo of your Speed Profi 25 please.
It should look like the attached pic.
See also my post below with manual for the 40 Amp version of the Speed Profi series.
Cheers, Doug 😎

RoyCv, really what i need is to know if this Speed Profi 20 (was my mistake before i wrote 25) can be utilize to control a motor in forward and reverse by starting with stick in central neutral position channel 1 of the TX. I will use a 6Volt battery and the motor will absorb 3 A is a Speed 500 Graupner with Brush.

Roycv, thanks for your replay but what i have is the Speed regulator attached on the picture here than is different from your papers. Thanks

Hi Fulvio there is no problem, are the servo connectors OK as the old type were bare pins on the esc. If you cut the servo plug off and then then join it to a servo lead red to red black to black and the lighter colour to yellow or whatever it is.
The centre null point may have moved slightly but it is easily adjustable. I have used old speed controllers and they work OK.
Roy

Hi Fulvio,
"SPEED PROFI 25 REGULATOR
Manufacturer number: 3804
on a boat for make forward and reverse mode."
Short answer is 'Yes'👍
Couldn't find the Profi 25 (25Amp) manual on a short search but did find the 40R (40Amp) version.
Same procedures as the Profi 25 I guess.
User manual attached, in German, English and French.
Good luck, Cheers, Doug 😎