Control

Electrics

Electric Components

Battery — 6V 4Ahr Lead Acid Gell 0.9kg 68 x 45 x 99 from www.jperkinsdistributors.co.uk
Connectors — 6mm Insulated female spade.
Fuse Holder — Scotchlok Blade. Now replaced with in-line fuse holder.
Fuse — 5 amp in-line Blade. Now replaced with cylindrical fuse.
ESC — Viper Marine 10 from www.mtroniks.net. 10 amp with BEC.
Motor — RE 360 from www.fmacomodrills.com 6 - 12v. Load 8320 rpm 0.46A Torque 32 g/cm.
U Joint — 2.3mm to 4M O/all length 43mm
Prop shaft — 4M x 6 inches with oiler tube.
Prop — 25mm 3 blade RH 4M from Raboesch
Servo — 4.2kg/cm 0.18s / 60deg 18 x 38 x 34
Added 2 x 300mm extension leads to servo and ESC.
Reciever — IF 455kHz Band width 5kHz 28 x 43 x 17 With BEC
Transmitter — 27MHz AM 2 Channel by Helger Stix-CS


 
      V     No load A     Load A
Battery Off     6.44  
Battery On     6.40  
Transmitter On     6.360.08 
Solenoid working     6.310.120.24
Motor low speed     6.290.300.20
Motor full speed     6.290.300.82
Max Load     6.270.501.02

 
 


 
Prop & Motor Prototype

New Old Prop pictures
Motor

Having built and sailed large sailing boats 27 & 35 foot, I wanted to fit a motor/prop as a safety feature, help manoverability and for no wind conditions.
The book "The Jolie Brise" by Robyn Bryer has a good picture showing the size and position of the prop. I used this to position a hole in the hull. I drilled 3mm diameter hole through frames 8 and 7 using a sharpened brass rod.
The dummy motor sits between frames 6 and 7. It is 25mm diameter x 30mm long. (40mm max dia). Frame 6 could be cut to take a longer motor. The shaft is 8" (200mm) long overall. The dummy prop is 25mm dia.
The waterline length is 76cm (30"). Weight of hull and masts is 3Kg (7lb) excluding ballast, battery, sails, rigging and deck fittings. The compartment is 240lg x 100w x 45+ high.


 
Prop & Motor

Motor and Prop

The first propshaft I bought was too long and difficult to locate the motor, coupling and its base. The position of the shaft when viewed from the outside is not exactly the same as the original photo for various reasons, but it works.
The propshaft has an oiler tube for lubrication. The shaft is a loose fit in the tube but it's hoped that the nylon washers will act as a good seal. A piece of copper was bent into a semi circle and fixed with Plastic Padding to the frame to direct water into the sump constructed betwen two frames. A top was fitted to the sump to stop water slopping about when healed. I fitted a plastic tube with strainer in the sump so I can suck out any water with a syringe

Sump for propshaft leakage


 
R/C system

The compartment was built before any R/C components were thought of. It appears that I am not alone in this respect.
The 0.9Kg Lead Acid battery was chosen to give a useful life and add ballast. It had to go near the centre line close to the mast.
The motor was sited to match the original position. It could be at a steeper angle.
The only way I could connect the Servo to the Rudder was by using cord running in plastic pipe. The rudder is at a steep angle and there is no room beneath the decking. A short arm was fixed to the rudder stock. The diameter of the drum was in the end dependant on getting acces to the oiler tube.
The only place for the aerial was up one of the main stays. To get the maximum lenght vertical, the reciever ended up being placed beside the battery, close to the motor.
It worked but was never really put to the test. It had minor glitches to both the servo and motor. But my main concern was the reciever stood a high risk of getting wet.
 
I should have read "The Complete Marine Radio Control Manual" by Hugh Bright, which highlights the good practice of having a Clean and Dirty side to the boat to avoid interferience. The obvious place for the Reciever is in the front hatch where it will be dry and very accessible. The distance of the horizontal lenght of the aerial is the same and was no problem to drill a hole through to run the cables.
This gave me the opportunity to modify the compartment to create a channel around the sides so that any water that came in would go into the bilges. The problem of removing that water can be solved later.
All the components were connected up; to my horror the rudder servo glitched badly. It was alright if you moved the rudder slowly but when moved it back to the centre point quickly, it did it twice; only on one side, how odd.
 
All the components were removed and then reconnected on the bench. Without the extension leads, everything was fine. One extension lead had been cut down as it was too long, this was not the problem as I swapped them around with no success.

Radio control components on the bench

Time to start researching as glitching must be a common problem. Google threw up a few interesting sites pointing to interference being picked up in the extension lead to the servo. The best site shows how to make a filter to insert into the lead, it is a site that I rate highly in the electronic section of my educational website.
Tech it Out explains basic electronic components and how they work, it has many links to other electronic sites.
Electronic Projects for R/C has many interesting projects, I am using "Noise trap for long leads". The first thing was to covert the circuit diagram into a board layout showing the components from the top and then the copper side showing where to break the tracks.

Schematic PCB layout
Filter PCB make up
Installing RC components