Wednesday, May 12, 2021

  My articles for the sailing magazine Compass

See also:

Tuesday, January 12, 2021

 XT Wind Vane DIY for Hydrovane Selfsteering


The Garden Hose Connector (left side) is glued to the outer Pipe at the T junction and locks the inner Pipe to the outer.

See it in operation here:

Monday, January 11, 2021

How to build remote control into a Simrad TP10 Tiller Pilot

Adding wireless remote control to a Simrad TP10 tiller pilot


This paper is about how you can buy a 433 MHz readymade transmitter/ receiver kit, put it into the casing of a Simrad TP10 tiller pilot and interface the PCB to gain remote control of the four buttons Port, Starboard, Tack and Standby/Auto. The same modification can be applied to a TP20 or TP30 as well. I will leave it to you to contemplate on the possible advantages of remote operation and instead point out a few possible disadvantages of doing this modification:


If you still have a valid guarantee it will be lost the moment you open the casing of the pilot.

A 5 mm hole has to be drilled in the inner PCB case for four wires. Water could enter here.

The RF receiver/relay board will be placed in the outer case. This has a seal but it’s not completely watertight in the push rod end. (However Simrad have them self placed a little Hall Effect board in this section)

You may damage the PCB with your soldering iron.

It is unknown to which extends the RF is susceptible to high frequency noise from other sources.   


Although I have no long term experience with these concerns I remain optimistic. Make a raincoat for the pilot. Many ocean cruising people do that.

So if you are still with me let’s get started!

First you have to buy exactly this INSMA radio transmitter/ receiver at Amazon (or elsewhere):



You'll may find it here: 


Price around 15 £. Yes it’s cheap, but reliable it seems. My own experience with it is limited, but I have checked more than 100 reviews on the net.


Prepare yourself with the following tools:

A large and a small screwdriver, both Phillips. A pliers. A multi meter (may not be necessary with this guide at your service). Soldering tin (mine is only Ø1 mm) but use as small a diameter you can find. A 12 volt battery or similar with capacity to deliver 5A for the final test with motor running. You can do with much less for setting up the INSMA kit.  A soldering iron with a small pointed tip and you will need to drill a 4-5 mm hole in the circuit board case. Some (hot) Glue.


When the order arrives at your disk open the lid of the white box and remove the 4 screws. You are not going to use any of this. Take a look at the RF receiver-relay unit. 4 relays are just enough as there is no need to "push" the calibrate button. 



In the left corner of the picture, just beside the LED and push button a small jumper that determines the mode of operation of the relays is located. Pull it off. Now the relay will close its contact (conduct) when you push a button on the key ring transmitter and release when you remove your finger. 



Use a red wire and blue wire Ø around 1½ - 2 mm outer diameter and length about 20 centimeter and connect 12V to the power terminals. Use red for +. (This is the only red wire you will need in this project. All signaling to the Simrad switches are done with negative). I butchered an old parallel printer cable and got some excellent wires from it. Don't reverse the polarity or you may damage the board. 

Now you have power on and the LED should shine bright.  


Paring the transmitters with the receiver (receiver stores the transmitters code in memory): 


Take one of the key ring transmitters and press button A shortly. The LED goes dark. Release A. The LED starts flashing 3 times.

Repeat this sequence with the other transmitter.

You can hear that the relay A that I have labeled A with a piece of masking tape in the picture above give a click whenever you press button A. The rest of the relays are located in alphabetical order.



Ok, now you have some serious wiring to do. So switch off the 12V power supply for now. From the negative (blue wire) power terminal you run a wire to relay A contact B. Yes you have to put two wires in the same terminal. That's why small diameter wires are handy. And the currents involved here are extremely small, so it's not a problem. I will put the next connection of wires in a small table:


 Relay  contact B       to           Relay  contact B

 Relay  contact B       to           Relay  contact B

 Relay  contact B       to           Relay  contact B

(All 4 contact terminals C should be left unused)


Next you just need to connect the last 4 wires. Make them about 50 centimeter each and of different colors and put them in the contact A terminal of each relay. They are going to enter the holy grail of the tiller pilot and give us what we want. Total control. I have chosen to make button A on the transmitter PORT, button B is STARBOARD, button C is Tack and button D is STBY/AUTO



It is time to open the tiller pilot! Put it on a towel on your table facing down and with the pushrod to the left. Start unscrewing in the right hand side at number 10 as indicated in the drawing below:





Gently turn the pilot back so the push button side is upwards taking care not to lose any screws.

Open the lid slowly. It’s interconnected to the other half where the motor is so you can't remove it entirely.