I loaded up the parameters I had set last year. It was set at 3 degrees. I changed it to 15 degrees. I forgot that last year I had reduced the power to 75%, So I changed that to 100%. I think I am going to reduce it after my first water test because it seems too powerful. Unfortunately since I changed 2 things I don’t know if the degree change did anything.
I have worked on several outboards and stern-drives. The water pumps have a soft rubber impeller that rubs against a stainless steel housing. It becomes a melted piece of rubber very quickly if you run them out of the water. In my application my water pump starts running when I plug in the batteries. I might be several minutes before I get in the water. I was wondering if I was risking damaging the pump. I disassembled the one I used last summer.
I found a very small amount of seaweed, a very small stick, and fleck of paint.
The motor has a off center bent shaft, which wobbles a disc (feels like silicone) that has 5 pistons built into it. Each piston displaces a small amount of water. Each piston has a small check valve.
Lots of people here use this pump. It appears that the pump could be run quite awhile dry without damage.
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Ran it hard today in the test tank, I have 1 cell in one of my LiPos that always drains early. Hit over 110 AMPS at full throttle .Things are good.
I got the same pump as you and hooked it up with a small reed switch in between. Once the board is in the water (i’m still building) i will place the magnet to start the pumping. This system is working on my table, next step is to hook it up with all the electrics in the board
HI,
Could post details of the pump that everyone is using
cheers
Why don’t you switch on and off your water pump remotely so you can activate it only when you are in the water? I used to do it with this %product-title% – Conrad Electronic Suisse and the second channel of my alien power remote, and now that I have the Maytech remote which has only one channel, I control my pump using this cheap system https://www.aliexpress.com/item/32858787597.html?productId=32858787597&productSubject=DC-12V-24V-2-CH-2CH-10A-RF-Wireless-Remote-Control-Switch-System-Waterproof-Transmitter-Receiver&spm=a2g0s.9042311.0.0.1aaf4c4dt6UXUn It works just perfect.
**Both of those products are nice, I will consider for future. I especially like the 2 channel remote.
I have had good luck with the reed switch/magnet for my safety lanyard.
For now, I am ready for some water testing. I am not changing anything more until I get some water testing done.
I hope to eventually get a smaller prop with shroud around it. Then I may eliminate the safety lanyard, and turn the reed switch into a ON/OFF switch for the board electronics including the pump.
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Is there a way you can detect throttle position (or at least throttle >0?) My setup turns on the water pump when it detects nonzero throttle.
Also, I got a simple in-tank fuel strainer to keep the larger goop out of the pump and lines.
Me too, think i will order one to try
i’m at 20 degrees, with the monitor on, i’m not sure it makes a big difference though.
regarding starting your pump, you can also used a temperature switch and not worry about start/stop…
i’m using a W1209.
it’s cheap, does its job and gives you a temperature reading.
I may try that filter idea. The pick up hose just dangles inside the motor pod. There might be room. My new pump does slightly out perform the one I took apart. It might be the stuff that was in it was causing the difference.
Mat,
I recall you took some data with your eagle tree data logger. Did you have trouble with the RPM’s jumping around, like double, like it did not know how to interpret the rpm signal.
yes, i posted screenshot of the recordings on my build thread.
it’s oscillating a bit like around +/- 7 or 8%, but not that much…
double might be a wire not connected properly may be…
i think they have several kind of sensors, mine is the Brushless Motor RPM Sensor V2
i connected it on 2 of the motor phase wires…
I have the same RPM sensor, the output is very erratic when running in my test tank. Sometimes it right on, sometimes off the chart.
Today I cut a hole in the ice and did a in water test. Well it felt like ice. I had a shorty wet suit on. I just rode around on my belly. I did not want to fall in the water.
I running with the 12S Lipos because I have not finished the new 18650 batteries yet. It ran really good. Observations.
This board is harder to get on than my old board. It is slippery to grab. Its wider so it is harder to reach over to grab the edge. It does not extend 2 feet aft of the mast like my old board, so you worry about your feet dangling in the prop. I need to install some hand holds to make climbing on easier.
My safety relay sometimes sticks ON, It did this on my last build occasionally. Now it seems to be permanently ON. I have a new spare. I think it is caused by my lack of a Anti-spark circuit. The relay gets sparked every time. So I am wondering if there is a simple circuit that would apply a ground to the ESC anti-spark lead about 1 second before the relay closes and supplies (In my case ground to the ESC).
may be check how your wires are ran, the are very thin and might be sensible to interference from the big power wires next to them. If i remember right, the wire from the motor phase to the module need to be as short as possible, if you need extension, it’s better to extend the signal wire from the recorder to the module, and may be put a ferrite thingy in there too.
and regarding the hand hold, that’s kind of a must … and it makes carrying the board easier, especially when you have to walk for a while if you forgot to come back to your starting point before you battery died 
I originally solder the rpm sensor on to the ESC where the phase wires exit the ESC. I have tried just two wires, one wire, and swamping to the other phase wire. Relocating the wires. Fortunately it seems to work better when I do a real water test. I have bigger fish to fry right now.
I bought a pair of these handles.If I like them I may add a second pair on the board.
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