58v Echo Trimmer Powered Small Outboard

mattpate

10 µW
Joined
Feb 6, 2019
Messages
6
Good day everyone. I am in need of a bit of assistance. My company specialises in small gas outboards for kayaks and small watercraft. I currently have began working with brushless setups from Echo and have attached the powerhead with the built in the removable battery pack. This paired with the geared lower unit has given me fantastic results and dependability. Have worked with DC voltage in depth, I am in need of converting the trigger to a pot style dial to control motor speed. The video of the build is below. Any help on this would be so appreciated. The company site is www.kayakbuddys.com and the YouTube link is https://youtu.be/dmuHr4Ramgw
[youtube]dmuHr4Ramgw[/youtube]
 
mattpate@comcast.net said:
I am in need of converting the trigger to a pot style dial to control motor speed.
Please post your questions in only one forum.

To answer your question, the pot you are replacing will be either a two or a three wire device. Three wire devices are easy; get the order right (+ - and wiper) and almost any pot will work. If it's a two wire device you have to match resistance exactly.
 
It would be good to know exactly what the stock trigger unit looks like and whether it is a potentiometer or hall effect type.
Most throttles will have 3 wires. One is ground, that goes to the battery negative, one is +5v for power, and one is the throttle signal that varies with throttle position. You can use a voltmeter to measure the signal range from zero to full throttle. This will tell you whether you have a hall effect or pot.

With either type, you can use a pot but you may need additional fixed resistors to get the output range right. The advantage of a hall effect device is you can totally waterproof it.

A standard ebike throttle might fit on the handle you have and work like a standard outboard throttle.
 
Regardless of the names, the 58V Echo and the 56V EGO yard tools both operate on 14 lithium cells in series (14S).

They both have batteries that can run a small inverter, if the 48V inverter has a 60V input limit. A full charge on a 14S pack is 14S X 4.2V per cell = 58.8V.

I would recommend that you consider trolling motor conversions with both Echo and EGO, while letting each customer decide which they prefer. Just a thought...
 
To be honest I did not think I would get the performance out of that powerhead, but I was flat out wrong. The electric version is a toy and was modified around the fact that you have a very lightweight small outboard that has simple packs that are built in to the chassis and can be replaced in seconds. Trolling motors do not attain this speed and have this ease of use. Any of these powerhead from Echo or Ego will work. I just need to figure out the 7 wire connector and reduce the wiring to work with a POT. These have hall sensors from what I understand. I will post the wiring colours, and voltages in a few minutes.
 
Here is the wiring diagram. I need a brushlessmmotor guru to help figure this out. I need the replace the variable speed switch and hi/low to a pot style configuration.

The wire color voltages are as follows.

Without trigger pressed. With trigger pressed.
Red 57v / 9.6v
Yellow 57v / 4.6v
Green 57v / 0v
Blue 0 / 0
White 0 / 0
Brown 57v / 9.6v
Black 57v / 4.6v

Page 4 in the link below.

https://manuals.ttigroupna.com/syst...32001_234_SSA-58V_307340001_235_r_05.pdf?2018
 
Here's the schematic:

Trimmer Schematic.JPG

You could try disconnecting the trigger and measure ohms between the legs to see if it is just a switch or if it is a variable resistance. If it's a resistance, it should vary continuously as you press the trigger.

If everything is just a switch, then you could make a grip with a cam that activates a pair of switches as it rotates.
Something similar to this:

Cam Switch.gif

If the cam was rounded, you could just press the existing trigger.

Another way to do it would be to build a little circuit that uses a regular pot and drives a couple of small relays to replace the switches. The circuit is fairly simple but would be some work to build.
 
I know for a fact it is a variable trigger, but the voltage is a steady 4.6v and 9.2v on certain wires an 0 for others. The voltage does not fluctuate on any of the trigger wires. I am using the factory trimmer grip and it works fine, but would prefer a dial so I can not have to constantly squeeze the throttle.
 
That's pretty strange. There has to be something changing somewhere to make it variable.

When you measured the voltages, what were you using as a reference point?

It's possible the trigger is sending pulses or digital data to control the speed, which you voltmeter can't sense. You may need an oscilloscope.
 
I extended the trigger line and cut the ends here it connects into the main 7 wire harness and attached these to an 8 circuit bar in order be able to have a remote trigger. I tested the lines live with the battery connected and then with the trigger depressed. I did use a voltmeter.
 
I can't speak to the Echo versions. The EGO mower is either on or off, but the string trimmer is definitely variable-speed based on how deep you pull the trigger.
 
mattpate@comcast.net said:
The wire color voltages are as follows.

Without trigger pressed. With trigger pressed.
Red 57v / 9.6v
Yellow 57v / 4.6v
Green 57v / 0v
Blue 0 / 0
White 0 / 0
Brown 57v / 9.6v
Black 57v / 4.6v

We probably need to also measure where the throttle is at minimum, with the motor running at its slowest speed. One of the voltages should vary as the motor goes from slow to fast.

Use the battery negative as the reference for measurements.
 
This weekend I will try to measure it under load once again. The trigger has variable resistance built in, no doubt. I just don't know if a variable POT style is available without fabricating the same voltage drop back to the hall sensor ring under the brushless motor.
 
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