How to reduce trolling motor power at low setting?

[tony_cliffy]

I recently installed a Motorguide Bulldog 40 lb. thrust trolling motor in a small 'pond prowler' style plastic boat (8' long). The boat weights about 135, and with me+gear about 500.

The trolling motor has 5 speeds. The lowest speed moves the boat faster than I like for trolling crappie jigs. Does anybody understand how the speed control works on these trolling motors and can guide me to alter it to slow down the low setting? Obviously something controls the current flow for settings 1 through 5, I'd like to 'reprogram' it for whatever it uses on setting one. I don't care if it violates the warranty, for now I'm just interested in understadning what it would take.

Thanks!

 

[SKEETR]

Re: How to reduce trolling motor power at low setting?

Maybe you could trim the prop some.

 

[tony_cliffy]

Re: How to reduce trolling motor power at low setting?

I only want to adjust the low setting, not impact all the other settings. I still want my top end power.

 

[a70eliminator]

Re: How to reduce trolling motor power at low setting?

Other than wiring up some elaborate rheostat, you could try tilting the motor as far out as you can without cavitating, or get a sea anchor to slow ya down. I wonder what a 6 volt supply would do to it.

 

[SKEETR]

Re: How to reduce trolling motor power at low setting?

Or rig a trolling flap of some kind. Removeable larger nosecone. Troll backwards???

 

[fishrdan]

Re: How to reduce trolling motor power at low setting?

The motor has speed coils, windings in the motor for the different speeds, so your stuck with the lowest speed. But you can do things to slow the boat, drop a 5 gallon bucket over the side to make drag, keep turning left, right, left, right, tilt motor up so it's pushing water UP. Bring a fat friend

I think I saw a digital speed control for standard trolling motors somewhere (cableas?), but it was kind of spendy. Had the same type of pulse (PWM) speed control used on the infinite speed trolling motors, but it was a separate unit.

 

[tony_cliffy]

Re: How to reduce trolling motor power at low setting?

fishrdan,

My unit has a foot pedal with a 5 setting rotating knob. I guess I thought the rotating knob controlled how much current was supplied to the trolling motor using some kind of rheostat. When I look at the underside of the foot pedal I see the knob going into a small sealed device with the name "Ark-Les" on it. Unfortunately I see no model number so I can't cross-check it on the manufacturers website. I doubt I could hack this device and rewire or solder in different resistors because it seems so small and compact.

If this think is a rheostat, that simply changes the resistance setting to the motor head. Do you think there is some additional device within the motor that uses the resistance value to decide how to control the current flow through the motor windings? Or is this rheostat simply providing a variable current to the motor by changing the resistance value at the pedal?

 

[Silvertip]

Re: How to reduce trolling motor power at low setting?

You can't have it both ways (modify slowest speed but retain high speed), without some external electrics like the pulse unit previously mentioned. If you are pond hopping, the highest speed should be a non-factor. You are out fishing and that is the main factor. My advice would be to look for a smaller diameter prop (or the same diameter) but with less pitch. This will slow the boat down yet it should not seriously impact the high speed to the point where it becomes an issue. It may even help battery life because the motor is unloaded a bit. You might even spend some time studying the prop and coming up a device (call it a spoiler) that you can clip on the prop blades to decrease its efficiency (adding slip).

 

[kandil]

Re: How to reduce trolling motor power at low setting?

Maybe you can build some thing like the happy troller that you slide down for drag and lift up for speed Or you can lower the motor deeper and you will slow down just don't hit any thing on the bottom of the lake

 

[Barnacle_Bill]

Re: How to reduce trolling motor power at low setting?

If you are handy with electronics you can build one of these. This was designed by a friend of mine who is a retired electronics instructor.

 

[TerryMSU]

Re: How to reduce trolling motor power at low setting?

Bhile:

That should work out OK, but has he (or anyone else) tried it on a trolling motor? If so, and someone were to build it, they should make sure to get a BIG heat sink under the transistors and possibly under the power diode. Again, the concept looks great, and in fact, I will likely use it as a discussion tool in a couple of electronics classes I am teaching at present. One BIG caution, the ground on the left side and the ground on the right side are not the same. DO NOT TIE THEM TOGETHER.

Thanks,
TerryMSU