Crappiebasser Posted November 25, 2012 Posted November 25, 2012 I have a 16' aluminum boat with an old Johnson 3 speed 12V TM. I like to troll for crappie and the low speed is way too fast. Does anyone know of a way to make it variable speed? Quote
BKeith Posted November 26, 2012 Posted November 26, 2012 Yes, if you can find you one of the old MinnKota maximizers that still works, they provide infinite control and makes the battery last a lot longer at the speeds you are talking about. These things were made back in the 80's but you still see one show up on ebay and different places. I have one that's totally useless to me, but I still keep it around, it don't eat and I don't have to pay taxes on it, so I've never seen a reason to get rid of it. There happens to be one on there now, but I think he's on dope for the price he's asking. The things only sold for about 1/2 that new. http://www.ebay.com/...34238699&crdt=0 One other thing, I think they are only rated for about 30 AMPS, but I think you should be in great shape for your motor. Something else you can probably do. Get you a 6 volt battery and try that while you are trolling at your slow speed for crappie. Might want to try before you buy but I think it will work just fine for you. The biggest problem is, about the only 6 volts you see around no are golf cart batteries and that sucker is going to be all kinds of heavy. Especially when you put it in there with the 12 volt battery (which you will still need if you want to go faster. Or, if you can find two small 6 volts, connect them in series and run across both when you want speed and just hook it across on when you want to go slow. Quote
Team_Dougherty Posted November 26, 2012 Posted November 26, 2012 You can also use this. It Is a PWM, pulse width modulation, the same as the old maximizer. hook your battery to the input and the motor to the output. Leave speed setting on the motor on High and use the PWM knob to change speed. you will have infinite speed control from 0 to 100% http://www.ebay.com/...56ecb82&vxp=mtr http://www.ogohho.com/index.php/product-131-HHO+PWM+30A+%28OGO-PWM%29+Kits.html Quote
Crappiebasser Posted November 27, 2012 Author Posted November 27, 2012 Thanks guys, that MK Maximizer is more than I care to spend but the PWM is about right. I haven't tested it yet but I can't imagine my TM pulling over 30A. Quote
ranger 361 Posted November 27, 2012 Posted November 27, 2012 crappie. a friend of mine wanted to slow his motor. what he did was to put his prop on a grinder made the prop smaller. i know other guys are going to say not to do this, but it worked for him. myself i would look for a smaller prop that would fit your motor Quote
Crappiebasser Posted November 27, 2012 Author Posted November 27, 2012 crappie. a friend of mine wanted to slow his motor. what he did was to put his prop on a grinder made the prop smaller. i know other guys are going to say not to do this, but it worked for him. myself i would look for a smaller prop that would fit your motor Thanks, I thought about that but the problem is what do you do when the wind gets up and you don't have the thrust to pull through it. It would be a pain to carry a spare prop and change out when you need more thrust. I think I will order the PWM after I check the draw. Quote
gramps50 Posted November 27, 2012 Posted November 27, 2012 You can also use this. It Is a PWM, pulse width modulation, the same as the old maximizer. hook your battery to the input and the motor to the output. Leave speed setting on the motor on High and use the PWM knob to change speed. you will have infinite speed control from 0 to 100% http://www.ebay.com/...56ecb82&vxp=mtr http://www.ogohho.co...-PWM) Kits.html I was going to say try one of those ceramic resistors that they use to lower the voltage to a coil on the older cars (60's 70's) but I like the PWM idea better. Price didn't look bad either. Quote
BKeith Posted November 27, 2012 Posted November 27, 2012 Those ceramic resistors would be too small of a wattage, you would burn it out before you got going. The PWM should be just the trick. I didn't know anyone still made something like that. That's all that old maximizer was. They just made it big enough it didn't need a fan. I doubt your TM would pull more than 30 amps. If it does, just don't run it on max. The old maximizer would trip itsefl out if you over loaded it, and then reset after it cooled, that PWM will probably do the same. If your motor does pull more than 30 amps, It would only be a problem if you were on max, so all you have to do is back off the speed control a couple of degrees and just run about 90% power. Quote
Team_Dougherty Posted November 27, 2012 Posted November 27, 2012 My 12V 52LB Minn Kota draws 30~32 amps on High, Quote
Crappiebasser Posted November 27, 2012 Author Posted November 27, 2012 I ordered the PWM this morning. My motor only draws 27 amps on high. Thanks for all the help. Quote
Team_Dougherty Posted November 27, 2012 Posted November 27, 2012 I ordered the PWM this morning. My motor only draws 27 amps on high. Thanks for all the help. Did you buy from ebay or direct.? Please keep us up to date on how it works. Quote
Crappiebasser Posted November 27, 2012 Author Posted November 27, 2012 Did you buy from ebay or direct.? Please keep us up to date on how it works. I bought it direct. Even though it was $24+ shipping it still came out cheaper than winning it for $20 on Ebay. I let you know when I get it installed. 1 Quote
Crappiebasser Posted December 13, 2012 Author Posted December 13, 2012 Any Update to this project? Sorry for the delay. I got the PWM wired and mounted and it seems to work well. I have not had a chance to use it in the water yet. I found a small oil leak in the seal below the water pump when i took it out of the water to install the PWM. I have the foot laying in the shop floor now waiting on my seal from iBoats. Quote
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