# turns on a brushed motor

[bwells]

would it be a safe assumption that the lower number of turns on a brushed motor equates to higher RPM but less torque and higher turns, more torque, less RPM? I'm thinking that boats need something between 15 and 25 turns, depending on their size. A light 32" possibly a 20 for a 550 can? Am I anywhere near close on these assumptions? I think I have a # of turn issue as I'm using a motor from an RC car that was gear driven, maybe 2:1, but in my boat, I'm running it direct. It goes at a fast walk. If I could get it to go the same speed as the car did, I would be happy. This is my first build and it turned out rather disappointing.

[domwilson]

Hello and welcome. A 550 motor on a 32' hull is too small. You would be better off with a brushless motor like a feigao XL or a Neu. Of course you will need an ESC to go with them. Something around 150 amps should be fine.

[bwells]

The boat is a newquida (NQD) from ebay and was junk from the get go. I gutted it and used the motor, combo esc/receiver and servor from a car. I used a bj26 outdrive, stuffing tube, flex shaft and prop shaft. I'm up to a hundred bucks and a lot of time on something that may not be savable. I can see another 50 bucks on a 700 brushed if it will work but to go to the complete brushless setup would be a gamble. I really like the hull though.

[bwells]

OH, by the way, it's the yellow one in my avatar

[domwilson]

A 700 with a larger prop might get you some pretty decent speeds. Go for it.

[bwells]

what about the number of turns? this hull is light as it is paper thin plastic but I reinforced the rear 30% with wood as I figured it would ride there

[bwells]

any explanation on the number of turns of a brushed motor would be appreciated, thank you

[Ub Hauled]

any explanation on the number of turns of a brushed motor would be appreciated, thank you

Get the SC700 from Steven (http://www.offshoreelectrics.com/)... that will take care of
your problems, it is a great motor.

AS far as the motor turns, you were on the money, less turn more RPM/less torque and more turns less RPM/more torque.

[Fluid]

Brushed 05 motors are too small for a 32" hull regardless of weight. They will need a small prop to avoid overheating, and then not push the boat fast enough to plane well. In a gear drive they can be made to work but direct drive. How much voltage are you using? Seven volts is not enough for that size hull if you want decent performance. With equal power, no boat will be nearly as fast as a car can go.

The 700 motor will work very well giving speeds in the low 30s....but what no one else mentioned is you will need 14 volts to do it. On 7 volts the 700 wil not work well at all.



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[bwells]

I used 8.4 volts on it but only ran it once in my pool and new immediately it had issues. I'll try 2 7.2 in series and see what happens but not sure if the combo esc/receiver can handle it as it is 15 years old. Thanks

[Ub Hauled]

14.8 volts on a 05 brushed motor is too much, what Fluid was saying is that you would need that voltage with a 700 motor.... NOT the 540 brushed you are using... that hull needs some muscle to get her going.

[bwells]

got it. Will order the 700, some caps and a new coupler, should be good to go. What does ose mean by brush cooling? I plan on doing a water cooling tube around the motor but not cover the brush holes.

[Ub Hauled]

got it. Will order the 700, some caps and a new coupler, should be good to go. What does ose mean by brush cooling? I plan on doing a water cooling tube around the motor but not cover the brush holes.

Look it up here...

http://www.offshoreelectrics.com/inf...cool-motor.php

look at the "tips and info" link on this site... good stuff there.

[greenblast]

b wells you should listen to these guys. buy get yourself a 700 and a nice esc or a xl and brushless esc.trust me you will save in the long run . i have had plenty of car motors that were fast for a week. 550 600 you name it. the only solid one i have is one i got on the swap shop about 2 years ago.its brushless. it still rips. i have had many esc .almost all my failureswere my fault .they were chepos or second hand. i now own my first (quality)esc.so far so good .2 season of this comfort zone i may send more money lol.

[domwilson]

got it. Will order the 700, some caps and a new coupler, should be good to go. What does ose mean by brush cooling? I plan on doing a water cooling tube around the motor but not cover the brush holes.

Don't forget to get a motor mount of some sort, water pickup, and some silicon tubing. Put some ply in the transom area. I think you'll have fun with this lil' scooter...
Also, Is this the 37" boat on ebay?