# 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?

[bwells]

ordered the 700 sc, caps, coupler and a diode and I will make the cooling coil myself. I have 4 36" 5/32 .014 alum tubing and can bend it perfectly when filled with salt. Hard part is getting the salt out.. I assume I will be making the motor mount if it doesn't work on the one I already made. I'll be at 170 bucks but I got a feeling I'm going to toast the combo esc/receiver to which has a hard wired servo that has 8 WIRES to it. I'm at the top of the hill now so worst case is new receiver, esc, and servo. I guess I like this boat hull alot or it made me mad when the wife called it my new pool toy!

[domwilson]

It might seem like alot now, but think of the joy you'll get once it's up and running. Not to mention the pride in doing it yourself. Later, if you like it, you may even want to go brushless with this.

[bwells]

domwilson Yes it is, speed x cyclone, paid 23 bucks for it and 25 shipping, one of those ebay tricks I guess. the hull is 32 inches, no clue where they got 37. The vortex steering is stopping one motor and the throttle is either on or off. I took the guts and mounted it all on a block of foam, slapped on a couple airplane props and now have a airboat rescue vehicle. I can now circle a dead boat without snagging the line with the prop. I love recycling!

[domwilson]

I'd like to see a video once you get it all done.

[Blackjack-sven]

I wouldn't power that boat with a brushless system, and I'd be cautious about putting too much power to this hull with a brushed motor as the hull will crack at the seams. I wouldn't go any faster than a 19t double with advanced timing. I ran an NQD boat as well with a 16 turn and the front of the hull cracked on me. Since then I've stuck with more hobby oriented equipment then toy oriented. If you want I can post pics of the hull crack as well.

[bwells]

ordered the 700sc last monday and received it on friday. fast shipping. I'm into it now with brushed and this motor is huge, with the cooling coils and brush cooling, caps and diode, it is a beautiful thing. I have pics but until I can get one of my kids to post them, we are out of luck. Stand by as I pay their insurance and they do what I say, sometimes!

[bwells]

sven I still haven't figured out the turns thing but I guess boats want 15 to 25 but no clue on the OSE 700sc not posted in the ad or on the motor, I figure they know better so I will not second guess them. I want to see this motor go or it will be back to the drawing board which I haven't used!

[Blackjack-sven]

sven I still haven't figured out the turns thing but I guess boats want 15 to 25 but no clue on the OSE 700sc not posted in the ad or on the motor, I figure they know better so I will not second guess them. I want to see this motor go or it will be back to the drawing board which I haven't used!

If I had to take a guess at it, since I can't find much on the net either, I did some checking in regards to comparisons of other brushed motors and it seems that the 700 sc would be running around the 23 turn area.