Author Topic: DeWalt 18v motor  (Read 8745 times)

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DuckOfDeth

• Beginner
• Posts: 2
DeWalt 18v motor
« on: July 12, 2006, 08:28:20 PM »
First time post, as I run rc electric boats. I am installing a DeWalt 18v motor in a 36" boat, and currently have three 7 cell 3700MaH NiMH packs. If I run 2 of the packs, I am only creating 16.8 volts, not enough to really make the motor get the rpms that I want or need to turn a 51mm prop.

My question to you learned people, is if I run 3 packs at 25.2 volts, will I

a) be happy as a clam,

b) wish I'd bought a 820BB motor from Graupner, or

c) watch in horror as the DeWalt motor heats up and melts a hole in my cheap ABS hull?

I ask this of you because the fine boating folk really don't have a need for such a motor as it weighs too much, and at 1100 rpm/v, doesn't really tickle thier fancy.

I was hoping that  one of you might know how far I can overvolt this 1.5 hp monster?

Many thanks in advance for your help.

Duck

• Supreme Robot
• Posts: 11,703
Re: DeWalt 18v motor
« Reply #1 on: July 13, 2006, 04:52:43 AM »
For other people reading this post, this link might be useful:
http://www.societyofrobots.com/actuators_dcmotors.shtml

What wattage is the motor rated for? You can calculate if your motor will overheat by multiplying the voltage you will use by the expected current. If that number is less than the rated wattage, it wont melt.

Is the motor casing heat sinkable?

Also, have you considering using a switching voltage regulator? They are similar to voltage regulators but much more efficient.
That one can only do 10W so you might need another in parallel. Do you know what the expected motor current drawn is?

So if you drop that 25.2V (or maybe higher with fully charged batteries?) to 21V with a switching regulator, and say your motor has about 2A draw, that would be about (25.2V-21V)*2A=8.4W

• Beginner
• Posts: 2