Overvolt drillmotors

19th June 2004, 15:05

I was wondering becaus I am building a 10 bar flipper and the valve that I have works on 24V. Now my drillmotors are 14.4V. So I was wondering if you could overvolt them to 24V. I was also thinking about seting the screw on the electronise speedo down to 75% of the maximum power but I am still not shore If my motors wil burn out. Does anyone have experience with overvotling drillmotors??

Thanks

**ewan** · 19th June 2004, 15:18

I have done many tests with drill motors (and still have around 10 lying about or burnt out

). If you want to overvolt to 24v, try to restrict the power going into the drill motor via the speed controller if possible, but no matter what you do with current limiting etc, you must use small wheels if you are to go to 24v. Anything over 70-80mm is too much and will strian the motors too much.

I wouldnt advise running on 24v at all infact but you can do some things to reduce the chance that they will blow.
- Make sure all air vents to the motor are open and that air can travel freely around it.
- If possible find a heat-sink from RC cars/planes to fit the motors (there are some sizes that would do)
- Use the correct amount of limiting from the controller.
- Use smaller wheels, around 60-80mm should be reasonable

How much current does the valve take? As you could use a regulator to give the drill motors about 18v, which would be fine for running, and give the valve 24v (only using one 18v battery).

Cheers, Ewan
http://www.micro-maul.co.ukwww.micro-maul.co.uk

**woody** · 19th June 2004, 18:37

Get a 12volt coil for your valve.

**philip_taylor** · 19th June 2004, 20:07

Resistors turn electrical energy into heat energy. This would be wastefull and the resistors would quickly fail. Your first idea is a winner. I was also thinking about seting the screw on the electronise speedo down to 75% of the maximum power

I like Woodys solution to your valve coil voltage problem.

**ewan** · 19th June 2004, 20:59

If it is possible to run off a PP3 battery for a valve, then it should be quite easy to make a regulator to feed the solenoid. All of these do reduce the chance of motors blowing, and will mean you dont habve to go to the hassle of installing cooling or heat sinks.

You may have less power, but the performance of a 14.4v drill on 14.4v isnt too bad, and should be fine for a LP flipper bot.

As Philip said, resistors are designed to turn the enerygy into heat, any resistor able to handle the current a drill motor is likely to draw would be large, and probably affixed to a heat sink, so forget that idea.

If you use 14.4v then you can use two Ni-Mh 7.2v race packs in series, which should give enough power for two drill motors and will be around half the weight of ni-cad packs.

Cheers, Ewan

19th June 2004, 21:19

Ewan I am really not understanding where you are going. A regulator reduces the voltage. That means given an imput of say 12v it would produce say 5v. I dont understand how you could regulate down the voltage from 18v to 24v?

Care to explain?
Regads
Ian