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View Full Version : Putting a cord on a cordless drill - How??



Mosside
01-29-2010, 09:08 AM
The title doesn't quite explain what I want to do. I have a project for which the low speed, high torque of a cordless drill would be a ideal inexpensive power source. But, I need it to be turned on and off automatically for set times with AC controls. Please forgive me for being a bit dull on the electrical side of things but can you clip wires from the battery charger to the battery plugs on the drill without it being a hazard?

Other than that is there another source for a inexpensive DC motor would be more satisfactory. The power supplied by a cheap drill would be enough.

Thanks,

Doug

ptjw7uk
01-29-2010, 09:26 AM
Only real problem with the battery charger is that at switch on the voltage will be far in excess of 12volts, you will need something in between like a battery.
Run the drill off a car battery.

Peter

Roy Andrews
01-29-2010, 09:40 AM
most cordless tool battery chargers are made to charge batteries and as such have a lot of circuitry that senses the temp and charge of the pack. this will make them unusable for your application. if it is a 12 volt i would use a cheap car battery charger or any other dc power supply. you may also be able to strip the controller from the drill battery charger and just use the transformer and rectifier from it.

mcskipper
01-29-2010, 09:43 AM
If you are talking about using the charger that came with the drill it will not supply the current needed to RUN the drill.

If it were me I would figure out a way the remote the battery and put a switch in one of the two wires running between the battery and the drill.

Doozer
01-29-2010, 09:51 AM
I thought about using a 12v drill and attaching a 8 foot cord on it, and attaching a motorcycle battery or non-spillable gel cell. That way, it is still portable for locations without power, and the bigger battery should provide some impressive run time.
I also thought of doing the same thing to my Canon digital camera that eats AA batteries. Make a plug-in cord and connect it to a pack of D cells or a 6v lantern battery.

--Doozer

Mosside
01-29-2010, 09:57 AM
If you are talking about using the charger that came with the drill it will not supply the current needed to RUN the drill.

If it were me I would figure out a way the remote the battery and put a switch in one of the two wires running between the battery and the drill.


Thanks guys for the quick replies, maybe I should be more clear on how this is going to be used. This will be part of an automated system that will be in operation 365 days a year for maybe 5 minutes a day when I would not be present to observe it's operation. Any use of a battery would not be ideal because they would run and switching batteries would not be acceptable. At some times of the year it will be cold and damp so it is must be housed in a protective box so dust and moisture are excluded.

Am I correct then in understanding that I could by a 12 volt drill and run it off a 12 volt trickle charger?

Doug

Dr. Rob
01-29-2010, 10:06 AM
I sometimes run my 12v drill off a 12v bcar battery charger. Works fine.

Do that, and add one of those appliance timer gizmos at the wall outlet. You know, the kind you use to turn lights off / on when you're away from home.

Ten-twenty bux and you're done.

.

ptjw7uk
01-29-2010, 10:06 AM
Your problem is the amount of current the drill will take, a trickle charger by its nature will only supply a limited current and voltage so as not to overcharge the battery.
A switched mode 12 volt supply is the best you could hope for, you really need to get some idea on the current required.
Bench power supplies capable of supplying several amps are costly.
How about a mains powered slow drill/mixer.

Peter

jcc3inc
01-29-2010, 10:09 AM
Sir,

A trickle charger supplies only a small amount current whereas the cordless drill needs a lot of current from the battery when it is driving a high load. Therefore a battery would be needed to supply the high, short term current.
Rather than go through using a cordless drill plus a battery plus a charger all fastened together, maybe you should consider a 115VAC drive such as a 1/2 inch 115V drill. It will supply the torque and it sounds like you DO have the 115V available.

Have I missed anything here?

Regards,
Jack C.

vpt
01-29-2010, 10:12 AM
If there is an outlet close enough to plug a charger in why not use a normal 110V drill with a timer?

topct
01-29-2010, 10:18 AM
A battery charger will work. The only drill I am familiar with is Makita. You have to watch the polarity. It can never be reversed unless you bypass the trigger and wire directly to the motor or to the forward reverse switch. Makitas have a very sophisticated speed control that cannot be hooked up backwards. I am picking used ones without batteries for under $10.

A trickle charger won't work, I would use a cheap battery charger, 6 amps or more.

Mosside
01-29-2010, 10:18 AM
[QUOTE=jcc3inc]Sir,

Rather than go through using a cordless drill plus a battery plus a charger all fastened together, maybe you should consider a 115VAC drive such as a 1/2 inch 115V drill. It will supply the torque and it sounds like you DO have the 115V available.

Have I missed anything here?


You are not!

I think you are right what I really should be doing is buying a 115V low rpm drill/mixer as ptjw7uk suggests.

This is part of a fairly sophisticated computer controlled automated system so timers are not the issue. Just finding the most trouble free way to drive a small metering device.

Doug

RTPBurnsville
01-29-2010, 10:41 AM
What about some of the 120VAC gear reduction motors from places like www.surpluscenter.com I don't know what your RPM requirements are but motors such as these are plenty cheap.

arcs_n_sparks
01-29-2010, 10:57 AM
This will be part of an automated system that will be in operation 365 days a year for maybe 5 minutes a day when I would not be present to observe it's operation. Any use of a battery would not be ideal because they would run and switching batteries would not be acceptable. At some times of the year it will be cold and damp so it is must be housed in a protective box so dust and moisture are excluded.

Then why not go with a conventional 120 volt drill?

vpt
01-29-2010, 11:05 AM
Then why not go with a conventional 120 volt drill?



That is a stellar idea! I am surprised no one mentioned that!

Mosside
01-29-2010, 11:21 AM
That is a stellar idea! I am surprised no one mentioned that!


Most all 120 volt drills run too fast for what I need. 100 rpm would be about max. A regular drill even if it was a variable speed slowed down would not have the torque I would need. I had not thought of the surplus geared reduction motor route. Thanks!

Doug

websterz
01-29-2010, 11:51 AM
Most all 120 volt drills run too fast for what I need. 100 rpm would be about max. A regular drill even if it was a variable speed slowed down would not have the torque I would need. I had not thought of the surplus geared reduction motor route. Thanks!

Doug

The power feed unit I built for my x2 mill utilizes the drill motor and gearbox from a 14.4 volt cordless drill I got on Ebay for a couple of bucks. It is powered by an ATX PC power supply on the 12 volt taps. I have put many dozens of hours on it with no adverse effects. The controller I use is a simple PWM setup I got online for $30. A rig like this could be run from a simple AC timer between the power supply and the wall. I don't see the problem you are having.

Black_Moons
01-29-2010, 07:26 PM
You'll need to measure how much current your motor draws under the load you intend to apply to it.
It could be anywhere from an amp or two, all the way to 30amps (Max that nicad C cells are typicaly good for)

Then get a power supply rated for at least that current, idealy more.

www.allelectronics.com is a good source of *cheap* surplus power supplys and is allways my first stop for some random power supply as it will likey be 1/2 to 1/10th the price of anywhere else.. if they have it in thier limited selection. If not, such a power supply could cost $20~150 depending on current required.

If you attempt to use a ATX psu or other multi rail output psu, be aware that a good precentage of them need some load on the other rails to function (typicaly the 5v (and sometimes 3.3v)) properly with a large 12v load, generaly only an amp or two load is required.

websterz
01-29-2010, 07:47 PM
You'll need to measure how much current your motor draws under the load you intend to apply to it.
It could be anywhere from an amp or two, all the way to 30amps (Max that nicad C cells are typicaly good for)

Then get a power supply rated for at least that current, idealy more.

www.allelectronics.com is a good source of *cheap* surplus power supplys and is allways my first stop for some random power supply as it will likey be 1/2 to 1/10th the price of anywhere else.. if they have it in thier limited selection. If not, such a power supply could cost $20~150 depending on current required.

If you attempt to use a ATX psu or other multi rail output psu, be aware that a good precentage of them need some load on the other rails to function (typicaly the 5v (and sometimes 3.3v)) properly with a large 12v load, generaly only an amp or two load is required.

I installed a 12v. 1 amp LED as a power indicator light. Works every time.

Your Old Dog
01-29-2010, 08:44 PM
I can't answer your question BUT, if you ever want to remove a cord from a Skill Saw there is a thread floating around in the archives that will tell you how to do it :D

(Evan, I'm sorry but the notion started bouncing around in the caverns of my head and I couldn't stop it from coming out!! You know I, as many here do, think the world of you Evan!)