Cordless drill upgrade for about $40

save hundreds on a drill by upgrading the power to 1.4 hp instead of buying new.


I needed a cordless drill to do some outdoor drilling, but I did not want to spend $200-$300 for a 18v-24v cordless from a store shelf. I got a cheap 6v cordless drill that I up graded by replacing the motor, the circuit ,the batteries; and I made box to hold the 16 C batteries. After the fabrication and assembly, I tested it and found that it was almost as powerful as my 120v AC corded drill from Skil. The price of this project would be $30 for the parts, $8 for the alkaline batteries, $40-$70 for nickel cadmium rechargeable batteries.The price depends on the quality of the drill I started with which would cost around 30$. If you have to buy an inexpensive cordless drill, and do this conversion, it will still be cheaper than an expensive cordless drill.

Please note that the photos are in mirrored image.

Step 1 Tools and parts list

the tools include :

1. soldering iron
2. circle guide or compass
3.solder (I suggest lead free)
4. electrical tape and masking tape
5. screw drivers
6. alligator clips
7. wire strippers
8. small hammer
9. red and black markers
10. drill
11. pliers
12. ruler
13. scissors
14. hand saw
15. file
16. pliers
17. wire cutters
18. super glue
19. volt meter or you could use a battery,
light bulb and wire instead to check conductance
20. drill bits
21.sand paper

22. hobby knife

parts include:

1. a metal or hard plastic box
2. metal sheet (I suggest aluminum)
3. battery holders
4. 24 volt motor
5. electrical connectors
6. insulated wire
7. small plastic box from an adapter
8. steel wire
9. 16 batteries
10. 4 button
11. coat hanger
12. CD box

The 1.4 hp motor it is normally used for RC cars, I got this one at a local hobby store for $10, if you can't find it locally you can get it at http://www.robotmarketplace.com/products/0-HTIM1.html

I found a good source for rechargeable battery's at http://www.cheapbatteries.com/nicd.htm I suggest
that you only use nickel cadmium batteries because they can be charged easily, just supply power of 1.7V multiplied by the number of 1.2V batteries, connect in Series or 1.7x) other batteries need a more complex charger.

The four buttons on the second slide of this page are not the same. The two blue buttons are on when at rest and off when pressed and the two red ones are off when at rest and on when pressed.
This will be explained later .

Comments

[nicholast]

I assume you realize that 1.4 HP is almost 50 amps at 24 volts (1.4 * 750 / 24)

That's more than enough current to melt those switches your using, my guess is that as with most cheap motors, its not putting out near what its rated at. Probably more around .3 - .5 HP

But still, for a drill that's an awesome bit of power :D

[tkjtkj]

well, ni-cads put out 1.2 vdc ..
and 16 of 'em can't make over 19 vdc or so ..
And 750w/hp divided by 19 is about 39amps, lots less than 50 .. and its only drawing that much current momentarily/rarely , if it ever does!
And that kind of amperage is a theoretical 'max' but is totally dependent upon the electron source being able to keep up with that demand ..
What happens in reality is that the battery voltage will drop substantially , and not be able to put out that kind of power ( Iexp2xR).
Motor specs are very different from power supply specs!

The point is that your instructable does the job, was well-written, and was interesting to review!

[alexander.m]

It's true that 50 amps will melt the inner components. You would only get 50 amps powering this drill if you hooked it up to two car battery. I tested this by powering it with two 6 A 12 V power Supplies, witch are more power full than 16 c batteries and it only withdrew 2.8 A with the motor staled. I wrote 1.4 hp because it's the greatest output of the motor, if you had a sports car, the manuel would say 300 hp but you would be lucky to get 250 hp. even though it doesn't have 1.4 hp the quote I said earlier about it being "almost as powerful as my 120v AC corded drill from Skil" is true.

[bircoe]

Good work on the instructions, how ever I'll stick with my $180aud 18v Ryobi.... It's gone through numerous brick walls without complaint!

[MrNagrom]

i just bought an extension cord. a 100 foot one. interesting hack though.

[alexander.m]

an extension cord and a 120 V drill will be cheaper but it is not vary convenient being tied to a plug,

[baggot]

It is also not very convenient to have to replace a bunch of disposable batteries plus it looks heavy. I converted from cordless to the 100ft extension method a few months ago and love it. That said, Good hack for the sake of hack.

[dark_prince702002]

why bother with this conversion? 18V drills are now less than $100 bucks at most stores. I can appreciate wanting to recycle old technology but realistically you aren't saving any money here.

[alexander.m]

if you all ready have a drill to start with and use the suppliers I suggested or a equal priced local supplier. Then this project will cost $40 for it to run on alkaline batteries, plus $12 to replace them, or $70 for it to run on rechargeable batteries. I ether way it will cost $70 or less.

[dark_prince702002]

why wouldn't you want a drill to run on rechargeable batteries? using regular ones is just terrible for the evoirnment. You can go to HD and get drills for as low as 30 bucks during the holidays

[alexander.m]

The drill I started with was $30, a $30 drill would be 12 V at most.

[GoodSamaritan]

Very innovative and you should be proud of your work. I hadn't thought of using a rc motor in a drill. On the flip side, I bought a cheap 18v rechargable at harbor freight for 14$ on sale. Regular price is $20. It is a tad slow for drilling through steel, but it runs screws just fine. Granted it isn't as stout as my 279$ 18v Bosch Hammer drill (with charger and 2 batteries) but it got the job done for a few weeks until I could get my old drill replaced. Alternatively I just picked up a Ryobi combo (which are surprisingly good) that came with a drill a skillsaw two batteries and a charger + my choice of one other ryobi tool for $100 at home depot. Of course if you buy one, you loose the ability to tell folks you made it yourself. GS

[coolpizzadude]

could you use a project box instead of the metal box because the metal box no afense looks sorta dumb.

[alexander.m]

check the first slide after the intro and the first item on the parts list, and it will say "a metal or hard plastic box" I used a metal box because I couldn't find a plastic box the right size.

[coolpizzadude]

ok I didn't know thats what it meant

[jakdedert]

I love it, too. There is a lot of innovation here. The idea of building a battery box, and the method of attaching it is ingenious. I would never have realized you could upgrade the motor so easily. All that said, I wonder how long this kludge (I use that word affectionately) will hold up...or whether it even matters. The gears, and the plastic housing them, are being subjected to a great deal more torque than for which they were designed. Some reinforcement of the housing is probably possible, but the gears themselves...not. Again, it might not matter. If it was put together for a single use--and it fulfills that need--it was worth it. Sometimes completing the project is it's own reward, if works at all...or if something is learned along the way. In closing; I'd love to hear how well it holds up over time. I'd also like to note that there are more powerful drills (than the original) available for much less than the several hundred dollar figure cited. Check pawn shops, auctions and yard sales for heavy-duty drills which are being discarded because replacement batteries are more expensive than buying a new drill. I have several 9.6v Makita drills which are much better suited to this project than the B&D used. I bought them at pawn shops, with serviceable batteries, several years ago. The batteries are almost all shot at this point. New batteries would cost more than I paid for the drills originally.

[alexander.m]

Thanks for your compliment, as for the strength of the drill, you might have to do some observation of the drill you start with, the one I used had a hard plastic shell along with 3/8 inch thick gears and didn't have any delicate clutch so it's unlikely that it will break. if you are afraid of the drill you start with breaking, you could reinforce the shell by adding steel rods and epoxy, or reduce the voltage. Keep in mind that power tools are often made stronger then they have to be. And as for the price, I will admit the a used drill will be cheeper but you don't know what damages it might have also rechargeable battery wear down over time. Either way you would have to put some thought in to this project, and in my case this project was practical. thanks again for the comment, and if you decide to upgrade the Makita drill you have I would hope to see an image the end result.

[jeff-o]

Heh, that is so ghetto - I love it!!