Two Surprising Ways to Start a Generator with a Drill
Have you ever heard that you can start a generator with a drill?
- To spin the nut under the recoil cord assembly to start your generator’s engine
- To “flash the field” and allow your generator to start producing electricity again by engaging the AVR (automatic voltage regulator)
If you’re caught in a power outage and your generator is not producing electricity or not starting, it might amaze you what a corded and cordless drill could do for you. Though these small tools can yield some magic to save the day, they aren’t necessarily the safest to use by any means.
When a generator is lacking residual magnetism in the alternator, a corded drill can certainly be used with relative safety to “flash the field” and give the alternator the push it needs to start generating electricity.
If you’re caught with a generator that will not start due to a pull cord being broken, then a cordless drill (with a fresh battery) can be used to start the engine but it doesn’t come without great risk.
I’m going to go over the two ways you can get your generator working like new with a corded and cordless drill and the risks associated with both methods.
No Power? Start a Generator’s Electricity Production With a Corded Drill
If you start up your generator and the engine is running just fine but there is no power output, you might be able to save the day with a corded drill (depending on the problem).
Actually, if you were to test the receptacles with a multimeter, you would likely see that there is a small amount of electricity being produced, but not enough to run any of your appliances with.
There are many reasons why your generator might not be producing electricity, and I have an article here with 6 common ones and how to go about fixing them. If your problem is that your generator has simply lost its residual magnetism in the alternator, then a corded drill can bail you out of a depressing power outage.
To understand how a corded drill can fix our problem, let’s briefly cover what’s happening inside the alternator that is causing the problem.
Is the Smallest Battery Greenworks 48-Volt 21″ Self-Propelled Mower Right for You?
Inside the alternator is the stationary stator, and inside of that is the rotating rotor. In order for these to become an effective electromagnet as the rotor spins inside of the stator, there must exist enough residual magnetism to produce enough volts when spinning to trigger the AVR (automatic voltage regulator) which will then supply the alternator with some of its own generated electricity in order to strengthen the magnetic field and produce the 120 or 240 volts that you’re requiring.
Normally, residual magnetism is stored in the rotor. When the engine starts and the rotor starts spinning, the residual magnetism is supposed to be enough to produce enough voltage to trigger the AVR (automatic voltage regulator) which then would bring the generator up to the full 120v or 240v that you are looking to use.
AVR on the bottom left (crescent-shaped), bearing in the middle, and the brushes are just above that and slightly offset to the left.
The AVR is responsible for sensing the output being produced by the generator and bringing it to a predetermined amount (120v, 240v, etc.).
Essentially, it does this by seizing a small portion of the electricity being produced by the alternator and feeding that same electricity back into the exciter coils to increase the magnetic field and produce more power. Conversely, if it senses that the generator is producing too much is reduces the amount of energy being fed to the exciter coils which reduces the magnetic field and reduces the electricity being produced.
Unfortunately, the residual magnetism can be lost due to a generator being banged around when not in use, being allowed to run out of gas when a load is being placed on it, being turned off with the engine start switch when a load is being placed on it, or simply by sitting in storage too long without being used.
A corded drill, when plugged into a receptacle on the generator can “flash the field” and trigger the AVR to start its job. With the drill in the forward position (it would sping clockwise) and the trigger pressed down, you can back feed electricity down the cord and to the AVR in the generator by quickly turning the drill chuck backward (counterclockwise).
To do this, follow the steps below:
- Have your generator running and the AC power turned on
- Plug your corded drill into one of the 120v outlets
- Remove anything from the drill chuck so that it is empty
- Have the drill set to the forward drilling position (so that the chuck would turn clockwise if you were to drill something)
- Press and hold the trigger down with one hand
- With the other hand, quickly grab and flick the chuck backward in the counter-clockwise position so that your hand is free and clear of the drill chuck at the end of the process
- After 1-3 turns backward the drill should start working in your hand as the AVR turns on and normal voltage levels are restored
Some people recommend wearing gloves in this process, but I come from a work background where I won’t put a gloved hand in front of a moving power tool — no matter how safe I’ve tried to render it.
Make sure the chuck is empty before attempting to “flash the field”.
Gloves, especially loose-fitting ones can become caught and drag your hand into places you don’t want it to go. A drill with an empty chuck will probably be alright, but I will stick with my safety philosophy. You are free to choose what you’d like to do. If the drill chuck had grooves that were too sharp on my hand, I would opt for a tight pair of leather gloves.
After you’ve successfully “flashed the field”, it is good practice to let your generator run with a load for a while (30-60 minutes at least) to build up the residual magnetism back in the alternator so that you don’t have to deal with this again.
Won’t Start? Start a Generator’s Engine with a Cordless Drill
Let me start off by saying that I don’t support this method. I don’t like it. I don’t want anything to do with it if I can help it.
The dangers associated with it far outweigh the benefits, in my humble opinion. If it were life and death, sure, but I’m not going to risk my safety to simply have some light bulbs running during a 6-hour power outage.
What is it exactly that I’m so opposed to?
The use of a drill to get your flywheel and rotor to start spinning by attaching a socket to the end of your drill and placing it over the nut inside the starter cup that keeps the whole flywheel assembly on the generator.
Don’t get me wrong, it certainly works and there are plenty of videos on YouTube to prove it.
The steps to start a generator’s engine with a drill are as follows:
(Not recommended, proceed at your own risk)
- Get everything ready on the generator as if you were starting it with the pull cord (choke on, open the fuel shutoff valve, etc.)
- Remove the recoil starter assembly (usually held on with 3-4 bolts) and it pulls straight out
- Find an appropriate sized socket to fit on the nut inside the starter cup that is securing everything on the shaft of the rotor
- Secure that socket to an attachment to fit in the drill chuck
- Turn your cordless drill to the forward (clockwise) position for the drill chuck
- Place the socket which is attached to the drill over the nut and press and hold the trigger until the engine starts
- Pull your drill away immediately when the engine starts or risk severe injury or property damage
The last step is the one that worries me. Your drill will spin at about 1,000-1,500 rpm’s (rotations per minute), whereas the generator will spin at 3,500-3,600 RPMs when it starts. I don’t care how strong you are – when that generator starts and you leave that socket on the nut of the rotor shaft for a fraction of a second too long it will rip that drill out of your hands faster than you can react.
You risk breaking your thumb, hand, and wrist just by trying to hang onto it. There’s also the risk of the generator throwing your drill across the room, or shooting a socket that comes detached. There’s also the danger of not only the drill spinning out of control in your hands but getting your hands tangled in the rotor cup or fan blades that are spinning at 3,600 RPMs as you fumble with your drill.
So no, I don’t recommend it but you can certainly start your generator’s engine with a drill.
Note that if this is a risk you are willing to take, do not use a cordless impact driver as a substitute for a cordless drill. The risk is higher that you’ll actually torque and tighten the nut which can put pressure on the flywheel, crack it, or throw off the harmonics. If you crack or damage your flywheel, your generator will not be usable.
Cordless drill on the left vs. Impact driver on the right.
Greenworks 48V 17″ Brushless Cordless Lawn Mower Review, Test | Top Brushless Cordless Lawn Mower
A safer method of starting a generator if you don’t have a functioning recoil cord assembly is to find a small rope (it could be the majority of what might be left from your recoil cord assembly) about 4′-6′ in length and make an overhand not on one end.
Then place that end inside the groove that’s cut out on the lip of the starter cup. Wrap the cord around the starter cup in a clockwise manner and leave yourself something to grab onto. Then, get your generator ready to run (choke engaged, fuel valve open, etc.). Pull the cord all the way through in one solid motion. The knot will fly out at you, so be aware of that, and you may have to do this a few times but you’ve essentially replaced your starter cord.
Insert the knot in the notch that’s cut out in the starter cup, wrap the cord around clockwise, and pull to start your engine if the recoil cord assembly isn’t working.
Though arguably safer than the drill method, they are both unsafe after being started due to the fan disk and rotor cup being exposed and spinning at 3,600 RPMs. If a pet, child, or anyone for that matter, touches it, there will be severe injuries or even possibly death. If you have to run a generator without the recoil cord assembly, make sure it is protected as well as possible from unauthorized users.
Robert lives in central Michigan and enjoys running, woodworking, and fixing up small engines.
One of the first things to cross everyone’s mind is does the water still work when the power goes out. Water makes hydration, personal hygiene, cooking, cleaning, and waste removal all.
Power outages are an inevitable part of life, often occurring during severe weather conditions or due to technical issues with the electricity supply. During these times, it’s essential to know how.
Hi! I’m Robert and this blog started with my journey of learning about battery banks, generators, and power outage preparations. I’ve been an avid hobbyist in these fields for over 7 years and I enjoy sharing what I’ve learned in a way that’s geared for beginners and those just getting their foot in the door with small engine repair and prepping. I’ve been doing maintenance and handyman work for the last several years and I’ll be including little home and garage tips and tricks that I learn along the way as well. Thanks for stopping by!
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Greenworks 2 x 24V (48V) 17″ Brushless Lawn Mower and Drill review – a gateway into the Greenworks ecosystem
REVIEW – Most of us have spent our entire lives using gasoline or corded electric lawn tools. I had infamously bad gas lawnmowers when I was a kid, where you had to yank the starter cord 10 or more times with all your kid-strength to get it going, then you had the hassle of mixing gasoline and oil for the 2-stroke engine, plus maintenance and breakdowns and running out of gas. Several years ago I switched from a gas mower to a corded electric mower which made maintenance and starting issues a thing of the past (not to mention being WAY cheaper than similar gas mowers), but navigating a 100 foot cord while mowing can get a bit annoying to say the least. I feel like we’re finally entering a new electric era with new battery technology and products from companies like Greenworks. They sent over their 2 x 24V (48V) 17″ Brushless Lawn Mower to review, so I put it through the paces (in a sweltering heat wave and drought here in the American West). Overall it was easy to setup and use, and I’m happy to report that it’s much better than the dreaded gas mower of my childhood!
The package that they sent me is an optional version that also includes a 24V screwdriver/drill, so I’ll include a section below about my thoughts on that as well.
What is it?
The Greenworks 2 x 24V (48V) 17″ Brushless Lawn Mower is a cordless (battery powered) electric lawn mower. It’s very lightweight, and can be used with a bag to collect trimmings, or you can plug it up and mulch the clippings back into the yard, depending on your preference.
The dual 24V battery configuration is very interesting to me, previously Greenworks and other companies had different lines of tools at lower and higher voltages (20/40/etc) to cover different needs. By using a standardized 24V pack that can double up in some tools for 48 volts they seem to offer the best of both worlds and give the user much more flexibility. A single charger and set of batteries can power over 75 different tools (and counting), though this number includes many duplicates like 10 different lawnmower models. Perusing their lineup shows that they seem to offer at least one model of just about any power tool that I’d use on a regular basis plus quite a few more exotic options (like a toddler Jeep ride-on!).
What’s in the box?
Included in the box is the Greenworks 2 x 24V (48V) 17″ Brushless Lawn Mower, 24V Drill/screwdriver, dual-charger, AC input for the charger, 2 x 24V battery packs at 4ah each, a belt clip for the screwdriver, the grass clippings bag, and manual.
Design and features
The Greenworks 2 x 24V (48V) 17″ Brushless Lawn Mower is constructed almost completely out of a high-impact plastic, which feels built to last a long time. There are also some metal parts like the handlebars. The height adjustment has an easy to read indicator as shown above, though the actual adjusting is done by a button and grab-bar on the top of the mower.
Here you can see the metal axles that the plastic wheels are attached to. Even after multiple hard bumps into concrete landscape edges, the wheels are solid with no signs of coming loose. Also pictured above is a plastic shroud that hangs across the back of the mower deck to prevent things from flying into your ankles as you go.
The mower blade itself is a standard affair, and looks like it’s easily removable for sharpening.
Here’s the backside, with the green plastic cover lifted up. If you want to collect the lawn clippings into a bag, you lift this up then remove the plastic plug on the right side, then slot the bag into the back of the mower.
The battery slots have a nice spring at the bottom, which assists in removing them for recharging. There’s no way to insert the batteries incorrectly, and they clipped in and removed nicely.
Speaking of the batteries, they’re also a nice high-impact plastic build, with a push-button to check power levels.
Installation and setup
The Greenworks 2 x 24V (48V) 17″ Brushless Lawn Mower came well protected in a very sturdy (and large) box. Quite a few zip ties secured everything and have to be cut off, and bubble wrap removed from various parts.
The handle is attached with quick-release bolts, which I found to be easy to install and remove (for storage).
Next up I plugged in the dual charger and charged up the batteries. From fully dead these took 3 hours to charge, so I’m glad they always lasted through cutting my lawn (1/8 acre with landscaping, Greenworks says they can do a quarter acre lawn but they were always reporting nearly dead by the end so that must be under ideal conditions like thin grass and a minor trim).
A safety key comes installed, but can be removed (great if you have curious kids who might find the bright green lawnmower something interesting to play with)
Next you push in the batteries until they catch. These slots fit well and weren’t difficult to install or remove batteries (unlike some previous battery tools I’ve used where you need a rock climber’s finger strength to get batteries out at times).
Installing the second battery is also required, this mower needs both to operate, and combines their 24 volts each to power a 48 volt motor.
Finally we’re ready to mow! Turning the mower on requires you to grip the safety bar to the handlebars, then hold the start button. This prevents accidental starts and cuts power immediately if you let go of the handlebars during operation.
As previously mentioned, I’ve used various gas and corded electric mowers in the past. I was worried that the battery powered electric mower would struggle with some of the thicker parts of our lawn (which alternates between dying brown spots and ultra-thick green spots), but it powered right through them as well or even better than other mowers I’ve used.
When it encounters a thick patch it revs up the motor higher, and I never felt like it was going to choke on the grass. I have a feeling that the higher power motor combined with a 17 inch cutting blade helps a lot with thick grass – I had previously used a 40 volt battery powered mower with a 22 inch cutting width and it did sometimes die on the thickest parts and have to be restarted.
I experimented with different cutting heights and using both the mulching plug as well as directing clippings to the included rear bag. The height adjustment was pretty easy to use, and you can go from fairly short to fairly long (I’ve seen mowers with both shorter and longer settings, but this range seems like it would be good for most scenarios). One note on the height adjustment – you press a button on the bar at the top back of the mower housing and then physically lift the mower higher or lower. It’s not super heavy, but it can be a bit awkward getting it into the highest cutting setting. All the other settings gave me no trouble. I prefer mulching my lawn clippings, but the rear bag option worked fine as well. Even with fairly wet grass both options worked as expected, I didn’t get any clippings building up and clogging anything. The rear bag is fairly small, requiring frequent stop-and-empty trips (I had to do this twice while mowing our smallish lawn).
As a side note, in the picture above, I folded the handle up against the mower for storage. Unlike other mowers I’ve used, this one doesn’t balance vertically (on its rear wheels), so it’s always going to take up a decent amount of space unless you lean it against a wall or something. This isn’t a dealbreaker, but it’s something I wish they’d addressed when designing it: our city only allows a small side yard shed and our garage is packed, so finding a storage space would have been a lot easier if it stored vertically. On the plus side, it’s light enough that I felt confident just hanging it from a tool hook eventually – something I never would have considered with previous mowers.
What I’d change
The Greenworks 2 x 24V (48V) 17″ Brushless Lawn Mower that was sent to me for review included a Greenworks 24V drill/screwdriver as a bonus. I used this repeatedly throughout the review period instead of my usual 20V Black and Decker cordless drill for various projects. Though the Greenworks 24V drill felt lighter, it seemed significantly more powerful and was able to apply more torque than my usual drill. It was more on-par with the corded drill I use when I really need some torque. It has an adjustable keyless chuck (you tighten/loosen the rings near the front to install/remove a drill bit or the included flathead/Phillips screwdriver head). It also has adjustable torque settings so you don’t over tighten screws.
I went into both Lowes and Home Depot during this review and perused their gas mowers for a comparison point. In my area the average price for a standard gas mower was about 200, with slightly wider cutting paths, but they were definitely heavier than the Greenworks mower. I think that as long as you’re also going to use other Greenworks tools like trimmers, blowers, and other power tools, then the value proposition is even if not better in favor of going electric. The other Greenworks tools without batteries included seem to be mostly cheaper than gas counterparts, for example the only gas trimmer in stock at the store was 190 and a similar-sized Greenworks trimmer clocked in at just over 40 with no battery included on Amazon (if you’re starting with this mower and 2 large capacity batteries you might not need more batteries with other tools). Overall, I found the Greenworks 2 x 24V (48V) 17″ Brushless Lawn Mower to be a competent and simple-to-use mower, and had no major issues or complaints after weeks of use.
Price: 359.99 Where to buy: Amazon Source: The sample for this review was provided by Greenworks
Have a Ryobi Battery That Won’t Charge? You Can Fix That.
Lithium ion batteries are a wondrous invention that are lightweight and long lasting. But it’s infuriating when the battery won’t recharge. You stick the battery in the charger and. nothing. Guess what? You can fix these batteries that appear to be completely dead. Read on.
This post is NOT sponsored by Ryobi. They do not approve of or endorse this method for fixing a Ryobi battery. AT all.
One of two things are going to happen as you read this post. You will either unfollow me due to my pathological boringness or. you will propose marriage. So get ready to act accordingly.
If you have any sort of cordless power tool, but especially one powered by a Ryobi 18V battery, you have no doubt encountered the dreaded flashing red charger light.
And if you haven’t. you will.
It inevitably goes like this. you run to the basement to grab your cordless drill because after 10 years of thinking about it, you’re finally going to build that 4 level, Tudor style treehouse with kitchenette.
Or you’re going to hang a picture.
Either way you put your battery in the charger and all you get is a flashing red light, which according to the label on the charger means your battery is defective. It isn’t just dead. It’s defective.
I’m here to tell you you it isn’t. You probably left it in the charger too long which drains the battery.
Your battery is fine. It just needs a little boost.
You Can Fix a Rechargeable Battery That Won’t Take a Charge.
You heard me right. You do NOT have to buy a new 50 battery. You do not have to call the company and swear at them because this stupid defective battery is only 2 weeks old. (although by all means feel free to do so) You do not have to wait until they ship you a replacement battery to finish your project. You can get that battery up and working in about 5 minutes.
NOTE: First try pulse charging.
Pulse charge your battery by plugging and unplugging your charger (with the battery in it) for 10 seconds. Try this a few times. If it doesn’t correct the problem, continue on with this tutorial.
How to Fix an 18V Battery
What You Need
- A multimeter. (this is actually optional but helpful. if you don’t have one don’t worry, you can still fix your battery)
Note: If you aren’t used to doing this sort of thing, or using things like a multimeter this is going to seem crazy and hard and way out of your DIY league. It isn’t.
Step 1. Cut the end off of your AC adapter. That’s right. Just cut it off. It’s for a 10 year old cell phone, you’re never going to use it again anyway. It’s frankly kind of weird that you saved it to begin with.
Step 2. Separate and strip off 1 of each wire. You have just made booster cables! Good for you.
Black wire = negative Striped or solid white wire = positive
IT IS VERY IMPORTANT TO NOT MIX THE TWO UP.
Step 3. Remove the screws holding the battery together.
For Ryobi batteries it’s a star shaped screw head like the one below.
A few years ago I bought a kit of small screwdriver heads from Amazon that has every small, weird, head you’d ever need.
There’s a hidden screw under a piece of plastic. You need to pry the plastic off to get at the screw underneath. I used a very thin screwdriver to pry it off.
Step 4. Pull the top off of the battery case.
Step 5. Remove the 2 plastic side pieces. They’re the things you press in to remove your battery from your drill.
Step 6. Lift the battery pack out.
Step 7. Set the Multimeter to read volts. For testing an 18 volt battery choose the 20 volts setting. This will give you the most accurate reading. (If you don’t have a multimeter skip to Step 9 and hope for the best)
Volts are symbolized by a V with one or two straight lines over it on a multimeter so it’s that section of the multimeter that you use. The section under the V with the straight line(s). Not the squiggly line. The straight line.
Step 8. Touching the red probe to the positive (red) terminal and the black probe to the negative (black) terminal, read the voltage shown on the multimeter. In my case the battery was carrying a charge of 0.06 volts. Which is almost nothing, but not completely nothing.
Step 9. Plug your AC adapter in and using the wires, boost your dead battery. Just touch the black wire to the negative terminal (the one with the black wire going to it) and the white wire (or striped wire) to the positive terminal (the one with the red wire going to it). Do this on and off for approximately a minute.
Apparently lithium ion batteries should be pulse charged. Which means you hold your wires down for 15 seconds or so, then release them. Then hold them down again. Over and over.
DOUBLE CHECK THAT YOU ARE TOUCHING POSITIVE TO POSITIVE AND NEGATIVE TO NEGATIVE.
Step 10. Test your the voltage on your battery pack again. It should be higher than it was before boosting. (Again, if you don’t have a multimeter don’t worry about this. you’ll just have to press on without one)
Mine went from 0.06 volts to 7.58 volts after a minute long boosting session.
Step 11. Put the plastic cover back on the battery pack (just the part that goes into the charger) and set your battery on the charger to see if it will take a charge.
If you still only get a red flashing light and the battery won’t charge, boost the battery some more. I find the battery charger will recognize that the battery is good again when you boost it to between 10 and 14 volts.
Just keep repeating the pulse boosting and testing the battery until it will finally be recognized by the charger and you get the green light.
To those of you who found this subject matter to be on par with spending 3 hours in a waiting room, sorry ’bout that.
For the rest of you? I know exactly how you feel. I felt the same way. Let me know exactly how elated you were after you brought your first battery back to life in the Комментарии и мнения владельцев section.
Here’s a 3 minute tutorial video showing me as I fix my own battery.
How to Fix a Ryobi 18v Rechargeable Battery
You have an almost brand new Ryobi battery that the charger won’t recognize and won’t charge. Here’s how to fix that.
NOTE: Before doing all this, first try to pulse charge your battery by plugging and unplugging your charger (with the battery in it) for 10 seconds. Try this a few times. If it doesn’t correct the problem, continue on with this tutorial.
Cut the end off of your AC adapter. That’s right. Just cut it off. It’s for a 10 year old cell phone, you’re never going to use it again anyway. It’s frankly kind of weird that you saved it to begin with.
Remove the screws holding the battery together. There’s a hidden screw under a piece of plastic. You need to pry the plastic off to get at the screw underneath. I used a very thin screwdriver to pry it off.
Remove the 2 plastic side pieces. They’re the things you press in to remove your battery from your drill.
Set the Multimeter to read volts. For testing an 18 volt battery choose the 20 volts setting. This will give you the most accurate reading. (If you don’t have a multimeter skip to Step 9 and hope for the best)
Touching the red probe to the positive (red) terminal and the black probe to the negative (black) terminal, read the voltage shown on the multimeter. In my case the battery was carrying a charge of 0.06 volts. Which is almost nothing, but not completely nothing.
Plug your AC adapter in and using the wires, boost your dead battery. Just touch the black wire to the negative terminal (the one with the black wire going to it) and the white wire (or striped wire) to the positive terminal (the one with the red wire going to it). Do this on and off for approximately a minute. DOUBLE CHECK THAT YOU ARE TOUCHING POSITIVE TO POSITIVE AND NEGATIVE TO NEGATIVE.
Test your the voltage on your battery pack again. It should be higher than it was before boosting. IF IT IS NOT, THEN STOP. YOUR CELL COULD BE DAMAGED AND CONTINUING COULD BE DANGEROUS.
Put the plastic cover back on the battery pack (just the part that goes into the charger) and set your battery on the charger to see if it will take a charge. If you still only get a red flashing light and the battery won’t charge, boost the battery some more. I find the battery charger will recognize that the battery is good again when you boost it to between 10 and 14 volts.
Repeat the pulse boosting and testing the battery until it will finally be recognized by the charger and you get the green light.
Impact Driver vs Drill: What’s the Difference?
It used to be so easy—drills took care of holes and that was that. Now that we have impact drivers, however, it gives us more options than we often know what to do with. many people have asked us recently about an impact driver vs drill and what’s the difference? In reality, how and when you use an impact driver vs drill matters. Then, there’s the question of using an impact driver vs hammer drill. That leads to even more questions. Before you get too far into it, realize these tools feature different mechanisms to get work done. They also favor different applications. Using each tool properly yields the greatest amount of efficiency—which is why you often see Pros carrying more than one tool.
We can give you the basic answers as well as some in-depth perspective on what you need to know as a more advanced tool user. This can be helpful if you want to know whether you should buy that two-tool combo kit or just stick with a basic drill. Taking a look at how manufacturers make these tools and how they differ should help you can decide for yourself which you need.
At the very least we can help you sound like you know what you’re talking about when the next tool deals arrive at Acme Tools, Home Depot, or Lowe’s!
Impact Driver vs Drill Basics
Simply enough, a drill spins the chuck at the front of the drill. Most chucks are now keyless, meaning you don’t need that funny-looking key that’s bent to 90 degrees to change out the bits. To use a keyless drill chuck, simply grab it and twist one way to loosen and the other to tighten. Ratcheting chucks in particular are strong enough to hold onto just about any shape that fits into it, including smooth drill bits.
Many drills have multiple speed settings and torque settings. The exact uses for those can be saved for a later discussion since we really just want to understand the major differences for now.
Impact drivers work in a similar way to a drill in that they spin the bit that you have attached. When using a drill to drive a large fastener, you may encounter a point where the drill can’t continue. It’s using all of its power and torque, but it just can’t budge the large fastener or bolt. That’s where the impact driver comes in.
They provide a whole lot more torque.
Impact Drivers When You Need Torque
Imagine working on a bolt that is too hard to loosen with a wrench. You lean on it and pull on it—but you still can’t budge it. To knock it loose, you finally decide to take a hammer and hit the handle of the wrench. That delivers extra, but short-lived, torque.
That’s kind of what an impact driver does. But it can do it several thousand times per minute.
When it gets to the point that it is stuck, a mechanism inside automatically starts “hitting” the chuck to continue driving the screw or tightening/loosening the bolt.
The impact driver is much stronger than a drill in terms of the way it can deliver that extra torque to break loose stuck bolts and screws or drive them deeper into the material.
Drills Offer Speed for Fasteners…at a Price
Since an impact driver mechanism repeats a cycle of the anvil driving the rotation of the chuck, it loses efficiency. Drills apply a constant force to the chuck, driving the fastener without stopping or pulsing. As a result, impact drivers, while giving you more torque, tend to drive fasteners a little more slowly.
We’ve seen this over and over again in our drill vs impact head-to-head comparisons. A capable drill will sink a ledger screw faster than an impact driver every time…almost. The exception comes when the torque required exceeds the power of the drill to maintain its optimal speed. When that happens, the drill slows down while the impact driver keeps driving the fastener into the material.
Impact Driver vs Drill Chucks
Impact drivers use a 1/4″ quick-lock hex chuck. These let you slip a hex bit in—and some automatically lock the bit in place. Other lesser designs require you to pull out the flange to insert the bit. To remove it, you again pull the chuck out, and it releases the bit.
One advantage to this system is that it makes for a more compact design to help you get into tighter spaces. The downside is that it requires a hex bit. Your round drill bits won’t fit these impact driver hex chucks.
Until recently, if you wanted to drill a hole, you had to use a drill. Companies like Milwaukee, Ridgid, and DeWALT now offer drill bits that fit impact drivers. There is a push in the industry to allow you to use an impact driver for everything that a drill can do. Be careful though! Impact drivers have a lot more torque than drills and some applications recommend the use of impact-rated bits, not just the standard ones that came in that big kit for 19.99 at Christmas time.
Many impact drivers on the market are single speed. However, as accessories are being made to include more drilling functions, some companies are offering impact drivers with multiple speed and torque settings.
What about Hammer Drills?
Hammer drills start with a traditional drilling action and have the same kind of chuck as the drill. In fact, most allow you to switch between drill and hammer drill modes. Like a drill, the hammer drill can also have multiple speeds. Instead of having that hitting action working in the same direction that the chuck spins like the impact driver, the hammer drill works by spinning the bit and “hitting” the bit forward the same way a hammer would deliver its force. Imagine using a drill and rapidly tapping the back of it with a hammer while you use it.
Hammer drills tend to do the best when working in concrete, masonry, stone, and other similar materials. There really isn’t a benefit to using the hammering action to drive into wood or drywall. In fact, the hammering action can often damage those softer materials. All hammer drills work with the hammering mechanism turned off when drilling into materials that don’t need it.
When to Use a Drill, Impact Driver, or Hammer Drill…Make it Simple for Me!
Use a Drill When
- Driving screws into wood, drywall, and other soft material
- Tightening/loosening bolts that don’t require an extreme amount of torque
- Drilling holes in wood, drywall, and other soft materials
Use Impact Drivers When
- Driving screws into wood or metal (you can use it for drywall if you’ve got a lower speed/torque option)
- Driving large diameter screws or lag bolts
- Tightening/loosening bolts, including those that should be very tight or have been stuck
- Drilling holes in wood, drywall or metal using new impact driver designed drill bits
Use a Hammer Drill When
- Drilling holes in concrete, masonry, or stone (in hammer drill mode)
- Driving screws into wood, drywall, and other soft material (in drill only mode)
- Tightening/loosening bolts (in drill only mode)
- Drilling holes in wood, drywall, and other soft materials (in drill only mode)
Should I Buy a Drill, Impact Driver, or Hammer Drill?
This is a tough question to answer since there are so many different needs out there. If you are only going to buy one product, I’d go with the impact driver. New bits allow you to do everything with it that you can do with a traditional drill. You’re only missing out on the hammering action that optimizes drilling in concrete or masonry materials.
If you can afford to buy a two-tool kit and know (or think) you might need to drill into concrete or stone, go with an impact driver/hammer drill kit. Even without the special bits, the hammer drill should have a drill-only mode that allows it to operate exactly like a drill, and then you’ll also have the impact driver for when you need more torque with nuts/bolts and lag bolts. If you’re not going to be around those masonry applications, stick with a drill/impact driver kit.
Impact Drivers vs Drills in Real-World Applications
I’ve had the chance to use these tools on several recent projects. For example, we helped to build a wheelchair ramp with a local church. For drilling pilot holes and driving screws, a drill was all we needed. So for projects like building a deck or putting up a wood fence, the drill is a fine choice.
We had to anchor the ramp to concrete on the end, so we employed a hammer drill to make the holes before using it to drive the Tapcons in place. When you need to drill a smaller hole in concrete a hammer drill makes the best tool. Large holes are usually done by a tool called a rotary hammer.
Surprisingly, impact drivers actually do very well making smaller holes in concrete when using multi-purpose bits. I’d limit their use to holes with diameters less than 3/8-inch.
I recently put together a grill and used my impact driver to ensure each connection was very tight. Mechanics will often use impact drivers to tighten and loosen bolts on an engine. A lot of gas engine machinery like mowers and trimmers will require the use of an impact driver (or impact wrench) to tighten and loosen bolts appropriately. Anytime you’re using bolts on metal or driving a screw into metal, you’re going to want an impact tool.
Our Personal Preferences
For the most part, the impact driver is my go-to tool. I personally keep a hammer drill/impact driver kit on hand that meets all of my needs for drilling and driving.
Do you still have questions? Ask us! We love getting to help other people understand the tools we love and how best to use them!
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