Brushless vs brush motors in drills
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pistolpete1313
Well-known member
Short answer no.
Brushless costs more, longer run time, more power. For home projects you probably can take a break if the batteries need to charge.
Brushless converts the DC to AC internally and has better power regulation and use for more power and efficiency.
Many think that brushed are tougher to abuse.
Brushless costs more, longer run time, more power. For home projects you probably can take a break if the batteries need to charge.
Brushless converts the DC to AC internally and has better power regulation and use for more power and efficiency.
Many think that brushed are tougher to abuse.
American Locomotive
Well-known member
The difference is, brush motors have a permanent magnet stator, and a "wound rotor" that the brushes send DC power power to. Brushless drills have a permanent magnet rotor, and a wound stator. The windings in a brushless motor aren't fed DC, they're actually fed 3-phase AC.
As mentioned, the brushless tools tend to be a bit more powerful with longer battery life. However, the electronics are more complicated and a little more prone to failure. The electronics also tend to be smarter, and will often prevent abuse. So if you got a big 4" hole saw on your brushless drill and really start to load it up, the drill's electronics will often just turn the motor off to prevent damage. A lot of brush-motor tools won't care and will let you get the motor hot & smokey.
Some guys get annoyed at the brushless safety features, because you can get in a situation where you need that 125% from the drill, but only briefly. Not long enough to hurt the motor, but the brushless controller cuts them off anyways. Not a big issue for the vast majority of people though.
Brushless is great if you were looking to replace your tools anyways (or had no tools to begin with), but I don't think it's worth upgrading to brushless if you already have competent brush motor tools.
As mentioned, the brushless tools tend to be a bit more powerful with longer battery life. However, the electronics are more complicated and a little more prone to failure. The electronics also tend to be smarter, and will often prevent abuse. So if you got a big 4" hole saw on your brushless drill and really start to load it up, the drill's electronics will often just turn the motor off to prevent damage. A lot of brush-motor tools won't care and will let you get the motor hot & smokey.
Some guys get annoyed at the brushless safety features, because you can get in a situation where you need that 125% from the drill, but only briefly. Not long enough to hurt the motor, but the brushless controller cuts them off anyways. Not a big issue for the vast majority of people though.
Brushless is great if you were looking to replace your tools anyways (or had no tools to begin with), but I don't think it's worth upgrading to brushless if you already have competent brush motor tools.
Ign
Well-known member
wafrederick
Well-known member
Heat and vibration kill the brushes,Milwaukee did their research on this and this is what they found what kills them.The brushless motors last longer too.
kctyphoon
Banned
I'm not being sarcastic, but google will give you a clear explanation of this.
Short answer is brushless motors are a actually an ac powered motor that is digitally controled. The magnets and windings are actually reversed on the motors, eliminating the need for a physical connection using brushes. It is a big step forward in technology. It increases performance, eliminates friction, reduces heat, extendes runtimes, and increases longevity of the tool.
There is no downside to brushless, besides cost. That said, a tool being brushless does NOT automatically mean it is more powerful than a brushed tool. It simply means its using a newer technology to power said tool. Each tool will still need to be judged and researched on an individual basis for torque ratings. Many people do not realize this. My brushed Milwaukee impact driver is much stronger than my brushless dewalt impact driver. My brushless m18 fuel is stronger still.. The M18 fuel line of tools is usually some of the best performing brushless tools in terms or torque ratings and quality, which is why they have such a big following on here.
Short answer is brushless motors are a actually an ac powered motor that is digitally controled. The magnets and windings are actually reversed on the motors, eliminating the need for a physical connection using brushes. It is a big step forward in technology. It increases performance, eliminates friction, reduces heat, extendes runtimes, and increases longevity of the tool.
There is no downside to brushless, besides cost. That said, a tool being brushless does NOT automatically mean it is more powerful than a brushed tool. It simply means its using a newer technology to power said tool. Each tool will still need to be judged and researched on an individual basis for torque ratings. Many people do not realize this. My brushed Milwaukee impact driver is much stronger than my brushless dewalt impact driver. My brushless m18 fuel is stronger still.. The M18 fuel line of tools is usually some of the best performing brushless tools in terms or torque ratings and quality, which is why they have such a big following on here.
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Ree75
Well-known member
to give you a little of a comparison, My boss and I have 2 brand new dewalts.
Mine: DCD771 with a brush motor and 1.3 AH battery
His: DCD790 with a brushless motor and 1.5 AH battery
mine can put in about 60-70 self tapping screws into very this galvanized metal with a battery straight of the charger.
His puts out well over 3 times that amount and still has battery juice.
I do kind of wonder if my battery, while labeled Lithium Ion, is actually NiCad. Compared to my larger battery that will go from full speed to nothing (more common for Lithium Ion) My new 1.3AH "lithium ion" batteries wind down, losing power as they get close to the end of their charge. These have been the only "Li-ION" batteries that have done this to me. and I really don't like it nor do I like how the NiCads do it either
Mine: DCD771 with a brush motor and 1.3 AH battery
His: DCD790 with a brushless motor and 1.5 AH battery
mine can put in about 60-70 self tapping screws into very this galvanized metal with a battery straight of the charger.
His puts out well over 3 times that amount and still has battery juice.
I do kind of wonder if my battery, while labeled Lithium Ion, is actually NiCad. Compared to my larger battery that will go from full speed to nothing (more common for Lithium Ion) My new 1.3AH "lithium ion" batteries wind down, losing power as they get close to the end of their charge. These have been the only "Li-ION" batteries that have done this to me. and I really don't like it nor do I like how the NiCads do it either
lightning02
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i bought all brushless for my home/shop use.
After several home renovations or remodels my brushED Makita impacts are finally showing some loss in impact power. Changing the brushes was relatively easy and they are back on the job. Picked up some brushLESS Milwaukee impacts last year and they are spec at greater in. lb but they both can be my go-to tools for construction. My cordless tool collection is limited because for me cordless is for convenience while corded is for sustained power to finish the job.
There is a rule that says reliability decreases exponentially with the increase in the number of parts. There is not much to fail on a brush motor. There is no doubt that brushless motors are better but initial cost and possible repair cost are much higher. They are not necessarily the best choice for everyone. I like the latest toys too but I don't replace working tools just to own them. When the time to replace comes I research the market. My guess is the price of brushless will come down like any other new technology. There were some very good explanations here on brushless technology. Thank you, very informative.
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kctyphoon
Banned
Milwaukee is the big name in brushless tools right now. Dewalt had their time with their 18v stick pack line (the only big nicad line still being sold), and makita before them. Every brand puts out a competitive line now, but "today" Milwaukee is the one with the biggest following because of their performance and vast choices of tools and cordless lighting among other things.
I was in the same boat when I joined this forum. I had a few nicad dewalt tools that I was happy with, but I HATED how the batteries always self discharged, and the tools power always seemed to drop quickly - one problem being the large batteries with still small amp hour ratings. I wanted to make the jump to lithium, didn't WANT to leave dewalt, but once I started researching, watching hours of videos online, compared lineups between brands, one brand stood out to me. I made my first purchase and never looked back. I've been very happy with every purchase I've made from Milwaukee, and I own a lot of them now. Much more than I ever really needed or expected to buy. That said, they make things so much easier, that I'm willing to spend the money just to make my life easier when I do need to use them. Also, I've never seem so many promotions and free tools given away from any other brand besides Milwaukee. They were recently "giving away" their new 9.0 battery ($199 at the time) and rapid charger ($70 retail) with cordless saw promo kits. Also just bought a $200 tripod light that came with a free 5.0 battery and dual charger too. Holidays come and they are almost handing out product with their sales..
Take a visit in the Milwaukee addiction thread, and you'll see what all the hype is over.
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wafrederick
Well-known member
Snap On still uses brushed motors in their cordless tools and are more money than Milwaukee brand new.
Thank you KC I'll check it out.
Depending on what you are looking at, I think battery type is more important then motor type when considering a upgrade.
Lithium-ion vs Nicad is a much bigger performance gap then brush vs brushless IMO.
Li-ion is much lighter, holds it charge better, and typically is regulated to stay in safe operating parameters.
So, I would first look at upgrading to at least Li-ion. Then consider brush vs brushless. That being said, go brushless, they all come w/ Li-ion these days.
Lithium-ion vs Nicad is a much bigger performance gap then brush vs brushless IMO.
Li-ion is much lighter, holds it charge better, and typically is regulated to stay in safe operating parameters.
So, I would first look at upgrading to at least Li-ion. Then consider brush vs brushless. That being said, go brushless, they all come w/ Li-ion these days.
You have to add in the tool truck factor. I am no SO authority. I don't know how much they actually make beside their high quality hand tools. They mark up the hell of stuff that is often sold for much less under other brands. There is a whole thread called tool truck equivalents. You are also paying for service support.It is in effect, an insurance policy added to the actual cost of rhe tool.
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It makes sense to buy brushless more because they are typically higher end versions than just for the fact that they are brushless. Higher end versions of the tools are typically much tougher and more powerful.
As far as brands go, be careful for closed minded fan boys. Dewalt, Makita, and Milwaukee all make some high end tools and I think there are trade offs for each line. Each of these brands hold peak power numbers in some of their tools where peak power makes sense and some where peak power is less important.
For me I have Dewalt 20v and Milwaukee 12v and am happy.
As far as brands go, be careful for closed minded fan boys. Dewalt, Makita, and Milwaukee all make some high end tools and I think there are trade offs for each line. Each of these brands hold peak power numbers in some of their tools where peak power makes sense and some where peak power is less important.
For me I have Dewalt 20v and Milwaukee 12v and am happy.
wafrederick
Well-known member
My Matco dealer gives nothing to a little bit for trade on them.Snap On does not give much of a warranty on them too,a year on the tool
I did not know. Many justify the high prices by claiming product support. So then there is little justification for paying the big bucks for tools similar to non truck tools, at better prices. I would not even open the can of worms about whether their hand tools are over priced
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pure baloney, where do you get this stuff?
Misconceptions that seem intuitively correct for the laymen, but it's a pure garbage statement to make. If this were true we'd never get a modern jet fighter off the ground not to mention go to the moon and back.
Wrong there all kinds of failure modes on a brushless motor most importantly there is usually no overload (current) protection and can simply be destroyed by overheating and melting parts / windings when overloaded beyond short term.
The switch has to pass the full motor current and sustain many arc overs due to sudden off /on with inductive windings.
The brushes wear.
Brushless designs address all of these shortcomings.
By all means disagree with your usual classless personal attack. With your rude approach, I don't care what you have to say. And I am sure you have a degree in rocket sience that no layman should dare question. Even if I am 100% wrong i will listen and if convinced, revise my opinion to some one that does nor start out like you.pure baloney, where do you get this stuff?
Misconceptions that seem intuitively correct for the laymen, but it's a pure garbage statement to make. If this were true we'd never get a modern jet fighter off the ground not to mention go to the moon and back.
Wrong there all kinds of failure modes on a brushless motor most importantly there is usually no overload (current) protection and can simply be destroyed by overheating and melting parts / windings when overloaded beyond short term.
The switch has to pass the full motor current and sustain many arc overs due to sudden off /on with inductive windings.
The brushes wear.
Brushless designs address all of these shortcomings.
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crewchief888
Well-known member
as mentioned, i wouldnt "jump to brushless" simply for the sake of it.
replacing worn out or non working tools/batteries is when i changed.
i have a real world situation, brushed 18v li-ion drill vs brushless 12v li-ion.
job requires (2) 1 1/4" holes through 3/16" + steel. in kinda an awkward position.
chuck up a brand new hole saw, killed both 18v 2.0 batteries before i was done, and finished with an air drill.
chuck up the same hole saw in the brushless drill, killed 1 2.0 battery, 3/4 charge still left in 2nd battery.
the 18v drill is bulkier/heavier than the 12v drill. my shoulder thanked me.
just my $0.02
lightning02
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same. i use my m12 brushless more then the other bigger stuff.
kctyphoon
Banned
Don't wanna stir the pot here, but I'm kinda sure there are less parts in a brushless motor.. hence it being called "brushless"
The digital controls also offers digital protection for the tools against overload and over heating. With a 5 yr warranty, and a huge number of people on this forum able to give first hand feedback, I'm pretty sure they are all ok..
theoldwizard1
Well-known member
Definitely less PHYSICAL parts. The electronics are more "complex", but part of that is things like battery charge indicator built into the tool and overload/overheat protection.
theoldwizard1
Well-known member
For those who do not follow this closely, Milwaukee still sells some BRUSHED tools. Only the tools that have "Fuel" on the side are bushless. They cost less and have a bit less power and probably consume batteries a bit faster.
The main reason BRUSHLESS tools have more power is that they spin faster. This means that can be gear down more producing more torque.
The main reason BRUSHLESS tools have more power is that they spin faster. This means that can be gear down more producing more torque.
simple
You made the extraordinary claim of a "exponential rule in reliability" so the burden of proof is upon you , not for me to convince you otherwise. It's silly for me to find proof of something that doesn't exist. Cite a credible source. It should appear in 'reliability basics 101, right.
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Pot calling the Kettle Black
Here I will put a link to your usual bad behavior encountered on my 1st posts when I recently joined GJ.
I have a solid state power engineering background and joined a conversation were I felt qualified to contribute. So here comes 6PT instead of asking me to clarify my advise to the OP, out of the blue he immediately launched a personal attack to try and discredit me. He attacks people not their ideas. now I'm the rude one
http://www.garagejournal.com/forum/showpost.php?p=6050273&postcount=13
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kctyphoon
Banned
To clarify, Milwaukee also sells a lower tier of drill and impact driver simple labeled "brushless" and not fuel.. also, they have the hydraulically driven "Surge" impact driver..
Definitely less parts, and brushless should be more reliable. They are, as others noted, just miniature 3-phase motors with VFD's powering them. Just like full size VFD systems, DC is converted to AC of varying frequency. But instead of rectifying the AC power from the wall outlet to get the DC (which ultimately is converted back to variable AC), the batteries already have DC power. Very simple, and much better speed regulation.
Thanks for all the explaintion guys. Went back and returned my 179 dollar m18 brushed driver went to but the 199 dollar brushless drill driver. Web said they had 2. Associates could not locate either.
Ended up giving me the combo brushes hammer drill and impact driver kit 249 fit the 199. Got an extra tool and lost a blow mold case. I'm good with that.
I really wanted the driver because I have the m18 fuel hammer drill and need somethig to set up with a driving bit so I don't need to keep swapping out the drill bit.
Ended up giving me the combo brushes hammer drill and impact driver kit 249 fit the 199. Got an extra tool and lost a blow mold case. I'm good with that.
I really wanted the driver because I have the m18 fuel hammer drill and need somethig to set up with a driving bit so I don't need to keep swapping out the drill bit.
What are everyones thoughts on the makita 18v brushless?Home crepot has a combo for
229.00 drill and impact driver, looks like the batteries are lower amp hr.,but I'm not in the
Trades anymore.It would be for home use and repairs to my landscape equipt.I like the impact driver with a 3/8 adapter for small stuff.I looked at it today felt pretty good in my hand.
229.00 drill and impact driver, looks like the batteries are lower amp hr.,but I'm not in the
Trades anymore.It would be for home use and repairs to my landscape equipt.I like the impact driver with a 3/8 adapter for small stuff.I looked at it today felt pretty good in my hand.
This is in principal true but misapplied here.
If you have 3 parts on a system, say, that are 99% reliable and any one failure causes the system to fail, the reliability will be 0.99 x 0.99 x 0.99 = 0.99^3 = 0.97 or 97%.
If you replace those 3 parts with 5 parts of higher reliability, say 99.5%, you can get higher reliabilty with more parts (0.995^5 = 0.975 = 97.5%).
Kind of useless to generalize this rule since it always comes down to system specifics and numbers.
Could be. The brush system is nothing but a battery and a rotor through the brushes and the speed control. The brushless system has to generate 3 phase AC That takes a lot of electronics. Like inverters and any switching power supply, the output semiconductors are often the point of failure. I was not talking about the motor being protected by the circuitry but the circuitry itself as a possible weak link. Amplifiers, inverters, IGBT's power supplies, it is always the power semis that let out the magic smoke. On top of that lithium batteries have to be baby sat. The safety circuitry has to prevent over charging, over discharging and in some cases current limiting. All I said is there are a lot of places for something to go wrong. I am no statistical analyst and value your input but I get really pissed off when somebody gets personal. Every time sonebody asks a silly question or offers an opinion that is not widely agreed with I know some people will be all over them with all kinds of derrogatory remarks.
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kctyphoon
Banned
ANY premium brand will work fine for you. The key with investing in cordless tools is to invest in a SYSTEM (meaning the collection of tools they offer). If you have no wants or needs over anything past the basic 4 or 5 core tools most people buy, then just buy what you like, what feels good in your hands. They will all make you happy, and do what you need.. if you're not a fanatic wanting the best of everything and the most choices possible on tools/batteries/lighting, anything will fit the bill..
The Surge still has a brushless motor. It's the hammer/anvil design that's different. Anyway, for a serious DIY guy or professional you can't go wrong with any of the major brands offerings. I'm in several systems; Milwaukee M12, M18, Dewalt 20v Max and FlexVolt, and they all have their pros and cons.
For basic drill/impact driver solutions Makita is the clear winner, most powerful drill and fastest impact. They also have tons of cool oddball stuff and a new rear-handle hypoid gear saw to compete with worm drive saws. Dewalt's FlexVolt line has more power than the Fuel gear and their new 6.0 20v Max packs and 3.0/9.0 FlexVolt packs use larger, more energy efficient battery cells for crazy runtime without thermal overload. Milwaukee has a diverse lineup and for auto, plumbing, electrical etc. I think you'd be crazy to go any other way. They have 5 year warranty and I'm very happy with my Fuel gear.
For basic drill/impact driver solutions Makita is the clear winner, most powerful drill and fastest impact. They also have tons of cool oddball stuff and a new rear-handle hypoid gear saw to compete with worm drive saws. Dewalt's FlexVolt line has more power than the Fuel gear and their new 6.0 20v Max packs and 3.0/9.0 FlexVolt packs use larger, more energy efficient battery cells for crazy runtime without thermal overload. Milwaukee has a diverse lineup and for auto, plumbing, electrical etc. I think you'd be crazy to go any other way. They have 5 year warranty and I'm very happy with my Fuel gear.