Bosch v Milwaukee

[SammyInnit]

The tools that are brushless say EC on the side

(EC=Electronically Commutated), another way of saying 18V Brushless.

Brushless motors in power tools make little practical difference, and are merely a marketing scheme to sell more tools

I'm going to leave it here because it's clear you're talking out of your arse.

 

[big-all]

I'm going to leave it here because it's clear you're talking out of your arse.

i prefer to think he has not done his research and is working on ill informed assumptions

 

[Deleted member 174758]

Brushless motors in power tools make little practical difference, and are merely a marketing scheme to sell more tools hence why many manufacturers added them to their lineup late in the game. The main saving is weight and size, but that's it. We've had brushless motors since 1885, so if they were the preferred choice they would have been used far earlier than now. Brushed motors have way more torque at the speeds that are useful for most tools since you're only limited by saturation of the core and winding size.

Pardon? Why is it, then, that my brushless SDS drill drills at a better rate than its' brushed predecessor (Makita DHR241 then DHR242) despite near identical specs, on paper? Why is it that my 3-speed impact drivers (Makita BTD146 and DTD170) run rings around the earlier 1-speed brushed models (BTD140, etc) in terms of power, speed and endurance? Why is it that in moving to brushless tools from brushed ones that in every case (drills, combis, SDS, circular saw, etc) I've ended up with tools which are lighter, smaller, more powerful and give me something like 40% extra run time from my batteries? And why is it that since the advent of brushless motors manufacturers have been able to build viable tools like cordless laminate trimmers (Makita DRT50), sanders (Makita DBO180), plunge saws (Makita DSP600), etc which simply would not have been feasible without a combination of large batteries and brushless motors.

I did try some of the earlier non-brushless products and frankly they simply couldn't hack it in a site environment - too heavy, not powerful enough, inadequate battery life (anyone remember the Porter-Cable router?). The current generation of brushless tools has in part freed me from power cords and PAT tests. For example I no longer need a corded SDS, corded laminate trimmer or corded palm sander because I now have viable cordless alternatives. More will follow, I'm sure. Please go out and try some of the tools you castigate and you may change your opinions about brushless tools.

 

[SammyInnit]

Makita have just released a 10" cordless mitre saw (Brushless), dewalt have the cordless 12" (Brushless), Makita have just made a 2x18v cordless breaker which outperforms their current corded SDS max breaker (Brushless). My Makita CXT 10.8v Brushless tools are even great options for working lite on site because they have so much more power and runtime.

The fact that you'd even consider Brushless tools to just be a marketing gimmick is amusing. You can't have the experience of coming from nicad brushed to lithium brushed to now lithium Brushless.

 

[aptsys]

I'm going to leave it here because it's clear you're talking out of your arse.

I design motor drives for half of the work we do. Brushless motors have their place, but if you look at the specifications for any brushless motor their peak torque is typically at far higher speeds than is useful for a power drill - at lower speeds you will saturate the core, peak currents will be high and your synchronous drive will be recirculating huge amounts of current. DC motors have peak torque at lower speeds where the back EMF, commutation losses and rotor inertia are at their least, as a side effect, you get less transmission losses in the gearbox.

You certainly won't get electrical efficiency savings in power tools from the choice of motor alone. Increased battery life is down to closed loop control of the motor which is a native to brushless motors, and only implemented on more expensive brushed motor tools. Compare a brushless tool to a CV brushed motor tool and then you'll be comparing apples with apples...

 

[aptsys]

Interesting misquote in your reply, SammyInnit. Try to quote with the correct context next time instead of talking out of your own arse.

As said, the VE is simply the designation for the robust line of tools.

 

[Deleted member 174758]

I design motor drives for half of the work we do. Brushless motors have their place, but if you look at the specifications for any brushless motor their peak torque is typically at far higher speeds than is useful for a power drill

I presume that you are aware that electric drills, both corded and cordless drive through a gearbox which reduces the speed (and increases the torque). By that means the manufacturers can tune the performance of the tool to the task at hand to an extent. Out of interest my old Stnley-Bridges corded drill (now 60 odd years old) actually runs at around 20,000 rpm - the output at the chuck is 2950rpm

 

[SammyInnit]

Interesting misquote in your reply, SammyInnit. Try to quote with the correct context next time instead of talking out of your own arse.

View attachment 136197

As said, the VE is simply the designation for the robust line of tools.

I wasn't talking about what Bosch drill is the best or worst. As said I don't use them, I think they're rubbish so if you expect me to know the product details you're a bit naive.


I was specifically referring to the EC part of the Brushless tools they make and how on the other hand you're suggesting it's a marketing gimmick. Looking at their lineup of combi drills on their website, the only drills to parallel the 'VE' drills are the 'EC' drills. So either Bosch are just using marketing **** or you're contradicting yourself.

Their top of the line combi is infact a Brushless motor. GSB-18-VE-EC.

I'm not overlooking the 36v model I'm plainly ignoring because that is ridiculous. It's not 1999 any more.

I'm not going to argue with you anymore. Brushless are better than brushed. Bosch are crap. That's that.

 

[Roger928]

Its interesting what aptsys is saying because I was buying a metabo cordless grinder recently and the metabo specialist explained the pros and cons of each. (brushed and brushless)
The technical aspects was all I was interested in and the brushed version made the most sense to acquire.

 

[Roger928]

And China...

Doesn't really matter I suppose.
I pulled out my Metabo 1/2 drive SSW 18 LTX 400 BL today to drive these...

To secure steel cladding to 350 feet of sidings.
And it eats them. A game changer...
The other guys with their 1/4 hex toys (Milwaukee, Makita, Bosch etc) were blown away.
All you need is one of these...

 

[aptsys]

I presume that you are aware that electric drills, both corded and cordless drive through a gearbox which reduces the speed (and increases the torque). By that means the manufacturers can tune the performance of the tool to the task at hand to an extent. Out of interest my old Stnley-Bridges corded drill (now 60 odd years old) actually runs at around 20,000 rpm - the output at the chuck is 2950rpm

Yes, but as I'm sure you're also aware, you get greater gearbox losses with increased ratios.

I'm not saying it's impossible to design the tool, I'm saying the advantages touted to purchases are to be taken with a pinch of salt. We've had the technology and made use of brushless motors for over 100 years, but it's only recently been added to cordless power tools. If they were the principal choice, why were they not used when we were stuck with actual efficiency issues from using NiCads! The question is rhetorical, I have colleagues in our consumer and industrial division who come from Black & Decker and Dyson (king of BS marketing)

 

[Deleted member 174758]

If they were the principal choice, why were they not used when we were stuck with actual efficiency issues from using NiCads! The question is rhetorical, I have colleagues in our consumer and industrial division who come from Black & Decker and Dyson (king of BS marketing)

Possibly because the electronics control technology wasn't anywhere near as good (and certainly nowhere near as cheap) 10 years ago? Possibly the removal of brushes reduces frictional resistance within a motor - and getting sufficient run life out of batteries continues to be an issue for some tools (hence no full-size 1/2in battery router). Possibly because of the great increase in production capacities of rare earth magnets over the last 20 years. You say you're the expert, so why not answer the question? From a user point of view the many advantages of the brushless motor cordless tools on the market over earlier brushed motors (plus the removal of the need to check and service brushes) make them a more obvious first choice in many cases.

 

[aptsys]

Possibly because the electronics control technology wasn't anywhere near as good (and certainly nowhere near as cheap) 10 years ago? Possibly the removal of brushes reduces frictional resistance within a motor - and getting sufficient run life out of batteries continues to be an issue for some tools (hence no full-size 1/2in battery router). Possibly because of the great increase in production capacities of rare earth magnets over the last 20 years. You say you're the expert, so why not answer the question? From a user point of view the many advantages of the brushless motor cordless tools on the market over earlier brushed motors (plus the removal of the need to check and service brushes) make them a more obvious first choice in many cases.

Brushless motor drives were just as cheap to design 10 years ago - Prices for discrete semiconductors has barely changed.

As I said earlier, the main push is to sell new tools and competition between manufacturers. People like 'new' technology.

Agreed, service life of the motor is improved as is size/weight.

 

[Deleted member 174758]

Brushless motor drives were just as cheap to design 10 years ago - Prices for discrete semiconductors has barely changed.

If semi-conductor prices have have barely changed, then that means they have actually dropped some 8 to 10% in real terms due to inflation over that period. There is also the effect of Moore's Law, which unless I'm much mistaken, still applies in terms of the cost of processing power and the relative power of chipsets. I was involved with computer technology long enough to understand that.

Agreed, service life of the motor is improved as is size/weight.

By your own admission the size/weight of the motor is improved - that in turn means that for a given (physical) size of motor you get a more powerful motor than an equivalent size/weight brushed motor. Additionally, unless my physics is completely up the creek, going brushless reduces the friction within a motor considerably - meaning that to produce a given output shaft power the motor should consume less input power. Battery life should thereby be enhanced (and surprise, surprise with the Makita brushless tools I've used it was about 40% more than the equivalent brushed tools. When you add that to the fact that most of the brushless replacement motors are smaller and lighter than their predecessors in any case, by your own admission, you get a generally more useable and attractive package for the end user - ergo 30 to 40% longer battery life, smaller size, more power and lighter weight (also because Li-Ion batteries are by their nature lighter than equivalent NiCd ones). Which is why many tradesmen prefer them. Bear in mind, also, that tradesmen purchase a lot more cordless tools than DIYers and that they have a life span of 2 to 5 years which is due to the harsh environments many tools are used in and it makes sense for manufacturers to continually renew their ranges with added functionality each time a new generation appears

 

[big-all]

as an aside
dewalt 18v used to top around 450-500w with 18v now they seem around 700w with brushless so by that we could assume all the 40% benefit is from brushless
or maybe from control delaying input to feild so better power delivery
or less tranmission losses through better electronics or better use off power or a mixture off all with brushless getting the credit who knows
its always the same we form opinions on what we know and assume but without the exact facts we will always fill in the gap as best we can