because air is about 14% efficient. you need 7HP of compressor to run 1HP of tool, continuously.
Milwaukee right angle die grinder vs straight version . same power as air?
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Jswain
Well-known member
So, you'd need a large box full of batteries to run a cordless model continuously.
Everyone always says cordless is great for quick, easy jobs and then as soon as you mention air they act like you need to have a big enough compressor to run it 24/7.
Bigger is better, sure...but sometimes you just need a few minutes, or even seconds of work, and if you need to wait 2 minutes for the compressor to cycle it doesn't really matter
not quite - the air powered model will consume air at the same rate, regardless of load. the battery tool's power consumption is heavily load dependent. so if you've got the trigger held down and you're doing detail work, the battery tool will last way longer than if you're doing heavy work. compared to air where the compressor has no idea how much work the tool is doing, only that the pressure is under cut-in and to run. it really depends on the application.
Jswain
Well-known member
Not quite - If you're doing fine detail work with air you can
A) adjust regulator = less pressure less CFM
B) adjust throttle valve on die grinder = smaller orifice less CFM
You don't always need everything WFO
dnschmidt
Well-known member
I HAVE a box full of M12 6.0 batteries. (Well actually it's a Milwaukee tool bag and not technically a box.) and at least 15 4.0 and 6.0 XC batteries along with a three bay simultaneous rapid charger so I think I'm good.
mrjaw14
Well-known member
I find that for 1-2" accessories the M12 die grinders do ok. The instructions say "optimized for 2" accessories." For larger roloc, wire wheels, cutting discs they sound like they will fly apart. my air die grinders will smoke the M12's, but they take a lot of air and it's portable. having said that, I typically reach for the M12 die grinders unless I really need something larger. It's awesome to be able to take that capability mobile as well.
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Just took a 2.0 battery from full to empty in 10 minutes today with a roloc disc on my right angle die grinder 
.
Only had 15 minutes of cleanup to do so I swapped to another one and it was fine, but yeah you're going to want at least 3 of the larger m12 batteries if you want continuous action.
.Only had 15 minutes of cleanup to do so I swapped to another one and it was fine, but yeah you're going to want at least 3 of the larger m12 batteries if you want continuous action.
Black300zx
Well-known member
My m12 RADG is my favorite m12 tool. Whether it can replace air 100% depends on what you're doing. For my uses (cleaning light rust, gasket material, brief grinding of metal with rolocs), it does everything that I'd be asking an air RADG to do. Yes it will kick off if I really lean into it, especially if the battery is low. If I was doing production metal fab work it probably wouldn't fly.
One thing I've noticed is that you do need to be aware of the air vent screens clogging up if you're grinding anything dusty. If they get clogged up, it will start kicking off under lighter loads. For me, that is probably the biggest difference vs air
One thing I've noticed is that you do need to be aware of the air vent screens clogging up if you're grinding anything dusty. If they get clogged up, it will start kicking off under lighter loads. For me, that is probably the biggest difference vs air
vanapplebomb
Well-known member
If you have access to shop air, go with pneumatic die grinders. Smaller, lighter, cheaper, more power. The value for money is only in the Milwaukee’s favor if you have no shop air.
Milwaukee annoys me with their advertising. They claim their die grinder is 20%more powerful than air… but they also spec it as 0.3 max hp… So what they are really saying is that their $200 90deg die grinder is 20% more powerful than a $25 air die grinder. Unfortunately they play the 20% more powerful than air to people who don’t know anything about air tools, and they get suckered into a very expensive and less than impressive tool.
For $50 you can get a decent air powered die grinder that is equally as powerful as the Milwaukee. For the same price as the Milwaukee, you can get a darn nice 1hp air die grinder.
My biggest dislike of the Milwaukee, and this is true of all electric die grinders, is that they are physically large. The 90deg heads are about the same size as a 2” sanding pad, which limits their usefulness in tight locations.
Milwaukee annoys me with their advertising. They claim their die grinder is 20%more powerful than air… but they also spec it as 0.3 max hp… So what they are really saying is that their $200 90deg die grinder is 20% more powerful than a $25 air die grinder. Unfortunately they play the 20% more powerful than air to people who don’t know anything about air tools, and they get suckered into a very expensive and less than impressive tool.
For $50 you can get a decent air powered die grinder that is equally as powerful as the Milwaukee. For the same price as the Milwaukee, you can get a darn nice 1hp air die grinder.
My biggest dislike of the Milwaukee, and this is true of all electric die grinders, is that they are physically large. The 90deg heads are about the same size as a 2” sanding pad, which limits their usefulness in tight locations.
That's a bunch of malarkey0.3HP
M12 FUEL™ 1/4" Right Angle Die Grinder | Milwaukee Tool
MILWAUKEE® M12 FUEL™ 1/4" Right Angle Die Grinder s the first cordless right angle die grinder that delivers the performance and size professional service mechanics demandwww.milwaukeetool.com
Garcky
Well-known member
IMO, if you have shop air, air tools are best overall. Smaller, lighter, and no batteries to charge. Cheaper, too. No shop air? Then you're stuck with cordless or corded tools.
Yesterday, I watched a video that showed a guy using a cordless ratchet to back out a long machine screw. Like 1/4" or 5/16". I watched it twice and timed it. I could have had that screw out in 1/3 of the time with a 1/4" drive speed handle, which is what I would have taken to that particular job, since there were multiple such fasteners involved.
Sometimes, old solutions are your best bet, really. That speed handle will go for hours without recharging and doesn't need an air hose sticking out of one end.
Yesterday, I watched a video that showed a guy using a cordless ratchet to back out a long machine screw. Like 1/4" or 5/16". I watched it twice and timed it. I could have had that screw out in 1/3 of the time with a 1/4" drive speed handle, which is what I would have taken to that particular job, since there were multiple such fasteners involved.
Sometimes, old solutions are your best bet, really. That speed handle will go for hours without recharging and doesn't need an air hose sticking out of one end.
dnschmidt
Well-known member
WRONG Garcky. That speed handle will go for minutes before our ancient elbows give out. They are also over a foot long so access is limited. Where they are great is when you have an engine on an engine stand. They truly do really shine there.
I use either a dewalt gyro screwdriver, or a milwaukee surge, almost exclusively for turning small screws/bolts, respectively. a cordless ratchet is the wrong tool, if you want to save time.
Garcky
Well-known member
There ya go. I'm an old man with very few cordless tools. The ones I have usually have a dead battery when I want to use them, though. I'm always forgetting to put a battery in the charger. So, that speed handle gets a lot of use. I also don't have an air compressor that will handle a 1/2" impact wrench, so a breaker bar and a 1/2" speed handle will have to do for me for lugnuts and the like. I do have plenty of time, though.
Garcky
Well-known member
Yabbut I'm old and set in my ways, see? Not too old to use a speed handle, though. You know the thing I like it best for? Oil pans. Both taking them off and putting them back on. Same thing with belly pans and covers of all kinds. One tool to do it all. The only tool that's better is a 3/8" butterfly impact tool, but I don't have shop air, so that sits in the bottom drawer now. Now, you're right; speed handles aren't good for close quarters, but they certainly have many uses when you're working on cars. They're cheaper than cordless tools, too. But, I'm old and set in my ways, like I said.
I have the right angle one. Even with the 4.0/6.0 battery, you definitely won't get the 'power' of an air grinder because of the protection circuitry. Not sure why it has to be crippled so severely considering the torque their other M12 tools can put out. I suppose it's the gearing/the fact that it puts out so much more rpm than, let's say a drill, so the torque output is proportionately reduced.
The torque is crippled enough that if I don't need the speed, I chuck the disc/whatever into a drill. I do have a 60 gal compressor, but have so much cordless at this point, i haven't run it for at least 5 years, so can't see airing up a 60 gallon compressor just to run an air die grinder for a few minutes. I'm DIY, so don't have a constant need for air.
The torque is crippled enough that if I don't need the speed, I chuck the disc/whatever into a drill. I do have a 60 gal compressor, but have so much cordless at this point, i haven't run it for at least 5 years, so can't see airing up a 60 gallon compressor just to run an air die grinder for a few minutes. I'm DIY, so don't have a constant need for air.
I've got a 90 degree milwaukee hex impact, too, for the low clearance places. don't get me wrong, I'll often have to break the bolts loose by hand, but I prefer the tools to zip bolts out rather than nuckle-busting between a rock and a hot place.There ya go. I'm an old man with very few cordless tools. The ones I have usually have a dead battery when I want to use them, though. I'm always forgetting to put a battery in the charger. So, that speed handle gets a lot of use. I also don't have an air compressor that will handle a 1/2" impact wrench, so a breaker bar and a 1/2" speed handle will have to do for me for lugnuts and the like. I do have plenty of time, though.
Michael_in_DE
Well-known member
I have the straight. It's straight up garbage. Its about the same as a weak dremel essentially. Glad I bought one that fell off the truck.
dnschmidt
Well-known member
I find the right angle to be great and the straight not so great. In either case you MUST use the big batteries with either as the compact batteries stall out immediately. With a 4.0, 5.0 or 6.0 the right angle is perfect and the straight at least passible. In the straight variety the M18 is vastly superior but it doesn't have the variable speed of the M12 which I do like.
strutaeng
Well-known member
I'm pretty sure I have that cheap $25 HF right angle die grinder on that video. I bought it to use them Roloc discs for cleaning automotive things. I did a large metal stair handrail + guardrail job on my house and bought some real carbide burr die grinder bits for it. The thing ate metal like crazy. Long sleeves, boots, gloves, safety glasses, face shield, ear muffs, metal shards everywhere. I wasn't messing around.
Did like 3-4 hours straight, which was a job in itself. Just had to use a good supply of air from my old Emglo compressor. Not sure I would want to be doing that with a giant batteries. Not sure what the deal is with cordless tools and those giant batteries. They getting to the size of car batteries! LOL.
I think for daily use I'd pick one of those long die grinders for better control in pneumatic. Name brand tool. Sometimes you gotta do with what you have.
Did like 3-4 hours straight, which was a job in itself. Just had to use a good supply of air from my old Emglo compressor. Not sure I would want to be doing that with a giant batteries. Not sure what the deal is with cordless tools and those giant batteries. They getting to the size of car batteries! LOL.
I think for daily use I'd pick one of those long die grinders for better control in pneumatic. Name brand tool. Sometimes you gotta do with what you have.
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vanapplebomb
Well-known member
Yup, as I suspected. The $200 cordless is about the same power as a $35 entry level air tool.
OH NO! a first generation BATTERY powered die grinder is as good as a tool thats been perfected over the last 6 decades and tethered to a $500+ air compressor!
What a fail...
vanapplebomb
Well-known member
If I have easy access to shop air with a minimum of 15 cfm for constant use, absolutely.
There are a lot of things I don’t care for about the 90 degree for the work I do. For others, it doesn’t matter.
However, in the case where I am on the road and may not have shop air, then I would resort to the electric and live with the drawbacks, because it’s all I got.
If doing light duty work, not it tight places, the electric works fine within its limits.
I happen to quite like value for money, and with access to shop air, pneumatic is really hard to beat for my personal needs.
There are a lot of things I don’t care for about the 90 degree for the work I do. For others, it doesn’t matter.
However, in the case where I am on the road and may not have shop air, then I would resort to the electric and live with the drawbacks, because it’s all I got.
If doing light duty work, not it tight places, the electric works fine within its limits.
I happen to quite like value for money, and with access to shop air, pneumatic is really hard to beat for my personal needs.
tyyost
Well-known member
I bought one when it came out, I’m much more invested in the M18 line so I only have one bigger battery as the ratchet I have isn’t a power hog. it runs ok with 2” stuff. Not exactly great, the overload is terrible when using discs or cut off wheels. Best with burrs, 1/2“ or so and runs as expected.
I am not sure I would buy it again but I use it plenty. Every third time I wish I would have fired up the compressor though. It took me two batteries (full charge) to make two cuts in a muffler clamp on Friday with a 3” wheel. I was wishing for a hackzall after that.
If they called it comparable to a 1/4HP die grinder I don't see the issue. Call it what it is, the tech isn't there yet for it to be comparable to a 1/3Hp die grinder, much less "20% more powerful than air" as they say. Saying stuff like that gets you called out obviously
ALL manufactures over inflate specs, this shouldnt be a surprise
dnschmidt
Well-known member
3M bristle discs.
dnschmidt
Well-known member
Pal, if you can find a $500 compressor that can power an air die grinder for more than a minute please tell me where I can get one. I have a 5HP 80 gallon 2-stage Quincy that I paid $2,000 for and it can keep up but just barely.
vanapplebomb
Well-known member
Yup, air hogs for sure. My compressor is also an 80 gallon two stage, and just keeps up. However, it is used for a lot of different tools and tasks, not strictly die grinders. This is why I make the point about access to shop air.
If you don’t have shop air, and don’t need a small tool due to working space restrictions, the M12 is just fine within its limits, which it certainly has. I wouldn’t consider it a heavy duty tool for bulk removal by any means. They just don’t hold up.
If you don’t have shop air, and don’t need a small tool due to working space restrictions, the M12 is just fine within its limits, which it certainly has. I wouldn’t consider it a heavy duty tool for bulk removal by any means. They just don’t hold up.
The other 1/3HP die grinders seemed to do just fine
If you can find the M12 battery that doesn't drop battery level bars and power after running the die grinder for more than a full minute tell me where I can get one.
mrjaw14
Well-known member
you definitely need a high-output 6ah battery with these. Mine run for a usable amount of time. you won't be working all day on a single charge for sure though, so you need multiple batteries if it's actively in service
dnschmidt
Well-known member
With the 5.0 or 6.0 battery it will easily last five minutes. The problem is Milwaukee sells this tool in a kit with tiny batteries and that's where people get the idea that they're useless. With the 5.0 High Output I think 10 minutes is easily within reason.
tyyost
Well-known member
Same here, the XC6.0 does better than the smaller ones but it still only lasts a few minutes.
Has anyone compared there RADG with the new 2.5 and 5.0 High Output M12 batteries?
I leave my RADG setup with a 2" Scotch-Brite pad for cleaning off gasket material and for very light grinding. It works perfect for that and I don't have to fill up my 80gal compressor to clean off a water pump gasket. I pretty much only use my compressor with an air nozzle for blowing off stuff these days.
If I need to port anything I'll use my M18 Fuel die grinder.
I leave my RADG setup with a 2" Scotch-Brite pad for cleaning off gasket material and for very light grinding. It works perfect for that and I don't have to fill up my 80gal compressor to clean off a water pump gasket. I pretty much only use my compressor with an air nozzle for blowing off stuff these days.
If I need to port anything I'll use my M18 Fuel die grinder.