A solid grinder for the M18 family
This review is a comparison between the last generation wired Milwaukee 4 1/2" grinder and their latest M18 cordless offering.
I've used a Milwaukee angle grinder for everything from cutting & grinding concrete to smoothing out rough-cut metal. Unlike a drill or a saw that operates linearly, a grinder needs the freedom to change angles quickly and often as an operator makes changes and adjustments to the workspace on the fly. This presents a perfect opportunity to go cordless, and Milwaukee has
... read more
taken the bait.
The Milwaukee 2780-20 grinder comes with a chuck tool, one battery, one charger, and a wider guard for thicker grinding disks and brushes. The first thing that immediately caught my eye was the single battery. I am a big advocate of two batteries, so that when one runs out, you've got a charged one ready to go. But my concerns were alleviated when i realized that this was an M18 product. More on that below.
One thing that was obviously absent was any actual disks to go with this grinder. This means that to actually USE this grinder, you need to go out and buy the grinding disks and cutoff wheels you need. Not a big deal, as every user will buy this for a different reason.
Another thing that is immediately evident is the size of this case. Measuring at 18.5" x 14.5", this thing is a small suitcase, in stark comparison with the cardboard box my last grinder came in. As you can see, the charger takes up the a large portion of of the case.
This grinder features the much touted Milwaukee M18 battery 18V technology. Featuring low temperature operation and double the lifetime of competing products, the M18 battery line is sure to please. There are close to a dozen tools featured in the Milwaukee cordless tool line that make use of these M18 batteries.
The Red Lithium (LiIon) Battery pack has a fantastic feature where with the press of a button, you can see the battery level of the battery pack. This means you'll never be caught off guard with a dead battery in the middle of a project. No need to carry spare batteries with you to the work site.
The downside is that these batteries are pretty hefty in weight. One XC4.0 battery (included) weights a whopping pound and a half.
Additionally, the chargers are meant to be universal for all of the M12 & M18 product lines, meaning that they'll be unusually large, and host additional charging ports that are of no use for this product.
The M18 cordless grinder weights in at nearly 6 LBs (!) which is noticeably more than his cordless sibling (4.5 LBs). However, when you remove the M18 battery, the grinder's weights are nearly identical. Unfortunately, this means that your arm will become fatigued quicker with the cordless model in exchange for the cordless freedom.
Another feature is that the cordless grinder accommodates up to a 5" grinding disk/wheel. The corded version maxes out at 4.5." However, Home Depot only caries 4.5" disks, so i'm not sure this is much of a benefit.
The cordless unit is also over 2" longer, mostly to accommodate a better sense of balance in the unit.
This is my first M18 tool. I wasn't sure what to expect. However, i'm quite pleased with the performance. I had no problem cutting concrete with a cutoff disk. The battery held up to quite a load, and didn't excessively strain the motor with even a large amount of pressure against the concrete.
The cordless freedom is definitely appreciated, as you have limitless range and mobility. The all rubber grip allows for easy holding of the grinder. There is no kickback when powering on this tool. However, this unit is surprisingly noisy for a battery operated tool.
From what i can tell, this cordless unit works just as well as its corded brethren.
The M18 battery technology is impressive in its longevity. But then again, it should be for its size and weight. This mobility comes at a price premium.
The grinder itself is well balanced, and easily usable. But at over 16" long, it is unwieldy without the handle installed.
Surprisingly loud for a battery operated unit.
The extremely large plastic case comes with an oversize charger, yet doesn't have much room to store spare disks & wheels.
Overall, a solid addition to the M18 family.