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After reading most of the positive and negative experiences from other buyers, I decided to gamble (yep - that's the right word!) on this grinder. I have owned and used many DeWALT tools over the years, and always been satisfied with their performance, a thing that weighted in my gambling decision. The warranty (3 years) was another reason why I chose this grinder as opposed to its JET counterpart.
As (too) many other reviewers pointed out, the moment I started the motor, it started to "walk" on the table. The vibration was so bad, I had to hold it in place until the wheels spun down to low rpm (rotations per minute). It turned out I received one of the many (the keyword is MANY) units featuring wobbling, unbalanced stones, as seen in the video. (I have another video showing how fast it walks on the table, but the Amazon system only allows one video per review.) The manual states that the grinder must be bolted down before use; however, all the torque the unbalanced/wobbly wheels create will definitely damage the ball bearings, and I'm not sure if it won't break something in the process (e.g. the wheels or eye protection attachments) that could create an injury.
It is clear DeWALT is aware of the problem: the unbalanced wheels have markings on them at the point of the heaviest region (see pictures). So, I tried to balance the tool by using the markings, rotating one wheel every 10 degrees increments relative to the other wheel. The vibration changed in both intensity and direction, making the grinder walk in a different direction. Eventually, after 2 hours of adjustments, I made it somewhat less shaky, however, the vibration and walking never disappeared.
That says something about the degrading QA in the DeWALT tools, a thing that one observes in the overall appearance of the tool (again, pictures!): debris left from the casting that was not cleaned up, and painted over it, chipped paint on the corner of one metal guards.
Another issue I would point out is the steel gauge of the wheel guards: IMHO, it is too thin. The user must be careful when tightening the screws after a wheel replacement, else (s)he will strip the two or three threads that exist in that thin sheet metal.
Considering this tool is a hit-and-miss, I am returning it for a replacement. I'll update the review after I received the replacement. Hopefully, the replacement will move my review from one to five stars...but I don't hold my breath on it!
UPDATE:
Amazon delivered the replacement within a day from the day I returned to faulty product, which was the following day after writing the review above. Here is my experience with the replacement:
Same packaging (obviously), cardboard a little damaged (see picture), but the items inside were protected by the thick Styrofoam lining. [Which lining, by-the-way, was broken due to the package being dropped on my concrete porch from certain height by the driver - I could hear the thud it made when contacting the porch. So much for a careful delivery! ;-) ]
I put the grinder on the same countertop like the previous (i.e. the replaced) grinder, and prepared to turn it on, hoping it won't waltz away like the previous one.
Before turning it on, I checked the wheels wobbling. The medium (left side) wheel did have a tiny wobble, and it was marked at the heaviest point. But the right one was dead on, and had no marking. That was encouraging! The I started the grinder, holding to it as a preventative measure.
It started smoothly, with mere vibration starting mid-speed until it reached the top speed, then smooth from that point on. Some tiny vibrations are felt if holding my hand on the grinder housing, but I think they are normal for this application. Left it running (under supervision, of course) for about 5 minutes to see if it changes the behavior. It didn't: it ran smoothly throughout. When I turned it off, it slowed down again without much vibration; the resonant vibration was somewhere around mid-RPMs (revolutions per minute), but it was insignificant. Restarted, let it run for a while, and shut down without holding it. No problems at all- it ran smoothly, without moving on the countertop. While it ran, I didn't observe to become hot, a complaint read in other reviews. It does get a little warm, which is normal considering the current it runs through it, and the torque required to rotate the heavy wheels (All devices running electric current through them become warm. it's Joule's law.)
Regarding starting and stopping times: the grinder reaches its top speed in 6-8 seconds. It slows to a halt in 2m20s. This is due to the fact that it doesn't have a speed brake, and those heavy wheels have a large moment of inertia.
On to mounting the tool stand and eye shields...
The tool rests:
Made of cast aluminum, with a machined surface. The wheel goes into a 3/8" (9.5 mm) groove... I like it, it has many uses! Size-wise, I would prefer them wider: they are 1.5" (38 mm) wide at the wheel face; I would have liked it at least an extra 1/2" (12 mm) wider.
The edges were not de-burred after machining. This poses a risk of cutting during handling and tool use later on, however, taking away the burrs is really easy: two-three strokes with sandpaper grit 220 on a block, and the burrs were gone. Still, having burrs on edges is a no-no.
The tool rest is mounted to the side of the wheel guard by a zinc-plated steel bracket. The bracket is stamped rather than machined, and (again) not de-burred. We'll do the rug dance again with 220-grit sandpaper to remove the burrs, but it's more difficult to do it on the mounting channel. Done!
Assembly:
Following the assembly instructions in the instruction manual is easy, with clear to understand instructions and graphics. One head-scratching situation occurs when the user wants to use a 7/16" wrench to tighten the 1/4"-20UNC bolts, and find out the wrench is too big. (I read about this weird situation in another review, and now I can confirm it.) The hex heads of these bolts are for a metric screw, namely M6, and have a 10 mm hex head; so, you'd need a 10 mm wrench to tighten the screws. IMHO, I fail to see why DeWALT used a SAE screw thread with a metric head; they should use either one or another. Given the thinness of the wheel guards, I would go with M6 screws as they have finer pitch than 1/4"-20.
Adjusting the eye protection and tool rest is easy, with a thumbscrew for the eye shields, and a 10 mm wrench for the tool rest. IMHO, It is a good engineering decision to have the tool rest adjusted/tightened with a wrench: it is more reliable, and safer than using a thumbscrew or lever.
After the assembly, I ran the grinder again, and was very happy with the outcome. I put it in its place on my workbench, started again, and proceed to correct some screwdrivers and a wood chisel. it all went smooth like butter. (Of course, I will follow all the proper safety instructions, like bolting it to the bench, and so on.) For now, I'm happy. It's a keeper!
Final thoughts:
As I mentioned in my initial review: this tool is a hit-and-miss. The replacement convinced me of this - first I got a lousy one, just to be replaced by a really good unit.
Noise: as mentioned above, the grinder is not loud. You can maintain a conversation two feet away when not grinding. However, it's not very quiet either, due to the thin gauge of the wheel guards. Mounting the tool rests makes it louder; the whole can (ahem... wheel guard!) vibrates. If you hold the tool rests, the noise is dampened a great deal. Even so, it is much quieter than when you'll start grinding some steel.
IMHO, it still has issues that must be addressed by DeWALT:
a) according to the reviews, more than 30% have negative observations like vibrations, wobbling, etc.;
b) there are still a number of things that can be improved on it: thicker steel gauge on the wheel guards, de-burring, better QA (leading to fewer returns);
c) deciding on whether to use metric or SAE screws;
d) perhaps some niceties like an attached lamp (?)
However, considering the whole package, cost, warranty, the fact that it didn't disintegrate after being dropped from 5 feet onto concrete, and (yes!) good looks I am not hesitant to move from one end of ratings (i.e. 1 star) to the other end. I believe you WILL get a good one if you insist and return it for a replacement, no matter how many times you must return it. (I know I was ready to return it over and over again until I would get a good unit.)
