Heavy Duty Long Shaft Electric Die Grinder

I don't have alot of hours on my Die Grinder yet so the best I can say at this point is so far so good. The torque is adequate and the speed is perfect for my needs. My use of the grinder so far has been to polish the hard to reach places on the lower sliders of the forks of my motercycle. It has worked well for that purpose. The only problem I've had in the polishing process using the die grinder was that the shank of one of the buffs I used was slightly undersized. It may have been a 6mm shank instead of a 1/4" shank. I was still able to use the buff however I had to bare down on the collet more that I wanted to. That is NOT the fault of the die grinder, but rather the maker of the buff. In the future I will measure the shanks of the tools I plan to use in the die grinder. If they're undersized. I just won't use them. Given what the seller is trying to sell and the amount of money being charged. It's not surprising that a few units are clinkers. Mine so far is not. It's been good to me and I would recomend it to a friend.J.P.

I'm an elevator mechanic which means I have to work in tight spaces. I got this to help me grind out welds that are otherwise impossible to reach and to elongate holes that were misdrilled. It doesn't have variable speeds which isn't a problem at all. It's very sturdy. When I put in good, sharp bits, this thing will knock down steel welds as quickly as a standard grinder. I'm very happy with it and it's saved my butt many times.

I needed to replace my old die grinder and saw this one on Amazon. Seemed to be a solid product, price was good so I purchased one. Arrived in timely manner, well packaged. During use, for me, it seemed to be heavy on the front end. The other thing was either I misread the description or mine came w/o variable speed, which you need for this type of tool. However over all this tool performs very well and I would recommend it as a good product.

Failed at nine months. Didn't get alot of use.

Apparently this unit is the same tool sold by several others -they just put their name on it. If I was planning to use a die grinder on a regular basis, I probably would have bought the Makita because all their tools, in my experience, are excellent.When I first went to use this tool, I chucked a tapered grinding bit on it to 'clean up' a few holes I made in steel with a cutting torch. This tool got super hot! I thought 'oh no; something's wrong'. Let it cool and used it again and worse; super hot and slowing down!Looked it up on Internet and found other reports saying theirs were getting super hot like mine, typically griping about 'made in China' (but I'm so glad to see China doing well since the iron curtain is fallen, for the people's sake)Not wanting to send mine back and fuss with the dealer, I took mine apart to see if I could notice anything wrong.The bearings in the shaft extension looked perfect but only tiny dab of clear grease visible. So I put drops of oil on the seal's parting lines, spun them, then put dabs of grease on the seal gaps and worked that in with a screwdriver, making sure I got grease into the front shaft bearings. I went ahead and loaded the front shaft cavity with approx. teaspoon full of grease. (like one might find inside an ordinary drill gear cavity)Put it back together and still ran the same; super hot & slowing down in a minute or so.So I took it apart further, noticing how hot the motor section was; removed the brushes (they weren't even fully seated yet) and examined the bearings on the armature (same kinda bearings as the front shaft; almost a sealed bearing but they have a tiny gap that will accept drops of oil) ...THEN I noticed the problem; there were obvious -visible- marks on the armature winding where it was contacting the outer field coil windings, and marks on one of the windings!That's why it was getting so hot, and once hot it drags the armature even more to make it start slowing down (by heat expansion make even more contact = excessive friction & and slowing down)SO, I took my armature and chucked it on my mini drill press and carefully used a mill bastard (flat file) to shave off some material where I could see it was making contact with the body/handle/case mounted field coils. Cleaned it, put drops of oil on those bearings, wiped off excess to make sure no oil gets on brush contacts. Re-assembled again. Tested; ran smooth, fast/full speed/no slowing down & noticeably less hot (still hot though even wearing leather work gloves)OK. So I began using it... an hour & still running slightly hot (but no slowing down like before)... another hour & I'm getting used to it... another hour and... it's beginning to run cooler! By the end of those several hours, when I finally put it down to quit for the day, it was no longer running uncomfortably hot -just warm to hold with the leather gloves on.Summary; this tool has anti-vibration rubber cup on the back bearing of the armature. I strongly suspect that the rubber cup may be slightly too soft and allows the armature to contact the field coils as the tool vibrates from running a less than perfect cutting bit. Once I shaved the armature slightly with a file, spinning it on my drill press, and got all the bearings lubed up better... then... it took a few hours of using it for it to 'break in' and become the tool I wanted to buy in the first place.Within the first hour of work, vibration from the tool caused the body of the tool to cut through the rubber extension boot that is supposed to function as a cord kink preventer. I just wrapped mine with tape there at the butt end of the case and kept working!After taping the cord there, shaving the armature slightly, and making sure there's lube on all the bearings...Now I have a good running electric die grinder... for the lowest price!I think rubber parts are not quite the correct chemical formula for the application and they are apparently too soft.The manufacturer needs to improve the rubber quality of the rear bearing anti vibration bushing, and make sure the armature does not contact the field coils, and improve the quality/type of rubber they use for the electric cord anti-kink extension on the butt end of the tool case. AND they should consider including a note of information to diagnose potential problems as the tool gets broken in.

the die grinder is a real poweful work hourse that can just make a bit clean metal that air takes time and withouut a compresserits faster and I am sure cheeperIt doesent like to be bound in a small area like reaming bolt holes under 1/2" but if you know and hold ittight it willll workFor all the other jobs arouund the shop itts king more than worth the money

So...I tried using this thing this weekend.Defiantly wear eye pro, probably a face sheild an gloves. Bystanders should be well clear and prepared to dial 911.This thing is junk!Upon touching the carbide bur to the work piece, the motor housing snapped off and the brushes flew out the sides.Take your money and throw it away if you still want this POS.

This blows the doors off my pnuematic grinder -- faster, more powerful. And it sure feels sturdy. Heavier than the pnuematic but that's completely expected. Whatch your hands with this!!!