DEWALT 20V MAX* XR String Trimmer, 14-Inch, Tool Only (DCST922B)

before I start, it's 5 stars from me - love this unit and I'm returning right now to buy a replacement. More on that below. Included some photos so you can see how the gunk will build inside the unit - gunk can build up exactly where the motor tries to breath! So I did my very best addressing this with some tips below.some care and usage tips after 1.5y solid runtime:- regularly CLEAN THE VENT HOLES for the motor at the head of the unit - it needs to breath. Use Qtips, for example, and perform these maintenances before or after EVERY RUN to keep the gunk from getting "pushed" in further by more gunk.- Edit: Turns out a WIRE BRUSH is enough 99% of the time. QTips not needed. I've been doing it *before* runs when the gunk buildup is dry. When I look into the vent holes, I can see this is doing a good job. Convenient, fast, and easy to do.- Mind that these small vent holes (at the top of the motorhead) are AIR INTAKES - so they attract material into the holes via negative air pressure (ie. slight vacuum). The larger holes below are exhausts - don't need to worry about those, they don't collect gunk buildup because they blow air out.- the vacuum effect is not too big of a problem, by the way - the intake vent hole vacuum isn't that strong. You could go 3 heavy runs without the vents getting too clogged - just depends on the nature of the runs. Just have to keep an eye on it, and have to consider running a wirebrush over it before every run - that's a good and easy maintenance.- the motor on this unit is down at the end of the pole, for that reason you might want to STICK TO DRY CONDITIONS with this unit- DO NOT WASH the head of the unit with water - use a wire brush- avoid sweeping the tool deep in bunches or piles of cuttings or other material (such as grass you just cut, where you want to make a 2nd, lower sweep to cut farther down) - that is a source of the "gunk" that can get in the vent holes.- combining the logic of some advice above: EVENING HOURS when its both dry and cooler are the best times to make runs.- as you would expect, this brushless motor can BURN OUT if you really push it.--- take some breaks especially during the hottest days--- don't just swap 5AH batteries in back-to-back without letting that motor cool off some--- sometimes the batteries get hot, and will prevent the unit from running - THATS GOOD (if annoying sometimes) - now listen: we can prevent the battery from making this decision by simply holding the trigger for a long time. THATS BAD, DONT DO THAT. LET THE UNIT REST. If the battery does this, and you feel like the motor shouldn't be running too hot (ie. you've been keeping gunk from the vent holes, ambient temp is avg or low, etc), then *maybe* it's an OK time to swap batteries just for a bit so you can keep working - the batteries do heat up faster than the motor.EDIT: I read that the motor also has heat sensors which will prevent the unit from running. In that case, it seems the point stands:- *Do* regularly let off the trigger to see if the unit wants to take a break.- just saying it one last time... It seems very important that the vent holes remain unobstructed by gunk, to help the motor stay cool.- It also seems that operators in more humid climates should take extra care, because very dry material, or conditions, won't lead to "gunking up" in the vent holes as deleteriously - although, plants generally are wet when cut. Apply discretion.- Dewalt probably wouldn't recommend this, but after maybe 1y of solid use, you might open it up to get Qtips farther in and keep the passageways unobstructed. Note: start unscrewing from the head back - the neck doesn't need unscrewed.- dont forget the high/low setting. Low will generate less heat, and low does great work when set against "easier targets". On the same token, if you use low against heavier targets, you'll end up running longer trying to wear the targets down, and it'll make more of a mess which means more gunk to obstruct the vent holes, and negate the efficiency of using low - so HIGH is better against those targets. EDIT: I've been just running on "low" lately with the new unit, and using dewalt's own .08 string .. why did I ever do anything different? Just run on low with their .08 string, it works great. The string is small and "cuts".- going to recommend sticking with dewalt's advice to only run their .08 line - that is what it is designed for and the longevity of the motor should take priority over the reasoning for using different string- not 100% sure on this, but I imagine (and from experience it does seem like) allowing the string out more often toward the 14" radius will help with many of the points above. The string travels at a higher MPH out farther from the head, cuts better, and the cuts are creating gunk at more of a distance from the motor. So that sounds like win-win right? I suppose so. EDIT: the string length does make the motor work a lil harder. Apply your own discretion.My situation:I let the head's vent holes get a bit cloggy and now I'm back to buy a 2nd unit (because I like this product so much). Basically I burned the motor out by running on high setting for 2 entire 5AH charges back-to-back (yes, I violated all my tips above) and it just died and wont start now. Dewalt does offer a "fixed in $79" guarantee via their website, but I figure after taxes and buying packing and everything I'd be out $110. So why not pay the extra $50 and get a brand new one. Won't be making the same mistake again. Might also be more careful about banging it to draw the string out ... don't want to bang it too hard - that trimmer head has electrical board & wiring in it! Not that I ever abused the unit too much ... or so I thought. Anyway, $160 for 1.5y of using this unit, for how light and convenient it is, and how quiet it is, and considering how much I used it, and the heavy jobs I set it on ... I'm too enamored to go without it, and getting a replacement.

This is works effectively and 100% better than my old weed eater. This works with my deWalt battery. My DeWalt 5.amp battery last long enough to finish my large front and back yard. The duel weed eater wire automatically extends. The only negatives is it’s heavy. Also, watch a YouTube video on how to load new weed eater wire. The instructions are horrible.

So I did the yard. Very nice tool. Weeds get caught between the head and shaft but come out easily. It is heavy and goes through smaller batteries like crazy. I used 2 3AH batteries and did the whole yard. Both batteries were drained though and recharging now.Very minor drawbacks. I am getting some 5AH Powerstack batteries anyway. Very happy. Also I only used the high setting one time for about 30 seconds. The rest was all low speed and worked great. I fully expect this tool to be much stronger with the 5AH Powerstack batteries. Awesome weed trimmer. 100% recommended.

Oilfield Engineer for 40 years. 38 US Patents. Pretty good mechanic to boot. Here's the skinny on this tool.I bought this because (a) needed a battery string trimmer for a new Bermuda lawn in South Texas (b) I'm already invested in the Dewalt 20V system, (c) have a big 20V/60V 6A battery that I rarely use, and (d) got a Black Friday Price.[BTW, here's my Dewalt 20V tool inventory: top-of-line drill and driver (used constantly), reciprocating saw, flashlights, caulking gun, PEX expansion tool]PROS(1) like all DEWALT Brushless tools, this one is VERY POWERFUL. On high speed/power, it easily knocked down the clump grass surrounding the Bermuda lawn using the standard .080" string. It'll supposedly take .095" string; might get a spool of that for trimming clump grass in the spring.(2) on Low Speed, it's much more controllable than my monster gas-powered Husqvarna brush cutter/string trimmer with the bicycle handles and fancy harness. OTOH the Husqvarna will cut 4" live oak saplings with the circular saw blade. In any case, it's perfect for trimming the Bermuda...(3) Quick, Quiet, No-Fuss Trimming. However, that's typical of all cordless trimmers I suppose.CONS(1) HEAVY and POORLY BALANCED. Even with the 6A battery loaded, the CG (center of gravity, or "balance point") is BELOW the hinge. The D-ring handle mounts ABOVE the hinge. Personally, I'd trade away the hinge "feature" for the ability to move the D-Handle done closer to the CG.One reviewer suggested cobbling-together a shoulder strap from a old laptop case strap. That seems like a good idea. The World Wonders why Dewalt didn't think of that.(2) battery shroud hides the battery condition buttons and lights. REALLY? Seems like a rookie mistake.There's one feature that I think is neither good or bad, just different: the string cartridge is NOT Quick-Change as on most gas powered trimmers. Instead, you feed 20 feet of string through the grommeted holes to the mid-point, then wind the string onto the bobbin by twisting the cartridge. For typical users (i.e. not pro landscapers) this is probably as good or better than the cartridges, as those can be finnicky to load...OVERALL, if you are already a Dewalt 20V System Owner and need a cordless string trimmer, this one is handy, powerful, and cheap (at the sub-$100 price, anyway). It's perfect for my application, and saves dragging-out the Husqvarna to trim some wimpy Bermuda Grass.If you are a typical lawn-owner who is NOT a Dewalt Person already, and have no need for a "family" of cordless tools, I do believe I would look elsewhere before considering this one. See Best String Trimmer reviews all over the internet and takes your pick.