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Cordless recip saw test: Ridgid comes last

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  • #31
    Re: Cordless recip saw test: Ridgid comes last

    Yes that is true about protecting the motor as well. I've mentioned that on here before. They are safeguarding against many things, including battery life, battery runtime, motor life, tool kickback.

    You have to define what it means by what the cells can handle. Yes they can put out 50 amps if you want, but they WILL get a lot hotter if you do that. The more you allow the cells to be exposed to that, the faster they will degrade. DeWalt wants the batteries to last, so they block the motor out from operating past the point where the efficiency sucks and the tool is not performing much useful work.

    Originally posted by DRC-Wartex View Post
    Captain Obvious strikes again !

    Yes, they cut the power because you will have nearly 50 Amps going thru your motor winding which will melt the varnish and cause a short, not because cells are in trouble. Makita cuts power in fear of cell detonation. My point was that the threshold is different, providing higher peak power with dewalt. Also, the highest power hog is the DC900 and the circ is not anywhere close in power draw when you use big auger bits. I noticed they toned this down on 28v version, effectively screwing you if your drill binds because BMS detects high current on startup and kills it before your drill bit even has a chance to move in the material.

    One thing we definitely agree on: DC415 is a freaking beast. I stuck a diamond disk in it once and cut a square hole in a concrete wall.

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    • #32
      Re: Cordless recip saw test: Ridgid comes last

      Well looks like I'll be getting a DC415 then!

      Here's my experience on battery trip protection. Some time ago I didn't have DW130 mixer drill around so I ended up using the DC900 36v drill and BHP451 18v Makita for mixing thinset and concrete, about two dozen buckets total. Turned out to be an interesting test that really gave them a workout. I can tell you one thing, Makita doesn't appear to have ANY battery protection circuitry built in. More on that later. The Makita has a ton of torque since it's geared to spin so slow. It still had to be used gently for mixing as it would still bog down and stall if forced too agressively. The DC900 is a beast. Torque is brutal even at it's faster RPM. Bogging it down was very difficult and could almost match the mixer! However the batteries tripped twice on the Dewalt when pushed really hard. Had to put them back on the charger to reset. Both drills got insanely hot after a while. It's a perfect example of why if a battery can pump out incredible current doesn't mean it should. The 36v battery trip easily saved the drill those two times. The makita after a while started to turn with less and less power until the point it simply wouldn't spin anymore. I thought the batteries got cooked but they worked fine in other tools. I took the drill apart and found out what happened. The plastic ring that holds the brushes quite literally melted! The brushes got fused in place and as they wore out lost contact with the commutator until it just stopped working.

      Comment


      • #33
        Re: Cordless recip saw test: Ridgid comes last

        Originally posted by hewood View Post
        It's just somebody's opinion who happens to have a platform for publicizing it. His (or their) favorite color is no more valid that your's. The same website reviewed hybrid saws a year or so ago, and their primary criteria was ripping speed. Nothing wrong with good ripping speed but there's a lot more aspects to choosing the right saw than that.

        Next month another mag will pick another group of winners and losers....who's right? Point being...it's not gospel.
        Well, no it's not gospel but an informed opinion is better than your buddy who buys nothing but DeWalt because they've worked great for him and that's what his daddy used.

        If these guys didn't review tools all the time, I'd say you had a stronger point though. I never take Consumer Reports very seriously, because their coverage is way too broad.

        But as fond as I am of that old saying about opinions stinking and everyone having one, some stink less than others.

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        • #34
          Re: Cordless recip saw test: Ridgid comes last

          Milwaukee batteries are not 3 Ah but 2.9 with effective capacity being around 2.8 because batteries always keep some charge to feed BMS when the battery is "dead".

          This is a cell spec sheet for Milwaukee battery cells, 11 Wh per cell, 7 cells = 77 Wh. http://forum.drc.su/files/IMR26700.pdf
          You can also see that after only 200 cycles cell capacity drops to 2.5 A, that's 14% permanent capacity loss. Dewalt loses 14% at 1000 cycles. For a contractor that relies on the recip daily, this is critical difference.

          Dewalt is 7.59 Wh per cell, 10 cells = 75.9 Wh, 2.3 Ah capacity (not 2.2) minor difference
          Spec sheet: http://forum.drc.su/files/ANR26650M1.pdf

          Dewalt has higher energy transfer due to higher voltage and lower current draw to do the same work. When discharged at high currents, cells die a lot faster (more energy is wasted). So despite having a liiiiitle bit higher energy Milwaukee will lose because of lower voltage. I doubt it has a super-efficient DC motor in it that will make up for this.

          I agree that dewalt saw vibrates a lot, every tool is imperfect in some ways, but battery technology and 4-position blade holder is big advantage.

          Milwaukee is not a bad saw but I stay away from it because of crappy batteries.

          Comment


          • #35
            Re: Cordless recip saw test: Ridgid comes last

            Hey Velosapien, nice job on this test. Too bad about your BHP451 though Maybe you can order new brushes and brushholder for it. The good thing about the Makita is that you can replace the individual motor components, so it shouldn't be too costly.

            I also mixed a bucket of concrete with my DC900 once as well (but not two-dozen buckets! lol) and was also really impressed with how it handled it.

            Originally posted by Velosapien View Post
            Well looks like I'll be getting a DC415 then!

            Here's my experience on battery trip protection. Some time ago I didn't have DW130 mixer drill around so I ended up using the DC900 36v drill and BHP451 18v Makita for mixing thinset and concrete, about two dozen buckets total. Turned out to be an interesting test that really gave them a workout. I can tell you one thing, Makita doesn't appear to have ANY battery protection circuitry built in. More on that later. The Makita has a ton of torque since it's geared to spin so slow. It still had to be used gently for mixing as it would still bog down and stall if forced too agressively. The DC900 is a beast. Torque is brutal even at it's faster RPM. Bogging it down was very difficult and could almost match the mixer! However the batteries tripped twice on the Dewalt when pushed really hard. Had to put them back on the charger to reset. Both drills got insanely hot after a while. It's a perfect example of why if a battery can pump out incredible current doesn't mean it should. The 36v battery trip easily saved the drill those two times. The makita after a while started to turn with less and less power until the point it simply wouldn't spin anymore. I thought the batteries got cooked but they worked fine in other tools. I took the drill apart and found out what happened. The plastic ring that holds the brushes quite literally melted! The brushes got fused in place and as they wore out lost contact with the commutator until it just stopped working.

            Comment


            • #36
              Re: Cordless recip saw test: Ridgid comes last

              I did repair the drill by butchering the compact BDP452 for the parts in the meantime until I order a replacement parts. Too bad makita doesn't have something like ServiceNet to order spare parts. Would make things so much easier. The drill does seem very well built with a nice beefy gearbox. The connectors from the brush lead cables to the trigger were a different but a quick trip to radio shack for the proper crimp terminators fixed that right away. I'll try to post some pics of the melted piece later. When I say the drill got hot it's an understatement. The air coming out out of the vent holes was so hot I had to hold the drill so the air wouldn't hit my arm. It was that hot. Any reasonable person would have stopped but I really needed to get the work done. I figured a replacement drill on ebay was cheaper than time lost . An interesting note is the cables to the brushes were 14 gauge so they wouldn't handle much more than 20 amps or so. If the batteries could pump out 70 amps it would be total meltdown.
              Last edited by Velosapien; 11-14-2008, 02:27 AM.

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              • #37
                Re: Cordless recip saw test: Ridgid comes last

                Parts List for Makita BHP451 18V 1/2" LXT Lithium-Ion Hammer Driver-Drill
                http://www.makita.com/en-us/Assets/I.../PB_BHP451.pdf

                You should be able to order parts from either a Makita owned and operated service center or a good independent authorized service center and have them mailed or sent FedEx or UPS.

                Makita Service Centers and other service related information:
                http://www.makita.com/en-us/Modules/...ceCenters.aspx

                This online web site has loads of power tool repair parts for many brands. It might be worth giving them a try.
                http://www.ereplacementparts.com/

                Another online tool parts dealer. (This is part of a big online tool dealer known as TOOL BARN)
                http://www.toolpartsdirect.com/
                Last edited by Woussko; 11-14-2008, 04:14 PM.

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