Is it possible ?

[L. D. Jeffries]

I have a Sears 5-1/2" trim saw that runs (?) on a 14.4 VDC battery, model #973.113080. Or should I say it should run on that, but even with a fully charged battery it won't cut a 6" piece of soft pine! It came as a set with a drill; such a bummer I gave the drill to a friends kid and tossed the saw under the work bench. My thought; can I get a DC transformer and wire the thing to run off of stepped down 120? Either a transformer or something like a Variac (sp)? Hate to throw it in the trash but its a piece of junk on batteries. What do you guys think, yes or no way? Thanks.

[phi1l]

First check the blade. I had that happen to my small abttery saw & then I looked at the blade, I had cut some acrylic with it & some of the acrylic had melted & stuck on the blade. After I got rid of that stuff it worked a lot better. Also your blade may be dull or damaged.


Since the saw runs on DC you can't just take transformer & step down you house current & get it to work. You might try a high capacity auto battery charger though. Car batteries are ~13.2V (nominally 12v) but charging voltage is somewhat more. So I expect a car battery charges should be about right for a 14.4V tool.

[master53yoda]

speaking from experience, it happened to me when i swapped the blade in a hurry and then it wouldn't cut soft butter....I had the blade on backwards

[Uncle Cracker]

I too would recommend you examine the blade closely. There could be pitch or gum stuck to it, or even a couple of teeth knocked off or dulled down can do you in.

[LCHIEN]

I was thinking that the blade could be in backwards, if its new to you.

And check the battery. You could have a defective battery - this happens if the battery has been sitting around a couple of years. A battery with a couple of bad (shorted) cells can be fully charged by a charger but a few volts short. It'll never produce the torque and speed that you need.

If you have a voltmeter, figure it this way:
Divide the rated voltage by 1.2 that will give you the number of cells (like a 12V system would be 10 cells), it should be an integer number.
Then take the number of cells and multiply by 1.45 which is the volts per cell coming off the charger, fully charged. If you don't get close to this voltage and are 1.45 or 2.9 or 4.35 etc volts short then you have dead cells. Like with ten cells you would expect 14.5 volts but instead you get 13.05.

[Chris S]

I have that combo and the saw is junk, even when brand new. In a recent post, I stated I was going to replace the stock 1300 mAh cells with 2000 mAh cells. I think this should help greatly. The only thing I've found the saw useful for is trimming the OSB floor I put down in my attic. I did all the ripping on my table saw, and simply trimmed the pieces to fit around wires, etc. with the saw while in the attic. This pushed it's abilities. When I get the cells replaced, I'll let you know what kind of impact on performance that has. As far as the drill, it's pretty decent with a fully charged battery, but obviously the charge falls off pretty quickly.

[phi1l]

if that is the case switching to a 2000mAh battery will just make it suck longer before the battery has to be recharged..

[L. D. Jeffries]

Thanks for all the answers. The saw blade and battery were NEW; it would cut but the problem was that 2/3 thru the cut the battery would lose so much power that the saw would just nearly stop. i expected more from something brand new! My idea about the x'former was to add a rectifier to turn AC into DC based on my experience in wiring up model railroads for low voltage and adding the rectifier for DC power. I will try the battery charger idea, thanks. If it burns up the saw, well junk to junk I guess. It's worth a try.

[LCHIEN]

the problem with those battery operated circ saws is that they never really have enough power/energy storage to do much of any work. I don't think they were intended for much more than a couple of cross cuts on 2x4 (will a 5.25" saw even cut thru a 2x4?) maybe a few feet of thin laminates, like 1/4" plywood.

Fundamentally using a transformer won't work well because its too hard to transfer the power into the low voltage at the saw motor with enuf current to do the job. Think about your model train motor and compare to the motors used in real circular saws and then scale up the power supply and wire sizes needed.

[L. D. Jeffries]

On giving it more thought I agree LCHIEN has the right handle on this. I guess I now have a 2.5 pound boat anchor as I gave the batteries to the kid I gave the drill to. Saw is not worth buying new batteries. Thanks guys for all the ideas, such a great site, as usual.

[sparkeyjames]

On giving it more thought I agree LCHIEN has the right handle on this. I guess I now have a 2.5 pound boat anchor as I gave the batteries to the kid I gave the drill to. Saw is not worth buying new batteries. Thanks guys for all the ideas, such a great site, as usual.

Batteries plus may have replacement batteries for that saw at far less than the OEM ones. Of course it may just have a second and more productive life as a boat anchor. (not affiliated with Batteries plus I just like the place). About the only time I saw a real use for one of those saws was at work. We had an electrician in for a wiring project and he used it to cut conduit (yes the metal conduit) would also be good for the plastic variety. Yes it was a real saw blade with teeth not an abrasive cutter blade.

[jackellis]

I have a Craftsman trim saw and about all it's good for is cutting 1/4" ply. Too bad because it is much easier to handle than my Craftsman circ saws.

[phi1l]

ya, .. but I like the light weight of those small saws. I have a 12V Li saw with a 4" blade. It will cut through small 1" boards. That thing is so light and easy to handle, you can comfortably hold a small piece of 1/4 ply in one had while cutting it with the saw in the other. When I have to do some "real" cutting with my 7 1/4 saw it feels like it weighs a ton.

[LinuxRandal]

Lightweight saws don't have to be cordless. Two batteries for the Craftsman, I would think be almost as much as one of these:

http://www.amazon.com/Skil-HD5510-6-...1836728&sr=8-1

http://www.amazon.com/Porter-Cable-3...ref=pd_cp_hi_2