what's wrong with my drill?

kawak

I've got a makita 12v driver/drill I've been using for a while that had no problems. usually I pull it out, charge up a battery, and it's good to go, but I rarely put in long hours with it.

just started up a big project, and the drill is extremely sluggish and low on power, even with freshly charged batteries (nimh).

I checked the batteries after a charge and after a bit of use, and they are both at or above 12v.

I changed the brushes on the drill, and cleaned it out, and still no improvement.

one thing that seems weird is that when I put in a fresh battery, it appears almost dead (slow, no power), but if I hold the trigger down for a minute, the battery appears to 'wake up' a bit, and responds better to the trigger, although nothing like I would expect. I doubt it's a weather/warm up problem, as I am in Hawaii, and it's still at least 85 degrees out when I'm working.

I've never really experienced a dying drill or battery pack, so excuse me if these symptons point to something obvious.

Thanks for the help!

NateHanson

If it's NiMH, then I'm guessing this is a newer driver (not more than a couple years old?)

If it were older, I'd just say your batteries are dead. I just had to replace the NiCad batteries for my Makita 12V, but I've had that for about 8 years or so, and it's been used pretty hard.

To eliminate the battery question, you need to find someone with a makita 12V tool that is working well and use their battery. If you still have the problem, it's your tool. Or if putting your battery in their tool makes theirs run slow, it's the battery.

space_coyote

Could be the trigger going bad?

RussellF

Bad battery contacts?

End Grain

If it's variable speed, and if the batteries are actually proven to NOT be the culprit, I'd agree that it's probably in the trigger mechanism. Sounds like very high resistance.

kawak

Thanks for the suggestions. I'll open up the drill and check the voltage out of the trigger, and see if I can't walk into a Home Depot or something with the drill and battery to do some testing.

kawak

opened up the drill to check out the trigger and don't think that is the problem. my meter shows very little resistance through the contacts with the trigger depressed, and voltage through it is still over 12 V.

something has to warm up to get it to work. I just discovered that if I hold the end so it can't turn (the drill has no torque when it's 'cold') and then hold the trigger for 30-60 seconds, when I release the end, it will have good speed and power after that. very weird.

I did notice that the part the brushes sit on was kind of sooty. cleaned it off, but it made no noticable difference.

might be time for a new drill....

Andy in ATL

Maybe. That kind of blows though. Makita is my brand and I get 18 mos. of VERY HARD use out of them.

End Grain

The more I think about this, the more I'm inclined to agree that it's battery related. Earlier on in the thread, it was suggested that a brand new or at least different 12V battery be inserted to test the drill itself. Good idea. If that doesn't do it, then buying a new drill is probably in order.