how do you reverse rotation direction on grinder

Thomp · #11 11-07-2006, 03:31 AM

OK i tore into the little grinder tonight and had catastrophic, results..

some how the commentator cage (fields) got twisted in the case and the brushes were pinned in and didn't align with the case perforations so they couldn't be extracted.

they finely busted while releasing the bearings from the safety guard/motor end cap. so im stuck in the water till i find the spare set.

i continued to remove the end cap on the left from manufactured position, and took it to the side grinder with a weld cutting blade i removed all the shroud except a small lip that would still seal the case. and hold it in center position, I polished the cut to smooth on the buffer and reassembled, but now the armature wont turn, but slightly im thinking its a small piece of the brush i didn't find in the case but i gave up and put it in a box...

maybe if i cant get it back together right, i can find another at the store, i really liked that mini bench grinder...

it was after midnight when i gave up on it and got cleaned up, but ill take another look in the daylight.

AlArchie · #12 11-07-2006, 12:05 PM

Has anyone come up with a wiring diagram on how to electrically reverse these things? I just checked my trusty old B&D electric AC, VS/R drill and it reverses with just a switch. Armature goes both ways, so it's not a mechanical reversal. I'm tempted to pull the darn thing apart to see what makes it "go" then "og", but I'll never get it back together again.

Al

Thomp · #13 11-07-2006, 01:04 PM

al,
my suggestion, "LEt it be one of the curriositys of how the world works" DONT OPEN IT!
HAW!
that said

with my luck, lately i would be running back to flip the breaker back on soon as i pulled the trigger to test it....

My grinder reversal efforts syatus:
these little grinders have a dang circut board in the base where the reostat is located,,, i still got electrical poentential to the brush housings in my little grinder now to make some brushes... cuz i know ill never find replacements,,,

Lynn O. Doughty · #14 11-07-2006, 02:22 PM

All this talk about changing polarity when the solution is so simple........

Just walk around to the other side and do your grinding there!

or......

Box up the grinder, buy a ticket to Rio and when you get there it will be working in the reverse direction due to the "Coriolis Force" of the earth's rotation.

AlArchie · #15 11-07-2006, 03:11 PM

Ya mean the earth spins the other way in Rio???

Al

Kenny_S · #16 11-07-2006, 03:12 PM

HEHEHEHEHEHE, Lynn, somhow I don't think the latter works. But who am I to say, Was funny though.
Kids have to play with their toys, eh?

I know I do, LOL

Lynn O. Doughty · #17 11-07-2006, 05:01 PM

Come on fellas.....didn't you pay attention in geography and physical science class? Haven't you ever been south of the equator? Water goes down the drain in the opposite direction and typhoons and weather patterns also rotate in the opposite direction as it does up here.

So....Rio, being south of the equator, would be a good place to see if it works for electric motors too. Besides, being as it's summer down there now, all the girls are on the beach wearing those little stringy things so, if my theory doesn't work you can go down to the beach, get yourself a rum & coke, soak up the rays, ooggle the ladies, and unwind in style! In the opposite direction of course!

AlArchie · #18 11-07-2006, 08:28 PM

Yep, the weather systems are influenced by the coreolis effect, but here's a piece on the "bathtub drain myth".
http://www.loc.gov/rr/scitech/mysteries/coriolis.html

Although, my head might be doing a bit of rotating on those southern beaches! I'm old; I ain't dead!
Al

Lynn O. Doughty · #19 11-07-2006, 09:58 PM

Al. Having lived in the southern climes for a number of years I can attest that water does indeed spiral down the drain in the opposite direction. Also, having lived in Accra, Ghana, also known as the "City nearest to nowhere" due to it's close proximity to 0 latitude, 0 longitude, the water there goes down the drain with almost no rotation at all!

AlArchie · #20 11-07-2006, 10:26 PM

Well, guess I'll concede the drain rotation, never having put in time in the sothern hemisphere, but I do know that sometimes here in the UP, the water goes straight down with no rotation. In fact sometimes in the depths of a -50 degree winter, it don't go down at all!

Then again, we live right where the magnetic compass declination is 0 degrees, and there are a few spots within 20 miles where a compass spins, but I don't know if that is a RHR or a LHR...have to check next time I cross one of those anamolies.

Hope nobody's taking this too seriously.......

Al