HF Long Nosed Die Grinder

I got one for Christmas and the metal part at the front gets hot awfully fast just running it at idle without even stressing it. In less than a minute it's uncomfortably hot, but not so hot that I can't hold it. Are they all like this or did I get one with a problem? It doesn't sound unusally noisy, and the parts breakdown shows it having ball bearing, not sleeves.

RWL

Reply to
GeoLane at PTD dot NET
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Use an in-line oiler full of trany fluid set pretty high. Messy, but will last a long time.

Reply to
Buerste

If this is the electric HF long nose grinder, I noticed the same issue. I've got a couple of hours use on mine now and it seems to run a bit cooler. Hasn't seized up yet, so I guess it's okay. I use it mainly with a cut off wheel for cutting rusty sheet metal, rusty bolts etc. Seems to have a lot more power than the air die grinders, although we have a $450 dollar Ingersol Rand air powered unit at work that probably has a little more zip. For $30 bucks it's hard to beat.

Reply to
oldjag

Thanks Tom, but this is the electric one.

RWL

Reply to
GeoLane at PTD dot NET

On Fri, 26 Dec 2008 22:44:59 -0500, the infamous GeoLane at PTD dot NET scrawled the following:

Sounds like either a poor design or a problem. Take it back to the store and ask about it. Most air tools get very cold when in constant use.

My 1/2" impact got very slightly warm after removing 4 wheels from a vehicle, but that's heavy use. It's the only air tool I've ever used which didn't get icy, and I used air tools daily for 15 years when I was wrenching.

Tawm's suggestion of an inline oiler is a good one, too, but I doubt that's the problem--if you put a couple drops in before running it.

-- We should take care not to make the intellect our god; it has, of course, powerful muscles, but no personality. -- Albert Einstein

Reply to
Larry Jaques

If it has speed control start out on lowest speed until it hits 100F or so and stop it to cool. Repeat. When it stays below 100F on lowest speed, bump up speed and repeat process until you can make it to full speed.

If all fails it is under warranty :)

Wes

Reply to
Wes

It's likely the end bearing, although just because a parts illustration shows a ball bearing assembly, it doesn't mean that's what's in there. They will probably happily exchange it, which shouldn't cost you anything if you have a store nearby.

Haven't you ever noticed the obscure or fine print on a warranty form or owner's manual that reads something like "parts and specifications subject to change without notice"?

When I disassembled a new Chinese angle grinder (as I always do), I found a steel bushing shaped like a ball bearing (ID, OD, thickness) in place on the output (spindle/wheel) shaft.

And no grease, but lots of dirt/grit.

Reply to
Wild_Bill

...and your point being?

Reply to
Buerste

Uncomfortable is probably not more than 120F or so, which is not unreasonable for a ball bearing running at high speed. Unless you think the bearing itself is much hotter than the housing, or gets even hotter over longer periods of time, and it's running smoothly, I wouldn't be concerned.

Reply to
Ned Simmons

On Sat, 27 Dec 2008 13:09:30 -0500, the infamous "Buerste" scrawled the following:

'Lecterkal motors take a weeeeeee bit less erl than air motors.

-- We should take care not to make the intellect our god; it has, of course, powerful muscles, but no personality. -- Albert Einstein

Reply to
Larry Jaques

Well, thanks for the response, but you're picturing the wrong type of die grinder. Mine is electric. You're picturing a pneumatic one.

RWL

Reply to
GeoLane at PTD dot NET

wrote: Well, thanks for the response, but you're picturing the wrong type of

^^^^^^^^^^^^^^^^^^^^^^^ Well, go get a pneumatic one, and if the problem persists, we can continue the discussion.

Reply to
Leo Lichtman

Apparently not this one!

Reply to
Buerste

You're going to have to adapt an air oiler to your model, it'll be just a bit more difficult.

Reply to
Buerste

I have had a similar Sears die grinder for 25 years. As you said in another post, yours is electric and so is mine. It, too gets hot to the touch after a short while, but It hasn't ever bound up on me. "Hot to the touch" is a relative term, but UL defines "too hot" as over 137° F. That's the point where most humans can't continue to hold onto something. If you get one of those Harbor Freight $10 non-contact thermometers, you can measure it. Most electrical things in the shop seem to be rated to be able to run at a "50° C rise". Assuming it's 70° F in the shop, that would mean the tool could get to: 70 + ((50*1.8)+32)= 70 + 122= 192°F before going over its spec. for temp rise. Again, mine does get "hot", but I have used it constantly for up to

1/2 hour at a time without a problem other than that end bearing coming loose now and then. BTW, my die grinder is rated at 1/4 hp. and is a single speed machine.

Pete Stanaitis

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GeoLane at PTD dot NET wrote:

Reply to
spaco

Too much grease as well as too little grease will cause high speed bearings to overheat.

John

Reply to
john

repeat process

........................................................

The 90 day warranty gave me the freedom to see if this would self correct as both of you said, or self destruct, the latter of which would make a return to Harbor Freight much easier. I decided to run it for 15-30 minute sessions once a day. I started this before I got Wes's suggestion to use a speed control, so I've been running it unloaded at full speed. With this program, the temp has come down to what I'd consider normal, which was similar to Oldjag's experience with his. To recap - the first time I ran the die grinder, the end got too hot to handle within 1 minute of turning it on. By running it for increasing lengths of time without load, it began to work itself in and now is at a reasonable temperature. I'll continue to run it for a few more long periods to be sure it won't have problems, but it looks like running it will allow it to self correct.

RWL

Reply to
GeoLane at PTD dot NET

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