Angle Grinder and Cup Wire Wheel Question.

[George7941]

I bought a 4in cup wire wheel from Fastenal, #0838653 and mounted it on my cordless Makita grinder, #BGA452.

I can feel a significant vibration when operating the grinder. Should I return this wheel to Fastenal as defective? This is the first time I have used a cup brush and it is much heavier than the grinding and cut-off wheels that I normally use on an angle grinder. Will all cup brushes make the grinder vibrate?

I cannot try this brush out on my corded Bosch angle grinder since it has a M14 arbor and the cup wheel is threaded 5/8-11.

Here is a photo of the setup and also a video of the grinder running (just click on the second photo).

 

[SuperDave456]

Just like a tire that is out of balance.

I haven't used a cup wire wheel on my angle grinder, but I'd imagine they all do it. What company is going to spend the time and money balancing them? I mean... they kind of get ground down just like everything else.

I'd just take it slow, or as slow as you are comfortable with, as Angle Grinders scare the heck out of me. Now that I think of it "Slow" and "Angle Grinder" really don't belong in the same sentence.

An angle grinder is kind of a "Get'er Dun!" type of tools. Sure you can be accurate... but you can also tear all kinds of things up in a hurry.

Be careful... and wear safety glasses!

 

[tig1]

Your good. They all do that. Also wear eye and face protection as wires can come out of the brush at a zillion MPH.

 

[yonyon]

Wires bend. Even if it were balanced it wouldn't stay balanced for long. A wire wheel should come with a rated maximum safe operating rotational speed. Obey the speed limit. Don't even think about using it without eye protection and when it starts throwing wires (that picture looks like one that will hold up for a long time) throw the thing out.

 

[Rock_Hudstone]

Originally Posted By: SuperDave456
I'd just take it slow, or as slow as you are comfortable with, as Angle Grinders scare the heck out of me.
but you can also tear all kinds of things up in a hurry.

Thats the truth.

I've used many cup brushes on my Porter Cable grinder, none vibrated. However, one took a nice gash on my shin when I was wearing shorts and it kicked back.

You must use two hands and be careful of the angle/direction of the brush to the work surface. Some of the cheaper versions lose metal bristle in use, they fly off hard and penetrate the skin. You have to pull them out like needles, wear heavy clothes and gloves.

 

[cchase]

Check rated speed of wheel, and compare to angle grinder speed. Do not exceed.

 

[Merkava_4]

What speed does your 4-1/2 inch grinder turn? I'd say somewhere between 9000 and 12000.
That 4 inch wire cup wheel is probably rated at 5000 or 6000 ... as in 7 or 9 inch grinder.

 

[George7941]

I am within the speed limit.

The Makita grinder is rated at 10000rpm no load, though when you turn it on, it does not feel anywhere near as fast as my corded angle grinder also rated at 10000rpm.. The Makita seems to get stronger as you load it and it gets the job done.

The cup is really heavy, it weighs as much as the grinder withouit its battery. The grinder is very lightweight. So I suppose it is not surprising there is some vibration.