Ideal speed for wire wheel on a bench grinder

[shamrock12]

As some of you may know, 5000-5500 FPM (peripheral feet per minute) is an ideal speed for aluminum oxide grinding stone against carbon and high speed steel but how about for wire wheel? Should the peripheral speed be more or less or the same?

 

[zkling]

Like many cutting operations it depends on your application, but I think the general consensus is the mile per minute rule so ~5000 sfpm.

Some special applications will have drastically different speeds. Ex. When I do carding, during the bluing process I run a very soft wire wheel at ~500RPM or ~1/7 of the speed of a common 6" bench grinder. In my expereince whire wheels are more sensitive to feed pressure than anything else. Then you start to get those nasty flying needles as I like to call them.

I'm curious to see what this thread brings up.

 

[shamrock12]

bump

 

[zkling]

Did you not like my response? What exactly are you trying to determine? I don't think you are going to find much published info on this like you will on grinding wheels. It is pretty application and thus user specific.

 

[d.mcfarland]

Another good point is this thread to back up zkling is that bench grinders are 3750 rpm or less ... cup brush attachments for angle grinders are 11000 rpm or whatever!! They both remove material, one is just more harsh ... therefore user and application specific!

 

[shamrock12]

Did you not like my response? What exactly are you trying to determine? I don't think you are going to find much published info on this like you will on grinding wheels. It is pretty application and thus user specific.

LOL, nope I didn't

Kidding aside, you said you are curious to see what this thread brings up ... guess we got our answer

I have 8" 3450RPM and 10" 1725RPM Baldor grinders. I am just trying to figure out which one to put wire wheels (twist knot for coarse work and crimped wire for medium/fine work) on ... or both. I also plan to put on two grinding stones (again, coarse and medium).

The 10" would be turning at approx. 4515 FPM (feet per minute) while the 8" would be turning at approx. 7225 FPM.

I am thinking about using 10" for larger, coarse work and use 8" for smaller, fine work. Or put both grinding stones on the 10" grinder and both wire wheels on the 8" grinder. Guess it will depend on which performs the best at these given speeds.

 

[A_Pmech]

Brush speed is not very critical in most applications. The higher the speed the longer the brush life in general as the wires flex less, unless you get the brush caught up on an edge. Higher speed usually results in a finer finish unless the metal is soft and starts flowing under the brush.

 

[shamrock12]

Thanks everyone ... it does depend heavily on the applications of the user. That's why bench grinders are so useful - there are countless options (wheel types) to choose from. They could be used for just about anything. I just did a bit of digging and found this great technical information from Weiler:

Weiler Technical Information

It sounds like higher speed is the way to go ... so it looks like the 8" grinder is getting some wire wheels

 

[jakemac]

Ok, that solves the wire wheel problem. Now, what about optimal speeds for polishing/buffing wheels on a grinder ?

 

[ZRX61]

ALWAYS stand to the side so that you don't accidently:
a) Staple your ballsack to your leg.

b) Staple your **** to your leg.

& worst of all:
c) Don't staple your **** to a testicle.


Leather apron is a GREAT idea.... Failing that, keep a pair of pliers REAL close to hand because you sure as **** won't be any condition to walk over to your toolbox to retrieve them.

 

[zkling]

Ok, that solves the wire wheel problem. Now, what about optimal speeds for polishing/buffing wheels on a grinder ?

I personally prefer the slower 1725/1800rpm and less buffers. Kinda the same thing with wire wheels. There is a broad RPM/SFPM range of what is acceptable for buffing wheels. Dependent on grit, density of wheel, material to be finished, finish desired.

As ZRX61 said, the buffing wheel can be the most dangerous tool in the shop. Especially the knife shop, thus most tend to lean towards a lower RPM buffer. Things happen slower and softer at lower RPM. Loose buffing wheels, like ones used to give that final high polish are hell bent on trying to grab the workpiece from your hands. Plus you have to consider heat induced into the workpiece.

Here is a basic guide.

http://www.caswellplating.com/buffman.htm

 

[Slackmaster G]

That is the ideal speed