max motor rpm with circular blade

[jman75]

I am trying to figure out the formula to figure out max rpm circular blade will spin I am confused using mnm. Here are my numbers can someone help with forumla

watss = 242.64
speed= 64,400
radius of blade is 1.5 inch
torque= 35 mnm here I am stuck what is foruula

 

[LionelHutz]

What is "watss"???
What is "mnm"???
What exactly are you trying to calculate? Assuming that speed number means 64400 rpm then why wouldn't the blade spin at 64400 rpm?

 

[jraef]

Maximum speed of a circular blade is the speed just below the point at which it cannot hold together and fractures, injuring or killing people nearby. In other words this is not primarily an electrical problem. Determine that speed first, determine a margin of safety, then go from there as to how you attain a safe maximum speed.


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

 

[waross]

Many blades are marked either on the blade or on the packaging to indicate the safe maximum RPM.
Not to doubt you but 64,400 RPM seems a bit fast.
We see standard induction motors that turn about 64,400 Revolutions Per Hour.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[jraef]

I suspect it was typos of Watts and N-m (Newton-meters, the metric measure of torque).
With those assumptions we are still left without knowing the meaning of "64,400". If that was meters-second of linear speed at the teeth of the blade, then maybe you want to calculate the speed in RPM necessary to get there? Hard to tell from a set of incomplete data points, let alone the fact that you are using something metric like N-m and Imperial like "1.5 inches". Either go all metric or all imperial, you'll get yourself tied up and twisted trying to mix units...


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

 

[Strong]

Google: convert watt to torque
for online formula
You will need the correct rotational speed (rpm) to make the calculation.

Walt