Blade Speed

glc24 · May 2, 2011

Hey guys

Does anyone know what the blade tip speed is on the 2520 with the 62D deck?
Engine rpm is 2500.

Thanks
Greg

pdp11 · May 2, 2011

I think all of the ratios for the gear box and belt drive are nearly 1:1, so the blade shaft speed should be the same as the PTO. If we assume that is the case, then it would be:

blade length x pi x RPM

21.5 x 3.14 x 2100 / 12 = 11,814 feet per minute or about 134 MPH

Someone correct me if I'm wrong.

PCABE5 · May 6, 2011

I was thinking the tip speed was somewhere around 15,000 or 16,000. Maybe I am way off.

PCABE5 · May 7, 2011

My 72"mmm has a tip speed of 15,300. Check the specification section of the owners manual that is where I found mine. Let us know.

glc24 · May 7, 2011

PCABE5 said:
My 72"mmm has a tip speed of 15,300. Check the specification section of the owners manual that is where I found mine. Let us know.

Hey PCABE5
This is all that is listed for specs on my deck.
Specifications
Really nice that yours had more info.:thumbsup:

I guess I could "assume" that the 62D is somewhere in that RPM range.
I was just curious,because when you bring the deck up to speed,you can tell they (blades) are really hummin' under there.

Greg

Transit · May 7, 2011

I approached the question and got the answer using a optical tack. Not just to answer the blade speed question. I have used the tach for many tasks. I found the tractor engine speed to be almost 200 rpms over spec. measured the engine speed that gives 540 at the PTO, calculated the overall engine to PTO ratio, calculated the brush hog speed gear box ratio and tip speed. The optical tach is amazingly accurate, just point it at a florescent light and it reads 3,600 run .

60 cycles/ sec x 60 sec/min = 3,600 rpm

http://www.harborfreight.com/digital-photo-sensor-tachometer-66632.html

bigtiller · May 7, 2011

Transit said:
I approached the question and got the answer using a optical tack. Not just to answer the blade speed question. I have used the tach for many tasks. I found the tractor engine speed to be almost 200 rpms over spec. measured the engine speed that gives 540 at the PTO, calculated the overall engine to PTO ratio, calculated the brush hog speed gear box ratio and tip speed. The optical tach is amazingly accurate, just point it at a florescent light and it reads 3,600 run .

60 cycles/ sec x 60 sec/min = 3,600 rpm

Digital Photo Sensor Tachometer