Mowing Is 1000 rpm PTO too fast for finish mower?

[Donman]

I was never happy with the cut that my used but sharp 48 inch Woods finish mower provided. Last Saturday just for the heck of it I tried the 1000 rpm setting and was amazed how much better it cut. I don't have an owners manual but I got to wondering what harm could be done besides wearing everything out a little faster?

 

[rickmacheske]

Sounds very dangerous. If it's a standard finish mower it's rated for 540 rpm.

 

[MrJimi]

I did not find a finish mower but I did find a 48 RC and it says 540 rpm.
see here
Woods Equipment Company - 48, 60, 72 & 84 Standard Duty Single Spindle Rotary Cutters
dont do it

 

[hbaird]

Were you running at the PTO output rating RPM? On my Jinma there is a green band on the tach for the correct PTO speed. I also find a slower, over the ground, speed can give a better cut. The blades make more passes over the same area. Higher blade speed does the same thing but may well be dangerous.
Harold

 

[RobJ]

Sounds a bit fast for me...and maybe the mower. Sounds like you have a 2 speed PTO. My BIL's old L175 also has 2 speeds.

 

[AndyMA]

I agree with the others. If's it's rated for 540 and you run it at 1000 you'll be generating blade tip speeds that are almost twice what is designed for. You should get a excellent cut at 540, make sure you are running at 540. also make sure the blades are sharp and the deck is set level.

Andy

 

[_RaT_]

I'm curious about this too. How did you get the PTO speed up to 1000RPM? Unless this tractor has a two speed PTO you could simply not do it off the PTO. Now if you changed pulleys on the mower I could see it. The tip speed is important. You will approach the speed of sound at the tips at some point and my understanding is that its not a good idea for safety reasons.

 

[toolsorbust]

I agree with the others. 1000 speed is mainly to be used as a power unit, that means tractor is stationary and used for pumps, grinders and in my case a sawmill. The gear boxes on mowers are sized for 540 rpm and faster will more than likely cause your seals and bearings to wear out more quickly because they cant disperse the heat as well. Just my 2 cents

 

[Highbeam]

I have a 2 speed PTO on my Kioti CK30. 540 forward, and 1000 rpm aft at the specified 2500 or so RPM setpoint. If you want more than 540 rpm but don't want to go way past the corresponding engine RPM then pop it down into the 1000 pto rpm setting and set the engine RPM lower so you might get 650. Whether or not it is dangerous is another issue.

The higher than rated input speed to the gearbox may sling oil away from the bearings or foam the oil. Generate too much heat. Or by some freak chance, your gearbox is rated for 1000 RPM input.

It's not just about how many times the blades pass over the grass it is also about vacuum to suck the blades of grass up into the machine blades. Think of it as a plane's propeller. Faster is gooder until you break things.

 

[Soundguy]

As others have said... running that cutter at near 2x it's rated speed is a recipie for disaster.

hopefully when it lets go it will only cause property damage, and not injuries.

good luck with that.

Soundguy