Can I use my 5ft finish mower minus one blade

[Tritonman]

Does your three point not work on the tractor so you can cut it a bit high and do it twice? I know that low gear is not very low on an 8n but I use to mow with an 8n and a woods mower and it worked just fine lifting it up. If nothing else sharpen the blades.

 

[RickB]

I realize I could just take half cuts each time but would forget to do this on every pass.
Thanks.

Pooh Bear

Having the tractor stall or overheat from taking a full cut would be a reminder to take less.
Dragging part of the deck over uncut grass will make it more difficult to cut, especially if you happen to be going in the opposite direction.
If you have a 5' rotary cutter, do your finish mower a favor and use the R/C.

 

[Bill_C]

Not sure I agree Rob. Blade or no blade, the belt is still exerting angular tension on the spindle. The spinning blade creates kinetic forces (like a top) that counteract the pull of the belt against the spindle bearings. Remove the blade, now the belt is going to exert uncompensated force on those bearings.

//greg//

Nope. Without the blade, there's just a pulley mounted on a shaft riding in a couple of bearings. Pretty much a standard idler pulley.

The spindle shaft is reasonably robust, and so are the bearings, which are probably rated for a dynamic load of a few thousand pounds per bearing. The force from the belt--a few dozen pounds at most--is insignificant compared to the forces of a blade cutting objects in the field.

In other words, he could remove a blade or two without any problem.

 

[Pooh_Bear]

I bought new blades for it and put all 3 of them on the mower.
If it ever quits raining long enough to dry out I'll try mowing.
The belt has only been on there for a few cuttings. Almost new.

The lift works pretty good actually. A few places I have no choice
but to cut it two or even three times. Be hard to mow it all that way.

I'll probably drag the rotary cutter out tomorrow and see if I
can sharpen the blades one more time and use it.
I really hate messing with that heavy monster.

Thanks for all the advice.

Pooh Bear

 

[ohiokubota]

I had a 8n tractor is yours a 4 cylinder or inline 6, mine was a 6, now i have a kubota b7100 and i use a 5 foot finish mower and it works good, i would put your tractor in 1st and the idle high and it should be alright. them 8n can pretty much handle anything you can throw at it

 

[greg_g]

In other words, he could remove a blade or two without any problem.

Well, neither of us has seen his mower. All I can say is that removing a blade could potentially damage the affected spindle on the finish mowers that I own. With a blade-tip speed of 15,300 fpm, the spindles is standing like a top - completely vertical against the bearings. That negates the horizontal pressure exerted by the spring loaded deck belt idler. Remove the blade, and most of the vertical force is removed, permitting the idler pull the spindle slightly off vertical. Premature wear results.

I think the RC idea has more merit than taking off a finish mower blade.

//greg//

 

[RickB]

With a blade-tip speed of 15,300 fpm, the spindles is standing like a top - completely vertical against the bearings. That negates the horizontal pressure exerted by the spring loaded deck belt idler.


//greg//

That's absolutely false. A properly balanced rotating blade exerts no radial load on the bearings supporting the blade and shaft. Therefore the absence of a blade would have no effect on radial loading.

 

[Leejohn]

I can't understand why a 8N Ford is having a hard time with a 5' mower. The ones I had I think I could of shaved the ground with a 5'.

 

[greg_g]

A properly balanced rotating blade exerts no radial load on the bearings supporting the blade and shaft.

I didn't use the same words, but that's exactly what I meant. Kinetic energy from the rapidly spinning and properly balanced blade stands the vertical spindle straight up - just like a kid's spinning top. That thrust relieves all but contact pressure from the bearings. Remove the blade, and you remove the kinetic source that commands the upright position. At that point the idler spring tension causes the belt to pull the spindle off vertical. Bearing wear ensues.

//greg//

 

[sandman2234]

The time it takes to remove/replace the blade could be better spent just doing partial cuts with the mower. The extra blade doing partial cuts will help mulch the already cut grass, and may aid in getting rid of the excess grass clumps. If your wheels are adjustable with shims like mine are, adjust the mower to the highest setting and make a pass around the yard with it. If there is anyway to lower the pins on the 3pt where they mount to the front of the mower, that also might be an option. Most of these options are just way too much trouble, over just doing partial cuts, letting seat time win over wrench time.
David from jax