Opinions on a mod

woodlandfarms · Jul 26, 2007

OK, I am in mower land. I have the 90" mower with 11"" blades 3/8" thick. I have gone to a number of sources to get blades and it is not as cheap as what everyone else has done (the 11" is too long for any decent half cuts).

The metal shop down the street is looking into making me some blades. They have some scrap 1/2 T1. I am also having new bushings made. So, this all said, do you think there is a reason that it would be Bad to use 1/2" instead of 3/8" blades?

Carl

KentT · Jul 26, 2007

woodlandfarms said:
OK, I am in mower land. I have the 90" mower with 11"" blades 3/8" thick. I have gone to a number of sources to get blades and it is not as cheap as what everyone else has done (the 11" is too long for any decent half cuts).

The metal shop down the street is looking into making me some blades. They have some scrap 1/2 T1. I am also having new bushings made. So, this all said, do you think there is a reason that it would be Bad to use 1/2" instead of 3/8" blades?

Carl

Downsides as I see them would be:

(1) more load on bearings, possibly more tendency to get out of balance

(2) more power required to spin them at the needed RPM -- they'd likely spin slower because of that

Upside would include the fact that anything you can get underneath there would get destroyed by them....

J_J · Jul 26, 2007

KentT said:
Downsides as I see them would be:

(1) more load on bearings, possibly more tendency to get out of balance

(2) more power required to spin them at the needed RPM -- they'd likely spin slower because of that

Upside would include the fact that anything you can get underneath there would get destroyed by them....

Carl

I think that T1 steel would make some excellent blades. You would have to match the bushings and bolts.

I also think the thickness of the blade is dependent on the material you are cutting or chopping. Grass and weeds is one thing, but if you are running through over grown woods, a thicker blade might be better. Once you get every thing chopped down, you could switch back to the lighter blades.

bbabineau · Jul 26, 2007

KentT said:
Downsides as I see them would be:

(1) more load on bearings, possibly more tendency to get out of balance

(2) more power required to spin them at the needed RPM -- they'd likely spin slower because of that

Upside would include the fact that anything you can get underneath there would get destroyed by them....

Just to put in my two cents - not sure how wide the blade is but assuming it is 4 inches - you achieve the exact same weight of blade by making a 1/2 in. thick blade 3 inches wide therefore it should not require more power to spin and there should be no more load on the bearings; however you probably would not achieve more strength since it is the exact same volume of steel in a different configuration.

J_J · Jul 26, 2007

bbabineau said:
Just to put in my two cents - not sure how wide the blade is but assuming it is 4 inches - you achieve the exact same weight of blade by making a 1/2 in. thick blade 3 inches wide therefore it should not require more power to spin and there should be no more load on the bearings; however you probably would not achieve more strength since it is the exact same volume of steel in a different configuration.

You are probably right on the impact force. This is a definition of T-1 steel

T-1 Steel - This is a steel with a higher yield strength and it is more difficult to form without cracking. HEIL uses this steel in flat plates mainly on the floors and tailgates of custom bodies. It has a minimum yield strength of 100,000 psi and an approximate Brinell hardness of 250-320.

I really don't know how this compares to the factory PT blades.

BEK · Jul 26, 2007

I don't have a roughcut mower but I have a72 inch hrush mower for my 1445
and after experiencing numerous problens with the blades and bushings wearing out and having to replace the 'stop' bolts numerous times in order to mow 20 acres of hay field i replaced them with with 'real' bush hog blades and bolts. I had to reinforce the stump jumper with 2 -1/2 x 3/4 flat stock welded to the inside, I then drilled new 1- 1/16 holes for the new bolts and installed the blades which are 4" wide 1/2" thick and 27" long with a 2" off-set. The blades weigh 15 pounds each and because of the off-set they can bypass each other if they hit something like a stump so I no longer need the 'stop' bolts. I have already mowed 40 acres of hay field with this setup and have experienced no problems, every thing is as tight as when I put them on. I have noticed that as for speed they run at the same speed as the OEM blades but it takes a couple of seconds longer to spin up but they don't slow down when mowing thick wet hay or brush.