Zd1211 blades

[Brown Dog]

I thought my 1211 was a smooth running engine until I got this 4cyl 1511.
It is way smoother & of coarse way more power & torque on my hills & thick grass around my farm.

The 1211 will cut it & pull the hills but it bogs down & don’t cut smooth.

You can’t make the 1511 bog down on hills with thick grass

The 1211 72” is fine on flat ground in thick heavy grass.

 

[RjCorazza]

Hopefully I'll get this right.
The ideal depth of cut is .206 instead of the .200 shown in the pic. The diameter of the turned down section should be about 1.120".

Pictures of the mod:

I know you did this machining over a year ago, but do you know if the blade bosses are hardened steel? I found a machine shop that can do the work, but only if the parts aren't hardened.
So far most shops either fail to respond to my inquires, or won't do the work

 

[Brown Dog]

My machine shop said they were hardened Idk

 

[gonnasellit]

The .206" depth and 1.120" diameter are the correct dimensions as shown in the picture. The blade bosses are hardened somewhat but can easily be cut with standard carbide insert lathe tooling. I am a hobbyist machinist and had no trouble at all doing the machine work. Some folks are afraid do a mod like this due to the potential liability involved. If the modified blade bosses were to break for any reason (they won't) you wouldn't even know it until the next time the blades were removed. The blade bosses would still be held together by the washers. In fact the blades with the 1.125" holes should be slightly stronger than the originals due to the smaller hole size.

 

[Buckeyebutch]

yep the 1st thing my machine shop did was a Rockwell test. Said they weren't a problem for them to cut. My hubs where almost a press fit, so I put them in the freezer and laid the blades out in the sun both for about 10 minuets. Everything worked great I've got about 15 hrs. on the new setup.

 

[gonnasellit]

yep the 1st thing my machine shop did was a Rockwell test. Said they weren't a problem for them to cut. My hubs where almost a press fit, so I put them in the freezer and laid the blades out in the sun both for about 10 minuets. Everything worked great I've got about 15 hrs. on the new setup.

The .005" clearance between the hole in the blades and the blade bosses is a pretty tight fit on some of the blades, but better too tight than too loose. I have had to tap the blades bosses into the holes on a couple of blades. Can you tell any difference in the cutting action between the original blades and the new ones?

 

[Buckeyebutch]

Yes I see a big difference in the cut and it now shows a very obvious strips in the grass.
As for the tight fit on the boss it mainly depends on how much paint or powder coat is in the bore on the blade.
I find it makes it easier to install the blade, one less thing to have to hold while installing.
I definitely recommend this modification.

 

[RjCorazza]

I got the parts yesterday... Hopefully the shop will work on them, but they implied that if hardened that they would not. We'll see.

 

[turbo246]

I put on the g6 gator blades on my 72 side discharge. There’s definitely more air flow out of the deck, but a lot more blow out from front of deck. With it being dry it covers the whole mower. Aside from that cut quality is about the same but it does mulch up clippings nice and leaves a better stripe.

 

[Brown Dog]

I agree with every word. Same thing here with my 72 SD

What height are you mowing at ?