[roody2333]

probably overthinking this but having trouble finding gator blades for my 1980s ransomes bobcat 36". I have two stock blades non-gator mulching (which don't actually mulch and are useless to me). I measured them 5/8 center hole and 17 3/4 length. Diagonal length is actually also the same. All I can easily find are 18" blades. I emailed sellers and they say I must be measuring wrong or the blade is not for my mower. I don't think they actually went and measured the blade like I asked though. If I use 18, it's very close, like 1/8 from the baffles. Can I grind like 1/8 off each end of the blade and make it 17 3/4?
I never balance blades, I have the tool but never do it and I don't think I'll make them too uneven if I grind them down. Only thing I'm worried about is that if I grind the ends, I'll grind the end most gator tooth which is the smallest already out of the 3 or 4 on each end of the blade and don't want to hit a rock or something and possibly shatter the tooth. It's a belt drive if that matters. if I go shorter 17.25" blade, I'm afraid I'll leave stringers/stragglers of uncut grass.
So just order the 18" and if it happens to be exactly 18", just grind off 1/8 from each end?

 

[roody2333]

maybe another sort of stupid question (in addition to can't I just grind down a blade 1/8" on each side?),
If the blade is like the image, can't I sharpen almost the whole edge of the blade with the grinder and make it mostly all a cutting edge vs the few inches they manufactured it with? Why would they do that? If you mow fast, won't that create a bad cut and possibly stringers?

 

[Ridin' Green]

Only the last inch or so out at the tip off any blade does the actual cutting. The added sharpened area is just to help pick up any strays that were missed by the end of the blade (think of how a saw tooth works on a circular saw blade. The tooth may be 3/4" long, but only the outer end of it does the cutting).

As far as your first question-

so what if the blade is only 1/8" from the baffle? Unless you have very worn bearings/spindles etc, the blade will always be 1/8" from the baffle. That's all you need.

What you need to be more concerned about is where the blades actually swing around to the point that they are pointing straight at each other. If they are too long for your machine, you'll know it about a millisecond after you engage the blades. Post a picture of your blades if you can. maybe the ends have been rounded off from poor sharpening practices and that is why they measure 17 3/4" instead of 18"?

 

[roody2333]

yea I think I'll just order 18s. Found some 17 and 7/8 ones too. But now I think I want g5 or g6s and this is like turning into a big project. But I'd rather have to grind an 18" down a bit than have a space of uncut grass with 17 1/2 or possibly 3/4.
An 1/8 space from the blade to the baffle with an 18" = I'm just a bit paranoid my deck might bend over time and catch the blade, although this never really bothered me with a push mowers. I've had the blades hit the deck sides and just turn it off and fix it. I beat up quite a few push mowers on real jacked up lawns with hidden debris and stumps and everything, flywheel key didn't break and thus the crankshaft got so bent the whole engine eventually cracked off the deck. that was before I knew how to mow tall grass with hidden debris under it - gotta go real slow and 9 out of 10 you nick the edge of said debris and get a warning sound to stop before actually breaking the flywheel key or bending the crankshaft.

 

[Ridin' Green]

Doesn't that old Bobcat have an inner front baffle? If so, the front skirt and then the baffle would have to bend before the blades would hit.

However, many new mowers on the market also have their blades running very close to the front baffle. Like you just said, you gotta be careful.

Shortening the blades may end up leaving a strip of uncut grass between the blades. Multi bladed decks all have some overlap of the blades, some more than others, but all have some. That's easy to check. Just turn the bades so they are all pointing straight to each side, then tip the deck up and get under there and look at the tips directly from the front.

 

[roody2333]

Doesn't that old Bobcat have an inner front baffle? If so, the front skirt and then the baffle would have to bend before the blades would hit.

not sure. my pic is last one on the bottom (yea need to wire brush grind, and enamel the deck soon) http://www.lawnsite.com/showthread.php?p=5234700

I just measured again, when I put the two blade tips pointing at each other, there's only 1/8 gap. So if I put 18s" on, they'll collide because 18" means an extra 1/8" on both ends of each blade and thus a 1/8 overlap in center. Also, the space from blade tip to baffle varies when I spin the blade around.

I think these are true 17 3/4 blades (or some stupid impossible measurement to find like 11/23ndths mm etc because it is actually like a 32nd inch larger than 17 3/4 when measured as correctly as possible with a tape measure [making sure the metal tip of the tape measure is pushed in 1/8" when not hooking said metal tip on the blade because that gives a different reading for when you push the tape up against something vs hooking on it]). But I still just might buy 18" g5 or g6 and just grind 1/8 off each tip because probably won't find g5/g6 in 17 3/4. I'm not really worried about unbalancing them from grinding the ends off, worried about weakening that last tooth if anything.

 

[Ridin' Green]

There is an inner baffle, but it only runs from part way in front of the left blade over to the discharge chute.

I see at least one blade tip/corner that looks to be fairly rounded off.

Having a gap open and close just from rotating the blade 180 degrees is a sure sign something is very worn or bent. I'd check into that before worrying about blades.

I found some blades on Oregons site that may be what you need or at least can use. They are for a Hustler fast Trac mini Z, 52" deck.They are 17 7/8" long, 5/8" center hole, 0 offset, 2.5"W, .203" thick, there is one with 13/16" lift, or 1 1/16" lift, or a G3 with 1" lift, or G5 and G6 with 1 1/4" lift.

The part # for the 13/16 lift is- #90-206
# for the 1 1/16 lift is- #92-044
# for the G3 is # 96-318
# for the G5 is #596-704
# for the G6 is #396-704


It looks to me like your old blades have about 3/8- 1/2" offset (center hump) and they have blades for them as well-

one is for the Super Z 52" deck. it has a 5/8" offset, is 3" wide with 1" lift and the same 5/8 center hole, #90-207


They have a G6 for the same mower that is #396-711

IHTH

 

[roody2333]

thank you very much for the help. Also, I read on oregons site about how I asked above why some manufacturers make blades only sharpened on the last few inches of the blades and Oregon says it's less efficient if made like that in section 6 of here http://www.oregonproducts.com/lookups/MoreInfo/OEP_USA_ENG_BladeLookup_MoreInfo.htm
Up to twice the cutting length optimizes the cutting efficiency with each revolution.

I googled those part numbers and found lots of results for the 17 7/8 thanks.

But now I'm not going to bother you anymore and ask if I should use gators or high lift gators or g3-6 because Oregon even says the gators are for enhancing bagging and discharging, not mulching with a sealed deck. I will mulch with my mulch plate installed %98 of the time. But what confuses me is I have used a non gator 'mulching' blade on a push and it is terrible leaves trails and piles of cliping. Although there is no mulching plug on that push mower but that compartment plugs itself with clippings acting as a plug anyway. I use a gator on a push and it works fantastic when mulching grass and leaves and others have said on here the same but then others say gators aren't for mulching with a closed off deck. The threads are like 15+ pages. Right now, I have the blades on in that photo I linked and I have a plate bolted over the discharge and it doesn't mulch that good but it's not too bad but blowout is a lot. I guess I just gotta try the gators with the plate over the discharge and see how it goes. Might just have to make and install a rubber blowout guard skirt made from strips of rubber car mats or something because I was told the deck on the 36 isn't a full on mulching baffle I guess I'm okay with that because I might not be able to bag with it now and then if it were.