[NA] Any sheave/pulley gurus/dealers here [NA]

timwinters

timwinters

Ejection Handle Pulled
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Conway, MO
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LTD
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KLBO---Lebanon, MO
I want to sheave up the blades on my ZTR. It skips slightly when running WOT unless the blades have just been sharpened. The current pulleys are 6". I'm looking for 5.5" pulleys (3 of 'em), keyed, (I'm not at home so I don't recall the exact diameter of the driven shafts...they may be 3/4" but I'm pulling that out of my ass.)

I've looked all over the internet and the rest of the universe and have drawn blanks.

Any help is appreciated.

(and, yes, I'm aware of the 19,000 FPM limit and I'll likely be bumping into it but not exceeding it...at least not by much...so no reason to start preaching)

Actually using the term "WOT" above is a misnomer aviation parallel. The machine is always WOT and when running WOT and "full forward" it runs 14 mph (It cuts 5'-1"). It'll flat lay down some grass!! (almost as much as I did in college)

When running "full forward" it'll skip if the blades haven't just been sharpened. I think a bit more tip speed will help immensely. Going from 6" to 5.5" will increase the speed by 9%
 
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Have you tried Baum Iron? I've gotten sheaves from them to repair all manner of farm equipment. You can mix and match hubs and sheaves if you have an odd size.
 
I'm not sure if I ran across that website or not. It looks promising. I'll call them once I'm home and have the rest of the required information.

Thanks.
 
You're going to hurt yourself or more likely someone else. I think your belts are slipping under load, I'd call the factory, something is probably out of line. Reducing the diameter to increase rpm will probably just make it worse.
 
PaulS said:
You're going to hurt yourself or more likely someone else. I think your belts are slipping under load, I'd call the factory, something is probably out of line. Reducing the diameter to increase rpm will probably just make it worse.
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No, everything is in adjustment, the "tensioning spring" is properly tensioned. The blades just aren't spinning fast enough to cut cleanly at 14mph.

But, hey, I'm glad you could diagnose my problem while never seeing my mower, knowing what brand it is, or what my current tip speed are...and all that from a few states away. That's takes some real talent.

If a 9% increase in tip speed hurts me I'm doomed

And I can't possibly hurt anyone else, I live dead center in the middle of 160 acres. Even if I sheaved it up 50% I couldn't throw a rock that far.

I'm not a mechanical idiot.

But you???

See post #1 where I said:

timwinters said:
(and, yes, I'm aware of the 19,000 FPM limit and I'll likely be bumping into it but not exceeding it...at least not by much...so no reason to start preaching)
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Let me reiterate...

I'm not asking for any ****ing opinions about what I'm doing. Only help in finding what I'm looking for.
 
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Tim, I'm a repair/modifier/tinkerer like you so if you can get it to work, cool.
However, do you think the engine will be able to provide the power required to achieve the additional tip speed? I'd be concerned it will just bog down and you won't get the desired effect. You know, power = torque x rpm or something like that. Good luck.
 
timwinters said:
No, everything is in adjustment, the "tensioning spring" is properly tensioned. The blades just aren't spinning fast enough to cut cleanly at 14mph.

But, hey, I'm glad you could diagnose my problem while never seeing my mower, knowing what brand it is, or what my current tip speed are...and all that from a few states away. That's takes some real talent.

If a 9% increase in tip speed hurts me I'm doomed

And I can't possibly hurt anyone else, I live dead center in the middle of 160 acres. Even if I sheaved it up 50% I couldn't throw a rock that far.

I'm not a mechanical idiot.

But you???

See post #1 where I said:



Let me reiterate...

I'm not asking for any ****ing opinions about what I'm doing. Only help in finding what I'm looking for.
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You are kind of a touch hole, but we knew that going in and you are posting on a forum asking for opinions, so here you go.

Your mower is optimized by engineers, you know the smart guys you think you are smarter than, to spin those blades at their maximum rpm when you are at full throttle, which is probably pretty close to the full power of the motor. You, in your infinite wisdom (that was sarcasm), have decided that you know better and are going to increase the rpm of the blades, without increasing the horsepower of the motor (that's important for what you are trying to do). So you are going to end up with a mower that is dangerous to the user and anyone or thing nearby and it will not cut grass any better or faster because you will be applying less torque to those blades with your different gearing. Momentum of the faster blades will carry you for about 5 feet into the grass you are mowing then the blades will slow and the motor will bog.

Now,if you weren't wound so tight, you would probably tell me that the engine doesn't bog now when it skips, so it has plenty of power, in which case I would refer you to my first post.


Good luck.
 
If it helps....I had a similar problem with my zero turn. I lowered the blades by about 0.50" (using washer spacers) and it made a big difference.

My engine is a Kawasaki FD620D....:-p
 
Dave,

I'm not sure...it may not hve the ponies...but...

The engine is a 25 hp two cylinder Kawasaki.

It runs 3600 rpm sitting still, with the PTO disengaged. At 3600 RPM the tips would be spinning right at the legal max of 19,000 fpm IF they were indeed spinning, but they're not.

Engage the PTO but remain still and the RPM drops to about 3550.

Running full forward, PTO engaged, the RPM is down to 3400. Even if I'm flying down the driveway not cutting grass. It doesn't decrease much more when actually cutting. This would lead me to believe that it takes just as much or more HP to move my fat ass and the machine at 14 MPH as it takes to cut the grass.

And if it doesn't work. Well, I wasted $100 and a few hours. Not the end of the world.

Back to previous commentary...regarding legalities and/or hurting myself or anyone else...

3400/3600 X 19000 X 1.09% = 19500.

Amazing!

(It's not like I hadn't already done that math :rolleyes:)
 
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Checkout_my_Six said:
If it helps....I had a similar problem with my zero turn. I lowered the blades by about 0.50" (using washer spacers) and it made a big difference.

My engine is a Kawasaki FD620D....:p
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That's an interesting concept. Not sure how that would affect the blade vs leading edge of the deck height on mine though. (i.e. If the front deck lip will still be far enough below the blades to provide adequate "bump" protection) I'll have to check that out. Interesting idea.
 
timwinters said:
That's an interesting concept. Not sure how that would affect the blade to leading edge of the deck height on mine though. (i.e. If the deck with still provide adequate "bump" protection) I'll have to check that out. Interesting idea.
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It won't provide more protection to the blades. It will get the blades more into the grass and improves the flowAge in thick grass. I do find that it can scalp easier if your deck isn't adjusted properly.
 
Oh, one more thing, most of those engines develop full hp at 3600 rpm, you are running at 2600, limited by a governor. You should be able to speed the motor up via governor adjustment to reach your desired blade rpm, probably without hurting anything mechanical and you aren't concerned about the increased blade speed. The upside to doing it this way is that the motor should produce more hp although you will probably get less torque.
 
Wow. I just realized we are talking mowers. Pass me the joint dude.
 
PaulS said:
Oh, one more thing, most of those engines develop full hp at 3600 rpm, you are running at 2600, limited by a governor. You should be able to speed the motor up via governor adjustment to reach your desired blade rpm, probably without hurting anything mechanical and you aren't concerned about the increased blade speed. The upside to doing it this way is that the motor should produce more hp although you will probably get less torque.
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Yep, brain fart. I was thinking airplanes...I'm not at home in front of my data, I'm in Ohio. It runs at 3600 not 2600. Post corrected.
 
PaulS said:
You are kind of a touch hole, but we knew that going in and you are posting on a forum asking for opinions, so here you go.
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Curious...

Where did I ask for an opinion? I simply asked if anyone had a good source for sheaves. In fact, in the OP I specifically said to not waste your breath.

But you decided to waste it anyway and that makes me the azzhole. Got it.

image.jpeg
 
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timwinters said:
Curious...

Where did I ask for an opinion? I simply asked if anyone had a good source for sheaves. In fact, in the OP I specifically said to not waste your breath.

But you decided to waste it anyway and that makes me the azzhole. Got it.

View attachment 46622
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Sure thing Tim, you're a real sweet heart, and your posts to forums are only to go exactly how you want it to go. Let us know how it works out, better yet, never mind, as I'm sure no matter what happens it will be reported a total success.
 
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