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If you try to throw a chunk of ice at -20 degrees, you will see plastic coming out of your chute. Just my guess though.
 

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Plastic composites have come a long way, from aerospace to auto manufacturing, manufacturers choose plastic over metal due to space/weight/shape constraints and prefer it over metal.

In this case however the choice was made to cut cost, so no bueno.

Beside being brittle than metal I wouldnt want a plastic impeller just because of the lack of momentum/torque compared to a metal one.
 

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If you try to throw a chunk of ice at -20 degrees, you will see plastic coming out of your chute. Just my guess though.
Has this ever happened? Is it a wide spread problem? What kind of plastic is it? Is there an epidemic of exploding impellers? Has it ever happened even once?
 

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A good % of the machines that I work-on have at least 1 impeller vane that nailed something... hard enough to distort.

I would be interested to see the outcome of a plastic impeller encountering whatever bent this vane from an old-school Toro.
 

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Plastic composites have come a long way, from aerospace to auto manufacturing, manufacturers choose plastic over metal due to space/weight/shape constraints and prefer it over metal.

In this case however the choice was made to cut cost, so no bueno.

Beside being brittle than metal I wouldnt want a plastic impeller just because of the lack of momentum/torque compared to a metal one.
Actually, plastics can be, and in this case I bet it is, more expensive to manufacture than metal.

And to your point, plastics can be shaped to be more effective than their metal counterparts.
 

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A good % of the machines that I work-on have at least 1 impeller vane that nailed something... hard enough to distort.

I would be interested to see the outcome of a plastic impeller encountering whatever bent this vane from an old-school Toro.
Depends on what the plastic is. There's lots of different kinds of plastic. What tends to kill plastics is SUN, UV RAYS. that's plastics mortal enemy. Makes them brittle.
 

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Depends on what the plastic is. There's lots of different kinds of plastic. What tends to kill plastics is SUN, UV RAYS. that's plastics mortal enemy. Makes them brittle.
The metal on those vanes requires a forge to reshape. Mapp and a sledge hammer wouldn't even nudge it.

On the otherhand, perhaps if my '89 toro 824 had a plastic impeller to vaporize, I wouldn't have had reweld the entire auger housing to correct the torsional twist.

before


during


correction:


after
 

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I have No Problem with Plastic For Certain Applications, But I Don't Want it on My Snowblower. Period.
 

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It would make adding the impeller mod a challenge if the machine needed one. On the other hand plastic might be a better choice if it holds up to ice chunks, frozen newspapers and the like IF it's lighter so less stress on the bearings and it is rustproof.

It's a knee jerk reaction hearing plastic and assuming it's cheap and of lesser quality than it's metal predecessor. Might be something we just need to see how it goes.
 

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I have No Problem with Plastic For Certain Applications, But I Don't Want it on My Snowblower. Period.
If I could build a snowblower out of plastic, I'd do it in a heartbeat. No rust, no chipping paint, stronger, lighter, lasts forever. Can be drilled, tapped, shaped in all different ways.

The reason it's not done, is because metal is CHEAPER. Plastic is more ridged, doesn't flex, no need for welds, can be done in one piece, can be designed much better. Metal is archaic. Not that it hasn't worked, but with today's technology plastics can out perform metals for every situation.

The range of plastics is really misunderstood. Ya know, bridges are made of plastic. I'm not talking bits and pieces here and there, I'm talking the WHOLE BRIDGE:

https://www.bing.com/images/search?q=frp+bridge&FORM=HDRSC2

I'm trying to build a new product for myself out of plastic, because it's better for my application, and it's way more expensive than building it out of metal. I've been researching this for over two years waiting for plastic to be competitive. It's not getting any better.

Ocean going yachts are made of plastic. Airplanes are made of plastic.

Stairs, I-Beams, Structural components.

https://www.bing.com/images/search?q=frp+structural+shapes&FORM=HDRSC2

Plastic does not automatically equal bad.
 

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It would make adding the impeller mod a challenge if the machine needed one.
Why? Could be easier if the plastic is thicker, and perform better. OR, with plastic manufacturing process, you may not even need the mod.
On the other hand plastic might be a better choice if it holds up to ice chunks, frozen newspapers and the like IF it lighter so less stress on the bearings and it is rustproof
.

Plastics used correctly is, many times, more effective than metals. Now, clearly I'm not talking about engines, cylinders, bearings, etc.. For that you'd have to look at Ceramics, but for housings and such, yeah.

It's a knee jerk reaction hearing plastic and assuming it's cheap and of lesser quality than it's metal predecessor. Might be something we just need to see how it goes.
Usually borne from ignorance of what plastics really are.
 

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Ceramic engine:


295HP 1.6 liter engine. Ceramic engines run hotter, don't need a cooling system, are more efficient, and last longer.

I bring this up because the mere suggestion of a ceramic engine, to parallel the plastic impeller, would be tantamount to saying "I won't have a coffee cup powering my blower"..

These pre-conceived biases without knowledge is just silly. I only know, because I've been trying to put out a stout plastic product and have no choice but to learn about it.
 

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There are a lot of different plastics, absolutely, with different fillers for reinforcement. Plastic doesn't simply mean it's made out of recycled milk jugs.

But this is an application with cold temperatures (where plastics get more brittle), and sudden impact loads. I work with plastics at work, but this is not an application where they'd be my first choice.

My Toro 1800 single-stage electric has a plastic paddle. It works fine, and fortunately I've never had one break. They do show signs of wear, with grooves and notches in them, but they've held up. But I use it for the deck, which doesn't get chunks of ice like EOD.

I think the earlier comparison was fair. If you hit something solid enough that it bends a metal impeller, the odds are decent that it might crack a plastic impeller.

The plastic chute in my MTD worked well, no complaints. But I would not be comfortable with a plastic impeller, personally. If they turn out to be robust, and still running strong after 20 years, that will be great, and I'm happy to be wrong. But I'd rather not have one on my machine.

As just a single reason for that opinion, if a metal piece on my machine cracks, I can weld it. But if a plastic impeller cracks, the best I could do is drill a hole at the end of the crack, and hope it doesn't continue to grow.

I don't think lighter weight of the impeller offers the machine a big benefit. The bearing still takes most of its load from the snow being flung, rather than from the weight of the impeller. A plastic impeller *can* probably have tighter tolerances for concentricity of the blade tips, allowing a smaller gap to the impeller housing. But the impeller housing is the other half of that discussion, so I'm not convinced you'll suddenly see a nice tight fit.
 

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Plastic does not automatically equal bad.
Unless is comes from China, right? :)
 

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There are a lot of different plastics, absolutely, with different fillers for reinforcement. Plastic doesn't simply mean it's made out of recycled milk jugs.

But this is an application with cold temperatures (where plastics get more brittle), and sudden impact loads. I work with plastics at work, but this is not an application where they'd be my first choice.

My Toro 1800 single-stage electric has a plastic paddle. It works fine, and fortunately I've never had one break. They do show signs of wear, with grooves and notches in them, but they've held up. But I use it for the deck, which doesn't get chunks of ice like EOD.

I think the earlier comparison was fair. If you hit something solid enough that it bends a metal impeller, the odds are decent that it might crack a plastic impeller.

The plastic chute in my MTD worked well, no complaints. But I would not be comfortable with a plastic impeller, personally. If they turn out to be robust, and still running strong after 20 years, that will be great, and I'm happy to be wrong. But I'd rather not have one on my machine.

As just a single reason for that opinion, if a metal piece on my machine cracks, I can weld it. But if a plastic impeller cracks, the best I could do is drill a hole at the end of the crack, and hope it doesn't continue to grow.

I don't think lighter weight of the impeller offers the machine a big benefit. The bearing still takes most of its load from the snow being flung, rather than from the weight of the impeller. A plastic impeller *can* probably have tighter tolerances for concentricity of the blade tips, allowing a smaller gap to the impeller housing. But the impeller housing is the other half of that discussion, so I'm not convinced you'll suddenly see a nice tight fit.
Thing is, and I'm just going by what I read, I don't see a huge clamoring of people complaining about broken plastic impellers. Not being your first choice, I get that. Personally, a well constructed FRP wouldn't be a bad thing, po-tay-to, po-tah-to. It's used for bridges, and structural materials all the time. But where's the problems?

If I'm wrong, and many of these are breaking, it could be that plastic wasn't a good choice, or they picked the wrong plastic, or plastic wasn't the right choice. But I'm not seeing a lot of threads about shattered impellers, nor can I find anything in an internet search.
 

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I've haven't seen reports either. But then again, I didn't realize there were plastic impellers for 2-stage machines until this morning :)

As was pointed out to me recently in a thread about another new blower technology, just because there aren't many reports doesn't mean there aren't problems. There are probably millions of steel-impeller machines out there. But how many plastic-impeller machines are in use?

And for normal use, especially when still young, they're probably fine. My concern is when you suck in a big chunk of ice, or ingest a newspaper. And things will get worse over time, as the plastic ages, and becomes more brittle.
 

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I've haven't seen reports either. But then again, I didn't realize there were plastic impellers for 2-stage machines until this morning :)
EXACTLY!!

As was pointed out to me recently in a thread about another new blower technology, just because there aren't many reports doesn't mean there aren't problems. There are probably millions of steel-impeller machines out there. But how many plastic-impeller machines are in use?

And for normal use, especially when still young, they're probably fine. My concern is when you suck in a big chunk of ice, or ingest a newspaper. And things will get worse over time, as the plastic ages, and becomes more brittle.
Fair nuff. I'll wait until we start seeing massive failures before I call it a failure. Metal fatigues over time, something plastic doesn't do.

On another note, what do you do in plastics, wondin' if I can tap your brain on what I'm trying to build. PM me if it's OK.

Thanks
 
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