Tiny Engine Could Make Leaf Blowers Sound Less Like Jets | Hacker News Reader

Tiny Engine Could Make Leaf Blowers Sound Less Like Jets

wired.com

29 pointsawjr43 comments

How about just leaving the leaves on the ground, because everyone hates leaf blowers, and blowing them around is pretty pointless due to this thing called wind. Never understood why apartment complexes don't just use bagging lawn mowers to basically cut their work in half and piss people off less.

I tend to agree. What about hard surfaces where leaves can cause slip hazard?

Just use a leaf rake - they work on soft and hard ground, are pretty silent, weigh less than a leaf blower, are cheaper, consume no gas, and are kind of outdoor workout.

But, much slower. And you'd need to follow it with a broom to satisfy my mother's standards.

Do bagging lawn mowers collect leaves as well?

Yes. But the baggers fill up very quickly. Getting leaves off of grass is easy, use a bagging lawn mover. Backpack blowers are best used to get leaves out of plant beds, driveways and sidewalks onto lawns.

Often such folks blow the debris into the road for the city street sweeper to collect at a later date.

Even better is a mulching lawn mower. As long as you mow relatively often while the leaves are falling, and don't mind your lawn being slightly less attractive for a couple weeks, you get rid of the leaves without having to haul all the bags of leaves and grass, and feed your lawn at the same time.

You'll never hear from them again:

“We’re not looking to manufacture engines,” says company president Alexander Shkolnik. Instead, the company plans to continue developing the engine and work with a manufacturing partner

That's always a warning sign. To me it means they don't want to make a company, but are rather looking for a quick sale and exit.

Also: "Because so many potential applications are in the lawn care and landscaping biz, the current design runs on a mix of gasoline and oil for lubrication."

I doubt they'll be able to meet emission standards, which is another reason you'll never hear from them again.

Couldn't they just license the patent?

Interesting comparison between automobiles and lawn equipment emissions:

http://www.edmunds.com/car-reviews/features/emissions-test-c...

The 2-stroke leaf blower was putting out 300 times the hydrocarbon emissions of a Ford F-150 Raptor. Looks like there's certainly room for improvement, and if this engine can beat it, it'll take some of the attention by the EPA away.

This has much to do with the crank-case scavenged valveless design of your typical two-stroke. Since it uses ports instead of valves there is a period of time where both the intake and exhaust ports are open and 20-30% of the unburned air-fuel charge goes right out the tail pipe. This allows for a very simple lightweight design but is no good for emissions or efficiency.

Secondary to that is that again since these small two-strokes have no valves they use tuned exhaust to try and retain the charge going straight through with a counter pulse, therefore it is very difficult if not impossible to do a catalytic converter in the exhaust as they will interfere with the tuning.

You notice the small 4-stroke is much better but not as good as the cars, this is because the 4-stroke has valves but no cat, it is also carbed instead of EFI.

2-strokes can be made with direct injection which delays injecting fuel until the exhaust port is closed by the piston, it adds much complexity and cost. Modern Evinrude E-TEC outboards marine engines have gone this route, whereas most other outboard makers have gone 4-stroke instead. Note that outboard marine engines do not require cats yet and emit about ten times the emissions per unit power that an automobile engine does. EPA is pushing for that soon though.

2-strokes can also be made with exhaust valves (called uniflow scavenging) this is usually done in large diesels since it also requires forced induction and no mixing of oil with fuel.

These small wankel like engines should probably have emissions similar to the small 4-stroke rather than the small 2-stroke as the Wankel design does not have intake and exhaust ports open at the same time but they are still carbed and no cat.

This is pretty much how ARM works. They only design the CPU's but don't actually build them.

Yeah but manufacturing competitive silicon nowadays requires mucho dollares. Making small-scale engines is probably several magnitudes below that.

Still, you've got a point.

Designing a CPU is very difficult and building one is very difficult, so this works for ARM.

But engines are not like that, there's little money in the design - there are tons of designs, they are interchangeable for the most part and one is only slightly better than another.

And building them is not hard either, so there is little money in being just a build shop without having an IP.

Usually a design-only firm licenses themselves exclusively to one retail company - they don't sell the component, only the final product. They goes on for a few years, then the retail company buys them and that's the end of it.

That's why you'll never hear from them again, some lawnmower or whatever company will lock them up and that will be all.

If they want to make an impact (and not just a quick exit) they become a supplier and sell full engines.

Besides what's already said, there's also big value for the manufacturer to guarantee that the CPU runs ARM code. Even if it was price competitive to design an ARM-based CPU from scratch, and avoid all the patents, you'd want something (bug) compatible with the real thing to in order to run real world code.

That seems overly cynical. Licensing is a perfectly valid business model, and it's becoming increasingly relevant as large companies do more outsourcing of R&D.

It is - in some fields. But normally only when you have a unique design that is hard to duplicate.

Not for something as commodity as an engine.

This, you need such an overwhelming value proposition to sell into a commodity market that such plans rarely succeed.

"Also: "Because so many potential applications are in the lawn care and landscaping biz, the current design runs on a mix of gasoline and oil for lubrication." I doubt they'll be able to meet emission standards, which is another reason you'll never hear from them again."

You do know that "mix of gasoline and oil for lubrication." is how EVERY 2-stroke gasoline engine works right? The handheld lawn & garden market is dominated by 2-stroke engines, all of which must meet EPA emission standards.

FWIW, there are good 4-stroke engines in this area, but they hold a small market compared to 2-stroke, mainly because of the increased weight of 4-stroke engines

This is neat, but it seems pretty clear to me that battery-powered electric motors are the future for this kind of application. I don't own a leaf blower, but both my lawnmower[1] and trimmer[2] are now battery-electric, and I would say both are essentially as good as any gas-powered ones I've used, and much quieter. I listen to podcasts while I mow the lawn now. It's great.

[1]: http://egopowerplus.com/products/mower [2]: http://egopowerplus.com/products/string-trimmer

I'd point out to anyone bringing up Apex seals as a potential problem: You must not be familiar with using a conventional mini 2 stroke. Chainsaws, leaf blowers, etc require exceptional levels of maintenance and aren't exactly known to run well. Most of them are either running too rich or lean at any given point, and therefore are either building up carbon, or burning themselves out.

Not to say there aren't some good ones, but small 2 strokes that this engine aims to replace are not exactly paragons of reliability.

Also, most small 2 strokes have abysmal emissions due to running too rich/lean all the time, having badly made carburetors, poor tolerances, no catalytic convertors, low thermal mass, etc.

This looked relatively simple to assemble, and would therefore be pretty easy to disassembler. My guess is that if there were any seals that needed to be replaced, it would be a relatively trivial job compared to a standard small 2 stroke.

Source: have rebuild many chainsaws, weed whackers, and leaf blowers. Used to build go-karts.

Actually most of the emission are a result of the valveless design of the typical two-stroke. Small carb 4-strokes have the same issues you describe but have much better emissions due to the valving, but lacking a cat they will never come close to and automobile as far as emissions go.

Seals wearing out will cause lower compression and more blow-by reducing power and increasing emissions but probably not as much as a valveless two-stroke which simply has intake and exhaust ports full open during part of the cycle.

I still like the StarRotor[1] better. No reciprocating, no problems with seals (which are a big problem/weakness in Wankel-types; rather unadressed in TFA). Biggest problem for StarRotor is that all the manufacturing chains are already super-optimized for existing engine designs and don't much care to experiment.

[1] http://www.starrotor.com/Expanders

The article fails to explain how this will make leaf blowers sound less like jet engines. Has the author ever heard a Wankel rotary at 15,000 RPM? Not to mention, the reason leaf blowers sound like a jet is because of the giant shrouded fan that is used to generate airflow. Electric leaf blowers sound like jet engines too, and their motors are extremely quiet in comparison.

"Sorry hun, I can't blow the leaves because the apex seals are shot in the leaf blower"

5 hp would actually make a great light weight moped.

I know I could really use one.

Have you looked at e-bikes recently? Interesting things going on.

A bit, and it is indeed. Also the light electric scooters are incredibly cheap now. But a combustion engine would still be great when you need the extra range.

it's called a broom!

Indeed! Leaf blowers are dreadful for the environment: ignoring the noise and combustion emissions, they blow all the coverage off the soil leaving a packed result that absorbs no water and can't support plant growth.

No leaf blowers (and low maintenance in general) on my yard leads to thick grass that doesn't need a lot of watering. My neighbors all use 'em and the strip of "lawn" next to the road on every other house looks like concrete.

I understand the gardeners like them because it's fun and empowering, but so would a flamethrower. Neither is much good for the garden.

If you've got a lot of trees and don't remove the leaves, you'll still have a lot throughout the year.

It seems to me it's best to remove the leaves in the early spring, rather than the fall. That way you have a protective, and fertilizing, leaf cover over the winter.

Mow them. The last time I used a rake was living on a tiny lot. Moved to a 1/2 acre lot and began to mow the leaves into tiny scraps. Now live on a much larger, exposed hilltop property and the wind takes care of the leaves for me :-)

I feel weird when I mow the leaves every year—everyone else is spending hours raking, while I take under two hours with the lawn tractor. I keep wondering why everyone doesn't do it, like I'm missing something. I also don't bag grass clippings; it seems silly to remove all of this potential fertilizer from my lawn, only to have to apply artificial fertilizer later on.

One better: I let them blow away. But I live on 80 acres; nearest neighbor half a mile away.

I never got the point of bagging grass clippings either, seems like useless work. Then again, I don't fertilize my lawn or spray it for weeds either. It's just grass (OK, grass, clover and dandelions in my case), why is everyone so anal about this shit?

I don't understand the obsession, either. I keep our lawn watered (no water shortages in Michigan) and mowed. Beyond that, I just let the fittest turf—whether it's regular grass, clover, or dandelions—survive. As long as it's not painful to walk on, it's fine. In fact, I like the variety.

Broom? Isn't it called a rake?

Not on pavement.

How do you use a broom on a gravel driveway?

...and also called being active!

And I'm surprised there isn't a Roomba for lawns.

There is. There are enough of them that here's a comparison page: http://www.probotics.com/robotic-lawn-mowers/robot-mower-com...

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