design of modern chain saws.

[Chris-PA]

Chainsaws have become commodity items. There are only a couple of manufacturers, and while they compete they're really pretty comfortable splitting up the market. Once there were a lot of small manufacturers coming up with new ideas - essentially the best design practices had not settled down and there were a lot more people doing independent development. They tried just about everything and saws were interesting thanks to all the variation. But that was also thanks to a booming market for hand held chainsaws in the forestry industry, which has changed too.

The manufacturers now are not going to spend any more money on product development than they have to. Without some major change, such as emissions or other regulations, fuel changes, etc., they'll just give you small styling changes and incremental improvements that don't cost them much. They're in this to make money.

The basic design works pretty well, although I still like horizontal cylinders. The A/V systems (also mostly driven by regulations I believe) are great, and the change in fuel tank position and materials works well. I like the strato and the Autotune, which they would never have done without being forced to, partially because it's genuine content rather than styling fluff and it took some actual investment in product development. Both of them are really darn clever solutions to problems that have existed for a long time. With those, gasoline chainsaws will be viable for a while, until fuel and oil become too expensive and hard to get. After that will go back to crosscut saws and axes, because batteries won't be able to compete with the energy density in gasoline.

 

[zogger]

Chainsaws have become commodity items. There are only a couple of manufacturers, and while they compete they're really pretty comfortable splitting up the market. Once there were a lot of small manufacturers coming up with new ideas - essentially the best design practices had not settled down and there were a lot more people doing independent development. They tried just about everything and saws were interesting thanks to all the variation. But that was also thanks to a booming market for hand held chainsaws in the forestry industry, which has changed too.

The manufacturers now are not going to spend any more money on product development than they have to. Without some major change, such as emissions or other regulations, fuel changes, etc., they'll just give you small styling changes and incremental improvements that don't cost them much. They're in this to make money.

The basic design works pretty well, although I still like horizontal cylinders. The A/V systems (also mostly driven by regulations I believe) are great, and the change in fuel tank position and materials works well. I like the strato and the Autotune, which they would never have done without being forced to, partially because it's genuine content rather than styling fluff and it took some actual investment in product development. Both of them are really darn clever solutions to problems that have existed for a long time. With those, gasoline chainsaws will be viable for a while, until fuel and oil become too expensive and hard to get. After that will go back to crosscut saws and axes, because batteries won't be able to compete with the energy density in gasoline.

--I think the battery saws still have a lot more potential. There are hundreds of research projects around the globe now working on advanced batteries. We have just now the second generation of battery saws and they are loads better than the first generation from just a few years ago.

 

[bcsizemo]

Supercharged using a modified cooling fan setup and having it divert some of the airflow to cooling the cylinder would be the best way to achieve positive pressure...

But like everyone said you're going to be blowing fuel out of the exhaust just because of the way 2 strokes work.

Honestly electric is the way of the future, but without better power sources it'll never get beyond light homeowner work.

 

[ckelp]

Supercharged using a modified cooling fan setup and having it divert some of the airflow to cooling the cylinder would be the best way to achieve positive pressure...

But like everyone said you're going to be blowing fuel out of the exhaust just because of the way 2 strokes work.

Honestly electric is the way of the future, but without better power sources it'll never get beyond light homeowner work.

it maybe the baleys in my coffie but if there was a way to make a supercharger work it would have to be on the ext. port pulling a vacuum on the engine, but there would be lot of wasted fuel..

 

[ft. churchill]

Just a thought but turbos cost about 700 bucks and up. You can but quite a powerful saw for that kind of cash, as well as I've never seen a turbo that would be small enough for a saw application.

 

[Zombiechopper]

forced induction 2 stroke saws are not going to happen.

I think the real future is fuel injection and computer controlled variable ignition timing.

If emissions controls continue to get worse we will see 4 stroke saws.

 

[wyk]

Just a thought but turbos cost about 700 bucks and up. You can but quite a powerful saw for that kind of cash, as well as I've never seen a turbo that would be small enough for a saw application.

We'd also have to get around the fact you need a pipe to make the turbo work well, and then piping from the turbo to the intake. And the turbo would have to be shielded from the user and wood debris, the ground, and the bar - which begs the question where it would live. And without an intercooler, it won't really be as efficient as you might need for a chainsaw. Where the hell would that live? A piston ported 2 stroke is already supercharged by virtue of how it operates. Industrial 2 strokes are a completely different design, and are MUCH larger and heavier. Turbo's also require gearing to be used efficiently, which adds weight, as well as does injection. Turbos have shown to be too peaky and laggy for use on motorcycles, and they have gearing. I doubt a turbocharged chainsaw would have enough power band to be useful in a hand-held device. A VVT turbo is heavy and expensive, as would twin turbo charging be. Unlike an industrial 2 stroke or a sled or a dirt bike, you have to hold the saw in your hands. This severely limits what you can do with the engine and intake. It always has, and it always will. Then there's the fact that human beings can only hold up so much weight for so long.

The more you add to a machine mechanically, the less reliable it generally becomes, as the more can go wrong with it. This also means it more likely becomes more expensive to maintain and service. Dirt bikes have resorted to porting in order to find gains and better powerbands, I would argue a very aggressively ported chainsaw would be more reliable than a relatively tame turbocharged one, and likely build more power per lb.

I believe electronics were inevitable on a chainsaw after seeing electronic fuel injection appear on 2 stroke bikes.

http://www.husqvarna-motorcycles.com/en/motorcycles/product/WR125#!/specifications

 

[husqyfan]

Dirt bike motor h.p.

Why do 80cc dirt bike motors make twice the hp of a similar sized saw? Is it the expansion chamber?

 

[Mastermind]

Why do 80cc dirt bike motors make twice the hp of a similar sized saw? Is it the expansion chamber?

Chainsaws have a very primitive ignition system and the carbs are also very simple with no additional enrichment circuits. The transfer area on a saw is a limiting factor as a bike engine has much more area. Then there's the exhaust.......and stroke length.....etc

 

[sunfish]

If it's new tech you want check under the hood of the M-Tronic and the Autotune saws. What about Stratified two strokes???? Hell man pay attention......lots of new and exciting stuff is happening right now.

Worth repeating!

I only have one of the newfangled things, but man is it Nice! :msp_biggrin:

 

[husqyfan]

2 stroke power

Chainsaws have a very primitive ignition system and the carbs are also very simple with no additional enrichment circuits. The transfer area on a saw is a limiting factor as a bike engine has much more area. Then there's the exhaust.......and stroke length.....etc

Not to get off subject but: I had a 95 banshee, when I put the toomey t5 pipes and jet kit in it felt like I added 50 hp to that motor. The four stroke motors they are making now, while very impressive, just aren't the same. And certainly don't sound as sweet.

 

[Eccentric]

husky air injection?

Remington did it 20+ years before Husky 'invented' it. Then there's the side access chain tensioner that people credit Stihl with. Homelite had it on the 650/750 saws in the early 1970's. McCulloch had optional chainbrakes in 1970 or so. Remington had a plastic rear handle/fuel tank in the early 1960's (I believe on the same model that had the flywheel forced air carb box setup). Vertical cylinders were used on one man saws long before horrizontal cylinders. Piston port 2-strokes date back to the turn of the century. 2-stroke motorcycles were almost all piston ported (or had rotary valves) until the 1970's when reed valves went into widespread use. Bruce's clunky 1960 or so manufactued Bolens Thrifty 3010 that I'm working on has rubber AV mounts for the handlebar. Solo had a twin cylinder one man saw in 1965, as did Echo about 20 years later. Then there's McCulloch's fantastic BP-1 of 1962. It's all been done....

Model Profile: 611 TWIN

Model Profile: CST-610EVL

http://www.acresinternet.com/cscc.n...378fb4451b521bbb88256b6100149cd3?OpenDocument

An electric start would be boss

While were at just put a rotary engine on it and be done with it.

BTW does anyone else rememer the saws years ago that had a blade that moved back and forth instead of a chain?

As Randy said, McCulloch did the electric start thing on some 10-series saws. Remington also had an electric start version of their Mighty Mite. Sachs Dolmar had a wankle powered saw in 1975 (KMS-4).

Model Profile: KMS-4

 

[mad murdock]

Robert Bourke an engineer for Boeing, in the late 40's- early 50's came up with a revolutionary piston engine design that to date has not been duplicated by any other engine configuration to date (except turbines). The Bourke engine has an extreme power to weight advantage, and equally impressive bsfc(brake specific fuel comsumption). At the time, turbine engines were just coming online and Boeing shelved the idea. Robert Bourke quit Boeing and spent the rest of his life developing his engine, and was unsuccessful bringing his idea to the masses before he died. That would be one design that if adapted to a chainsaw would have a major impact on the market.

 

[Chris-PA]

I think people underestimate how significant the combination of strato + Autotune is, in terms if reducing fuel use.

For me, a chainsaw is one of the best ways to get an appreciation of just how much energy is contained in gasoline - that's a mighty small amount of fuel in the tank, and look what you can do with it! The fuel I use in my saws cutting my firewood prevents the use of a large amount of fossil fuels of some sort in order to heat my house. So I can justify paying quite a bit for the fuel I need to do that. Still, the cost does start to add up, and you have to be able to get it. So while I don't mind paying for fuel that's going to do something for me, I don't much care to pay for it just to blow it out the exhaust unburned, doing nothing, or to use more because nobody bothered to put a decent carb on the thing and it's running stinking rich everywhere but max load.

It'll be a while before Autotune works its way into homeowner saws, and they start to show up on the used market where I might get one. But I have my eye on a strato saw that I'd like to try.

Anyway, the "modern saw" is just taking a big step change right now.

 

[zogger]

link 0 rama

Robert Bourke an engineer for Boeing, in the late 40's- early 50's came up with a revolutionary piston engine design that to date has not been duplicated by any other engine configuration to date (except turbines). The Bourke engine has an extreme power to weight advantage, and equally impressive bsfc(brake specific fuel comsumption). At the time, turbine engines were just coming online and Boeing shelved the idea. Robert Bourke quit Boeing and spent the rest of his life developing his engine, and was unsuccessful bringing his idea to the masses before he died. That would be one design that if adapted to a chainsaw would have a major impact on the market.

neat stuff

Bourke engine - Wikipedia, the free encyclopedia

 

[tallguys]

neat stuff

Bourke engine - Wikipedia, the free encyclopedia

Fascinating stuff. Especially like the part where the good professor states that "There is no use wasting your time and mine, Mr Bourke - this engine cannot possibly run. Good day."

Seems that the more education some folks attain, the further up their backsides their heads get stuck.

 

[cnpser]

The other thing is ROI, are professionals all of a sudden going to change from a $500-$600 saw to a $1000 to $1500 saw? Would homeowners go from a $150 saw to a $500 saw? Probably not.

 

[cnpser]

Seems that the more education some folks attain, the further up their backsides their heads get stuck.

I am convinced that colleges have classes that are not listed like Common Sense 101 where they line them up against the wall and beat it out of them.

 

[promac850]

Robert Bourke an engineer for Boeing, in the late 40's- early 50's came up with a revolutionary piston engine design that to date has not been duplicated by any other engine configuration to date (except turbines). The Bourke engine has an extreme power to weight advantage, and equally impressive bsfc(brake specific fuel comsumption). At the time, turbine engines were just coming online and Boeing shelved the idea. Robert Bourke quit Boeing and spent the rest of his life developing his engine, and was unsuccessful bringing his idea to the masses before he died. That would be one design that if adapted to a chainsaw would have a major impact on the market.

neat stuff

Bourke engine - Wikipedia, the free encyclopedia

There is an engine that sort of resembles that... they are hoping to bring it to market in a couple of years. Look up the OPOC (opposed cylinder, opposed piston) engine. Fascinating, and it is a two stroke. Testing so far has been very successful, minimal emissions, and excellent performance and reliability. Question is whether others in the engines/auto industry are going to try to sabotage the whole thing kind of like they did with the Tucker Torpedo in the 50's, or not. These guys that developed it are Michiganders. They and a few Germans came up with the design, IIRC.

 

[Mpbowyer]

I am convinced that colleges have classes that are not listed like Common Sense 101 where they line them up against the wall and beat it out of them.

oh, that's called the admissions department, they just send the smart ones away.