chain weight

[Monster]

I'm no chainsaw expert, but to me the weight will make very little if any difference, because your still dragging the chain through the wood. Irregardless if the chain is heavy or light the amount of tension (or pull) on the chain from cutting, is far greater than that little bit of weight.
It takes alot of energy to accelerate an object in comparrison to the amount it takes to maintain speed. If you were to go WOT with your saw with either heavy or light chain I bet the WOT RPM would be pretty much the same. That little chain is no match for a 2 stroke of that power. In fact that may be a good way to check the power loss of a heavy chain if you have a tach for your saw. Take the light chain and measure the RPM with a cut and free spinning and quickly swap the chain and measure the RPM again.

Mac tools has a cool little tach that measures rpms 2-stroke/4-stroke, 1cyl up to12 cyl that you just have to put beside the coil.
Pretty cool toy to have, I'm tempted to get one myself, but then I fix cars for a living.

Just my 5 cents worth

 

[Fish]

Since the introduction of my "synthetic" bar oil, friction is
no longer a factor. The bar also runs so cool that the stellite
becomes superconductive, and with the field generated by the
motion of the flywheel, the chain never actually touches the
bar. It's just another theory I am working on. I am trying to
integrate it into Fish's Unified Field Theory, but am having a
rough time with the math involved, all of this beer has fogged
my thinking.
Walt Galer is whipping out the racing chains for my prototype
model, which shall challenge the giants of the saw world.

 

[jokers]

Hey Fish, I was wondering how long you planned on holding out about your new MAG-LEV cutting attachments. With the :exclusive rights for distribution" agreement that you have worked out with Poulan, it should put them back in the game. Russ

 

[Fish]

Poulan, sheesh, they would just paint it Orange and call it
Husqvarna. They also have a group of lawyers that are
concerned about mixing liquid nitrogen and synthetic bar oil,
too much red tape. I will try the Koreans that bought out
McCulloch, they seem a little more receptive to my radical
innovations.

 

[eyolf]

I like the 5# vs 10# brick on a rope theory. Unortunately, there isn't as much difference between two brands of chain as there is between the bricks. At the "ends" of the "rotating" mass, energy still must be sacrificed to change direction of the chain components, but the amounts involved are small, and the differences between them are smaller yet. While the difference might be calculable, would it be measurable?

I believed that the folks who doctor up chains for racing do so to optimize cutting and chip flow. Some racers use 1/2" chisel chain if they can get it, when lighter chain with more and smaller cutters is certainly more available. There must be more advantages than just the added strength of the chain...

 

[fun_chopper]

wieght and inertia are relative, thats a given thanks to Newton. In racing I would think that to increase cutting performance, you would have to reduce friction on the cutting surface ie. grinding it down as small as possible, that would have greater efect than reducing weight. The boot analgy is the perfect example, weight drives inertia, and inertia maintains relative motion to an extent. The only variable in this total equasion is friction in the cutting surface, because the rest are given, weight, inertia,bar friction, travel, so only cutting friction is left as the only real changeable variable.

 

[timberwolf]

Cumulative effect

Granted the mass of the chain likely only makes a small difference, so does a lot of other aspects like; polishing the ports, filing the gulets, thining the botom side of the top plated, using synthetic oil, filing back the tooth, replacing the choke plate with a primer, upgrading the air filter, various engine tweeks, ect ect ect........ 1% here 2% there. Many of the improvements are cumulative and even coumpouding to each other, and many are win-win with no apparent, relevent or unacceptable draw backs.

Building a winning race car is not just about building the best engine, it is considdering and maximizing all available potentials.
Don't forget many of the best consumer sports cars were developed for the race track. Speaking of race cars, why would they even considder using aluminum and magnesium wheels, drive lines and engine components if there was not an advantage in reducing rotational weight.

As long as the engine and drive components are strong enough and have enough momentum to get the piston/s back up to TDC, enything more is just weight.

Sure it is only 10% more chain weight, but that make the diference between the power head of the saw moving 25 tons and 22.5 tons an hour.

Timberwolf

 

[Fish]

I think with the amount of contact that the chain has on the bar
and making a full 180 degree turn twice, makes the inertia
thought not realistic. On a circular saw, more like the analogies
introduced earlier, it is an entirely different scenario. Turn a
chainsaw of while at full rpms, then a circular saw, then the stop
times are dramatically different. On a chainsaw, the friction
is a constant drag on the system, even as cutting fibre is
moreso. If a given engine cutting the same fibre, with the
same chain, except for reduced weight on the sidestraps and/or
drivelinks on one, the lighter one would cut faster, as the engine
requires less energy to run the lighter chain. Introducing too
many variables just makes it confusing. But I think inertia is a
tangeant that has little merit.
In everyday cutting, chain weight is not worth thinking about.
In racing, I would suggest that the lighter weight chain, with
the same cutters, would cut faster. Common sense would dictate
that, I would think.

 

[Crofter]

Fun _Chopper
You are slightly confused about what inertia and momentum are. I thought you would see in the ridiculous analogy of the heavy rubber boots that the energy lost to drive the boots up and down has very little to do with their simple inertia and momentum in the linear plane. With any thing as crude as the contours of saw chain drive tangs and the respective sprockets, there is nothing like the effortless exchange of energy in sine wave motion. It doesn't all come back. Look at Timberwolfs original post; look at the number of foot pounds of energy involved. With heavier components it takes proportionately more centripetal force to overcome the added centrifugal force.This must be applied from end to end across the arc of the bar top and bottom in purely sliding friction. The additional weight is not inconsequential!! This is not purely rotary motion like a round flywheel. If this were the case , I would agree with more of what you are saying.

Frank

 

[fun_chopper]

I am saying that weight has nothing to do with anything..thats my point, and to support that point I sated that a light chain has less inertia, and better acceleration.A heavy chain has more inertia and slower acceleration. The counteracting forces slow the effects of inertia. The bottom line here is what does cain weight have to do with anything, in a car you move the entire machine, therefore weight does matter. On a chainsaw you move the chain, and since all things are relative except for the friction induced by the cut, the only factor left for a chain is the reduction of friction in the wood by reducing the surface area of the cutting surafces. Your analogy was dead on more power was lost during acceleration, but as you approached a constant speed, the momentum you created in the boots caused an energy drop off meaning you expended less energy to keep the boots going at a constant speed, whereas with tennins shoes you wouls have to expend a constant amount of energy to maintain a constant speed. This is inertia..so tell me again what does chain weight have to do with anything?

 

[Gypo Logger]

This whole dicussion has come full circle and may bring us to a laymans term known as tractive effort. Just picture in your mind a log skidder with bald tires trying to get up a steep slope against gravity, as it were. Its just that life exists as torque, and if it wasnt for lube, none of us would be here.
John

 

[Crofter]

Gypo Logger!

I'm trying to make sense out your last post.Could you please send me some of the same fungus that generated it.

Frank

 

[Gypo Logger]

Hi Crofter, in actuality, it was 3 King of Beers, fragrant Cherry wood fibre and two or three 5 cube + saws. I hope you know I come by it honestly.
John

 

[Crofter]

Boom Up Gypo, you're gonna take the pickets off. That sure is nice cherry. Up here on the north shore of Lake Huron it is just shrubs.

Frank

 

[Fish]

So , cutting through a 12" log, could you cut faster with a 16"
bar and chain, or a 24"?

 

[Tony Snyder]

Of course, 16 should have a slight advantage, but maybe to little of difference to measure without the set up of a designed experiment.

I expect one operator to the next would show more difference than the chain weight thing.

Twelve inch stuff sounds like 2159 stuff to me.

 

[Fish]

Ok, a 14" bar and a 36" bar, with the same chain and saw.
Which would cut through the 12" log first? I am going to an
extreme to illustrate a point.

 

[Tony Snyder]

The 14" bar I reckon, if you could find a 14 and a 36 with the same tail pattern.

But if the power head has the power to keep both chains at full rpm in your hypothetical 12" log, it should be a tie. For instance an 066 might not even notice the difference in chain weight or friction. Or the extra weight and down force of the 36" might get thru the log first.

Just tell me your point. I am not opposing you.

 

[Fish]

In a contest for speed, the saw is likely pushed to the upper
limits. If you were to say that the 14" bar would win, then weight is a factor, as obviously the longer chain has much
more weight. No matter how powerful the engine. The greater
weight also entails more friction. Friction is proportional to
weight. The original question was "Is weight important?", I
just say it is.
I also say inertia has nothing to do with it.

 

[Crofter]

Fish
I'll be the devils advocate and say that if it were a large governed rpm saw the times would be the same ( but you'd burn more fuel to do it with the long bar) Now which side am I on? You see I enjoy discussion so much, I will even switch sides if necessary to prolong an argument! lol.

Frank