Saw video thread

[RI Chevy]

Hmmmm.

 

[dolmarkid]

Dam cold weather

 

[dolmarkid]

We might need arctic versions of stihls

 

[CR500]

We might need arctic versions of stihls

Mine appeared normal here...not sure if the arctic helps

Sent from my non internal combustion device.

 

[X 66 stang347 X]

I tried to run saws today but they all ran like *s-word at 15 degrees outside.
Maybe tomorrow

It was 76 here today. Crazy

 

[Moondoggie]

My Christmas present from a couple of awesome members!

New ring, base gasket delete, MM, carb rebuild. First tank of fuel!

 

[bikemike]

I tried to run saws today but they all ran like *s-word at 15 degrees outside.
Maybe tomorrow

15 degrees is nice out. -10 and colder sucks

 

[awol]

A saw is balanced at a certain rpm.

Cut the counter weight off the flywheel and see if it makes a difference.

The piston has no affect on the balance of the rotating Assembly.
It's balanced with no piston or a 10lb one.
The piston goes back and forth not around.

So explain to me please, why are there counterweights on the crank? If you spin a rotating assembly over with a drill, without the rod, piston, and jug installed, it will absolutely jump off the bench!

The manufacturer does the best they can to balance reciprocating mass, with rotating mass; anti-vibe takes care of the rest!

 

[dall]

how are you james havent seen you in a few days

 

[bikemike]

The 661 didn't like the cold weather
It ran and started fine but had 3/4 of its normal power.

Yeah they do that. Though they were supposed to run awesome all the time with m tronic cool dense air make more power or supposed to. But it's not the saw. Blame the bar oil lol

 

[Moondoggie]

how are you james havent seen you in a few days

I'm good. I have been busy. I spend most of my internet time on AS. I have friends over here now so i will stop in more often. I also have 4 toddler's at home. So i don't have much free time.

 

[MustangMike]

Jason, you are an excellent saw builder, but your statement on saw balance does not make any sense.

As stated, they try to get the balance close based on the expected rod & piston, but then they put an overly strong rod on it cause they do not balance each one. This allows you to change or modify the piston w/o getting into trouble.

If the crank, rod & bearings were not designed to be stronger than they need to be, then balancing the engine would be critical and would need to be done with each change in piston weight.

A properly balanced engine will likely last far longer, and run stronger (all else being equal).

 

[jmssaws]

How can a lightened piston or a big bore be possible if changing piston weight done anything?

Regardless of the load the crank is pushing back and forth it's still balanced.


If changing the amount of weight made it unbalanced then so would increasing compression.
It is externally balanced by the flywheel.
On a 2+ cylinder motor piston weight would affect it.

This discussion has happened a few times before.
Make a piston out of rice cakes and one from lead and the cranks is still balanced
How can it change it? It goes up and down in the cylinder,not around with it

Why would something that just goes back and forth need balanced?

If I grind 10 grams off a piston does it change balance?
If I use a heavy meteor instead of a lighter oem piston does it change balance?
No nope nada

 

[Brewz]

All it should change is the load on the crank rod

 

[MustangMike]

I respectfully disagree, they are called counter weights because they are designed to "counter" the weight of the rod & piston. Because they are "over built" a saw will survive with a lot of "out of balance", but if you take it too far, it will not last. The piston is very light compared to the rod, etc, but if you put a pound of lead in a piston ... make sure your are wearing a Motorcycle helmet with a face shield when you take it up to 15,000!

 

[jmssaws]

All it should change is the load on the crank rod

That's correct and load applied has no affect on balance or when you increase compression it would change balance.

The rotating Assembly is balanced absolutely but the piston doesn't affect it on a single cylinder engine

 

[Brewz]

Because you put too much load on the rod.
If the counter weights are over sized, won't increasing the weight of the piston bring it closer to balanced by that theory?

Not arguing, enjoying the discussion

 

[jmssaws]

I respectfully disagree, they are called counter weights because they are designed to "counter" the weight of the rod & piston. Because they are "over built" a saw will survive with a lot of "out of balance", but if you take it too far, it will not last. The piston is very light compared to the rod, etc, but if you put a pound of lead in a piston ... make sure your are wearing a Motorcycle helmet with a face shield when you take it up to 15,000!

All it would change is load applied.
So essentially what you are saying is that the harder you push on a saw or the more aggressive the chain is to load the saw more will change balance?

Load applied to the crank can't affect balance or a simple change in rpm would throw everything out of wack.

 

[jmssaws]

The flywheel weights are opposed to the crank throws and that is what balances it.

 

[jmssaws]

To cold outside to cut today so a piss rev video is the best I could do