hello,
I have aother questions about chainsaws and cutting firewood, on youtube I see some of the titles on the video's say like ported ms361 or ms880 and was wondering what ported meant. another question is I see a lot of people making plunge cuts when they are cutting down trees, and was wondering what the purpose of that was? thanks you all for the information ;D
Porting involves opening up the exhaust port and muffler to make more power a.k.a hot rodding. Takes some skill and deep pockets, the learning curve can be expensive. ;D
Plunge or bore cuts are made with the tip of the bar, they are often used during felling to help form the hinge on larger trees. Not a good exercise for someone not properly trained.
Sawguy hit the porting issue pretty well. It's just about making the saw breathe better and make more power. Stuff that factories can't do due to emissions or other factors.
Bore cutting is often used on leaning trees that have a tendency to "barberchair", or split up the middle instead of falling over like a normal tree. I've had it happen once, and never again. Not something for amateurs to try unless you like to eat saw bars. Can be dangerous if you don't know what you are doing. It's essentially pushing the bar nose first through the tree and cutting a slot while leaving a "backstrap" where you would normally start cutting for the fall. You cut the backstrap when you are ready to tip the tree.
Mark
I saw a Youtube with a bad barberchair last week. Tossed that saw about 20 feet in the air, and about 40 feet from the tree. :o
QuoteI see a lot of people making plunge cuts when they are cutting down trees, and was wondering what the purpose of that was?
Have a read of this PDF, it's basic (and some more advanced stuff) on chainsaw use put out by the NZ version of OSHA.
http://www.osh.govt.nz/order/catalogue/pdf/treefell.pdf (http://www.osh.govt.nz/order/catalogue/pdf/treefell.pdf)
Check page 41 for felling heavy leaners and using a plunge cut to avoid the tree splitting into a barberchair.
It's definatly worth learning if you are ever going to cut big leaners. Best to practise on some smaller non-critical trees to get it right. The only tricky part is the initial entry of the bar tip into the tree. Make sure you start on an angle with the bottom corner of the bar tip, then swivel the saw around to 90 deg once the bar is well into the tree. Once the bar is in the tree there is not much that can go wrong.
Bonus points when the leaner is twice your bar length and you have to plunge cut from both sides ;) ;D
Ian
Plunge cuts are made with non "safety" chain. "Safety" chain has guard links which extend outward from the chain as the chain is pulled across the nose of the bar. "Safety" chain is designed to reduce kick-back from the chain as it passes over the upper quadrant of the nose sprocket. If inadvertantly the upper half of the nose makes contact with immoveable objects then the reactionary force propels the bar back up towards the operator.
I try to avoid youtube when learning about things like how to cut down trees ::)
Porting can mean anything from opening the muffler up and the saw breath a little easier, but it can also mean working the transfer ports over, changing the port timing, and the like.
As well as throating the carb,blueprinting the jug/carb intake,stabbing a velocity stack on board and feeding the literal fire with a K&N.
A great bar and a monster chain are often overlooked as well................
Now you are getting carried away :D :D :D :D
I cut for money and little things matter much..............