Trouble with Plunge Cut

[Turbo]

Guys, need some thoughts on what the issue might be as to why I'm having trouble plunge cutting lately. I've got an MS362 C-M, the bar and chain that I seem to be having some trouble with is a Stihl RS chain with Rollomatic "E" bar. At one time I could plunge cut with this set-up, but something has happened that has led to an increased amount of grabbing and kick-backs. There is no issue until I straighten the saw out and the top half of the bar nose radius starts to contact the wood, then it jumps and kicks quite violently. Wonder if its a chain sharpening issue? Thoughts?

 

[three feathers]

Make sure that the rakers are not filed too short. Only thing I can think of.

 

[Turbo]

Make sure that the rakers are not filed too short. Only thing I can think of.

Yeah for sure, about the time I took them down a bit, was when it started, however, I did check them again and they are high, so taking a smaller bite then they would be if I had them flush with the depth gauge. Good tip, thanks for the suggestion.

 

[woodhog73]

Rakers too short

Depending on cutting conditions, generally I touch up my rakers every 4th sharpen or so

But then again I touch up my cutters several times a day over a morning till night day of cutting.

 

[CountryBoy19]

Technique maybe?

Are you cutting deep enough before you straighten the bar/saw up?

 

[Turbo]

Technique maybe?

Are you cutting deep enough before you straighten the bar/saw up?

I would have thought so, but I'll take a little deeper on a larger diameter tree and see if it works. If not, I'm thinking I'll take the chain in for a pro sharpening to "true" up the geometry, perhaps that's not helping?

 

[BenTN]

Agree with guys above. Short rakers. Might just be 1 or 2 that are short. I have a hard time boring with rs chain too, it's quite aggressive when sharp. I have heard semi-chisel is much friendlier for plunging, I prefer the h30 narrow kerf on my 550.

 

[DUMF]

Simple: bore or plunge cut technique needs a correctly sharpened chain, tight on the bar, with rakers to spec for the specific chain.
It's important to use the bottom edge of the bar to start (never the top or front of the bar ),and full RPM's always.
When I first learned to use bore techniques (CLP )it was in softwoods only. It does take practice, thinking about what you're doing, and a sharp, tight chain. Also at first use a shorter bar, 16" or less.
Try it.

 

[woodhog73]

and full RPM's

This is so true and I've seen guys get nervous plunge cutting and back off the throttle. Probably not good. No matter how perfect your chain is if your plunging into hardwood and you hit a nasty knot in the center with the bar tip buried into the trunk, the saws probably going to kick back like it wants to push itself out of the hole your making. It can be very intimidating, especially if your running a big and heavy saw.

But to me plunge cutting is necessary, especially on heavy leaning trees. I always plunge cut from my hinge wood and cut back away from the hinge, to leave a strap of wood on the backside or tension side of the trunk. It prevents dangerous barber charing on heavy leaners where the weight of the heavy lean can cause the trunk to split in the center before you have your hinge where it should be. So plunge cutting is very important in some cases. Definitely worth getting good at in my opinion

 

[DUMF]

Woops ! Forgot one other skill and tools that goes along with bore cuts in your arsenal: wedges. See what woodhog has written.
Using the bore with a "strap" allows you to 'push' a tree where you want it with wedges hammered into the cut on either side of the strap.
Safer with leaners giving you time to hammer the wedge(s) to break the hinge. We use Bailey's florescent green plastic wedges.
We never cut without a good heavy hand sledge or good axe with a flat head.
Wedges can save your a$$ when the bar gets stuck (never happens, huh ? ) in a compression cut that goes south.
Plenty to learn. Spend time with a pro logger or arborist.