Boring or Plunge Cutting with Full Skip Full Chisel. Is it not possible or not done.

[HuskStihl]

Yes I did which is why I wondered if I wasn't turning enough RPM's at the time. Later that day I did over time lean out the mixture to 1 whole turn of the H screw. Not sure how many RPMS that works out to? Would that make a difference?

Also opinions on how well this set up would take a full comp chain are appreciated.

I don't think your saws tune is going to be the issue. A new full skip chisel chain on a powerful saw with a long bar vertically plunging into oak is pretty much what chain brakes were developed for. I'll plunge horizontally while stumping with full skip, but I'm not good enough with a saw to try it in an orientation in which the likely bad outcome would be kickback directed at my face. Stay with full comp if it's what u'r used to or be patient with skip as it is gonna be jumpy. Stay safe and use u'r ppe

 

[MCW]

I'll plunge horizontally while stumping with full skip, but I'm not good enough with a saw to try it in an orientation in which the likely bad outcome would be kickback directed at my face. Stay with full comp if it's what u'r used to or be patient with skip as it is gonna be jumpy. Stay safe and use u'r ppe

The technique for both horizontal and vertical bore cutting is exactly the same as is the technique between non skip and skip chain.

 

[mile9socounty]

Okay so when you say a slight twist are you meaning to the side. Doing a vertical cut with the bar in a ways a slight twist of the saw to the left or right when turning the bar in?

The technique for both horizontal and vertical bore cutting is exactly the same as is the technique between non skip and skip chain.

What MCW said. If your doing a vertical bore cut, bore into the wood a ways. Twist the power head left or right. I dont remember how it was explained to me 13 years ago. But it works.

 

[slowp]

Okay so when you say a slight twist are you meaning to the side. Doing a vertical cut with the bar in a ways a slight twist of the saw to the left or right when turning the bar in?

I call it a wiggle wobble. Without anything in your hand, hold out your arm, and then by moving/twisting your wrist, wiggle your hand back and forth. That's what you do, just a little bit with you throttle hand to help keep the saw from pushing back. Not kicking back, it is more of a push back.

Other folks have disagreed about this method. I was told that you don't need to wiggle wobble if your chain is sharp.

I will continue to keep the wiggle wobble (twist) as something to use. It works.

 

[HuskStihl]

The technique for both horizontal and vertical bore cutting is exactly the same as is the technique between non skip and skip chain.

I absolutely agree regarding technique, and I'm sure mine's faulty, but was suggesting that if someone is unfamiliar with a setup to be careful and to stick to what you know. The OP indicated that his experience was with full comp on a 20, and that he twice activated the brake trying this. Unless I've got it backwards, the kickback generated when the bar is vertical will be directed more or less at your head, rather than out to the side. I do find that skip chain tends to be touchier/jumpier than comp, and that longer bars will require more attention when using the tip. Obviously JMO, and I am not trying to argue technique with professional loggers, just urging caution in this particular situation.

 

[slowp]

When the strange yellow orb appears, and the permafrost melts a wee bit, I may have to git my camera on a tripod, and film the wiggle wobble. Not sure if I have anything to actually cut and show it, but I can demonstrate it without running the saw.

 

[BigDaddyR]

As far as the saw tune goes. I had to lean it out a whole turn. What does that do to RPMS's and therefore chain speed?

That being still in question I used the same technique I used to do a horizontal bore cut. I had no issues doing them vertically or horizontally. I'm the dork that had a big stump available so decided to practice the cut in a controlled situation with no felling danger before hacking at a tree. Each time I was able to execute the cut smooth as butter with no bucking, no intertial chainbrake testing/verification. Horizontally and vertically.

Things that changed - larger saw, saw not tuned properly, full skip chain full chisel not full comp, longer bar without low profile tip.

Apparently the saw and chain are not the issue, bar and bar size are not the issue.

In my mind that leaves technique and tuning.

I've done it succesfully before but am big enough to say that it could be my technique and I need to get more experience, I will not also rule out tuning as even thought the 372 is pretty powerful- it cut like crap until I got it in tune which leaves me to believe chain speed could have been a factor.

I will be out there this weekend and will make it a point to execute it again the same way and see what the results are and then report back. If not successful I'll try the wiggle method. If still not successful then I will not use that cut until I've tried it with full comp and smaller bar and then go from there.

Safety is very important to me so I always wear full PPE minus a forest jacket with torso protection. I also realize that this cut can be dangerous if your not well versed in the technique, dangers, and precautions to take.

I made sure that when I attempted it my head and majority of my body were out of the line of kickback and had an iron grip on the saw. I will say I was amazed how well the intertia chain brake worked as it barely kicked an inch from the tree before it enguaged. The bar never got more than 2" from the tree with the grip I had on it.

I appreciate all the feedback and this and time everyone has taken to respond and give an honest assesment. I hope this thread helps some others as well as myself.

I will report back next chance I get which may not be until next Sat.

 

[HuskStihl]

Assuming you're not bumping against the limiter, properly leaning out the tune will increase engine and chain speed, as well as make more power.
In my hands, this maneuver is more challenging with a long bar and skip chain. My 385 is also a totally different and much less forgiving animal than my 359. Had I known how seriously you take safety I wouldn't have butted in in the first place!

 

[BigDaddyR]

Assuming you're not bumping against the limiter, properly leaning out the tune will increase engine and chain speed, as well as make more power.
In my hands, this maneuver is more challenging with a long bar and skip chain. My 385 is also a totally different and much less forgiving animal than my 359. Had I known how seriously you take safety I wouldn't have butted in in the first place!

I don't belive I'm bumping the limiter as it was majorly 4 stroking in the wood before the adjustment and now barely doing it while coming out of the wood. If it were hitting the limiter it would have continued doing what it was doing or stayed the same per my understanding and what I've read in my manual. Dealer set it very rich.

I don't look at it as butting in at all but offering your experience and opinion in which was asked for and is valued. Just wanted to present a full picture for analysis. I think in the end it will come down to a little of both. Technique with a new saw b/c combo and initial poor tuning. I may try to video it next attempt just for general purposes. I do take safety very serioulsy or I would have never asked a question like this on here where I knew people might be like, it's you dummy. The more things like this are discussed in the open the more I learn and hopefully others learn.



I agree that this saw is a different animal than my 455 Rancher was and certainly respect it.

 

[MCW]

I absolutely agree regarding technique, and I'm sure mine's faulty, but was suggesting that if someone is unfamiliar with a setup to be careful and to stick to what you know. The OP indicated that his experience was with full comp on a 20, and that he twice activated the brake trying this. Unless I've got it backwards, the kickback generated when the bar is vertical will be directed more or less at your head, rather than out to the side. I do find that skip chain tends to be touchier/jumpier than comp, and that longer bars will require more attention when using the tip. Obviously JMO, and I am not trying to argue technique with professional loggers, just urging caution in this particular situation.

Luckily I'm not a professional logger then
As far as vertical kickback goes you are correct, it will come straight back towards vertical but your head should actually be off to the left side of the saw in an ideal world.
The worst kickback I've ever had was doing neither horizontal or vertical borecuts but having powerful saws in the actual borecut bite on the top of the chain and shoot the saw straight back out of the cut. I've still got an egg on my shin from my ported 390XP when stumping and god knows how the hell I ever fathered a child after a Husky 3120 and 42" incident when the chain stopped clearing chips in a plunging bore cut and bound up shooting the saw at warp speed straight into the upper thigh...
Left a good bruise that one and actually lifted my 120kg frame clean off the ground.
With long bars in certain timber non skip chain can actually increase the risk of kickback while bore cutting as it sometimes doesn't clear chips like skip chain.

Unless the chain brake is well worn in it is actually very difficult to set a chain brake off. It requires a lot more inertia than most people think.

After experiencing just how nasty kickback can be on larger saws I'm very wary letting less experienced users run my more powerful saws doing anything but crosscutting.

 

[Tzed250]

The big difference between the saw being horizontal and vertical is the fact that in the vertical once the nose stops noodling the chain has to start severing the fibers as if it was a ripping cut. Normal saw chain isn't designed to do that. If you need to plunge for rot then just do it horizontally.

 

[BigDaddyR]

The big difference between the saw being horizontal and vertical is the fact that in the vertical once the nose stops noodling the chain has to start severing the fibers as if it was a ripping cut. Normal saw chain isn't designed to do that. If you need to plunge for rot then just do it horizontally.

That is actually a very good idea. I was trying to do it vertically as that was how I've seen it done but the result is the same either way. You get a look at the chips from the inside of the tree to judge rot. It amazed me as the outside of the tree had a layer of punk on it about 2" thick but the inside of the tree was great. Nice and juicy red oak, no rot in the center at all.

 

[BigDaddyR]

Update after test today.

Okay so I went out to cut and had my 10 year old with me. After warming up the saw I talked to him about the boring/plunge cuts and what I was going to do. He got to video tape me and you can see the results below. No kickback, no major vibration. I'm concluding the issue I had last week was becase of chain speed/tuning. Same setup, same tree, different result. Here is the video below.

<iframe width="640" height="360" src="http://www.youtube.com/embed/4WPhWLQDYPs?feature=player_detailpage" frameborder="0" allowfullscreen></iframe>

 

[HuskStihl]

Good work. Nice to see success with a controlled experiment

 

[BigDaddyR]

Good work. Nice to see success with a controlled experiment

Thanks. While I know now that chain speed had a role to play in it I'm sure my technique needs some smoothing out as well. All in good time I suppose.