Grabbiness

[davidwyby]

From another discussion…

I know the hook and raker height affect grabbiness, but I have a feeling full chisel is inherently the most grabby, and semi chisel and square are probably less grabby…hmm.

 

[farminkarman]

From another discussion…

I know the hook and raker height affect grabbiness, but I have a feeling full chisel is inherently the most grabby, and semi chisel and square are probably less grabby…hmm.

In my limited experience, I have seen semi-chisel be the most grabby. I haven't run into much issues with full chisel or square, but I tend to not take the rakers down more than .030". Keep in mind this is coming from someone who only cuts 6-8 cords/ year.

 

[davidwyby]

That makes sense. If one grinds the chain so it grabs, the blunt corner will not easily slice off the bite it grabs. I thought the sharp point of chisel would be grabbier, but as long as that delicate point stays sharp, it's probably better. Now that you mention it, I got some semi chis duracut (triple chrome) and was unhapy with the speed. Trying to make it fast made it grabby. I recently tried new off the roll stihl 3/8" semi chis felling on my 288 and was pleasantly surprised with it's smoothness and speed, though it was in soft wood.

I think at the end of the day square is king. Faster, smoother, more durable, better for cleaning faces...

 

[Stem]

hook angle, top plate angle, raker height, type of wood, chain speed, rpms I think all have an affect on grabbiness. heck, in todays day & age climate change, barometric pressure, cow farts etc also have an affect LOL.

 

[CR888]

Inner top plate

 

[mainer_in_ak]

If a saw has good power, I like a saw to be set on the wood, with minimal feed pressure and just eat.

Stock raker depth on new EXL, LGX and LPX chains is too conservative. Always somewhere around .0295" and cuts slow as fk.

Bucking firewood, some folks have a tendency to dig in the felling spikes, trying to speed things up. The friction slows the saw, but cut speed isn't helped much.

When raker depth is set to .055", my muffler modded and woods-ported saws really dig in, frozen wood or not, soft wood or hardwood.

I find less feed-pressure I fatigue less, is easier on the saw and less chain stretch too.

.055" is my ideal raker depth, all season, all types of Alaskan wood.

 

[Woodslasher]

For whatever it's worth, I've been told that booze causes grabbiness.....

 

[davidwyby]

@mainer_in_ak are you sure on the .029” and .055”? I think stock is usually .025” or less…and .055” is lot…

 

[mainer_in_ak]

David,
Yes I just set up a saw with new lgx .325 chain and two other saws with new exl 3/8 chain.

All three new chains, the raker depth was slightly below an Oregon .025 depth gauge. The raker depth measured out to .029 on all three chains.

Yes, even the local saw shop here in interior Alaska, recently set me up a custom ground ripping chain with raker depth at .055".

Alaskan birch has very high moisture content. We even tap the trees in spring for making syrup. White spruce is a very light, very soft wood.

So may be different than the species of wood you cut.

But for me, in my region with my saws, .055 raker depth has been ideal.

 

[davidwyby]

Yes, I have cut some in more northern places. That makes sense. What size bar length and powerhead size are you running?

 

[mainer_in_ak]

David,
20" bars on 50 cc saws,
24-28" bars on 60-70 cc saws
36" bars on 90-100+ cc saws.

 

[Wilhelm]

Yes, I have cut some in more northern places. That makes sense. What size bar length and powerhead size are you running?

David,
20" bars on 50 cc saws,
24-28" bars on 60-70 cc saws
36" bars on 90-100+ cc saws.

I run 20" on my ported EA5000 and it is a lot for the saw to handle if fully utilized.
Also, the ballance/handling is off quite a bit.

For me:
</=18" = 50cc
</=20" = 60cc
=20-36" = 70+cc (73 & 79cc in my case)
=36" = 90cc (dedicated large bar saw for bucking, not for felling)

In terms of grabbiness, I like my chains to grab the wood fibers and pull through the entire bucking cut - the chain bites, loads the PH and You get a continuous under load RPM without vibrations, stalls, nor slips.
When my chain keeps grabbing and slipping throughout a bucking cut it is not sharpened well, it is uncomfortable and tiring to use such a chain.
In what I cut I found that staying conservative on the rakers yields faster bucking cuts and causes less operator fatigue. Also, my saws sound happier maintaining a certain in cut/under load RPM range.

Take the above with a grain of salt as I am in no way a professional chainsaw operator.
I am just a homeowner firewood hack with one too many saws!

 

[Woodwater]

those damn variables

 

[Wilhelm]

From another discussion…

I know the hook and raker height affect grabbiness, but I have a feeling full chisel is inherently the most grabby, and semi chisel and square are probably less grabby…hmm.

IMHO, semi chisel is just as grabby as full chisel and loads the PH even more than a full chisel does as it doesn't cut the wood fibers anywhere as well as full chisel does.
Instead it "eats" a big amount of PH power cutting the same fibers multiple times.

When I utilize semi chisel on a saw I am used to run full chisel on it feels like the particular saw lost 10cc no matter how well the semi chisel chain is sharpened.
Switch back to full chisel and it is like "wow!!!".

Semi chisel for dirty wood - YES.
Semi chisel for clean wood - firm NO.
What You think You gain in less sharpening You loose in slower cutting, higher equipment wear, higher fuel consumption, higher operator fatigue.
I'd rather swap out a full chisel chain with another to keep cutting, than continuously run a semi chisel chain.

 

[davidwyby]

@Wilhelm that has been my experience with semi chisel. However, I finally tried some stihl semi...only felling on my 288 but it seems promising. Bunch of random pics of cutters | Outdoor Power Equipment Forum (opeforum.com)

 

[Wilhelm]

@Wilhelm that has been my experience with semi chisel. However, I finally tried some stihl semi...only felling on my 288 but it seems promising. Bunch of random pics of cutters | Outdoor Power Equipment Forum (opeforum.com)

If You like it and if it works for what You use it for good for You!

I have Stihl RM and I am not impressed.
I will most likely use it up bucking dirty skidded logs once I kill/retire the couple cheapo loops I currently utilize for this purpose.

We each go about the same thing in different ways.
We handle saws differently, we use different saws, we sharpen chains differently, our definition of a sharp chain differs, we use our saws under different conditions and in different wood.
There is no ONE recipe for a good sharp work chain.

The other day I ground a 3/8" Picco chain for a friend.
He insisted to try it on my dry barkless cracked up ash test log, he pushed so hard and utilized the saws dawgs he stalled the saw several times.
The log is only 10" in diameter, his saw is a Stihl MS180.
I did not touch the rakers, chain was an AM full chisel with nice looking cutters and it wasn't sharpened prior to me grinding it.
I would have let the chain do its thing, possibly supplying mild pressure on the front handle.