SKIP chain full or semi

[Lobo]

I know skip chain is the standard on the west coast in those large soft lumbers but I am curious in knowing if anybody uses skip or semi-skip in our eastern hardwoods and what advantages if any have you found if that be the case. What setup are using this chain on.

 

[jokers]

Full skip is good on long bars in hardwood, 36" and up. It`s due to a combination of chip clearance and available horsepower.

Russ

 

[Billy_Bob]

So far as I know, the reason to use a skip chain is long length of bar and power of saw.

If you are using a long bar, the chain needs to get all those wood chips out of the way - works better with a skip chain.

And power of saw - If you are using a long bar, it is better to go fast with a skip chain than to "bog down" and go slower with a full chain.

On one of my saws I have a 32 inch bar and I am using a full skip chain. It does not bog down and does a good job of removing the chips. On my 18 inch full saw, if I try bucking an 18 inch log, it bogs down and has trouble removing the chips.

My full skip saw works just as fast on a 25 inch diameter log as my 18 inch full does on a 12 inch diameter log.

 

[Al Smith]

I have both skip and full comp on my long bars[ 36" and 48"].I really can't tell much difference in these hard woods.

 

[John Ellison]

I like the semi skip on 28 to 36" bars, mainly because they are smoother and faster limbers. Smoother for sure but faster might just be in my mind.

John

 

[PWB]

Got a stihl chisel full skip .404 on my Dolmar 153, came with the saw. works well on the 33" hardnose bar the saw came with.

Got a Carlton full skip chisel (.375) on my 064 (24") at the moment, came with the saw, package deal. Not impressed. The saw cuts a lot better (faster too) with a full chisel chain.

 

[fishhuntcutwood]

Full skip is good on long bars in hardwood, 36" and up. It`s due to a combination of chip clearance and available horsepower.

Russ

Russ, I didn't think hp was a consideration when talking about skip chain. We had that extensive thread over in the used equipment forum where everyone corrected my assertion that fewer teeth cutting would help the saw remain in it's powerband, and keep the rpms where they needed to be, and that if one was relying on skip chain to allow the saw to do it's work properly, then that one was using too small a saw with too long a bar. The general consensus was that full skip was for primarily chip clearance, and everything else was a secondary benefit at best.

The frictional loss of horsepower of a skip chain being dragged through the wood is going to approach that of the full comp chain passing through(and cutting) the wood, and yet it is only taking 2/3 to 1/2 the cuts per chain revolution.

Excepting chip clearance problems, I believe that the motor of the saw running full comp chain would have to be reduced by several hundred rpm below that of the saw running skip chain before the cutting speed is completely or even theoretically even, and with the exception of specific cases where the saw is grossly underpowered, peak "in the cut" speed is going to be more directly and significantly influenced by where the engine is built to produce peak Hp than by the number of teeth on the chain.

I understand that for the most part, all else being equal, full comp will cut faster, we've established that, and I'll agree, but are we now saying that full skip will in fact rob the saw of less hp, and that skip chain is oriented to hp as well as chip clearance?

Not trying to stir things up, you know I respect what you have to say, just clarifying. :angel:

Jeff

 

[jokers]

Jeff,

I keep trying to post a long winded, loopy reply to you but AS freezes every time I hit submit or preview. A few other guys have noted the same problem over the last few weeks so I suspect that the Admins have possibly enabled a size based filter to halt either certain photos or......long winded posts, lol. I would suspect a timer but I just keep trying to copy and paste it from Note Pad. Anyway, I`m going to try and send it through in a few posts.

Not trying to stir things up, you know I respect what you have to say, just clarifying. :angel:

Jeff

Yes you are, you young punk!

I asserted and do believe that the skip chain has a lower efficiency for cutting but maybe we aren`t as far apart on this whole thing as I had thought.

I continue to maintain that a saw running full comp would have to be several hundred rpm below it`s peak power in order for a comparable saw and bar outfitted with skip chain to outcut it UNLESS chip clearance is an issue. The drag from chips being pulled along and double cut is a very significant horsepower drain.

 

[jokers]

An alternate way to look at this is that if we are cutting a log where the first powerhead is maintaining it`s peak power rpm of say 9.5k, how fast would the skip chain powerhead have to be spinning to keep up with it?

Maybe it is semantics, or even rationalization, but practical limits exist. That`s why I maintain that the powerhead is too small for the bar if it won`t pull a full comp chain unless the bar is over 36 or so inches. 36" is not carved in stone, but it seems to me that the saws recommended by the manufacturers to pull a bar that long don`t require skip chain for 36" or anything less under almost all circumstances. So yeah, Horsepower is a factor, especially for you west coasters who insist upon running longer than recommended bars.

The first practical limit that I alluded to earlier is how big a tooth and chip channel is available for chip clearance? If both the skip and full comp chains are the same pitch, it`s almost a sure thing that the cutters will have equal proportions. So if a chain is wallowing through a pile of chips in a cut instead dragging them clear, what`s going to be the end result? Double cut and unnecessary hp drain.

 

[jokers]

The second practical limit would be how big a powerhead is reasonable for a cutter to haul around? If a guy is flushing 4' or 5' stumps 10 yards from his truck, carrying an 088 or 3120 isn`t such a big deal. If he has to hike a few miles into the bush, an ms660 is going to seem alot more practical.

So what is more important, being able to run a bar longer than the manufacturer deems appropriate on a small saw when a bigger saw is practical to use or cutting faster? I suppose that depends on your individual circumstances.

I still think that a 24" or 28" bar is too long for an ms361.

Russ

 

[West Texas]

I was running a 20" bar on my 361; but, when Dave finishes working on it; I'm going to try both an 18" AND a 20" for comparison of 'feel' and 'performance'.

 

[jokers]

West Texas,

I`d say that you could probably run a 24"er on that saw when you get it back. Good mods make a huge difference.

Russ

 

[donnyman]

Semi chisel.Not as fast to cut as full chisle ,but for cutting fire wood with sand or skided up forst dirt chain stayes sharp longer.Less fileings needed.Boils down to more production.My expierance.Don.

 

[Billy_Bob]

I went up to cut firewood today. I pulled right in next to a guy who had his truck 1/4 loaded. I cut my wood and filled my truck. When I left the other guy only had his truck 1/2 full. Plus he was driving a small import pick-up and I was driving a full size long bed.

He was running a small bar with full comp chain and I was using full skip on a long bar (square ground full chisel).

He saw me zipping through my cuts and wanted to know where he could get a saw like mine, etc.

So I think my chain is plenty fast.

I call my saw and chain the "couch potato model" because I can be at home laying on my couch instead of still being up there cutting wood...

 

[fishhuntcutwood]

Thanks Russ, and I'll even agree that a 28" is too much bar for a 361.

I pm'd ya.

Jeff