iDRY Vacuum Kilns

Sponsors:

Depth Gauge Height

Started by double clutchin weasel, January 05, 2015, 02:49:26 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

double clutchin weasel

Several times a week, someone around here asks me my opinion on the "correct" height to file depth gauges to.  My answer is always the same, "Well, it depends".

Note that opinions are like...  Well, you know!  Also, we called 'em "drags" around here.  Folks in other areas called 'em "rakers".  Pick your own name!

First a little background on the 'Weasel...

My life with chainsaws involved clearing right-of-way for power lines.  Rough country.  Variety of trees.  Steep ground.  Short timelines.  You name it.  Clearing is different from logging.  I knew loggers.  They had different problem to deal with than us clearing guys.  After all, they wanted to save the tree!  We wanted it gone!  Totally different problems...and solutions.

Factor #1: Stumps on a power line had to be LOW.  The spec was under 4", but some inspectors included the mound around the stump.  So, we had to cut them LOOOOW.  Right on the ground.

Factor #2: We typically carried 28" bars.  This allowed for dropping most trees with a single pass.  This is important, as we had a quota of sorts to cut every day.  But, most trees we cut were closer to 12-18" in diameter.  So, if you "dogged" the saw into the tree, there was a good bit of bar/chain sticking out the other side.  Combine this with factor #1, and you have a dull chain very quickly!  So, we learned very quickly to cut on the outboard end of the bar.  And, if cutting on that end, you have very little leverage to push the bar into the cut.

Factor #3: We rarely did any bucking.  The weight of a saw in a bucking cut helps feed it into the cut.  But, with the saw on its side for felling, that weight no longer does anything for you.

So, given these parameters, it is little wonder that we typically cut the drags quite a bit lower than the "standard" 0.025".  I have seen them at 0.050-0.060".  I personally have little use for anything less than about 0.045".  My first boss had me run a Homelite 925 for a week with no felling dogs.  That week started out rough!  But, by Friday, I hardly noticed their absence.  He wanted me to learn NOT to depend on the dogs.

After that week, I had gotten pretty good at filing a chain.  And, I learned to let the saw do the work, not me.  So, even to this day, I prefer not to "ride" my saws.  I let them "pull" me along.

Of course, the correct depth gauge height for any particular job can be altered by the size of the saw, the length of the bar, the type of chain, the size of the tree, the type of wood, and maybe even the phase of the moon!

Ideally, while in a pretty-much "full-bar cut", the RPM of the saw should be right at the manufacturer's "maximum power" RPM.  If the RPM is too low, so are the drags!  If the RPM is too high, or you are having to push the saw to make it cut, the drags are probably too high.

One thing is for sure.  If you see the paint burned off the bar, the drags are probably too high.  If somebody is pushing the saw into the cut, because it won't self-feed, that force causes friction between the bar and chain, causing a lot of heat.  That is usually why the paint is burned off!  By bars don't get that hot.  The chain is pulling the bar along, not being pushed by it.

But, again, there are as many "right" answers to this as there are operators.  If you do mostly bucking, and use the dogs to pivot on, you will be happy with much less depth of cut. 

Incidentally, I have heard stories of guys "cutting the drags completely off".  I'd have to see that one to believe it!  Unless it's on a souped-up "race" saw, I doubt the saw could even pull the cut!

Maybe this will help somebody.  At least it's free!
Eagles may soar, but weasels don't get sucked into jet engines.

Jeff

Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

HolmenTree

 A good cutting self feeding chain is determined how sharp the cutting edges of the chain are with the factory recommended angles. Not how low the depth gauges are filed to.

Even in the felling position without the help of leverage dogs, a well sharpened chain can self feed with very low hand pressure applied with the depth gauges as high as .015"

I've met a lot of line cutters and loggers in my day and I found the ones who cut with a  poorly sharpened  dull chain always filed the depth gauge down low .040 and over........ to compensate for their poor sharpening skills. ;)
Making a living with a saw since age 16.

HolmenTree

To add to my post.
How I saw this was when I was logging I was on the safety committee and we did monthly safety tours checking in on the crews.
We used a machinist depth gauge tool and measured all the fallers depth gauges on their saws.Any chains we found with them lowered below .030 the faller was instructed to file the cutters back to get them back up to spec again or retire the chain.
We allowed low settings when the chains cutters were filed down small and the depth gauges were progressively lowered with the Carlton File O Plate where the setting would be approximately .038 when cutters are filed back to the witness marks.
Even without the Carlton method we allowed the .040 range when the chain was filed down to the end of its life.

On my travels working for Stihl meeting end users I did the same. Only difference was I didn't enforce anything , just gave some serious recommendations.  :D
Making a living with a saw since age 16.

double clutchin weasel

My teeth are razor sharp, and I am meticulous about the angles. Stating that the sharpness of the teeth affects the self feeding characteristics of the chain more than the height of the drags strikes me as a little implausible. Sure, a dull chain will affect cutting efficiency.  But, there is no way the height of the drags won't affect the feeding characteristics.

But, like I said originally, you will get as many opinions on this issue as there are operators.

To each his own...
Eagles may soar, but weasels don't get sucked into jet engines.

HolmenTree

All I was saying was if you have to lower your depth gauges that low to self feed then you gotta get those cutting edges cutting better.
My fastest chains in stock saw timbersport speed buck have their D.G. at .015 and that's with a 8 pin sprocket. Wood in 12"-16" diameter range.
Making a living with a saw since age 16.

HiTech

Too many people who sharpen a chain do so with the chain lose on the bar. When the file is applied to the cutter it goes or tips at an angle. This changes the way the cutters cut. When filing or touching up I make sure the chain is at proper tension or snug. Sometimes I change the angle of the cutter a bit but mostly I try to keep it the same angle as factory. I have found you can't beat a brand new out of the box chain for cutting down trees. They feed themselves nicely into the wood with minimal effort.

double clutchin weasel

Quote from: HiTech on January 06, 2015, 07:19:17 AM
Too many people who sharpen a chain do so with the chain lose on the bar. When the file is applied to the cutter it goes or tips at an angle. This changes the way the cutters cut. When filing or touching up I make sure the chain is at proper tension or snug. Sometimes I change the angle of the cutter a bit but mostly I try to keep it the same angle as factory. I have found you can't beat a brand new out of the box chain for cutting down trees. They feed themselves nicely into the wood with minimal effort.

The chain tension comment is absolutely correct.  That tilting of the teeth in the cut is a huge factor in the "effective" depth of cut.  Thanks very much for mentioning that, as I forgot to include it as a "factor".

And, just for reference, I think new, out of the box chains are terrible.  So, that gives us a common frame of reference!  If you like the way a new chain cuts, then your preference in chain "behavior" is considerably different than mine.  I consider the penetration rate of a new chain to be waaaaay too slow, and require too much pressure.  So, there is the difference in "preference" between too operators!
Eagles may soar, but weasels don't get sucked into jet engines.

TLahti

Hi Guys:
  Does the proper raker height vary with the type of tooth?
I prefer full chisel, but a friend gave me a dozen chipper chains, some of them only used once because they did not cut well with the factory raker height.
  I found that the chipper chains required much lower rakers to work well at all. Some of them had three rakers between cutting teeth.
   I never bother lowering the rakers on my chisel chains, they seem to cut well to the bitter end as is.
   I cut about 10 cords of firewood a year, mostly maple, and I have old (1975 to 1980s, no plastic) but good, saws.
  Terry

HolmenTree

Quote from: double clutchin weasel on January 06, 2015, 07:25:19 AM
And, just for reference, I think new, out of the box chains are terrible.  So, that gives us a common frame of reference!  If you like the way a new chain cuts, then your preference in chain "behavior" is considerably different than mine.  I consider the penetration rate of a new chain to be waaaaay too slow, and require too much pressure.  So, there is the difference in "preference" between too operators!
Actually today's most sought after chain the Stihl and Oregon 3/8 chisel chains like the 33RSC and 72LGX for example.... come out of the box very aggressive they way they are ground from the factory with their excessive side plate angle "hook".

Only the out of box Carlton chain sold today and chains from years ago needed extra work to get them to feed good.
What chain are you running? ???   
Making a living with a saw since age 16.

double clutchin weasel

Quote from: HolmenTree on January 06, 2015, 01:54:21 PM
Quote from: double clutchin weasel on January 06, 2015, 07:25:19 AM
And, just for reference, I think new, out of the box chains are terrible.  So, that gives us a common frame of reference!  If you like the way a new chain cuts, then your preference in chain "behavior" is considerably different than mine.  I consider the penetration rate of a new chain to be waaaaay too slow, and require too much pressure.  So, there is the difference in "preference" between too operators!
Actually today's most sought after chain the Stihl and Oregon 3/8 chisel chains like the 33RSC and 72LGX for example.... come out of the box very aggressive they way they are ground from the factory with their excessive side plate angle "hook".

Only the out of box Carlton chain sold today and chains from years ago needed extra work to get them to feed good.
What chain are you running? ???

Running 33RS, H47, and 72LGX.

My whole point here is that there are different preferences as to how the chains cut.  I prefer to hold back on mine, rather than push on them.  Not saying I'm right and anybody is wrong.  Just saying I like mine that way.

My advice to anybody has always been to start shallow, and sneak up on a depth you like.  I have seen some (like I said originally) that are in the 0.060" range.  I can't personally work with those.  I like mine between 0.040-0.050"...unless the cuts are full-bar-length.  Then I generally back them up a little shallower.

I'm really glad people are talking about new chains of specific types now.  That gives us a known reference point.  And, to that point, I do not personally like the way a new, out of the box chain cuts.  I like mine a good bit "hungrier".  But, I have a very light touch on the saw, and the motor runs in its sweet spot.  So, it works.  If you are a little more heavy-handed, you might not like mine...but, I might not like yours either!

Regardless, thanks for weighing in...and being specific.
Eagles may soar, but weasels don't get sucked into jet engines.

HiTech

Let's take this a bit further. I cut hardwood species not softwood. Depth gage could play a part there also. Normally in softwood i have seen people run far more aggressive depths than in hardwood. New chains do not grab they work. Which they are intended to do. Smooth almost effortless cut. When falling with a new chain I even hate limbing with it for fear of hitting something....like the ground. lol I can remember one time I had a brand new chain on and had about 5 trees down with it. I was cutting the next tree and hit something in the tree. It ruined the chain..got both sides which is unusual. I went back out to the truck and got a new chain. My buddy cut that tree in a different spot and it was good there. We marked it so we could tell it when we got it to the landing. Hate to send one of those to a mill...it might have more metal in it.  I kept the damaged chain but by the time I got done filing it there wasn't much tooth left. I put it on my landing saw.

John Mc

I'm with HolmenTree on this. The new Oregon chains have way too much hook right out of the box. It's a pain in the butt bore-cutting with them - they are too grabby. The sharp thin tip also doesn't hold up well, at least not in the maple/oak/beech I'm cutting. Maybe I'd like them better if I were cutting softwood, I don't know. 

They didn't use to be that way. I've generally found that touching up a new chain with a file improves it's performance. I'm not doing anything fancy, just sharpening it to the specs given by the manufacturer. On the newer chains, they may cut fast enough out of the box, but the grabbiness and lack of durability are a problem. I tend not to sharpen these right out of the box, but I'm usually not happy with them until they've been sharpened a couple of times to reshape the excessive hook.
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

CX3

I had to laugh a little at some of the posts.  This is why this site is great, we have master loggers on one end, and guys that look at chainsaws on the shelf at Lowes on the other end.  Its great for everyone to learn. 

I log full time.  We open face bore nearly all trees that are felled.  I like my drags about 40 thousandths.  But I also drastically sharpen the tooth, with angles that aren't mentioned in the stihl books lol.  There are some good tricks to learn about this, that can take a lifetime to learn.

The comment on a new chain working really well in the timber, well....... I spend at least 25 minutes sharpening a brand new chain.  Ill just say that a new chain is NOT sharp. 

And I agree about the chain tension.  This is an extremely important variable to how the chain cuts.  Each little thing you do is just splitting hairs.  But if you split all the hairs, and have them all working together, then you'll no doubt hit a rock just minutes after completely sharpening the perfect chain lol
John 3:16
You Better Believe It!

HolmenTree

We have to be careful giving advice about filing saw chain with low depth gauges to the masses. Some members here are as young as 14, sure don't want to see them try filing a brand new chain to .040.....050 and then get a serious kickback injuring themselves.

Like I said about todays round ground chisel chains their side plate angles are coming from the factory with way too much hook. Abuse the depth gauges and someone inexperienced can hurt them selves bad.
I preferred the old chains from 20-30 years ago that had blunt angles with almost straight verticle side plates, where I had to file my angles in to make them cut the way they should.

Now today it seems even though these new chains out of the box DO NEED to be touched up with the file to get them sharp,  they have enough aggressive hook to make them SEEM like their cutting fast. Just don't file them down to .040 right out of the box and endanger yourself. :o

I guess the market today demands a disposable like chain for the endusers who don't want to file or don't know how to file well.......if it slows down file down the depth gauges and hang on :D
Making a living with a saw since age 16.

HolmenTree

To add to my last post here's some photos of some out of the box never filed chain I owned from over the years to help better explain what I trying to say about safety.
The first photo shows how the side plate "hook" angle has changed from the factory over the years.
Bottom chain is from about 20 years ago, middle from about 15 years ago. Top chain from today.

Last photo shows todays Stihl and Oregon out of the box chain.....pretty darn aggressive eh? Now put a .040 depth gauge setting on that ............


  

 
Making a living with a saw since age 16.

Maine logger88

I run 73LGX and I will always take a little time to file it. A new out of the box chain will cut but a new chain filed will cut well. I usually run my felling chains between .020 and .025 for me that makes the smoothest fastest cutting chain. When a chain gets around half wore out I'll use it for the yard of cutting up firewood then I will lower the rakers down to .035 to .040 to make up for the less sharp tooth as in the yard there more likely to get dull faster and with the lower rakers it will continue to cut a little longer between fillings.
79 TJ 225 81 JD 540B Husky and Jonsered saws

hacknchop

Im with DC Weasel i think one big difference is that when i cut powerline right of ways got paid by the acre and that meant you had to be cutting steady ussually fill up the saw and cut till tanks empty.I also got use to aggresive rakers and have been known to use small hand grinder to take them down, with the saw in a wise in my garage of course not out on the line and yes not for the novice.
Often wrong never indoubt

mad murdock

All I will add is that the most important thing to a good cutting chain is consistency in sharpening.  making sure each tooth profile is not only correct, but as close to the same as you are able to make them.  as far s D. G.'s, I like a chain that self feeds, that way when I am using the tip of the bar, it is easier to "feel" where the tip is, when cutting with the top of the bar, and I physically cannot see the tip, in regards to whether I am "in" or "out" of the wood with the bar tip.  If I have to push a saw at all to cut, I will not use it till I get the chain to where it is self feeding.
Turbosawmill M6 (now M8) Warrior Ultra liteweight, Granberg Alaskan III, lots of saws-gas powered and human powered :D

HolmenTree

Quote from: hacknchop on January 09, 2015, 12:56:17 AM
Im with DC Weasel i think one big difference is that when i cut powerline right of ways got paid by the acre and that meant you had to be cutting steady ussually fill up the saw and cut till tanks empty.I also got use to aggresive rakers and have been known to use small hand grinder to take them down, with the saw in a wise in my garage of course not out on the line and yes not for the novice.
I have cut and widened many powerline right aways too that other contractors couldn't do.
And I would never take my depth gauges down with a hand grinder.....only with a file ;)


    
Making a living with a saw since age 16.

thecfarm

HolmenTree,interesting on the chain angles. In all my junk,I'm surprised I don't have a chain from 20-30 years ago.
Model 6020-20hp Manual Thomas bandsaw,TC40A 4wd 40 hp New Holland tractor, 450 Norse Winch, Heatmor 400 OWB,YCC 1978-79

HolmenTree

I have kept alot of never filed short pieces of chain from over the years when I shorten/lengthen loops.
Making a living with a saw since age 16.

hacknchop

Im not sugesting that others take a grinder to their rakers my point simply is that way to much is made of  .020 or.035 or. 050  you need to concentrate on the fact that a saw is like any other tool and is best set up for the person and the job at hand. Anyone who has much experience with a jockey grinder gets use to taking the same amount and very lightly by times on each tooth. The main thing is sharp saw cuts straight and true.
Often wrong never indoubt

OntarioAl

HolmenTree
I whole heartily agree with all you have stated.
I am an Instructor/Trainer/Certifier here in Ontario (over 45 years power saw experience)
The manufacturers depth gauge specs are part of the safety aspects (kickback) designed into that particular chain model. Filing them beyond is consider altering or removing  a safety device.
In Ontario a on site visit by a Ministry of Labour Inspector found your chain filed .045 or more (when specs call for.025) would issue a compliance order (which guarantees revisits) and perhaps fines for you, your supervisor and the company owner .
If the visit is the result of an accident investigation all bets are off charges will be laid all around.
In Ontario Safety has top priority and supervisors, company owners and corporate executives are held responsible.
To that effect no person can be employed operating a power saw without  accredited training (three days classroom and field) This does not make the trainee an instant power saw operator that only comes with hands on experience the training is all about safety working with power saws.
The result is when the potential employee shows up on the job site he/she will know standard is expected of them and employers and supervisors who chose to ignore safety related issues do so at their own peril the fines start in the thousands. 
Al
Al Raman

John Mc

HomenTree -

I like my chains to look about like the middle one in your first picture, which is usually where they end up when I file them. Those narrow beaks on the newer grind just don't hold up and are grabby. I do wish they'd stop grinding them that way. It wastes material in the tooth. It also doesn't match their own spec for what a chin is supposed to look like when you sharpen it.
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

Thank You Sponsors!