Sawchain Depthgauge Maintainence question - Vanguard & Tripple Hump

[Walt Galer]

Howdy,

I have a question, especially for anyone professionally maintaining saw chain for others.

How in the heck do you set the depthgauges on Vanguard chains, or those new Stihl "Low Kickback" Triple Hump model sawchain.

The Vanguard depthgauges seem next to impossible to file without destroying the file.

The Triple Hump, being on the opposite side from the depthgauge and equal in height with it, causes the file to chatter and dull, no matter which side you file from.

File gauges and guides are another problem. I see Oregon claims to have a special one for Vanguard, but I have not been able to get hold of one to try as yet. For the Triple Hump, I have been using the old Windsor filemate. (And a special dial indicator setup that I made). These durn chains seem to cost a heck of a lot of extra time to maintain properly, and if not done, they just stop cutting!

I'm afraid they may actually cause accidents (other than kickback, but accidents none the less). Also I have had a few people ask to have the chain either "made to cut" or taken off. Then you have to go into the whole Kickback explaination thing.

Regards,
Walt Galer

 

[Gypo Logger]

Hi Walt, I recall when the Vangaurd chain first came out and there were claims by Oregon that it would cut 30% faster than any other chain they made including LG. So out I go and buy a 100' reel. What a fool I was, Vangaurd cuts 50% slower than LG.
Anyway, that same year I attended the Woodsman's Field Days in Booneville N.Y. and saw the Oregon rep and told him of my findings. He said," All ya gotta do is lean on the racker with a flat file". Ya, maybe with a hand held grinder, because I have never seen a gauge for taking them down.
I pawn off the Vangaurd chain to encorageable woodcutters who dont know the difference because they ruin good chain almost religously. So basically a saddle should be issued with every Vangaurd loop of chain to ride it through the cut.
Ride Em Cowboy!

 

[Kevin]

Walt, what`s triple hump?

John, get your mind out of the gutter.

 

[HUSKYMAN]

Kevin triple hump refers to the three "humps" on the bumper link of Stihl safety chain.

 

[Mr. O]

Hey Walt

Check your private messages, I sent you a bunch of info about the chain last night. Wasn't sure if you were still tracking the post from yesterday. I had some incorrect info, I put the correct info in last night. Thanks
Mr.O

 

[Walt Galer]

Howdy,

Come on guys. Doesn't anyone know of any official serious recommendation for maintaining these chains? My answers to the manufacturer's went unanswered. It is the only chain not mentioned in Stihl's maintainence manual. Oregon's manual shows a depthgauging guide, but no one seems to stock it.

Yesterday I had the "chainsaw grandma" come in and cuss me up one side and down the other, because I had put a triple hump on her Dolmar saw. After I explained the kickback thing, again, to her, she gave me this sideways evil eye, and told me to make it cut over the nose, or install another chain. I'm sorry to have to admit, I ground the trailing tangs ???? near clear off on a bench grinder freehand, leaving the other two humps at full height. depth gauges were set at .030. Initial word is she is accepting that, at least for her backup saw. I could not make the thing kickback when I tested it in my log pile, but it would now bore and cut over the nose.

I am beginning to suspect that the manufacturer's must be smoking the funny grass.

Regards,
Walt Galer

 

[HUSKYMAN]

Well Walt you asked for it so here it is:
Solution #1---Dont buy this junk in the first place

Solution #2---buy a very small (or wore out) sharpening stone for your dremel tool and do them one at a time just eyeballing them

solution #3---Do what you have already figured out, grind away until you feel better

 

[Kevin]

I was and still am of the opinion that chain manufacturers don`t want you to lower safety links.

 

[WRW]

Walt,
The triple humps have service limit marks, same as the rakers. You could try a Pferd file guide, mine hits both raker and hump. Or, if I'm not mistaken, RM chain can be purchased without the triple hump feature. If the "chainsaw grandma" is cutting dirty wood and can't abide the green safety chain, that may be an option.

 

[HUSKYMAN]

I was out looking at the only Vangaurd chain I have and it looks to me like the safety link is low enough that it would not interfere with a flat file until the absolute end of cutter life

 

[Walt Galer]

Howdy,

My experience has been that most customers discover that the cutting performance falls off drastically by half cutter life. This effect is even worse if there is advancing bottom wear due to cutting with dull chain or due to poor lubrication. The cutter simply looses it's bite and the heavy depthgauge interfears with the working action of the cutter. (Cutters are supposed to work in and out of the wood in two planes, according to the available horsepower and torgue of the saw motor).

The idea of designing the chain so the depthgauges never have to be reset, was a consideration in the design of the original 91 series chains. They were supposed to at least be able to cut, even if slowly, on a small saw at end of life with no lowering of the depthgauge. The cutter was quite short enabling this. If a reasonable cutter length is used, then the 7 degree topplate relief angle dictates that resetting is inevitable.

The triple hump design guardlink chain is quite another problem, the trouble being the way the guardlink rises up higher than the depthgauge as the chain turns around the bar nose radius. This is deliberate I'm sure to try to keep the customer from cutting with the bar nose. Ok, that may be fine for someone who is only prunning or bucking small squaw wood, but you have to be able to use the nose to cut larger wood, or wood lying on uneven ground, among many other scenarios. Folks who have much of any knowledge about chainsaws, find the taking away of over the nose cutting, quite unacceptable. (And you wind up being asked to file the safety out of the chain. I can't believe that an Oregon rep actually said to do this, as was previously mentioned)!

In my work in the industry, I found that the rising up guardlink idea worked great for black chain (Low profile chain without chromeplate, that was only sold OE or to people who had no idea what they were doing with a chainsaw), and it was used for Windsor 50RS chain. I used this chain myself for splitting a moose in half (was great for that) but never for much of anything else. On this chain the guardlink function was an extension on the back of the drivelink that also served as the only depthgauge when the chain was on the main length of the guidebar. It jointed out as the chain turned over the bar nose. You could bore only by forcing it. Needless to say, it did not exactly set the world on fire in sales.

Regards,
Walt Galer

 

[Walt Galer]

Howdy WRW,

I have found that the facts are: the triple hump protruding tail just can not be filed effeciently on the chain. The problem is that it is on the oposite side of the chain from the depthgauge. If you file into either the depthgauge first, or the sidelink side first, the part on the side where you begin chatters under the file. This breaks the toothtips off of the file promptly. This leaves a shiney strip on the file as you look on it, where the teeth have been dulled. You vertually destroy a file per chain. I have found no file that will withstand this use.

With the Vanguard chain, I find that I can file the depthgauge if I file backwards from normal. That is if you file from the outside in. It seems most of these depthgauges have some chrome plate on them as new, which destroys the file, so I touch with the grinder first to break through the chrome. You still have some chatter problem in any event. Problem is, all this takes time and if you are doing 20 to 40 chains per day it is highly objectionable. In addition the excess consumption of files greatly increases costs, on an operation that at best is only a breakeven for the shop. (If you figure shop standard costs,including labor, plus cost of materials). If you are doing this privately, and not carrying the shop overhead, you can make money on chain sharpening, but your trips to the bank will be somewhat widely spaced.

That's why I asked if anyone had any good tips on maintaining these chains.

I refuse to use the chain grinder to set depthgauges. When I dial indicate the results when the chain is set with a grinder, the variance cutter to cutter around the chain is not acceptable. Remember, when setting depthgauges, a variance of .005 is a lot, a huge amount in fact as related to the effect on kickback energy. Most factory chains are designed so the effective bite as the chain turns around the nose radius on the intended bar nose size, is only .003 or so. What do think happens when the setting varies by .005?
Most folks do not even think of this effect.

Regards,
Walt Galer

 

[WRW]

Walt,
.008 is still a drastic reduction from .025-.030. But I see what you mean, especially with liability being what it is. If it was me for my chain, I'd grind it once with a bench grinder to the service line and subsequent sharpenings would be depth guides and cutters only.

 

[Walt Galer]

Howdy,

Your recommendation is about what I did with the triple hump models on customer's saw at the shop. I did not go quite that far however, as if the chains were only 1/3 or so back, I lowered the link about 1/2 way to the line. I figured that Stihl must have ment that line to represent an end of life condition and/or limit.

The thing about the depthgauge setting on the bar nose is an effect most people are not aware of. If you draw a bar nose radius, and then draw a cutter on the flat of the bar behind it, then the same cutter up on the nose radius contour centerline with the part bottom of the cutter touching the radius line, and then you draw a radius above just intersecting the cutter's cutting edge, you will note that the back of the topplate heel and the depthgauge top ride actually above the line! In otherwords, these surfaces are acting as quardlinks! Now look what happens if you lower that depthgauge at all.

If you have a draftsman lay this out accurately, say at 10 times size, you can measure the effects, quite nicely. Another way is to just put a chain on a bar nose that is bolted or clamped to a fixture in a vise, with a dial indicator on centerline of the bar. Then you can measure the realitive heights of the cutter's heel, cutting face and depthgauge. This will normaly yield a bite of .003 to .005 on a factory cutter - standard 3/8 pitch over a bar nose radius equal to an 11 tooth 3/8 sprocket nose. There will just be an even heel interference effect. For measurements sake you want to use a stellite bar so the chain is better secured, but you can do it with a sprocketnose if you hold the chain tension tight.

This little demonstration can be used to make a person a real believer in accurately setting depthgauges!

Regards,
Walt Galer

 

[homelite360]

i hate that chain. around my way we call it the retard guard chain. it is about as useless as the great invention that homelite came up with - the safety tip. if i get a saw and it has that i take it off and throw it as far as i can so i never see it again. i bought a poulan a few years back and it came with a VG chain on it. i took it off and bought a real chain and sold the VG chain to some yuppie that was down at the parts store when i was getting the new chain. got 10 bucks for the chain.

 

[WRW]

I'll say this much for the triple humped chain. With a stem laying on the ground and tension on the ends I can start my cut on the top quadrant of the nose,bottom of the log, and cut up without experiencing a kickback and by doing so avoid the pinch as the log settles. I don't recommend that type of cutting, and it is faster to go ahead and take the precautions with regular chain, but for one not familiar with chainsaws I recommend the extra safety features of the triple hump.
The yuppie won, he got safety chain. You won, you got $10.00 for the chain. We all won, cause the CPSC won't have the opportunity to scrutinize chain since an accident has been avoided...hopefully.
As for safety tips, don't some Echos have them also?

 

[Kevin]

Here`s a little something from Oregami ...

Note: Do not file or alter the tops of kickback-reducing bumper tie straps or bumper-drive links,except on 33SL, 34SL and 35SL chains. Only on 33SL, 34SL, and 35SL will the bumper tie straps be filed down while the cutter depth gauges are filed.

 

[chainsawworld]

walt,
when i first saw the "tripple rake" chain it was my belief it was an entry level chain for new sayers. semi-chiesl, extreamly reduced kick-back and no possible way to cut the rakes down to get the full use of the cutter. oh, and reduced chain speed due to extra drag.
as far as vangaurd, it looked like a chain meant to cut dirty logs because it has a shovel in front of the cutter. but why is it full-chisel? kick-back is horrific. forget trying to bore cut.
funny, i have noticed, most deals such as buy one chain get one free or buy any new saw get a free chain the free chain is one of these.
protect yourselves; marty

 

[Fish]

My impression of the Vanguard chain was that it must be
cheaply produced, looked like to adjust the depth gauges
you should bend them on down with pliers. Never have
touched the depth gauges on them, and no, I do not
recommend trying to bend them down, I was just telling
my first reaction when I saw them. But I still believe it is
probably cheaper to produce, but I have nothing to back up that
belief.
Fish

 

[WRW]

Walt,
I re-read your post on the radii of cutters and guards. If I understand what you are saying, isn't the diminished depth of cut more a function of the length of the guard than the overall height of the guard? On the straight of the bar, the raker determines the depth of cut.
You know why the chain is made that way, for the inexperienced user that might not be aware of the consequences of accidental tip contact. The reason the guard height exceeeds cutter height is that a round of wood that might be contacted will have an arc opposite the arc of the tip, allowing tooth contact even with the guard sitting higher than the tooth.
Good for plunge cutting...no. Good for allowing the inexperienced cutter to get his/her feet wet...

I agree. They are a PITA to work on.