Using flat file with depth gauge

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

DickRussell

Feeling the Heat
Mar 1, 2011
269
central NH
I bought the Oregon 40466 depth gauge file kit, but I suspect I'm not using it correctly. It seems that the flat file that came with the kit is very slow at cutting down the height of the depth gauge (raker) that appears above the slot in the tool. The section of the Oregon video on sharpening a chain that addresses filing the depth gauges suggests the flat file ought to take down what's needed in relatively few strokes. Am I doing something wrong?
 

DodgyNomad

Minister of Fire
Dec 19, 2009
699
West Michigan
I bought the Oregon 40466 depth gauge file kit, but I suspect I'm not using it correctly. It seems that the flat file that came with the kit is very slow at cutting down the height of the depth gauge (raker) that appears above the slot in the tool. The section of the Oregon video on sharpening a chain that addresses filing the depth gauges suggests the flat file ought to take down what's needed in relatively few strokes. Am I doing something wrong?

check that the file is cutting in the correct direction, and chuck up a small bolt or a nail in the vise and file it to see if it's biting. Could be a poorly heat treated file with low hardness, or you're not putting enough pressure on it.

Or, get a Stihl/pferd 2 in 1 file and save yourself the extra time and headache of filing your rakers separately.
 
get a Stihl/pferd 2 in 1 file and save yourself the extra time and headache of filing your rakers separately.
Money well spent .. ;)
 

jetsam

Minister of Fire
Dec 12, 2015
5,337
Long Island, NY
youtu.be
This method is fine for new chain, and it stinks for chain with moderate to heavy wear. (The Pferd/Stihl does it the same way as the old .025 gauge, it rests a rail on the tooth you are cutting and the next tooth, and has a flat file .025 lower than the bottoms of those rails.)

20210318_132532_1024x768.jpg

How many times have y'all said, "Well, I did what the depth gauge says, but these rakers need another lick... still making sawdust, maybe a few more..."

There's a good reason for that. (The reason is that .025" makes a 5.7° angle with the wood on a new tooth and about a 2° angle with the wood on a used up tooth.) The answer to the problem is progressive raker adjustment. The simple method is the old Fileoplate gauges (FOP is gone but Husky still makes them). This chain has most of the tooth left and the rakers are adjusted to a 6° AoA- you can see the Husky gauge almost agrees with this height. (This chain cuts like a light saber too.)

20210318_133813_1024x474.jpg

A significantly better but slower method is to directly measure the angle between the tooth and the raker (done with a pair of calipers and some math, or with an angle finder.)

20210318_133929_1024x1156.jpg


Here's that same raker with an old 0.025 flat gauge on it. This style gauge says that 6° is WAY too low!- and this chain has most of its tooth length left! (Factory grind is usually 5.7°.) If this was an old worn out chain the difference would be even more.

20210318_134254_1024x768.jpg

I think we're not supposed to link other forums but I am going to anyway, because everyone who uses a chainsaw more than a little should know how great this idea is. (And not great as in, "that sounds great", but great as in, "all my worn out old chains cut like new ones".)

If the link gets automoderated out, Google for "Are FOP really progressive depth raker generators?"

BobL's classic progressive raker adjustment thread