An idea I have while looking at the geometry of the chain as three layers. The center layer consists of drive links with their tangs or drive spurs in a groove in the bar. It looks possible that the pawl could bear against the center drive link with its wedging effect primarily focused there, but also having a bearing point against the back edge of the cutter. Thickness of the pawl could be the same as the thickness of the center drive link so it could remain centered in the chain width while either side cutters were being sharpened. Looking at the angles from the side as if looking through the axis of the rivets, the tip of the pawl would be landing on the drive link between the drive link rivets directly above the tang and a vertical edge of the pawl would bear against the back edge of the cutter only at that point in the middle of the thickness of the 3 links riveted together like a sandwich. The thickness of the pawl at the points where it bears against the chain would not be the whole width of the chain, but only the thickness of the middle drive link, so it could operate on that center line and not need to be moved. The pawl could be thicker for stiffness but have its edges ground like a chisel to an edge thickness at the bearing points that is like the edge of a dull butter knife and just under the thickness of a drive link where the tip of the pawl will bear and wedge against the chain directly under the back edge of the cutter. If the pawl geometry can be ground to fit and operate this way, it should hold the cutter more firmly in the vise. But truly, the clamping jaw scheme like used on the bar mount where the curved clamps bear against the rivets is a better way of holding the cutter securely by pinching the rivets fore and aft on the cutter. Vises that pinch flat against the drive link tangs can slip more easily than those more flimsy looking thinner clamps that bear against the rivets but do a better job of securing the cutter link being filed or ground.
It amazed me that Stihl have not got the pawl 100% when working at the end of life of chain. The 5mm width pawl is not even central to the bar groove. 4mm works ok. But I was thinking of making one that fitted between the tie strap gap but that would have to be 1.1mm for .043 gauge. I also just made a new pawl with differ upright angle so the pawl sits against the tooth and sloping away from the tooth. Like the FG2 slope. At the witness mark it has 1mm clearence from the wheel approx so that has solved the problem. Some of the engineers at Stihl must be blind if they fail simple geometry. Design check change check it. We call that simple research. Making sure your product works as intended. The pawl is also giving same problem on most grinders you see the edges ground away from the wheel. Quality control is very poor.
@@ChainsawUsers The gauge thickness for the layers in that sandwich is enough. Before I had mentioned there is a long narrow strip of stainless steel spring stock used as a retainer backing for a rubber squeegee strip in windshield wiper blades. Being a scrap collector I pull those strips from old wiper blades and save them as scrap bits of stainless. About 1/32" by 3/32" is the dimension for those strips. Yes thickness of drive links is small but as a bearing point for an edge on a stop pawl it is plenty for a hard material. Today I am supposed to receive the precision linear bearing rods that I am going to use to replace the rods on the Tecomec bar mount guides hoping to smooth the operation there. Probably the best bar mounting scheme would be to have dual units fastened together in tandem as a pair with one set to the angle for the left hand cutters and the other set to the angle for the right hand cutters, so the unit not being used is flipped up out of the way. The base for holding the saw to be sharpened has two stump vises 14 inches apart with a pivot between the two stump vises so the entire work can pivot like the bar was in a swivel, 2/3 of a half turn for bringing around the file guide to the same position first used to file the right hand cutters. Two of those Tecomec DeLuxe file guides strapped together in tandem arrangement could have their angle settings set one time not involve a setup process every time the tool is used. The rivets locate the bar mount so it would drop right into place each time it was used and would be easy to use in such a setup that swivels. There are heavy duty swivel mounts used for boat seats that I have been considering as a pivot sturdy enough.
@@ChainsawUsers Those stainless steel spatulas like are used to turn burgers on the grill are a stiff spring steel about like the gauge material I am contemplating would work for a pawl material and just a bit thinner than the drive link. The pawl could be the center of a sandwich itself with the outer pieces set back from the bearing edges of the center piece of the laminated pawl. The laminate could be riveted or even super glued together with some of that adhesive used to fasten rear view mirror attachment mounts to car windshields. With the wedge tip of the pawl on top of the drive link and the angle close to vertical for the pawl also hitting the back edge of the cutter so the wedge point coincides closely at both locations, that pawl latching should be very solid, and the bonus is the center line would stay fixed in the middle of the groove.
An idea I have while looking at the geometry of the chain as three layers.
The center layer consists of drive links with their tangs or drive spurs in
a groove in the bar. It looks possible that the pawl could bear against the
center drive link with its wedging effect primarily focused there, but also
having a bearing point against the back edge of the cutter. Thickness
of the pawl could be the same as the thickness of the center drive link
so it could remain centered in the chain width while either side cutters
were being sharpened. Looking at the angles from the side as if looking
through the axis of the rivets, the tip of the pawl would be landing on
the drive link between the drive link rivets directly above the tang and
a vertical edge of the pawl would bear against the back edge of the
cutter only at that point in the middle of the thickness of the 3 links
riveted together like a sandwich. The thickness of the pawl at the
points where it bears against the chain would not be the whole width
of the chain, but only the thickness of the middle drive link, so it could
operate on that center line and not need to be moved. The pawl could
be thicker for stiffness but have its edges ground like a chisel to an
edge thickness at the bearing points that is like the edge of a dull
butter knife and just under the thickness of a drive link where the
tip of the pawl will bear and wedge against the chain directly under
the back edge of the cutter. If the pawl geometry can be ground to
fit and operate this way, it should hold the cutter more firmly in the
vise. But truly, the clamping jaw scheme like used on the bar mount
where the curved clamps bear against the rivets is a better way of
holding the cutter securely by pinching the rivets fore and aft on
the cutter. Vises that pinch flat against the drive link tangs can
slip more easily than those more flimsy looking thinner clamps
that bear against the rivets but do a better job of securing the
cutter link being filed or ground.
It amazed me that Stihl have not got the pawl 100% when working at the end of life of chain. The 5mm width pawl is not even central to the bar groove. 4mm works ok. But I was thinking of making one that fitted between the tie strap gap but that would have to be 1.1mm for .043 gauge. I also just made a new pawl with differ upright angle so the pawl sits against the tooth and sloping away from the tooth. Like the FG2 slope. At the witness mark it has 1mm clearence from the wheel approx so that has solved the problem. Some of the engineers at Stihl must be blind if they fail simple geometry. Design check change check it. We call that simple research. Making sure your product works as intended. The pawl is also giving same problem on most grinders you see the edges ground away from the wheel. Quality control is very poor.
@@ChainsawUsers The gauge thickness for the layers in that
sandwich is enough. Before I had mentioned there is a long
narrow strip of stainless steel spring stock used as a retainer
backing for a rubber squeegee strip in windshield wiper blades.
Being a scrap collector I pull those strips from old wiper blades
and save them as scrap bits of stainless. About 1/32" by 3/32"
is the dimension for those strips. Yes thickness of drive links
is small but as a bearing point for an edge on a stop pawl it is
plenty for a hard material. Today I am supposed to receive the
precision linear bearing rods that I am going to use to replace
the rods on the Tecomec bar mount guides hoping to smooth
the operation there. Probably the best bar mounting scheme
would be to have dual units fastened together in tandem as
a pair with one set to the angle for the left hand cutters and
the other set to the angle for the right hand cutters, so the
unit not being used is flipped up out of the way. The base
for holding the saw to be sharpened has two stump vises
14 inches apart with a pivot between the two stump vises
so the entire work can pivot like the bar was in a swivel,
2/3 of a half turn for bringing around the file guide to the
same position first used to file the right hand cutters.
Two of those Tecomec DeLuxe file guides strapped
together in tandem arrangement could have their angle
settings set one time not involve a setup process every
time the tool is used. The rivets locate the bar mount
so it would drop right into place each time it was used
and would be easy to use in such a setup that swivels.
There are heavy duty swivel mounts used for boat seats
that I have been considering as a pivot sturdy enough.
@@ChainsawUsers Those stainless steel spatulas like are used
to turn burgers on the grill are a stiff spring steel about like the
gauge material I am contemplating would work for a pawl material
and just a bit thinner than the drive link. The pawl could be the
center of a sandwich itself with the outer pieces set back from
the bearing edges of the center piece of the laminated pawl.
The laminate could be riveted or even super glued together
with some of that adhesive used to fasten rear view mirror
attachment mounts to car windshields. With the wedge tip
of the pawl on top of the drive link and the angle close to
vertical for the pawl also hitting the back edge of the cutter
so the wedge point coincides closely at both locations,
that pawl latching should be very solid, and the bonus is
the center line would stay fixed in the middle of the groove.