Stihl won't cut when sharpened at 30 Degrees

G

Greg107

Location
Bozeman
I have 018C and a MS170 which use the 61PMM3 50 14" chain, Picco Micro Mini. I bought a new chain and cut two cords of wood. I then decided to sharpen the chain using a new Stihl 2 in 1 sharpener. I sharpened the chain at 30 degrees and at a 90 degrees to the bar as recommended by stihl's owners manual. The chain would not cut. I them decided to sharpen it at about 40 degrees and it cut through a log. The sharpener is the correct one the 3/8th chain. What could cause it not to cut when sharpened at the recommended 30 degrees?

Thank you

Greg
 
What size is the file you used?
It should be a 5/32 , might need a magnifying glass it’s hard to see it sometimes but it should be on the file. Could also zoom in with phone or digital camera if you can’t find a magnifying glass.

3/8 is the pitch and doesn’t tell much about the cutter size. I got 35cc top handle saws and 77cc pro saws and they both run 3/8 chain but there’s a big difference in the chains, the smaller ones are 3/8 low pro and different gauge.

And yes pics are always helpful.
 
Greg107 said:
I am using a 5/16th file. I thought the 2 in 1 sharpener would take care of the rakers. Here is a picture.

Thank YouView attachment 63053
Click to expand...
160125_STIHL_Blog_Rundfeile_Tiefenbegrenzerabstand.png

A smaller file will get you the hook in the tooth shown here, where yours is almost at a back slant. Once you change your file, and it will take a few passes to correct it, you should be good to go.



Another note, if your running a stihl brand chain each tooth will have a mark like the 3 in the image that I posted. It corresponds with the correct file size for that chain. Screenshot_20191021-203907_Drive.webp
 
I hate to ask, but are you sure that 2-n-1 says "3/8P" and not "3/8". But 5/16 is way too big. That's like 8mm, twice the size it should be.
 
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One more question, can you describe the difference in cutting between a 30* and 40* sharpening say on a scale from 1 to 10. When you said 30* "wouldn't cut log", we just want to quantify.
 
It might help to get rid of that "safety chain" and get a pro chain. Safety chain creats more friction and heat. You might try fileing off the burs on your bar, it looks like it's seen a fair amount of abuse. Hope you'll see chips again soon.
 
That PMM3 always cuts good out of the box, but once you file it a few times, the performance drops. The explanation is 1) more than recommended aggressive hook when new; 2) defined peak on depth gauge. As you file, the hook will become normal, meaning the recommended angle; AND the depth gauge will develop a big wide plateau which creates a pivot point for the "porpoising" action quickly getting farther from cutter which lowers the angle of attack of cutter producing shallower cut. The 2-n-1 gauge has the "Stihl recommended" hook, though it may not appear so. But the depth gauge problem is remedied by taking a flat file and filing the gauge at a downward angle so that the part of the plateau nearest the cutter is the highest part. I have confirmed this phenomenon and can attest that sloping those depth gauges will get that PMM3 cutting again. Otherwise, that chain is cutting just like Stihl's lawyers and marketing folks want that .043 gauge to cut.

We discussed this one time in this thread http://www.treebuzz.com/forum/threa...harpener-rake-grinder-units.40859/post-611701

The real solution is to do what @Treezybreez daid and get some more aggressive chain. You will need to switch to a .050 gauge bar, but you can run Stihl PS3, PM3, PS, PM, or even Oregon PXL which is pretty aggressive for safety chain. I love PS3. Don't worry, at 14" bar, you can pull any of those with .025" depth gauge on your saw. I run 16" PS3 on a 30cc saw with no issues.
 
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The top of the cutter has been filed away, and there’s no gullet. Press harder downward.
There’s still a lot of metal left on the cutter, it can be salvaged. You probably won’t need to take much off the rakers so be gentle. You can always take more off the rakers later.
If it chatters/ vibrates excessively when cutting, it means you took too much off the rakers.
 
Blow up the pic and take a look at these and see if you can't make some connections. The only place you find PMM3 is on homeowner saws and pruners if that tells you where Stihl sees this chain in the marketing lineup.
1) NEW Stihl PS3 - aggressive, fast, smooth, chips
2) NEW Oregon PXL - aggressive, fast, chatter, chips
3) NEW Stihl PMM3 - mildly aggressive, med-fast, smooth, smaller chips
4) OLD Stihl PMM3 - not aggressive, slow, smooth, dusty chips
5) OLD Stihl PMM3 (leading side of rakers removed plateau narrowed) - mildy aggressive, med-fast, smooth, smaller chips, similar to new just not quite there.
1025191020.jpg
 
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You got something very wrong in your filing, you got zero hook in your tooth on side plate , get yourself a new chain and look at the side of the tooth and file your own chain so the side plate has the same outline , the way your chain is in the picture shows zero hook and your top plate and side plate has no point so your tooth is dull , the 30 degree angle is not the problem
 
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