Sharpening Raisman .404” semi chis

[davidwyby]

I got a 42” loop of this for hard stuff with my ported 3120 from @Armbru84. Cut great until I hit nails. I tried to freehand sharpen in the field but didn’t have a good setup, and I stink at semi chisel anyway, and I was miserable hot and irritated. Didn’t cut well, and cut crooked as I recall. That was a couple months ago. So I ordered a husky roller guide and finally went to fix it right tonight because I have a job for it this weekend. If I use a 7/32” file with the roller guide, it takes all the hook off, like it holds the file too high. The cutters do seem short height-wise for .404”. So I ended up using a 3/16” file and calipers to try to keep the cutters the same length. The roller I got didn’t come with a progressive raker guide like most, so I used my 3/8” to at least get them consistent. Using a straight edge and caliper, I get around .025”. Could probably take more... I guess we’ll see this weekend. I had the presence of mind to take pictures of the cutters when it was new before I bunged it all up, but forgot to take after sharpening pics.

 

[Maintenance Chief]

I take it those are the before photos?
At the very least you should be using a 7/32 file on those teeth and there might not be a guide available for them. Using a smaller file to drop down farther into the guide is gonna mess with the side plate which is doing your chip production after the corner cuts the fiber.
Honestly I would not try to recreate the factory angles of the new tooth in the picture as it looks to be less than a 25° angle on the side plate.
I've even used a 1/4 file on some of the bigger tooth .404 to drop into the whole gullet and have a 5% above top plate for the file.

A very used chain , .404 27j Oregon micro chisel (semi) . This is my big nasty stump chain with a coulpe of filings.

 

[Maintenance Chief]

This is a once used chain (same make) filed by hand that is used on my 088 with a 41" bar , you can see the larger side plate cutting area on this pretty good.
By no means I'm I an expert, but these 2 chains work very well for my style of cutting .
Also note the depth gauges are not even breathed on, with a power house saw its temping to start dropping them but from the factory they are good for a couple of times sharpening.

 

[davidwyby]

Yes, those are before pics. The factory top angle was very blunt, yes, but it cut well and the stay sharp is reputed to be very good. I'm cutting euc that's been baked into concrete in the desert for 20 years. The angle is now probably 25* or whatever the husky roller is. These cutters are pretty short top to bottom - about 3/16" side plate cutting area. Looking at the before pic reminded me that when I first sharpened with 7/32", it was heck because of having to file out that little nub in the gullet in order to get under the top plate. But that low area isn't cutting or anything, and isn't important for chip flow cutting dry hard stuff from what I understand. I was also getting into the side plates with 7/32". Now that I think about it, where the 3/16" might have hurt me is getting too small and low, and the top plate edge may be too thin/delicate and not hold it's edge. I'll get some pics after work. I almost got up at 4 and dragged it to work where my wood pile is and tested it this morning, but nah.

Makes me want a grinder...

 

[davidwyby]

I think that might do it. Still need to try it in euc, but don’t want to go nail hunting and have to fix it again.

Taching fat at 11,500, gonna have to adjust for elevation tomorrow anyway. Just wanted to see if it would cut straight.


Feels good, just hungry enough I don’t need the dogs much, which is nice since I’ll be felling.

I love my ported 3120. It’s like the Thor’s hammer of saws...

 

[Maintenance Chief]

That looks a little bit better, but why is the chain hungry?

 

[davidwyby]

That looks a little bit better, but why is the chain hungry?

Prolly cuz I kissed the rakers a lick or three depending on how bad they got "nailed" - based off the progressive raker gauge. Should have waited until I tried it, but it's ok...and it will need another sharpening or two soon enough if it needs backed off. It may not be as hungry in the euc as it's real hard, and hard to get a bite.

I forgot to take some comparo shots with the guide and files.

 

[Maintenance Chief]

Sounds good , at least you don't have to swipe the rakers again for a while.
I have some 20" locust fence posts in the yard that the old farmer gave me to burn , hes 82 and probably put them in as a kid .
These posts are as hard as your gonna find in this part of the country. I'll test a semi chisel chain on them, if it just pulls dust ... back to the bench till I can get chips.

 

[huskihl]

Prolly cuz I kissed the rakers a lick or three depending on how bad they got "nailed" - based off the progressive raker gauge. Should have waited until I tried it, but it's ok...and it will need another sharpening or two soon enough if it needs backed off. It may not be as hungry in the euc as it's real hard, and hard to get a bite.

I forgot to take some comparo shots with the guide and files.

I look at it the other way. If I had just got done sharpening that chain, I would take another swipe or two off the rakers so I didn’t have to use the dogs. Once the chain in your video makes two or three cuts you’ll have to be on the dogs to get it to feed at all

 

[davidwyby]

I look at it the other way. If I had just got done sharpening that chain, I would take another swipe or two off the rakers so I didn’t have to use the dogs. Once the chain in your video makes two or three cuts you’ll have to be on the dogs to get it to feed at all

I was being conservative as I’m still learning this chain...I wanted some to play with if it cut crooked or something.

 

[huskihl]

I was being conservative as I’m still learning this chain...I wanted some to play with if it cut crooked or something.

Absolutely

 

[Maintenance Chief]

I was being conservative as I’m still learning this chain...I wanted some to play with if it cut crooked or something.

Just like cutting anything, its easier to remove material than put it back.