Stihl RS chain points

B

Bart_

Carpal tunnel level member
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RS is rapid super and has a squared cutting point (at the junction of the side cutting face and the top cutting face) as opposed to safer chains which round off that corner.

I "rocked" a chain into hidden metal and it combo bent those points in/down and scraped off the sharpness of the cutting edge. Conventional solution is to file or grind until those points reappear but that's a lot of tooth to lose in one go. I field fixed it till I had 95% of the upper edge back but got tired of filing. Rakers seemed ok didn't have dremel so left them. Chain cut again (from zero/powder!) but small chips, needed extra pressure.

Has anyone ever lowered the rakers to compensate slight rs chain tooth tip damage? I hate to lose that much tooth for an instantaneous metal encounter. About to recheck further filing w/out raker lower to see that partial solution. rakers seem to be on oem new 0.016" below tips height, still near that after my filing.
 
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Search 'progressive depth gauge filing guide'.

Stihl makes them and so do others.
 
I think the only guide I've got was for my first ms260 and it showed slight raker tip recess on a new in box rs chain with the 0.016" feeler gauge raker-lower-height-than-tips. post filing, the bad chain might now be 0.012 or 0.014 with bit of variation, looks like the same gap by eye. oh yeah, height checked at least bar curvature near muffler

I guess I'm partly curious how magical the RS pointy tip really is since safety chains cut ok and have bupkuss point

The geometry failing of my not complete filing is that right at the point for a mm or so width of the top cutting edge the cutting edge is whatever thousandths below the intended height, but still forms a sharp point at that lower height, so the proper height top edge next to the point may be making the iniiation of the cut. still haven't done cut test
 
Bart_ said:
I guess I'm partly curious how magical the RS pointy tip really is since safety chains cut ok and have bupkuss point
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I haven’t used a gauge in years, I set rakers by eye, but every chain in our shop is sharpened on a grinder on a bench. I do not like hand filing chains, nor do I like it when people do it because they don’t get them consistent.

That magical point is very important, as you will quickly discover if you don’t reestablish it. You will lose a lot of cutting speed. We use RSK chain on almost everything - really aggressive, but lose that point and it doesn’t cut worth anything.
 
Reach said:
I haven’t used a gauge in years, I set rakers by eye, but every chain in our shop is sharpened on a grinder on a bench. I do not like hand filing chains, nor do I like it when people do it because they don’t get them consistent.

That magical point is very important, as you will quickly discover if you don’t reestablish it. You will lose a lot of cutting speed. We use RSK chain on almost everything - really aggressive, but lose that point and it doesn’t cut worth anything.
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Agreed, that point matters much more than the angle it’s filed to. I found that it’s the most critical to maintain and rakes second. As long as all the cutters are the same angle it will cut good.

The only adjustment to my filing I make is if I’m cutting certain hardwoods, but we don’t have true hardwoods here. Alder and bigleaf maple cut just about the same as Doug fir so I don’t do much adjustment in angle. Getting into oaks I’ll give a closer to the factory specs or line on the chain.
All minor tweaks within reason, and part of the reason I prefer hand filing.

Regardless of the chain type the leading part is the most critical, rakers second. Assuming consistency thought-out the chain
 
Our hardwoods mean we run all our chains ground to factory angles, I wouldn’t know what to do with your trees, cutting that fast would be wild!

Consistency throughout the chain is really important, or you end up with just a few cutters that do all the work and the saw jumps and bucks and does all kinds of things except cut. I’ve run some of those chains, usually caused by one of my climbers who liked to hand file his own chains and should not have.

The need for consistency is why I insist all chains are sharpened on the grinders in the shop. We can maintain consistency that way, always, and that’s more important to me than saving some chain wear. Compared to production time lost due to a poorly sharpened chain, new chains are cheap!
 
Friedrich said:
interesting to hear that you are set against handfiling. i handfile all my chain until they are gone and they are cutting fast and straight.
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I am against hand filing because most people cannot consistently keep the angles, correct. Most people also do not properly set rakers by hand, would be interesting to compare one of your chains side-by-side with a machine ground chain. You might be able to do it properly, there are people who can, but most, in my experience, do not.
 
i can try to take a picture later.

also i wouldn’t wanna pay someone to handfile rocked 36“ and longer chains.
i just file my own and usually 28“ bar is sufficient around here.
 
Would the speed difference between a properly pointed RS vs slightly muffed point RS be the same dfferential as RS vs round tipped safety chain? I'm talking very slight point muff, not gross neglect. 0.010 to 0.020 muff width, but sharp edge at the lower altitude

edit - did non-adjusted raker, partly bad tips - sucked wind though still making chips
aggressive raker lowering, partly bad tips - massive improvement perhaps 80% as new - staved of 0.030 to 0.040 tooth length shortening!
 
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Bart_ said:
Would the speed difference between a properly pointed RS vs slightly muffed point RS be the same dfferential as RS vs round tipped safety chain? I'm talking very slight point muff, not gross neglect. 0.010 to 0.020 muff width, but sharp edge at the lower altitude
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I have never compared them side-by-side, but I would guess it would be at least as much different, probably more because RS chain does not cut very well when the point is not correct. That point does the majority of the cutting on the chain.

I realize that I may look at some things differently than others because my operation is a little bit different, but the way I see it, chain is cheap compared to labor. If a doll chain cross you even 15 minutes a day in additional cutting time, it would be cheaper to throw away twice as many chains or more than to spend the extra in labor.

Time is the most valuable thing there is. It is the one thing that, no matter what value you place on it, you can never get back. You never get more time than what you have, so why waste even a little of it on something under performing?
 
Safety chain has double rakers, etc. I think you are referring to semi chisel which has a round point. May or may not be Safety. Cuts slower but is more durable.

You can lower the rakers until it grabs, but you might not like it in hard wood. Also, once you actually get it sharp, it may be really grabby with low rakers. You can mitigate grabbiness by using a larger dia file or raising it to give the cutter less hook.
 
Matias said:
Shit, now I'm confused. I thought that flatter angles cut a little slower, but keep an edge longer in hard wood, and the steeper angles cut faster, but wear down faster too.
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I found this to be true in real hardwood trees. I go less steep in softwoods and find it cuts much better. Best to make little adjustments flattening the angle to find the sweet spot for softwoods. Also depends on the bar length and powerhead.
IF you go too flat it will still cut well but chatter more and bog/grab so technique in cutting plays a role. A high power saw with ~25 degrees (or a little less) in soft wood can allow for much more dogging in the cut making for faster cutting.
For clarity I view alder as a softwood, this setup chews right though it.
 
FWIW I'm going to tune up the teeth points some more and redo some top edges that had bad edges hiding under the file flash. I guess that's why some manuals spec scraping off the file flash with a small piece of hardwood after sharpening. I think its 30 or 35 deg chain, pretty substantial angle

I once de-rakered a pole saw chain so bad it turned into a chatter machine in hardwood, full cut but went through small soft branches like lightning. Many years ago.

edit - according to my Stihl file gauge its 25 deg top cut edge. don't know where 30 or 35 came from - old guy memory:)
 
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