Help please!!!

[Travis Edwards]

looks like will is running about 40 degree hook angle but is only running about 28 thou raker/cutter difference there Bob which to me seems a bit little, looks like you are running a similar hook but between 35 and 40 thou height difference. Not sure what you did to the op's pic but it stands out even more just how poorly they are sharpened. Personally I would condemn that chain for safety sake. even 404 isn't strong enough to withstand constant stressing of the amount that you would be forcing that to endure.

[Travis Edwards]

I presume you have richened up the carby (ie dropped the max revs by 300 - 500 rpm)? This will also help look after the saw.

How do I do this?

How do you sharpen your chain? Electric or jig and file?
I use a hand held electric grinder, but find it hard to keep them even. What are the best jigs to use? And maybe you could explain "progressive raker setting" to me BobL

Don't know if you see what I do bobL but it looks like the tops of the rakers have been filed way too low as well

You got me Travis. It is a brand new chain but I took to the rakers before I started. Though it migh help spped up the cuts! But the cutters have never been sharpened. It is as I bought it, except for the rakers.
Thanks heaps, Mark

Rakers come at a relative height for a reason and a small amount either side of that setting (I am talking thousandths of an inch) makes a big difference. as I say the rakers are your friend and basically provide the control for what the cutter will do. Until you know exactly how they work I would leave them right alone.

[BobL]

I presume you have richened up the carby (ie dropped the max revs by 300 - 500 rpm)? This will also help look after the saw.

How do I do this?

If you don't feel comfortable about tuning your own carby I would leave it to someone else.

To do this properly you will need a tacho. Set the saw to factory tuning and then turn the H carby screw so that it increases the mix/air ratio. this usually translates into a 300-500 rpm reduction at WOT. Before you do this make sure the saw is properly tuned and not bouncing off the governor.

How do you sharpen your chain? Electric or jig and file?

I touch up by hand ie file only, sharpen using an Oregon file holder jig and fix rocked chains with an electric grinder.

And maybe you could explain "progressive raker setting" to me BobL

Progressive raker setting is using a raker setting that is a proportion or percentage of the gullet width. This maintains a constant wood-cutter/tip-raker angle irrespective of the gullet width. A general rule of thumb is that the raker depth should be 1/10th of the gullet width. On an 090 that can be as low as 1/7th of gullet width. Old timers like travis can probably eyeball a lot of this stuff but I use a digital angle finder. A simple way to ensure you have progressive rakers is to use a Carlton File-o-plate (FOP) jig but the ratio they generate will underwhelm an 090. If you want to read about progressive raker setting in grimy detail - look here http://www.arboristsite.com/chainsaw/114624.htm

QUOTE]You got me Travis. It is a brand new chain but I took to the rakers before I started. Though it migh help spped up the cuts! But the cutters have never been sharpened. It is as I bought it, except for the rakers.[/QUOTE]

As witnessed by the fact that the gullets are not very wide, the chain is fairly new, but someone has taken to the cutters in a big way with a file.

The left hand side cutter in this picture has a negative rake or more precisely a backslope.

This is a picture from the Carlton chain guide that discusses this.

Backsloped cutters ruin chain and bars and overload the motor.

That chain needs professional attention to get all the cutters back into shape and then the rakers need to be set properly - and not just flat - they need to have the leading edges rounded over.

[Travis Edwards]

I do not normally put pics of my chains up but here goes. This is one of the few carltons I have that I would say performs well. Generally I find they are not aggressive enough for my liking and prefer stihl RSC or the old windsor 63a I think it is. This one has only ever been filed by me free hand, with most carlton chain I find the cutter lengths vary somewhat cutter to cutter from new and the first thing I do is get them all the same length.

This is a crosscutting chain and is blunt at the moment, but still cuts better than most peoples sharp chain.

BobL have you tried a square ground/filed chain for milling? I am thinking of giving one a go but am hesitant to sacrifice a chain, although I guess I could always just restore it to right I guess.

[Bushmiller]

For the sharpening experts.

All the books, and indeed yourselves, say that after lowering the depth gauges they should be returned to the original profile (rather than leaving the flattened shape.)

I do this, although probably not as well as I might, but I don't remember seeing stated anywhere why it is important. Is it to maintain smoothness in the cutting action?

Regards
Paul

[Softbreeze]

I think I read somewhere that the leading edge should be rounded on the rakers to take the chatter out of it when cutting, thus improving chain and bar life. But I didn't do this so maybe don't listen to me eh!

That chain's cutters have definitely not been touched by myself since I bough it new. Maybe I should take it back and have a word to the shop about it??
When you say a Carlton FOP will underwhelm the saw, do you mean the rakers won't be filed low enough?

Cheers Mark

[Softbreeze]

Wow Travis I just looked closely at your chains. The rakers are really rounded. Is that how they should be? I thought they only had to be flat with a slight rounded front edge but maybe not. Does it take a fair bit of filing to get them to look like that?

Gotta say to BobL I love that photo of you milling. I think that is what I will aspire to when/if I get things all running right!!

Cheers Mark

[BobL]

I think I read somewhere that the leading edge should be rounded on the rakers to take the chatter out of it when cutting, thus improving chain and bar life. But I didn't do this so maybe don't listen to me eh!

That is partially correct. Most people think that chain cutters sits flat on the bar when cutting but they do not. The cutters rock back and forth pivoting between cutter tip and raker and rise up off the bar till the chain tension snaps them back onto the bar. A flat raker means the rocking happens between the cutter tip and unrounded corner of the raker. This is like dragging a point across a surface compared to a skid or a rounded corner. Raker actually dig slightly into the wood, squared corner chatters their way across wood compared to the rounded ones which tends to slide. Square corners make for uneven cutting - rounded corners make for smoother cutting. Ideally rounded corners like Travis' are best but at least sloped faces like mine are better than square corners.

That chain's cutters have definitely not been touched by myself since I bough it new. Maybe I should take it back and have a word to the shop about it??
When you say a Carlton FOP will underwhelm the saw, do you mean the rakers won't be filed low enough?

Correct - most FOP or derivatives generate a cutting angle of ~4.5º whereas for a 3/8 chain on a 30 - 40" bar on a 90 to 120 cc saw in most Aussie hardwood can use a cutting angle of 6 to 7º.

This is what I mean by cutting angle.


BTW you won't see this cutting angle discussed anywhere else. Maybe they think it is too technical but chain saw or chain manufacturers don't discuss it. The company that comes closest to discussing it is Carlton. My guess is they want you to but a new chain. But using progressive raker setting enables a chain to cut as effectively when it near the end of its life as when it is new.

Heres a vid of me setting my rakers
[ame=http://www.youtube.com/watch?v=FSr9j2EDoqk]YouTube - ‪rakersetting.m4v‬‏[/ame]
I don't do this everytime I touch the rakers - I just do this before I go milling. In the field I swipe the rakers a couple of times every 3 or 4 touch ups.

Here's a vid of me doing a cutter touch up with a file guide (I do this in the field with just a file), ~4 seconds per cutter. The 60" bar has 96 cutters = ~400 seconds or 6.5 minutes. I can can touch up faster than I can swap chains.
[ame=http://www.youtube.com/watch?v=vWwLEuY5Iao]YouTube - ‪sharpening.m4v‬‏[/ame]

[itsposs]

Great work Bob is that little box thing the file guide ?

[Softbreeze]

Thanks BobL, the videos make it a lot clearer after talking about it. Where did you get the digital angle finder? The file guide is used to keep the angle is that right?
Regards
Mark

[pjt]

Hi Mark,
I started a thread a while back asking about rakers and cutters and 1/10rule, to which BobL and others answered/commented on, might be worth a further look to further the understanding,https://www.woodworkforums.com/f132/c...rs-etc-107669/

Pete

[Travis Edwards]

Wow Travis I just looked closely at your chains. The rakers are really rounded. Is that how they should be? I thought they only had to be flat with a slight rounded front edge but maybe not. Does it take a fair bit of filing to get them to look like that?

Gotta say to BobL I love that photo of you milling. I think that is what I will aspire to when/if I get things all running right!!

Cheers Mark

Practice and a gentle touch are the secrets to making it happen and I agree with what BobL says a sloping leading edge is generally sufficient. I usually avoid a flat spot on top no matter what. use a fine file with edges that are not cut and roll the file through the stroke to follow the existing profile of the chain. It does not take a lot of metal removed from the rakers to make a difference in the way they cut. always aim to remove the same amount from all the rakers, keep your cutters the same length on both sides and you will achieve consistent results. A lot of the stihl chains actually have a line marked on both the rakers and the cutter this performs a couple of things it indicates where each should be when the chain has reached the maximum sharpening and shows the relative amount of metal that should be removed from the rakers relative to the cutters, It also gives you something to eyeball to help maintain sharpening angles and raker profile shape.

[BobL]

Great work Bob is that little box thing the file guide ?

The little box thing is a digital angle finder. This is just a fancy way of measuring the cutter angle - I like to use ~6º


Using a digital angle finder is a geeky over the top method and can be done just as easily by using one of these.


This is a raker gauge with 4 different raker depth settings.

When the gullet is between 0.25 and 0.30" use the 0.025" raker slot
When the gullet is between 0.03 and 0.35 use the 0.030" raker slot
between 0.35 and 0.40 use the 0.035 slot
etc

if you want to go to a higher cutting angle (ie shorter bar, softer wood or bigger saw) go up one notch on teh raker setting.

[BobL]

Hi Mark,
I started a thread a while back asking about rakers and cutters and 1/10rule, to which BobL and others answered/commented on, might be worth a further look to further the understanding,https://www.woodworkforums.com/f132/c...rs-etc-107669/

Pete

I forgot about that - thanks for digging that one up - it will save repeating myself quite a bit.

[Softbreeze]

Thanks Pete, will have a read.

Regards
Mark