Thread: Chainsaw sharpening

I take it you are trying to convert regular "cross cutting chain" to "ripping chain" for milling.

There ia no need to convert the top plate cutting angle in one go, regular cross cut will still mill timber just fine
What I do is convert the angle over successive sharpening - ie a bit at a time, ~5º at a time.

I sharpen/touch up using one of these.
Screen Shot 2022-02-26 at 8.42.16 am.png
These guides usually have 25 or 30º markings on them so I just use divide these up into 5º segments and scribe lines onto the guide.
There's no need to be exact about it. As long as you don't go below zero.

I am a novice in sharpening terms but have been happy with the Stihl 2 in 1 sharpener, you still get to use traditional files with it

2-in-1 File Holder -

MA

The theory is that the 10° angle produces a smoother cut for ripping and may last a little longer than the standard 25°/30°. But, it is slower. Also there is conjecture as to whether this technique is necessary. When comparing the performance, you should use new chains as they do not cut so well as they wear down. If you change the angle on a chain that has the cutters already half worn you won't get a fair comparison with a brand new chain at 25°.

Changing the cutter angle may be unnecessary work for a board that you will end up putting on a jointer and/or through a thicknesser anyway: Just something to consider.

A friend, who was a logging contractor said they discarded their chains when they were about half worn as the efficiency dropped off. There are marks on some makes of chains to indicate when they should be replaced. Myself, being a bit tight for chains and in a non commercial scenario wait until the first tooth breaks off!



If you wish to continue sharpening freehand, draw lines on a sheet of paper placed under the bar and, as Bob says, you can progressively move towards 10°.

Regards
Paul

PS: The above is all on the assumption you are using a chainsaw mill of some description for ripping. If you are cross cutting, don't do it.

Originally Posted by Beardy

I am a novice in sharpening terms but have been happy with the Stihl 2 in 1 sharpener, you still get to use traditional files with it

2-in-1 File Holder -

Unfortunately that sort of a guide will not file the raker correctly and as the cutter wears (gullet gets wider) it will leave the raker too high. Nearly all guides are like this and is why worn chains cut poorly. The raker guide I've found that does the best job is the Carlton File-O-plate but even more performance can be wrung out of a chain by using the progressive raker depth setting. More on this below.

Originally Posted by Bushmiller

The theory is that the 10° angle produces a smoother cut for ripping and may last a little longer than the standard 25°/30°. But, it is slower. Also there is conjecture as to whether this technique is necessary.

My experience is that smoothness of cut is more operator and less chain dependent.
Over the last few days there has been some discussion on the Arborisite about how skip chain produces a better finish than full comp chain and I show a series of photos where I progress from Skip to Full Comp over a few years and my finish just gets better and better.
Chain for a 395xp 62" bar? Skip vs ripping? | Arborist, Chainsaw & Tree Work Forum

My summary is that the following are more important than skip V full comp and I'd say its the same for top plate filing angle
The following contributed to improving the finish.
- better firmer/steadier log rail setups.
- maintaining sharpness
- no horizontal seesawing
- no "fanging" a running saw on restart into a cut.
- maintaining steady pressure on the mill by using slopes etc

My understanding is that low top plate filing angle V higher cross cut filing angle is as follows.

During cross cutting it's the the side plate of a cutter that "severs across wood fibres" but it's not very efficient at cutting and also does a lot of tearing leaving some fibres hanging in the kerf. These fibres better retains sawdust and may bind the B&D in the cut. Higher top plate angles help because the cutters to dive sideways into the kerf thereby cutting a slightly wider kerf and allowing for better clearance.

When milling the fibres mainly are" cut, torn and removed' by the top plate so there's far fewer fibres to hang in the cut. A lower top plate angle reduces the kerf slightly meaning less wood is cut thereby taking a small load off the engine.

I have tried some experiments to try and demo this and the results have been inconclusive.

When comparing the performance, you should use new chains as they do not cut so well as they wear down. If you change the angle on a chain that has the cutters already half worn you won't get a fair comparison with a brand new chain at 25°

The reason for this is that "non-progressive" or "constant raker depths" are commonly used. If progressive raker depths setting is employed then a well used chain can cat very close to the same efficiency as a new chain.

PROGRESSIVE Raker depth setting
There are two key factors that determine how much wood a cutter will grab.
1) The top plate filing angle (hook) and not to be confuse with the top plate filing angle (that's normally 10º on a milling chain)
2 The raker depth but more specifically it's the angle between the wood, the cutter tip (apex) and the top pf teh raker that first contacts the wood (see Photo).
I call this the "raker angle" NOTE its not the angle on the top of the raker.
This photo is from a cutter diagnosis I performed for an Arborisite member - his raker angle is about 3º - its too low
cutterraker.jpg
If the hook is too high and angle AND the Raker angle is too low this will produce few chips and fine dust and very slow cutting.

If the same raker depth (eg 0.025") is used during the life of teh chain as the cutter wears the raker angle gets smaller and smaller so you can have all the hook on the world but the low raker angle will not enable that hook to grab much wood.

A simple approach to this is sa follows.
New 3/8 chain has a nominal raker depth of 0.025" and gullet of 0.25" 0r a ratio of gullet to raker depth of 10:1 this is equivalent to a raker angle of about 5.7º.
When the gullet reaches 0.3" to maintain the same raker angle the raker depth should be 0.030"
When the gullet reaches 0.4" to maintain the same raker angle the raker depth should be 0.040"
When the gullet reaches 0.5" to maintain the same raker angle the raker depth should be 0.050"

All the this means the usual 0.025" or normal raker depths gauges cannot be used.
Oregon do make different raker depths gushes (0.030". 0.035"., 0.040" etc) and if you can get them working to the nearest 0.005" would be OK BUT the not hard to work with the raker angle that suits your setup.
eg: on my small CSM I use a 441 with a 25" bar and Loprochain which has a narrow kerf. For this I use raker angles of ~7.5º and chains cut like a hot knife thru butter (HKTB) up until the teeth start falling off.

On my larger CSM (880 saw and 42 and 60" bars) I use a raker angle of 6.5º. The first thing I do when I make up a fresh loop of chain is touch up the cutters and then drop the rakers, Here's how I first set my rakers

Note how much cutter is left - not much but this chain still cuts like a HKTB

BTW I don't futz around to get to within 0.1º - when I say 6.5º I take anywhere between 6.5 and 7.0º
Here is what these cutters look like - note how much of the raker is missing
Nicecutter.jpg
There is a quid-pro-quo and these include, more B&C wear and tear so aux oilers become essential even on small mill, poor finish there's increased vibe and if the saw is used for non-,milling purposes a greater chance of kick back. In a mill the nose should not normally make contact with wood so kickback is less of an issue - BUT if you take a saw with a high raker angle chain out of a mill you need to be aware of what's going on.
This is why stock chain is sold with a raker angle of 5.7º - but it is on the wussy side for chainsaw milling.
There are CSMers using angles as high as 9.5º on North American softwoods.
Sure the CSM is chattering away much more than usual but if all you want is quick lumber then why not?

My dad was a timber miller in the late 50's and 60's. He rarely used a raker gauge. All he did was take swipes of the rakers until the chain produced an acceptable bite. In fact he would bring the rakers down almost until the chain would grab. If you go this far you have to take swipes of your cutter to lower the raker angle back to where the chain does not grab.

I don't use the video methods to maintain raker angles. In the field I touch up (3-4 stokes) with the chain still on the mills after every tank of mix and swipe the rakers (2-3 times) after every 3-4 tanks. This way teh rakers are always on song.

Every 10-20 hours of cutting I check the rakers as per the video - Its surprising how close they remain to their original setting.

Now I could spend half an hour discussing raker top shape - but maybe leave that unless someone expresses some interest in this i topic.

FWIW:


I haven't done any milling yet. I had a heap of data to burn a few months back so I watched a LOT of youtube videos on this.


Many offered the same opinion as said above that a normal chain will do a reasonable job. I guess if you are doing a lot of milling it's worth setting up a different chain. Maybe a saw dedicated to it if you have one..


As I have said previously I am very happy with my $100 chinese 22" saw but then I don't do that much tree felling. Mostly big branches.


I use the file guide shown by BobL above or a similar one and I'm very happy with it. I picked it up at a mower shop and it seems to work ok. The difference between a well sharpened chain and one mucked up or blunt is remarkable.


I intend to try milling when I fell a tree big enough. There are 2 types of portable mills.


Vertical Chainsaw Mill Lumber Cutting Guide Rail Saw Chainsaw Attachment | eBay


It seems to me these are good for the first cut as they account for the taper in the log and give a face parrallel to the center of the trunk.


Chainsaw Mill Chain Planking Milling Adjustable Suit Up To a 24/36/48 Inches Bar | eBay


These seem to be the go for subsequent slabbing. No idea of relitive quality of various brands on the market. It would be worth knowing if the ebay cheapies work ok. I'm probably more interested in beams than thin slabs. I've got a fence to build when I get to it.

Originally Posted by damian

FWIW:
I haven't done any milling yet. I had a heap of data to burn a few months back so I watched a LOT of youtube videos on this.

Most youtube milling videos I've seen show people making very heavy weather of the task and I get a sore back, knees, arms shoulder just watching them.
Chainsaw milling I can be a very thing (no, exhausting) process so maybe have a look at this "milling 101" thread on the ArboristSite
CS Milling 101, Hints tips and tricks | Arborist, Chainsaw & Tree Work Forum
It has loads of good stuff in there about how to do things efficiently.

Many offered the same opinion as said above that a normal chain will do a reasonable job. I guess if you are doing a lot of milling it's worth setting up a different chain. Maybe a saw dedicated to it if you have one..

I've got dozens of loops of different chains mainly because I had about a dozen different sizes of bars/saws. To then turn around and keep a set of chains for just cross cutting would just add to chain storage problems. So, apart from my 50cc Homelite pruning saw, I file everything at 10º top plate filing angle ie milling file and just wear the fact that they might be tad slower on cross cutting a bit log. Mind you teh 441 with teh 25: bar and the 7.5º ranker angle is a very fast cross cutter.

I use the file guide shown by BobL above or a similar one and I'm very happy with it. I picked it up at a mower shop and it seems to work ok. The difference between a well sharpened chain and one mucked up or blunt is remarkable.

Agree 100%

I intend to try milling when I fell a tree big enough. There are 2 types of portable mills.
Vertical Chainsaw Mill Lumber Cutting Guide Rail Saw Chainsaw Attachment | eBay

The single point bar grabbing mechanism on these is mechanically a weak point - it's too easy to rotate the bar so the chain contacts the clamp ie not good.
This type of mill also showers the operator with sawdust - also not good.

I had a similar one of those mills that I used to break up thick slabs, but got tired of being covered in sawdust so I made my own that cuts with the back of the bar so squirts most of the sawdust downwards.
start.jpg

Chainsaw Mill Chain Planking Milling Adjustable Suit Up To a 24/36/48 Inches Bar | eBay
These seem to be the go for subsequent slabbing. No idea of relitive quality of various brands on the market. It would be worth knowing if the ebay cheapies work ok. I'm probably more interested in beams than thin slabs. I've got a fence to build when I get to it.

These types of mills are called Alaskan mills and I reckon you can't really go wrong with them.
You will need a set of rails or an Al ladder to get the first cut straight.
eg
faceshield.jpg

Thanks Bob, Paul and Damian. My intentions are a little more humble. Some may have seen the apple handle I made from timber I "milled" and seasoned. I found the rip cuts slow through the firewood sized rounds and hoping to make slightly more even "planks". My method is to sit the round vertically on a chopping block and cut "straight" down, eyeballing the width. Surely changing the teeth angle should improve things?

Originally Posted by Mountain Ash

Thanks Bob, Paul and Damian. My intentions are a little more humble. Some may have seen the apple handle I made from timber I "milled" and seasoned. I found the rip cuts slow through the firewood sized rounds and hoping to make slightly more even "planks". My method is to sit the round vertically on a chopping block and cut "straight" down, eyeballing the width. Surely changing the teeth angle should improve things?

If you only need planks or pieces no longer than your bar then try this.
Cross cut the wood so it's no longer than your bar
Clamp a short thick board between two saw horses.
Lay the log across the middle of the thick board and clamp a pieces of wood either side of the log to stop to rolling.
Cut the log with the bar along the grain (its called noodling).
After each cut re-clamp two pieces of wood hard up either side of the remaining log to make subsequent cuts.
Noodle is WAAAAAAAY easier than either cross cutting or straight down vertically
If your chains is sharp you will get great long stings of wood, like "noodles"

I'll have a look at your link when I get a chance. Thank you.


So you just don't bother about the taper ? I guess your only cutting just off the center line of the trunk especially on eucalypt.

Originally Posted by damian

I'll have a look at your link when I get a chance. Thank you.
So you just don't bother about the taper ? I guess your only cutting just off the center line of the trunk especially on eucalypt.

Yes I do bother about taper but usually only if it's significant eg more than 15-20%

On the bandsaw mills we have I level the centre line of the log on the bed of the mil by placing support blocks under the narrow end. Then all cuts will be parallel to this line.

With the CSM the log rails are adjusted using wedges or other gizmos so the rails are parallel to the centre line of the log and also to each other (this is critical others you can end up with a twisted cut.

Unfortunately I don't have many photos of my CSM starting setups but here are a few.

Below shows a Marri with no taper so the rails can just sit into the log like this
Rail twist is measure with a digital angle finder placed on the angle iron end cross pieces and adjusted using small wedges under the rails once level the pointy headed bolts in threaded holes in the angle iron are screwed tight into the ends of the log.
layout.jpg


Below is an example of a log with significant taper and with a lump in the middle
A CS was used to remove some of the lump so the rails can lay flat.
Support rails at narrow end using the "support gizmo" as shown - the verticals on the gizmo are C-channels so the horizontals between the uprights can be slid up and down to get the rails level with the centre line of the log. Once level locking bolts hold everything tight
Sometimes I make a "support gizmo" out of wood just TEK screwed together
DSC00157.jpg


The setup on this Small jarrah wisas a rough already example where after removing a bit of the taper at one end with a chainsaw I just Tek screwed a plastic patio board to the cut flat
Just had to make sure the first cut extended below the ends of the Tek screws.
strange.jpg

The boomerang Marri log in the pic below is one of the trickiest I've tackled.
Im photo below you can see the support gizmo in use again to cater for the taper and a block of wood on a ruggedised saw horse that supports the middle part of the rail that is largely unsupported.
The 42" bar is long enough to reach across the rails and boomerang shape to make the cut,
When I got close to the supporting block of wood I stopped and moved the saw horse and block back to a section that had already been cut and kept going
marriboomsetup.jpg

marriboomarang.jpg

I started reading the other forum but that thread is pretty long.


Thank you for the photos. I'm thinking a long narrow ladder might be worth looking out for. When no being used as a saw guide it can double as a ladder


Anyway I'll save my study for when I have more time or get closer to actually doing some. Just now we are an island so a tad difficult to focus on other things.


Thank you for the information.

Originally Posted by damian

I started reading the other forum but that thread is pretty long.

Yes it is - that thread has been running for about 12 years so its only natural that it contains a lot of posts.

Thank you for the photos. I'm thinking a long narrow ladder might be worth looking out for. When no being used as a saw guide it can double as a ladder

Not too narrow although I guess it depends on the length of your DS bar.

when the time comes if you feel like IT contact me and I'll send you some picks of a ladder set uo I did in 2009.