Need advice on "making" a Granberg(ish) ripping chain.

[csmillingnoob]

Okay, I just picked up a skip tooth, round-file, full chisel chain. I intend to grind off half of every other set of cutters - like Granberg. Then, I intend to cut the top plate angle on the remaining full cutters to 5 degrees using a drop angle of 10 degrees.

Should the narrow "clearing cutters" match the full width cutters' top plate angles - or be something different?

Also, should the rakers be set at the same depth for the two different cutters - or should one be set more aggressively?

Answers to these two questions and any other advice would be greatly appreciated.

 

[RockChucker30]

Why not just gradually sharpen top plates to 5 or 10 degrees and use as is? You may be thrilled with the performance as is, and grinding the "scoring cutters" risks messing up the chain.

 

[Hoodiegadoo]

I’d save yourself the trouble and just use the chain as is. Definitely not a big enough difference to justify the hassle.

 

[csmillingnoob]

I’d save yourself the trouble and just use the chain as is. Definitely not a big enough difference to justify the hassle.

Can't do it. I have this obsession to learn - even if I screw up in doing so..

 

[Leeroy]

If you have an obsession to learn, may I suggest square filed chain?
It will cut faster and leave a smoother finish IMO.

 

[csmillingnoob]

If you have an obsession to learn, may I suggest square filed chain?
It will cut faster and leave a smoother finish IMO.

Next in the progression,

 

[BobL]

I agree with the other posters. Before you do anything mill a few dozen or so logs with regular milling chain - THEN you have a reliable back ground experience by which to make comparisons.
Maybe direct your obsession into getting the raker angles right your for your saw/bar/wood etc.
This will consume more time than making a Granberg style milling chain but will be much more productive since you should optimise the raker angle for whatever chains you are using (few folks bother doing it).

 

[csmillingnoob]

Yeah, I'm a weekend warrior noob, but one who is gaining experience pretty quickly. I have milled 6 logs of over 30" diameter since January. Oak and pecan. (Okay, I gave up on the Live Oak and cut it into firewood) I use a Husqvarna progressive depth gauge (.025 hardwood and .030 softwood) and have experimented with those settings enough to know that I prefer the .030 even in hardwood. I don't mill softwood and rarely crosscut it. Like I said, I like to learn even if that means learning through mistakes. The "regular milling chain" had a top plate angle of 20 degrees. I did not like the coarseness of the cut and have filed those chains back to 5 degrees and am much happier with smoother boards. I am trying the skip chain to see if it pulls the chips out easier and helps my saw run cooler, etc. It's about learning. Chains are (relatively speaking for an addictive substance) cheap.

Okay, I'll mill a couple of pecan and red oak boards with the factory 30 degree top plate angle this weekend. I'll take the advice and only cut it back to 20 degrees next weekend. I will start with the factory raker settings but will experiment with lowering them after this weekend. Who knows, maybe I'll like 20 with the skip even though I did not like it in full comp. I probably won't grind back every other set of cutters Granberg style - yet - but I know I will eventually just to do it and learn what it cuts like.

Skip chain - 40.00
+ Time hand filing - 2 hours
= Cheap

Experience to gain = priceless. So, I don't mind some failures even if I ruin a chain in the process

 

[Ancient One]

I gave up and bought a Super Jolly after counting 177 drivers on my 404 milling chains. One is full comp with 10 degree top angle. The other is a Granberg grind. I bought a reel of 404 milling chain from Archer to try out. It has a 10 degree top angle.

Madsens has some good info about milling chain on their site. Click on Bars & Saw chain, then Ripping Chain. Gives the filing angles for ripping/milling chain.

From the Granberg site:

In terms of stone (or file) size, you will use a 5/32 round file on LoPro, 3/16 round file on .325 and a 7/32 for both 3/8 and .404 chain. Filing angles will vary. In general, .325 chain will be sharpened at 20 degrees on the scoring cutters and 0 degrees on the clearing cutters. Most of the time, 3/8 and .404 chain will be sharpened at 10 degrees for both scoring and clearing. Occasionally however, the usual stock of 3/8 chain will be unavailable and we will have to use a different modification process. This 3/8 chain will be sharpened at 20 degrees for the scoring and 0 degrees for the clearing cutters. Checking the angle with a round file set against the clearing cutters should tell you what angle you should be using to tune up your chain.

One of the 177 driver chains on the drip pan in the background. The chain in the grinder is a 3/8 for a regular grind, it goes on my little Husky 455.

Granberg chain:

 

[BobL]

The Husky so called progressive depth gauges are not truly progressive, none of the jigs I've seen are.
The fixed Granberg chain raker depths are not progressive and will also lead to the chain making more and more dust as the cutter is filed back.

True progressive raker depth settings uses a constant ratio between the gullet width and the raker depths.
Most new chain has a ratio of 10: 1 , ie gullet of 0.25" and a raker depth of 0.025" which produces a raker angle of 5.7º.
This is on the wussy side especially for a bigger saw in soft wood.
Raker angles of 6.5º are the minimum I use in big hard wood and I'm talking wood harder than dry hickory.
For your hardwoods 7.5º and softwoods, up to to 8.5º can be used.
Only you can determine what raker angle works for your setup.

A 10:1 ratio means when the gullet is 0.30" the raker depth should 0.030", when the gullet is 0.40 the raker depth should be 0.40" etc.
I have a few chains with raker depth of more than 0.05" and only a nub of cutter length left that still cut like near new chains.
If a gullet width/raker depth ratio is not staying constant but dropping as the cutter wears then progressive raker setting ain't happening.

If a chain is constantly touched up when milling (I touch up my cutters after every tank of mix and the rakers get a couple of swipes after every 3-4 tanks) there's no need for a long sharpening session at the end of the day. Touching up cutters can be quick - 3-4 seconds per cutter so the chain for a medium length bar should no take up more than a few minutes.

Here is a typical touch up - I can do it faster than this but there's little point in saving a few seconds on this task. Apologies for the burry vids, they were made some 10 years ago with an old cell phone.

I touch up to remove what I call "glint" on the edge of a cutter, All cutters get two file swipes and then extra ones to remove any visible glint. If I am religious about touching up, only a handful of cutters on a chain will show glint. I haven't worried about cutter length for ~10 years - what happens is the cutters which are a bit longer will show more glint and get filed back more on this basis.

Even though I do not need to remove the saw from my mill to remove the chain, I can still touch up the cutters on my 42" bar while they are on the mill faster than I can swap the chain.
For the 60" bar I am marginally slower than swapping a chain but I still touch up on the mill otherwise I would need dozens of chains to maintain a truly sharp chain whilst milling a big log.

Setting up a new chains for a specific progressive raker setting does takes a bit of time but you will recover that time easily by the improved cutting performance

Of course I don't pull out a digital angle finder(DAF) when I'm milling. Once a chain has been setup up, 2-3 swipes of the raker per 3-4 tanks of mix will usually be close enough for a full day of milling.
At the end of a milling day I do a random check of a few raker angles with the DAF and only do a full reset if they are way out or are markedly different.

 

[Ancient One]

I bought the Alaskan Mill used, there was a bit of chain abuse. The Granberg chain that came with the package is lightly used but needs a small amount of work, cutters are dull. The other chain is a full comp Carlton from Madsens, never used, but it lived in the bottom of a wood box for years and had "sticky joint syndrome" combined with a lot of dirt. So I soaked the chain in carb cleaner, then brake cleaner, then old 50:1 gas mix then penetrating oil until it was clean and free. It needs a touch up on the cutters to bring back the razor edge.

After considerable research and reading all of BobL's threads, I do not think the Granberg grind is a requirement for good milling. But I will give the chain a try to see how it performs against the Madsen grind (10 degree top cutter) and the Archer chain that I recently purchased.

Thanks Bob for your great posts, you have a world of experience!

 

[csmillingnoob]

The Husky so called progressive depth gauges are not truly progressive, none of the jigs I've seen are.
The fixed Granberg chain raker depths are not progressive and will also lead to the chain making more and more dust as the cutter is filed back.

True progressive raker depth settings uses a constant ratio between the gullet width and the raker depths.
Most new chain has a ratio of 10: 1 , ie gullet of 0.25" and a raker depth of 0.025" which produces a raker angle of 5.7º.
This is on the wussy side especially for a bigger saw in soft wood.
Raker angles of 6.5º are the minimum I use in big hard wood and I'm talking wood harder than dry hickory.
For your hardwoods 7.5º and softwoods, up to to 8.5º can be used.
Only you can determine what raker angle works for your setup.

A 10:1 ratio means when the gullet is 0.30" the raker depth should 0.030", when the gullet is 0.40 the raker depth should be 0.40" etc.
I have a few chains with raker depth of more than 0.05" and only a nub of cutter length left that still cut like near new chains.
If a gullet width/raker depth ratio is not staying constant but dropping as the cutter wears then progressive raker setting ain't happening.

If a chain is constantly touched up when milling (I touch up my cutters after every tank of mix and the rakers get a couple of swipes after every 3-4 tanks) there's no need for a long sharpening session at the end of the day. Touching up cutters can be quick - 3-4 seconds per cutter so the chain for a medium length bar should no take up more than a few minutes.

Here is a typical touch up - I can do it faster than this but there's little point in saving a few seconds on this task. Apologies for the burry vids, they were made some 10 years ago with an old cell phone.

I touch up to remove what I call "glint" on the edge of a cutter, All cutters get two file swipes and then extra ones to remove any visible glint. If I am religious about touching up, only a handful of cutters on a chain will show glint. I haven't worried about cutter length for ~10 years - what happens is the cutters which are a bit longer will show more glint and get filed back more on this basis.

Even though I do not need to remove the saw from my mill to remove the chain, I can still touch up the cutters on my 42" bar while they are on the mill faster than I can swap the chain.
For the 60" bar I am marginally slower than swapping a chain but I still touch up on the mill otherwise I would need dozens of chains to maintain a truly sharp chain whilst milling a big log.

Setting up a new chains for a specific progressive raker setting does takes a bit of time but you will recover that time easily by the improved cutting performance

Of course I don't pull out a digital angle finder(DAF) when I'm milling. Once a chain has been setup up, 2-3 swipes of the raker per 3-4 tanks of mix will usually be close enough for a full day of milling.
At the end of a milling day I do a random check of a few raker angles with the DAF and only do a full reset if they are way out or are markedly different.

Thanks Bob!

I guess I had best think of the Husqvarna depth gauge as "Quasi-progressive" in the future. (Meaning more progressive than the ones that span the top of the cutters, but not truly progressive)

Looks like I need to get a Digital Angle Finder to see what I'm really doing to my chains. After reading this, I looked up some other post of yours on the subject of DAF use for raker settings. Thank you for sharing your expertise. I consider myself a pretty decent sharpener (better than most of the local so-called pro tree cutters), but I want to become excellent as a sharpener in the future. I have a way to go but you are a great help.

I usually take milling chains of 32, 36 and two 42" with me in the field. For most of my logs (30"- 36" x 9') I can get a couple of cuts with the 32, a couple of cuts with the 36 and then switch to the 43' as I move into the widest sections of the log. Barring embedded metal, etc., I generally make 3 cuts with one 42" chain, then change and make 3 cuts with the second 42 incher. My board-mounted vice that clamps to my tailgate allows for quick chain change and solid sharpening base.

Then I take a food and hand-file break (3 cutter strokes without touching the rakers) before finishing up the day. Full comp filing has been killing me on the 42" . The skip chain is certainly gonna help in that regard. That will also increase me to three 42" milling chains. On many logs, that will mean I only have to touch up the 32 & 36 to finish the bottom of the log.

Then, back to the shop for more refined sharpening with a Granberg bar mount.

 

[Brent Nowell]

I think this is a good idea personally, and in the end you are out 60$ if it doesn’t work. Sometimes to make progress with your ideas it’s gonna cost you, if you can accept that go for it.

The hardest part about this is going to be trying to get a square cut (straight line) down the top plate. Also to keep it the same thickness as the others cut to that size. This is where machines come in, like from a factory imo
However if I were to attempt this, a Dremel with thin cutting discs and a vice is where I would start.
Good luck

 

[BobL]

. . . . . I have a way to go but you are a great help.

Cheers CSMN,

I usually take milling chains of 32, 36 and two 42" with me in the field. For most of my logs (30"- 36" x 9') I can get a couple of cuts with the 32, a couple of cuts with the 36 and then switch to the 43' as I move into the widest sections of the log. Barring embedded metal, etc., I generally make 3 cuts with one 42" chain, then change and make 3 cuts with the second 42 incher. My board-mounted vice that clamps to my tailgate allows for quick chain change and solid sharpening base.

That sounds like a lot of extra chains and swapping around to me but I know some folks don't mind doing it.
I use the 441 with the 25" bar and Lopro chain for stuff <18", the 880 with the 42" for stuff up to 39" and the 60" (both with 3/8 regular) for everything above that. That means only needing to take an extra 3chainsa as spares with me when milling . I have many loops of other chains, square ground, skip, 404 etc but they nearly always stay at home in the shop.

Then I take a food and hand-file break (3 cutter strokes without touching the rakers) before finishing up the day. Full comp filing has been killing me on the 42" . The skip chain is certainly gonna help in that regard. That will also increase me to three 42" milling chains. On many logs, that will mean I only have to touch up the 32 & 36 to finish the bottom of the log.

It probably doesn't happen as much in your softer woods but I found skip chain went blunt faster, so the last 1/3 - 1/4 of wide cuts was much slower. With the full comp it still slowed but not as much.
When Milling I touch up with the chain on the mill.
I take with me a low portable table and a plastic chair.

I lay the mill over on its side and clamp the mill to the table and this enables me to touch up one side while sitting.
The other side requires me bend across the mill and file thru the mill frame - this is indeed a PITA (especially with my dud back) but its failure quick.

One important component of a CSM that can get in the way is when the full length handle is too low, or close to the main mill frame.
This is what I made my full length handle higher than most other CSMs.
This is shown in the following photos.
The long handle doesn't get in the way when touching up through the mill, and it enables a more upright milling stance to be maintained especially if a remote throttle is employed.


Here you can see the full length handle is much close to the main mill frame.

 

[Tarki0]

If you have an obsession to learn, may I suggest square filed chain?
It will cut faster and leave a smoother finish IMO.

bingo!