# Open discussion on hook angle for CSM chain



## oldsaw (Mar 10, 2011)

Okay guys, been doing some searching and this is a topic that gets mentioned on occasion, but never really gets fully addressed. I'm gearing up for a big milling season and am going to get my chains fully tuned.

I'm going to BobL's raker advice, thinking this is one place I'm having some major problems due to the advancing age of some of my chains. However, Northern has their grinder back on sale for $100, and I'm wondering if it's worth the the investment for messing with hook angles.

The floor is now open.


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## BobL (Mar 10, 2011)

oldsaw said:


> Okay guys, been doing some searching and this is a topic that gets mentioned on occasion, but never really gets fully addressed. I'm gearing up for a big milling season and am going to get my chains fully tuned.
> 
> I'm going to BobL's raker advice, thinking this is one place I'm having some major problems due to the advancing age of some of my chains. However, Northern has their grinder back on sale for $100, and I'm wondering if it's worth the the investment for messing with hook angles.
> 
> The floor is now open.



Do you mean using "progressive raker" depths or "cutter hook"?


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## oldsaw (Mar 10, 2011)

BobL said:


> Do you mean using "progressive raker" depths or "cutter hook"?


 
Cutter hook, I understand the raker issue and am adopting it, great work, btw, even though you have been preaching it for some time. I've had the saws parked for way too long. This is one aspect of sharpening I've never messed with.


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## BobL (Mar 10, 2011)

oldsaw said:


> Cutter hook, I understand the raker issue and am adopting it, great work, btw, even though you have been preaching it for some time. I've had the saws parked for way too long. This is one aspect of sharpening I've never messed with.


 
I haven't messed as much with hook as I have with rakers because I
reckon as long as the saw is self feeding on a slight slope and doesn't go blunt too quickly then I don't worry about it too much.

For a number of years I used a 13/64" file on a 5/32" file guide in the belief that it reduced the hook but after thinking about it during the year I realized this setup increased the hook. I'm moving to a 13/64" file on a 3/16" guide to see if this improves cutter edge life.


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## lumberjackchef (Mar 10, 2011)

I have adopted the sharpening method that I read in the book "Chainsaw Lumbermaking" with very favorable results. I bought one of the Chinese made northern tool grinders which has served me well for this purpose.

I start with a new loop of Carlton full comp/full chisel chain and use these angles:

Top plate: 0 degrees/hook angle: 50 degrees from vertical =slowest feed rate but smoothest finish.

Top plate 10 or 15 degrees/hook angle: 50 degrees from vertical= faster feed rate but a little rougher finish.


The later one with a 15 degree top plate is my standard grind anymore. It was noticeably faster than the woodland pro ripping chain that came with our 48" mill. I actually ground the ripping chain this way when I finally put it on the grinder. Now it will cruise through the wood too! 

I primarily sharpen my chains on the grinder, then a couple of times in the field with the file, then back to the grinder to even everything up again and drop the raker depth accordingly. 

IMHO there is nothing better than the quality of Carlton full chisel it will simply hold an edge longer than any other chain.(especially fresh off the grinder) And let me say i have tried them all on my carving saws over the years.


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## mtngun (Mar 10, 2011)

From Will's book:


Will Malloff said:


> I grind my ripping chain cutters straight across the fronts at 50 degrees from vertical (40 degrees from horizontal)














I barely started experimenting with the hook angle last fall and didn't get very far. Will try again this summer.


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## mtngun (Apr 25, 2011)

Lo-pro ground 40/10/10.

Got hook ? :msp_sneaky:





40 degrees was easier said than done. First off, the wheel guard was hitting the vise handle, so I had to completely remove the wheel guard.

Only about 1/2 of the cutter length is left on this chain, so there was plenty of room for the wheel to fit between the cutter and the raker -- but I doubt there would be enough room on a newer chain. 

And yes, I did have to re-shape the bottom of the grinding wheel, as Malloff suggested.

Will try to speed test it later this week.


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## mtngun (Apr 27, 2011)

Time to speed test the Malloff grind. :msp_sneaky:

My usual 12 1/4" pine cant. A hot-rodded 066, 36" bar, injecta-sharp lo-pro chain ground 40/10/10 as shown in the previous post. 6 degree rakers.

1st test -- 1.26 inch/sec

2nd test -- 1.26 inch/sec

3rd test -- 1.20 inch/sec

Average -- *1.24* inch/sec :msp_thumbsup:

That's *30%* faster than 60/10/10 lo-pro had done with the same saw in the same cant. 

OK, so the Malloff grind is faster. There's got to be a downside ?

-- it'll probably get dull faster, especially in hardwood.

-- it's harder to grind, prolly impossible to grind on brand new chain. With a new chain, you may have to start out at 60 degrees and then gradually change the hook angle a little each time you sharpen.

Malloff used a 0 degree top plate angle, not 10, so that's yet another experiment for me to tackle.


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## john taliaferro (Apr 28, 2011)

Found his book in the fall and tried 0 on the top cuts slick ,smooth ,sweet and doesn't seam to dull earley . but i was going the wrong way on the hook ,and hit a wall on horse power .My 88 got doggy slow so tore it apart was fine, put a 36 " bar on and it makes cookies quick . You can bet its gonna make a big differance dropping the hook to 40 degrees. Got to get a grinder , its time.


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## BobL (Apr 30, 2011)

mtngun said:


> There's got to be a downside ?
> 
> -- it'll probably get dull faster, especially in hardwood.


Yep but as long as it make it thru one big cut in hardwood, chain's gonna be touched up anyway. 



> -- it's harder to grind, prolly impossible to grind on brand new chain. With a new chain, you may have to start out at 60 degrees and then gradually change the hook angle a little each time you sharpen.


Or start with a file 



> Malloff used a 0 degree top plate angle, not 10, so that's yet another experiment for me to tackle


My guess is that will slow it down - I'm thinking skew plane/chisel?


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## mtngun (May 7, 2011)

Another variation on the Malloff grind.

3/8 WP milling chain, 40 hook, 0 tilt, and 2 degree top plate. Used a 1/8" wheel rather than the usual 3/16" wheel. 6.1 degree raker angle.





Why 0 tilt ? Just an experiment. It's easier not to tilt, so if it cuts just as well, why not ?

Why 2 degree top plate ? BobL had mentioned somewhere that if you grind to 0 top plate, you run the risk of making it slightly negative, which would be a bad thing. So I set the grinder on 2 degrees to make sure any error would be on the positive side.

This chain will be tested on my rebuilt and mildly ported 084. I've got to make some new cants, so it probably won't get done until tomorrow.


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## 820wards (May 8, 2011)

mtngun said:


> Another variation on the Malloff grind.
> 
> 3/8 WP milling chain, 40 hook, 0 tilt, and 2 degree top plate. Used a 1/8" wheel rather than the usual 3/16" wheel. 6.1 degree raker angle.
> 
> ...


 
Mtngun,

Can you let us know how the finish turns out when you make your tests. I have been thinking if filing my chains with more hook, but was afraid I wouldn't get as smooth of a finish as I'm getting now. I'm filing my chains at 10* with very little hook.

jerry-


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## mtngun (May 8, 2011)

820wards said:


> Can you let us know how the finish turns out when you make your tests. I have been thinking if filing my chains with more hook, but was afraid I wouldn't get as smooth of a finish as I'm getting now. I


Haven't tested the 3/8 yet but have made several cuts with lo-pro at 40/10/10. Looks no better or worse than the finish from regular WP ripping chain.


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## betterbuilt (May 8, 2011)

Can somebody explain top plate angle and tilt angle. Thanks.


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## mtngun (May 8, 2011)

betterbuilt said:


> Can somebody explain top plate angle and tilt angle. Thanks.


Tilt is the tilt of the grinder vise, or if you are filing, if refers to whether you hold the file horizontal or 10 degrees from horizontal. 

Top plate angle as shown in Malloff's drawing, except his drawing labels 0 degree top plate as 90 degree for some odd reason.


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## 820wards (May 8, 2011)

I'll have to give it a try on one of my chains. 

Thanks
jerry-


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## betterbuilt (May 8, 2011)

Okay I'm following. I just wasn't sure if I knew where the numbers were coming from. 

It does seem like it would dull easier. Interesting.



Thanks, Mtngun.


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## mtngun (May 8, 2011)

OK, 40/0/2 3/8 as described previously.

Mildly ported 084.

8 pin rim.

12 1/4" seasoned pine cant.

1st pass -- 0.75 inch/sec

2nd pass -- 0.86 inch/sec

3rd pass -- 0.86 inch/sec

average -- 0.82 inch sec.

This was the first time the 084 had cut wood, so I don't have a direct comparison. It bogged easily with the 8 pin, so I will retest with a 7 pin.

Finish was quite a bit rougher than my 066. Again, this was the first time the 084 had cut wood, so I don't have a direct comparison. Will retest with the standard WP grind.


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## BobL (May 8, 2011)

Nice work mtngun. 

Re: Washboard, It looks like you are getting chain speed and log width synchronicity. Try angling the mill relative to the log so that the synchronicity is disturbed.

Cheers


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## john taliaferro (May 9, 2011)

I like the cool texture, just the 7 pin might do it . It almost looks a bent {arrant } tooth . Bob they are just ripples in the chain caused by narrow lumber and empty chain at the right frequency .


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## BlueRider (May 9, 2011)

When thinking of hook it is easiest to think in extremes. If the hook were ground at 90* the cutting edge would be very strong but it would take a lot of power to make a cut with it. if the hook were ground to 20* it would take much less power to pull it through the wood but it will get dull very easily. the optimum hook is somewhere in the middle, something that optimizes cutting speed with the available power and maximizes the sharpness of the cutting edge. put another way it will depend on what saw and what wood you are cutting as for what hook angle is best. 

That all said I file my chains with 40* hook, 10 top plate and no tilt. because I hand file I tend to keep them the same rather than change them to suit the wood I am miling, a bit of lazyness on my part.


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## glennschumann (May 9, 2011)

mntgun,

Nice work. I'd like to know the results of changing the 8 pin to 7 if you run the same set up... will you get the same wash board effect with the 7 pin. The reason I ask is that I had a lot of wash boarding with an 8 pin on my 066 set up, while the 7 pin gave smoother cuts. I could not remember if this was the only variable between the cuts, but my theory is (If it was the only variable) is that chains repeat their sequence every 8 drive links, and if the chain gets the same "oomph" from a combustion event every time, say, a right hand cutter is in the same place in the log, it may lead to a tendency for some sort of sympathetic vibration or wobble in the chain resulting in the wash board. Since I use a 7 pin on everything except my 24" bars, and my 24" bars (one old, one brand new) give more wash boarding, it is a theory I want to test when I get back to milling after a few honey-do projects.


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## redoakneck (May 9, 2011)

opcorn:

Very interesting, and all this is for hardwood for a fine smooth finish??

40 degrees, 0 degree top plate. I have to sharpen some wp 3/8 ripping with a file, I may try to head my chains in that direction.

I mill mostly hardwood.



Anyone try a triangular file for that 40 degree cutter face angle, or are you using 7/32 or 13/64????(round)


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## mtngun (May 9, 2011)

redoakneck said:


> all this is for hardwood for a fine smooth finish??


Only softwood here, unfortunately. Motivated by A NEED FOR SPEED. :cool2:


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## mtngun (May 9, 2011)

Retested the 084 with a 7 pin rim. Same 40/0/2 chain which hasn't been touched up.

1st test -- 0.92 inch/sec

I then leaned out the H another 1/16 turn. Sounded perfect to my ear.

2nd test -- 0.89 inch/sec

3rd test -- 0.82 inch/sec

Average -- 0.87 inch/sec

Speed in cut was still only 7000 - 8000 rpm, and it still required a light touch to avoid bogging.

So maybe a hair faster with the 7 pin, but not a huge difference. 

Finish was slightly better than with the 8 pin, but still not as smooth as my 066. Perhaps because chain speed is slower ?










Next step will be to retest the same chain with my 066. I'm betting the 066 will actually outcut the 084 with the same chain.


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## redoakneck (May 10, 2011)

BobL said:


> Nice work mtngun.
> 
> Re: Washboard, It looks like you are getting chain speed and log width synchronicity. Try angling the mill relative to the log so that the synchronicity is disturbed.
> 
> Cheers



Will pushing the wedges in tighter keep the board from vibrating or is this not caused by the board vibrating??? 

I don't know but that washboarding seems could be caused if your chain was too loose?? I seem to have to tighten my chains pretty tight to keep them from dancing all over. I can move them with my hands with some force, need to get a fish scale to see just how hard they are to pull. I am new at this and still trying to get all the info I can.:bang:

Man it is hard to file to that 5 degree angle when you are used to 25-30 for reg chain!!! Seems like driving on the left side of the road when you are used to the right. :msp_w00t:


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## BlueRider (May 12, 2011)

An often over looked cause of excessive washboarding is a bent bar. I had a bar with a very slight twist, so slight that I had to pull it off the saw and lay it on my table saw to see that it was bent. It milled fine but would pull strong to one side when bucking,like half the teeth were dull. 

Check your bar groove for excessive wear too.


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## john taliaferro (May 12, 2011)

Its that new 084 it just isn't any good for milling soft wood . Ive got a nice 036 i could trade you for, if it would help ya any:hmm3grin2orange:


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## mtngun (May 12, 2011)

That's thoughtful of you to offer to trade your 036, John. But, I'll force myself to live with this overweight, overrated 084. :msp_biggrin:

More speed tests, the usual 12 1/4" wide ponderosa cant.

First up, the hi-comp 066 wearing the same 40/0/2 3/8 chain discussed in previous posts.

1st test -- 1.26 inch/sec (average 9000 rpm in cut)

2nd test -- 1.2 inch/sec (average 9000 rpm in cut)

3rd test -- 1.2 inch sec (average 9000 rpm in cut)

average -- *1.22* inch/sec

Compare that to 0.82 inch/sec on the same saw with WP 3/8 milling chain ! Impressive.  It's also nearly as fast as the 1.24 inch/sec turned in by the same saw with the lo-pro Malloff grind. I don't understand why 3/8 was almost as fast as lo-pro ? 

Here's the finish left by the 066 with the 3/8 Malloff grind. 





Next, the mildly ported 084. Last time I tested the 084, it had the muffler screen installed, but today I removed the muffler screen. It's running a 7 pin rim.

A granberg'd WP milling chain, ground 40/10/10 on all the teeth. Cutting rakers are slightly less than 6 degrees and scoring rakers are slightly more than 6 degrees.





1st test -- 1.04 inch/sec (averaging 9000 rpm in cut)

2nd test -- 0.89 inch/sec (experimented with 9500 rpm in the cut)

3rd test -- 1.04 inch/sec (back to 9000 rpm)

average -- *0.99 *inch/sec

And here's the finish with the 40/10/10 granberg.





Next, the 084 with WP milling chain and the conventional 60/10/10 grind.

1st test -- 1.0 inch/sec (9000 - 9500 rpm in cut)

2nd test -- 1.09 inch/sec (9000 - 9500 rpm in cut)

3rd test -- 0.96 inch/sec (9000 - 9500 rpm in cut)

average -- *1.02 *inch/sec

The standard 60 degree grind spun a little faster and was a little harder to bog than the 40 degree grind. Makes sense, because the 60 degree grind does not cut as aggressively.

Here's the finish with the 60 degree grind, definitely the smoothest of the day. 





Conclusions: 40 degrees is usually, but not always faster than 60 degrees. It's more aggressive, so it may bog easier, or perhaps the raker angle could be adjusted to compensate ? 

Finish is slightly rougher with 40 degrees, but not necessarily enough to worry about, depending on your chain speed. Higher chain speed seems to produce a smoother finish.

I'll try to have one more speed test later, the screenless 084 with 40/0/2 3/8.


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## mtngun (May 12, 2011)

Screenless 084 with 40/0/2 3/8.

It so happened that I'd used up a cant and had to switch to a different cant for this speed test. Same width, same species, and same age, but still -- it's a natural product with natural variations. Just so you know. :msp_rolleyes:

1st test -- 1.85 inch/sec (average rpm 9300)

2nd test -- 1.85 inch/sec (average rpm 9300)

3rd test -- 1.71 inch/sec (average rpm 9300)

average -- *1.80 *inch/sec

That's my all time best speed for any saw or any chain. However, my gut feeling is that this new cant is simply softer than the previous cant. :msp_mad:

Here's the finish with the 40/0/2 at 9300 rpm.





And another spot on the same board. 





Conclusions: The 40/0/2 grind seems to work as well as anything, if you don't mind a slightly rougher finish.


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## mtngun (May 14, 2011)

I did a little more porting on the 084 and retested. Same 40/0/2 chain and same 7 pin rim.

Here's an end view of the cant used for the test. The sapwood has "blued," which I think is the equivalent of spalting. Anyway, the sapwood is pretty soft.

The previous cut -- the one that turned in the amazing 1.8 inch second -- was 100% sapwood. That's probably why the speed was higher than expected.





Today's cut was about 50% heartwood. Not surprisingly, the speed was slower even though I'm hoping my mods gave the saw a little boost. 





1st test -- 1.5 inch/sec (9000 - 9500

2nd test -- 1.5 inch/sec ( 9000 - 9500 rpm)

3rd test -- 1.85 inch/sec (8800 rpm -- I deliberately pushed harder)

Average -- *1.62* inch/sec

I'm not going to draw any firm conclusions from the speeds on this particular cant because the wood seems to be the biggest variable. Also, how hard you push and what RPM you maintain seems to matter. It's a bit of a guessing game to find the optimal RPM. 

I guess I need some fresh cants, seasoned but not spalted ?

Why was today's cut rougher than the previous cut ? Well, I don't have a push-o-meter, but it felt like I was pushing the saw a little harder today, forcing it to take bigger bites.


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## OH_Varmntr (May 16, 2011)

Very interesting!


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## 820wards (May 16, 2011)

Mtngun,

Here are few pictures of the Ponderosa pine I milled using a 12* angle on my chain. I'm also running an 8 x .404 rim and I have contoured my rakers very similar to what BobL has done on his chains. The cuts from my mill came out real smooth. Going with the 8 x .404 sped up the chain and I can feel the difference even when milling hard dry oak.

The tree I milled into a bench had only been on the ground for a week, so I don't know if that makes much difference being green. Maybe it does.

The other two trees I milled have been down since last August and they also milled quite smooth. Your logs look like they have been down for awhile and dry, do you find that dryer pine mills rougher or do you think the hook angle on the teeth make for a rougher cut?

These pictures were taken at different areas of bench from the log we milled. I was trying to make the pass without stopping and keeping the mill RPM at a constant speed. With the 8 pin rim I only need to run the motor at just over half throttle. I would say that without the aid of an rpm gauge, my mill head is turning between 6-7K rpm.


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## mtngun (May 16, 2011)

820wards said:


> Your logs look like they have been down for awhile and dry, do you find that dryer pine mills rougher or do you think the hook angle on the teeth make for a rougher cut?


Roughness seems to be a combination of the hook angle and the 084. Have yet to run into a significant finish problem with 60 degree hook, or with the 066. 

Why only 1/2 throttle ? Does that max out the RPM's ?


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## 820wards (May 17, 2011)

> Why only 1/2 throttle ? Does that max out the RPM's ?



I have found that just above 1/2 throttle the 820 PowerBee motors torque curve or power-band drives the chain at a fast comfortable speed once I begin the cut. I could make more power with the motor by installing a higher compression piston and removing one of the three stacked head gaskets, but I haven't seen the need. It has the torque to pull the chain through the wood with ease at a lower rpm. I also have cut my rakers to .043". 

The factory rpm range for a stock 820 motor is only about 7600 rpm using points. I am running an aftermarket electric ignition, carbon fiber reed valves and a 1" intake/carb. with a 2" exhaust pipe, so it breathes. I can rpm the motor pretty good when I need to, I just don't need to run it a full throttle to make my cuts. I use less fuel at better than 1/2 throttle without loosing any cutting power. Just to see how rich I could run my mixture, I mixed the last gas I used at 32:1 and I didn't feel much difference in top end power. I normally mix at 40:1. 

I have another one of these 820 motors and I'm seriously thinking of building it up to use strictly as a mini-mill motor so I don't have to use my Husky 365 Special for mini-mill work. I was thinking of saving the motor as a spare, and then thought, what am I saving it for. Maybe this motor I'll take out one of the head gaskets and do some porting on the intake runners. I just found a company that sells a .060" cylinder and high compression piston for these motors. I think it would take the 134cc motor and put it very close to a 140cc's. Where's BobL to figure this out when I need him.... :msp_confused:

So, are you changing the hook angle on the tooth to speed up the cutting time? I think it's cool that you are trying the different angles and testing them for cutting times. It will give us all good bench marks to work with. Good milling and thanks for the information you have provided to all.

jerry-


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## mtngun (May 17, 2011)

820wards said:


> So, are you changing the hook angle on the tooth to speed up the cutting time?


Yep.


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