Milling Dead Wood

[BobL]

Hey guys and Bob: Thanks much for your replies. Bob: can you please answer my original question? What to do with my chain with a few teeth out of it: Should I cut off some more teeth to make it more of a skip chain? Does it matter if it isn't perfectly symmetric skip, as long as total number of missing teeth is same on left vs. right sides of chain? What should I do to get these chains usable again with the missing teeth?

I don't think it really matters if there is a tooth or two missing on a chain as long as they are not adjacent to each other

Bob, not questioning "MAX SAW CHAIN SPEED POSSIBLE", which is controlled as you say by the RPM of the sprocket and size of the sprocket. But when buried deep in a log milling, and NOT HAVING A 80cc or huge saw doing it with huge torque, smaller saws WILL bog down in the cut as the friction of milling is high, especially if the streams of cuttings just can't get out and ACTUAL REALIZED chain speed then drops.

Sorry I read it as Max speed. I agree freshly sharpened skip chain will maintain a higher chain speed in a cut, and a smaller cc saw with a longer bar may only ever be able to cut that full width with a skip chain. Although they don't scale exactly there's some similarities between a 50 cc saw with a 30" bar and a 100cc saw with 60" bar

However some of the "cutting speed" skip chain gains by extra chain speed may be lost because there are fewer cutters removing wood. If the chain has fewer cutters and the CS is up to it then it may be possible to get the cutters to grab more wood by lowering the rakers - but of course this will drop the chain speed and blunten the cutters faster so it/s swings and roundabouts again.

If the max chain speed generated by the saw can be cranked up by increasing engine rpm and using larger sprockets (like on hot saws) then skip chains have a definite advantage which is why skip are used on hot saws. But milling is not like a sprint, its more of a marathon. Skip chains have fewer cutters so have to go blunter quicker, which hot saws running for a few seconds don't care about. I admit I haven't tried skip on anything shorter than 42" and a 111cc saw in hard hardwoods so maybe in softer woods bluntness is less of an issue. It would be good if someone was to time some milling cuts comparing skip and full comp chain. I couldn't detect any difference on narrow cuts but that was probably due to plenty of engine power while several times I recall my skip chains struggling to get to the end of a wide cut on a long log. I've not had this with full comp chain.

The other way to get increased chain speed in the cut is to run a smaller chain like the lopro. Its my standard chain on my 441 - like you say less friction

Thos chains have been run on an bar with bar rail tops not square to the side of the bar. This wears the underside of one side of the ties more than the other - after that the chain will never cut straight. Keeping the bar dressed square eliminates this problem

Thanks, I will do some serious bar investigation on those chains/saw next. Could be. The bar isn't that old though or worn. Paint still all on it. I will do some careful inspections.

It doesn't take much to kick it over. I have one of those chains for my 441 - I just let it go too far and theres naught I can do about it

I've found with that, it requires less saw size and less oil to mill well than with the horizontal milling with the Alaskan. I think again because the chip streams can easily get out of the cut vertically vs. horizontally, plus the binding on the saw blade isn't there with vertical cuts, as with horizontal the wood slab will press down on the blade while cutting more (even with wedges moved frequently). Low friction is good, high is bad, unless you have a giant saw and it doesn't matter much.

I agree about the vertical mill. Mine is able to cut using the back of the bar which fires the sawdust straight onto the ground
If you want to experience friction from poor sawdust removal try making a long blind cut with a saw held vertically (i.e. no bar nose poking out the other side of the cut).
Like this

If not enough sawdust is ejected and there is a need to deepen the cut then the residual sawdust really chokes the cutting action. It's a bit like trying to make a cut with a whole lot of small wooden balls in the way

One more quick question: What oil type is best for milling? I've heard car oil like 10W-30 is terrible, bad, don't do it! And I've also heard the lower viscosity is great for milling and getting where it needs to be. What does the forum recommend?

Old engine oil is full of gunk and makes a real mess.
New engine oil is fine (Lucas mill slabbers with 6o" bars use it neat) for lower speed chains but for higher speeds some tackifire is needed.
I used to use premium bar oil in the saw, and to save a few $$ , canola in the Aux oiler but over a couple of years the canola made a real mess of the mill.
I now use re-cleaned engine oil with tackifire added to my specification in both[/QUOTE][/QUOTE]

 

[Adamant]

There are a lot of things that can cause curving in the cut. My B&C was diving and binding ie. By the end of the cut the bar is being pushed down so hard (by the extra thickness of the slab between the mill and the B&C) that I sometimes could not even finish the slab. So, things to check

 

[Adamant]

Sorry, always seem to accidentally post before finishing. Anyway, short answer: buying a chain grinder fixed my problem... sort of. So , some things to check: uneven bar wear (can be bar rail tops not square with bar sides, but also after a while the inside surfaces of the rails wear unevenly so the top of one rail can be thinner than the other) this leads to the chain angling more to one side than the other. Uneven chain sharpening, this was where the grinder came in handy. I'm just not good enough at hand filing to get the consistency required (all angles and hook) to eliminate the chain as the problem. Bar, mill rails and tracks flat, straight and in parallel planes. A combination square or vernier callipers and straight edge check distance vertically between the bar and bottom of mill rails at front and rear of bar at both ends

 

[Adamant]

It's so fiddly doing this on my phone! Keep hitting post ! Grr! Check mill rails are parallel to each other also. And if bar is parallel with mill in direction of travel is it flat along its length, not bowed up by mill or weight of power head and not sagging down under its own weight (this can affect the angle of the chain). Like Bob said, check the straps on the chain for uneven wear comparing one side to the other. Even small differences will matter.

I believe the biggest single thing is uneven chain sharpening, followed by bar rails not square or splayed. Good luck. I probably have the least experience but I spent a lot of time on this one problem.

 

[Pauls_Workshop]

I don't think it really matters if there is a tooth or two missing on a chain as long as they are not adjacent to each other



Sorry I read it as Max speed. I agree freshly sharpened skip chain will maintain a higher chain speed in a cut, and a smaller cc saw with a longer bar may only ever be able to cut that full width with a skip chain. Although they don't scale exactly there's some similarities between a 50 cc saw with a 30" bar and a 100cc saw with 60" bar

However some of the "cutting speed" skip chain gains by extra chain speed may be lost because there are fewer cutters removing wood. If the chain has fewer cutters and the CS is up to it then it may be possible to get the cutters to grab more wood by lowering the rakers - but of course this will drop the chain speed and blunten the cutters faster so it/s swings and roundabouts again.

If the max chain speed generated by the saw can be cranked up by increasing engine rpm and using larger sprockets (like on hot saws) then skip chains have a definite advantage which is why skip are used on hot saws. But milling is not like a sprint, its more of a marathon. Skip chains have fewer cutters so have to go blunter quicker, which hot saws running for a few seconds don't care about. I admit I haven't tried skip on anything shorter than 42" and a 111cc saw in hard hardwoods so maybe in softer woods bluntness is less of an issue. It would be good if someone was to time some milling cuts comparing skip and full comp chain. I couldn't detect any difference on narrow cuts but that was probably due to plenty of engine power while several times I recall my skip chains struggling to get to the end of a wide cut on a long log. I've not had this with full comp chain.

The other way to get increased chain speed in the cut is to run a smaller chain like the lopro. Its my standard chain on my 441 - like you say less friction



It doesn't take much to kick it over. I have one of those chains for my 441 - I just let it go too far and theres naught I can do about it




I agree about the vertical mill. Mine is able to cut using the back of the bar which fires the sawdust straight onto the ground
If you want to experience friction from poor sawdust removal try making a long blind cut with a saw held vertically (i.e. no bar nose poking out the other side of the cut).
Like this

If not enough sawdust is ejected and there is a need to deepen the cut then the residual sawdust really chokes the cutting action. It's a bit like trying to make a cut with a whole lot of small wooden balls in the way



Old engine oil is full of gunk and makes a real mess.
New engine oil is fine (Lucas mill slabbers with 6o" bars use it neat) for lower speed chains but for higher speeds some tackifire is needed.
I used to use premium bar oil in the saw, and to save a few $$ , canola in the Aux oiler but over a couple of years the canola made a real mess of the mill.
I now use re-cleaned engine oil with tackifire added to my specification in both

[/QUOTE][/QUOTE]

Bob: Many thanks for your thorough replies. Lots of great information, as the norm!

Good discussion on the skip chain. YES, with 1/2 the cutters, they will and do wear down and need a resharpening more rapidly. This is a very small tradeoff for me as I could not do it at all in 28" otherwise. I found I could cut easily 2 passes in my English Walnut, which was 8' long and 22" wide at the greatest in the log before needing a touch up. Could almost do 3 passes. Not bad. I really had to do the same thing when I used the 20" bar and normal chain though too. Using the Dremel with the diamond coated grinder bits, I can sharpen a tooth in 3 passes in about 20 seconds each tooth and I don't take the chain off the saw. So sharpening for me is not a big deal. The max blade they recommended for the echo cs-590 was 27" by Echo. So using a 28" on it, *and* milling with that, I am pushing beyond what the manufacturer said you could even do. So I bought full skip and it works just great on it. I did not even buy normal non-skip chain for the 28" bar and probably won't for it. Now I might though when I get my new to me old cs-8000 going at 80 cc. as they can share bars/chains. If I do might be a good "timed" excercise between them, but don't have any normal chain for now there.

I really like that beam structure for that top down mill! and the way it clamps to the bar. I used a 2x4 for mine but it worked fine. Planar accuracy not perfect, but I cut pretty thick slabs and will plane and joint them when dry, so doesn't matter too much for me. I can see how not getting the chips out would make that cut really hard to do there. I would not ever try to do that milling, any way you wanted to unless there was just no choice.

I think for new people wanting to mill I want to share a few thoughts as I am only now on year 2 of it: I can recommend rather than going whole hawg into it with a giant 80cc + saw, start out more like I did: 1. Get a beam machine or similar top down mini mill like above to learn how to do it and what matters with a smaller saw or whatever you have, 40 cc +. If you blow it up also, much less entry cost to the milling hobby as you're learning things. 2. Start on less wide wood like 6" or 8" wide first. 3. Learn how to safely do the cut while milling. Basically, entry and exit of the ends of the log are the hardest parts to be safe about. It is trapped in the middle after that and more safe to use. Learn how to be totally safe before using that giant saw and milling 16" + wide boards. 4. Learn about how to sharpen chains to be *really* sharp. This is required for milling really and absolutely needed to cut hard woods with smaller size saws. I spent my first year milling learning how to do this part. I recommend doing at least some yourself with a hand file or Dremel hand grinder. I think you just can't replace the "feel" of what you are doing using a full grinder machine all the time with the more manual process. 5. Learn about Bob's raker method too. I missed that part and now see how my not quite same length cutters and "variable" raker depth as I was putting different sorts of front side rounds on mine not controlled at all for progressive angle could be causing variable cuts per tooth. I was just controlling normal raker depth with normal methods and squaring off the top to depth. This may be part of my chain problems I can try to fix next. 6. Also don't forget the bar, which i did a bit on some of mine. 7. This sort of process helped me learn all about friction and sharpness and "actual" chain speed in a cut well. Now I'm more ready to handle bigger cuts with a bigger saw, which I'll do soon with a CS-8000 once I get it going. The Echo Cs-590 at 60 cc makes a *great* hobby milling saw for most people! I would highly recommend getting one of those to start with milling! I could use mine forever for it, but want to see what an 80cc class saw can do next. Look for the rare 30% off coupon deal from Zoro Tools (division of Grainger). I got my new Cs-590 for about $330 during that sale, a super deal. Sign up for their email deals. They usually do this on cyber Monday after Thanksgiving for a day only. 8. Learn about how to *fix* and repair small engines and saws at least a little bit yourself. I do whatever myself completely whenever I can. It is about learning but also then better understanding how it all works together after you have learned. Bob is a great example of this concept, how doing it all yourself leads to learning and then mentoring others too. I love that! 9. Lastly, be sure to learn how to grind milling or ripping chain teeth vs. normal crosscutting chain teeth. People say you can cut with whatever, but milling teeth makes a *huge* lower cutting friction difference than normal teeth when milling with a smaller saw. If you can fit the smaller width chain on your saw as Bob mentioned above, that is great too, but I would absolutly use milling chain, which is flat on the front of the teeth and with little angle vertically at the tooth edge, 10 degrees or less. This also is one less angle to worry about when hand grinding the teeth to sharpen and it is easy to just get one angle the same (harder to get two the same by hand but I can do it after practice).

So it is now clear to me what I need to do next: Properly go over each of my problem chains/bars again using your progressive raker settings and check for uneven wear on the chain and the bar. Also finish straightening out my one bar. This all may take me a while as I got two little kids! Yikes! And just a hobby. But I want to get back into finishing a 100 year old English Walnut I've been working on in next few months.

Thanks again Bob! - Paul

 

[Pauls_Workshop]

It's so fiddly doing this on my phone! Keep hitting post ! Grr! Check mill rails are parallel to each other also. And if bar is parallel with mill in direction of travel is it flat along its length, not bowed up by mill or weight of power head and not sagging down under its own weight (this can affect the angle of the chain). Like Bob said, check the straps on the chain for uneven wear comparing one side to the other. Even small differences will matter.

I believe the biggest single thing is uneven chain sharpening, followed by bar rails not square or splayed. Good luck. I probably have the least experience but I spent a lot of time on this one problem.

Adam, thanks for your *many* cell phone replies above!

Yes, everything you said. I have a set of mics and calipers and will be doing this thorough inspection next. I do know *now after the fact* my Alaskan wasn't set up just perfect distance above bar at front to rear of it. Off maybe an 1/8" of inch before. I don't know if that helped create the bend or not, but when I clamped down the Alaskan, it may be put in the bend. Then running it just a little hot messing up the oil setting may have helped to set that bend in. I have to figure out how to get the bar straight next. I don't think this bar has much wear but I need to check everything. I have other bars/chains though I have used alot with wear and I'm sure I'll find some things there when I get to it. Right now, my milling or chain saw hobby time is only about 20 hours a month at the most free, so may take me some time! I have a 4 year old boy and a 2 year old girl later in life! Yikes! Takes a lot of time, but even more rewarding than a curly pattern in a 20" wide 8' board you just opened up! - Paul

 

[BobL]

Using the Dremel with the diamond coated grinder bits, I can sharpen a tooth in 3 passes in about 20 seconds each tooth and I don't take the chain off the saw. So sharpening for me is not a big deal.

While it's better to be careful than not, 20s sounds like a longish time per cutter using a diamond dremel. Just using a file in a file guide my touch ups take 4 seconds per cutter. A full comp 42" bar has 68 cutters so that's about 272 secs which is about 3.5 minutes. If you really need 20 seconds it could be you are letting the chain get too blunt or you are removing too much metal. All that is needed is to remove enough metal to remove the edge glint.

I really like that beam structure for that top down mill! and the way it clamps to the bar. I used a 2x4 for mine but it worked fine. Planar accuracy not perfect, but I cut pretty thick slabs and will plane and joint them when dry, so doesn't matter too much for me. I can see how not getting the chips out would make that cut really hard to do there. I would not ever try to do that milling, any way you wanted to unless there was just no choice.

It wasn't really milling - that was carving some park bench furniture.

So it is now clear to me what I need to do next: Properly go over each of my problem chains/bars again using your progressive raker settings and check for uneven wear on the chain and the bar. Also finish straightening out my one bar. This all may take me a while as I got two little kids! Yikes! And just a hobby. But I want to get back into finishing a 100 year old English Walnut I've been working on in next few months.

Kids - my "ne and only" had left home by the time I got into milling and SWMBO rediscovered horses. so I had a lot of spare time to put into it even when I was working.

 

[Pauls_Workshop]

Wow you are fast, my internet ink electrons didn't even dry on the screen yet Bob!

Well, I say 20 seconds, that is really 1.357 seconds per pass per tooth and 15.929 seconds per tooth of making sure the angle and start of cut are just what I want on that tooth before I have the courage to move the Dremel forward just slightly to do the job!

Ah, carving the park bench makes sense as it almost looked like that blade would have cleared the log diameter if tried. Very good.

Yeah, we had lost two babies to miscarriage younger and told we couldn't have kids. Later found on the 2nd just needed a hormone lacking. Later still ended up having our first at 43 each! Yikes! Then ran across a drug baby up for adoption and we went for it as we had the one and how hard can two be than just one! All the brochures said it would be easy! So have an almost 2 year old baby girl addicted to drugs at birth. She was stoned the first month of her life. Doing pretty well now but refuses to talk much! Or do anything she is told to do! Though she understands fine! I'm hoping this aspect improves as she grows and later becomes a teenager! So at 47 each, we got two under 5! Yikes! By the way, Red River Birch comes out with a beautiful pink interior color. I'm going to make some girl stuff with it for the baby girl. My "shop" is woodworking. The milling is to get my own free wood for my woodworking hobby! - Paul

 

[BobL]

Well, I say 20 seconds, that is really 1.357 seconds per pass per tooth and 15.929 seconds per tooth of making sure the angle and start of cut are just what I want on that tooth before I have the courage to move the Dremel forward just slightly to do the job!

1.357 + 15.929 = ~18s , so what's the other 2 seconds for?

 

[Pauls_Workshop]

1.357 + 15.929 = ~18s , so what's the other 2 seconds for?

Ah, recall I said 3 passes per tooth. 1.357 x 3 + 15.929 = 20s

Note, the error in my measurements above is +/- 0.843s per pass, depending on how hasty I am feeling at the time to get the work done or whether the exhaustion of the work requires a quick sip of brew before the next pass gets done.

(I am actually a mechanical engineer in real life Bob, as you can probably discern from my accuracy in my numbers above and my focus on friction, but I didn't want to focus on that here, as I have much to learn about things too and people get all touchy when they know they are talking to an engineer. I've put engine parts into production though and I actually have a couple patents. Not small engines like these cute little saw engines though! We can all learn from each other something or many things, every day. I've learned a lot from you and others here so far and sharing just a few things I can pass on along the way! ) - Paul

 

[BobL]

Ah, recall I said 3 passes per tooth. 1.357 x 3 + 15.929 = 20sl

OK

Note, the error in my measurements above is +/- 0.843s per pass, depending on how hasty I am feeling at the time to get the work done or whether the exhaustion of the work requires a quick sip of brew before the next pass gets done.
(I am actually a mechanical engineer in real life Bob, as you can probably discern from my accuracy in my numbers l

A scientist would write 20.000 s

above and my focus on friction, but I didn't want to focus on that here, as I have much to learn about things too and people get all touchy when they know they are talking to an engineer. I've put engine parts into production though and I actually have a couple patents. Not small engines like these cute little saw engines though! We can all learn from each other something or many things, every day. I've learned a lot from you and others here so far and sharing just a few things I can pass on along the way! ) - Paul

Yep we're all learning.
When I joined here in 2007, 3 members I learned a lot from were WoodShop and AggiewoodButchr and Mtngun. AggiewoodButchr's CSM mods are what inspired elements of BIL mill.
Woodshop's jigs and the crafty things he made with the wood he milled ere legendary. Its a shame their photos are gone and they are not still on the forum.
Any good point - being able to see an application of one process/part to another is

 

[Pauls_Workshop]

Yeah, what is up with that? The site lost all its old photos? Not good. That is what backups are supposed to be for. I would love to see all their posts.

I'm not a scientist. I just round up or use my thumb! - Paul

 

[BobL]

Yeah, what is up with that? The site lost all its old photos? Not good. That is what backups are supposed to be for. I would love to see all their posts. I'm not a scientist. I just round up or use my thumb! - Paul

The site was compromised in 2013 and all the images were lost. For about a year members were able to reinsert their own pics and I did reinsert a few of mine, Fortunately I keep copies of all my pics and I post almost identical pics and posts on another site so I could find them all quite easily.

 

[Pauls_Workshop]

The site was compromised in 2013 and all the images were lost. For about a year members were able to reinsert their own pics and I did reinsert a few of mine, Fortunately I keep copies of all my pics and I post almost identical pics and posts on another site so I could find them all quite easily.

So I went over today and reread the whole Milling 101 thread. I'm so glad Bob you took the time and effort to reload your photos there. The bit on the details of the chain sharpening is just gold. I did NOT realize you like not quite 0 degree top plate as Madoff suggests but just slightly higher. I'll employ that as well as I've been doing Zero. I have read Madoff's book. Also the bits on the other details of Madoff vs Bob method. Just fascinating stuff in there! I've become "good" at my manual chain sharpening for milling but I hope to get to "great" now with this knowledge once I can apply it correctly. You may go and have a beer sir!

I may try to run my 8000 an hour or two this weekend and see how it does vs the cs-590. I like to also sometimes just "noodle" my way down a log vertically by hand without any guide rails when doing smaller dia shorter logs. I have some maple I need to get cut as they've been sitting out all winter and may noodle a bit with the 8000. I find I can get to about +/- 3/16" planar accuracy just noodling a 5' long log or so and not take any setup time for any mill at all. After drying/warping, that is accurate enough for me as it will go through jointer/planer later on. I like to at least get one cut in them down the middle to begin the drying process right as soon as possible. You would find some of my hobby milling humorous Bob compared to your serious Aussie trees! Wow! But I refuse to throw any good wood away to be burned or composted!

So far here is some of what I've milled (some of which you cannot buy from lumber yards here in the US at all):

Hawthorne (really hard and strong stuff that blacksmiths would use to burn in their forge hotter than almost anything else), Dogwood (very strong bushy small tree), Silver Maple, English Walnut, Apple, Plum, White Ash, Black Walnut, and a favorite in Black Locust, another horribly hard wood to cut at all much less mill! The sparks fly there and a dull chain doesn't just not cut, it bounces off like rain! Some of mine is spalted too lihe the Hawthorne and some Ash, just some beautiful grain varieties all for future woodworking projects once it all dries. Oh left out a bit of Red River Birch, beautiful pink grain color there. Will do more of that soon. Later in the summer I will tackle a giant Black Cherry tree at my sister's that has to come down, two big trunks, about 25" dia each at the base and about 80' tall. Perhaps the biggest Cherry I've ever seen. And finish up my English Walnut this season. For my hobby, two-three big trees is the whole year! - Paul

 

[BobL]

So I went over today and reread the whole Milling 101 thread. I'm so glad Bob you took the time and effort to reload your photos there. The bit on the details of the chain sharpening is just gold. I did NOT realize you like not quite 0 degree top plate as Madoff suggests but just slightly higher. I'll employ that as well as I've been doing Zero.

If you use a grinder and can accurately set zero top plate filing angle then that's fine. It's just that it is difficult to do that by filing and if he angle is less than zero that is not good as it slews the cutter towards the middle of the bar so that it cuts a narrower kerf. This is less of an issue when the cutters are long (and wide) but as the cutters get shorter they cut a narrower kerf so a <0º TPFA can end up jamming the bar - not a good thing to happen on a SCM

I have read Madoff's book. Also the bits on the other details of Madoff vs Bob method. Just fascinating stuff in there! I've become "good" at my manual chain sharpening for milling but I hope to get to "great" now with this knowledge once I can apply it correctly. You may go and have a beer sir!

Cheers.

I may try to run my 8000 an hour or two this weekend and see how it does vs the cs-590. I like to also sometimes just "noodle" my way down a log vertically by hand without any guide rails when doing smaller dia shorter logs.

Yeah its fun, at least for a while