Milling at an angle

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Remle

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i haven’t done a lot of milling yet. My main setup right now is a 48” mill and a Stihl 075 with a 36” bar and the dogs removed. My prior experiences milling surprised me with the fine sawdust that end grain cuts produce and how long they take to complete. Considering that lengthwise cuts are so much more efficient what I’m wondering is if it would make sense to set up the largest bar/mill combination I could afford, (I need a new bar anyway), and then to try to cut at the most aggressive angle possible. It seems to me that cutting at a 45 or 60 degree angle would radically speed up the pace of milling.

I’m sure it’s been done before, so does anyone here have any experience with this and whether it’s worth pursuing?
 
W
i haven’t done a lot of milling yet. My main setup right now is a 48” mill and a Stihl 075 with a 36” bar and the dogs removed. My prior experiences milling surprised me with the fine sawdust that end grain cuts produce and how long they take to complete. Considering that lengthwise cuts are so much more efficient what I’m wondering is if it would make sense to set up the largest bar/mill combination I could afford, (I need a new bar anyway), and then to try to cut at the most aggressive angle possible. It seems to me that cutting at a 45 or 60 degree angle would radically speed up the pace of milling.

I’m sure it’s been done before, so does anyone here have any experience with this and whether it’s worth pursuing?
What type of chain are you running?
 
That's an interesting idea. Instead of cuttingnthe end grain, you'd be cutting more along with it. Noodling a log definately goes faster and the noodles are easier to clean up than the powder sawdust.

It might be possible to grab a 12" log and try the 2 different methods with yoir current setup. See how long it takes with a regular cut, then move to the 45 degree angle on the next.
 
This has been discussed many times.
Unfortunately there is no radical improvement in cutting speed because the more you angle the mill across the log the greater amount of of the bar/chain is in the cut.
(for those that know their math, the cut length increases proportional to the inverse cosine of of the angle)
When the mill is held at 10º away from the usual straight across milling position the cut width increases by 2%.
With the bar held at 20º the cut length increases by 6%
With the bar held at 40º the cut length increases by 30%
With the bar at 60º the cut length doubles.

The amount of "along" versus "across" grain cutting increases in the same proportion as the amount of B&C in the cut so the net gain is zero
In fact you end up going slightly backwards if you deliberately add a longer bar and chain because then you also need more HP just to keep the chain moving.

With something like a wood plane or chisel, making the angle shallower makes a big difference because the length of the cut stays constant - if every time you lowered the angle the bade width increased it would not be so good.

If you are getting powder/dust that tells me you chain is not setup right. Post a close up, direct side on, photo of a cutter or two for a diagnosis of your chain.
 
i haven’t done a lot of milling yet. My main setup right now is a 48” mill and a Stihl 075 with a 36” bar and the dogs removed. My prior experiences milling surprised me with the fine sawdust that end grain cuts produce and how long they take to complete. Considering that lengthwise cuts are so much more efficient what I’m wondering is if it would make sense to set up the largest bar/mill combination I could afford, (I need a new bar anyway), and then to try to cut at the most aggressive angle possible. It seems to me that cutting at a 45 or 60 degree angle would radically speed up the pace of milling.

I’m sure it’s been done before, so does anyone here have any experience with this and whether it’s worth pursuing?
What BobL states above is absolutely on the money. In my experience, using the oiled side of the bar, and about 15° degree angle has me kind of side stepping to the right. The handle end is pressing into the front of my right hip, left hand is placing a few wedges in between regulating feed speed if needed. There has been the appearance of faster cutting speed in the same log.
The most important part is the sharpest cutters tuned to your PH by height of the rakers.
I was using skip square chisel in a maximum diameter of 38" with 72 cc saw pulling chain around a 42" bar. It threw nice chips and worked well. With BobL's math that angle added about 1 1/2" of cutting length, but as the thoughts you shared, moved the angle to a less resistant cut than 90° to the length of the log. I have a ported 661c and a 72" bar, that if I mill 69" or less long log it will be a case of noodle milling, but it will be thicker slabs. The reason being ; I lack faith in the smoothness of that cut with no experience yet.
My avatar shows a 60" bar on that PH. All that was available to get those table tops. Sharp chains and regulate feed to power head.
Mill safe and enjoy
 
Unless you can get it almost parallel with the grain you should take it perpendicular to the grain, anywhere in between gets tedious
 
Hi all , I am about to build myself a new logosol type mill with 8m rails , should be done in about 2 weeks . I ran a little experiment the other day as i am not a fan of 90 deg milling , its too hard on your gear , anyway i made a few cuts in a cyress log i have , about 4 cuts 4 foot long at an angle of between 30- 50 degs , using a 5skip chain , cut like a champion , bugger all noodling mainly just good chips , should hold its edfge a lot longer this way as well and i will still be able to mill up to a 600mm log at 30 degs , i have already worked it into my new mill design . cheers Henry
 
Hi all , I am about to build myself a new logosol type mill with 8m rails , should be done in about 2 weeks . I ran a little experiment the other day as i am not a fan of 90 deg milling , its too hard on your gear

Never found this to be a problem in even the hardest timbers - the key is keeping cutters sharp and rakers at the optimum height.
A 30º cut will not do much if anything for cut times.
While the back force on the cutter decreases by 0.866, the length of cut increases by 1/0.866 - net effect will be zero change in time.
For a logosol type mill it also means running a longer bar which is something I'm told they are not very good at.
 
Hi all , well I already have one logosol type mill , but it is only capable of handling a 2.8m length log , I did my tests with a 36 inch bar , definitely longer width cut , due to angle , as for slower , definitely not and chainsaw doing it easy , because it cuts so much easier , just not practical on really large cuts , as the bar length would be ridiculous , i used on my old mill , with bar end support . If you use a proper chain grinder , teeth are always sharp , if you are one of the peanuts that does it by hand file , good luck , most blokes end up with teeth different lengths and angles , just wasting chain and time , those blokes need to buy themselves a steam train . I was pretty impressed with the cutting speed , I expect the chain to stay sharp , for a much longer period of time . I only intend to cut logs between a max of 500 -600mm diameter . Anyone that's been milling timber for a long time knows end grain milling is hard on your gear , I have been milling for about 18 years , its time to put some other ideas into actual practice , not just theory . Cheers Henry
 
Anyone that's been milling timber for a long time knows end grain milling is hard on your gear , I have been milling for about 18 years , its time to put some other ideas into actual practice , not just theory . Cheers Henry

Humm . . my "experience" is "demonstrated" for all to see on these forums by the 7500 odd posts going back to 2007, many with pictures and detailed explanations . The fact that I understand any theory is just a bonus. In contrast you have two posts and no images - I'd say the onus is on you to demonstrate "experience" rather than just claiming it.
 
What raker height do you guys recommend for milling?
What works well in my 046 is close enough for the Ms-460, but a bit high for the 066 and then the ported 661 lives well with deeper bites. That is in the same log, different log, even of the same species but different lay time can change the right angle from the cutters leading edge
BobL has a whole educational series in 101 top of this area of discussion. You will understand about my reference to angle once you've taken that course on sharping chains.
Mill safe
 
What raker height do you guys recommend for milling?
As deep as your PH x DL x Wood hardness can handle.

I'm finding less heat and a better cut with greater self feeding by getting really aggressive with rakers.
Even though the planks are usually quite wide, I'm running a 3120 in softwoods so consider that situation before filing off piles of metal.

48567990566_9daa2c75db_c.jpg
 
BTW
Ana hadsent me the following pic from that day.
It's taken after I filed the rakers to aprox .045 plus rounding over. Also gave a couple clean up passes with file on cutters.
If you compare the quality of cut with the picture in previous post which was the stock chain (rakers flush with Oregon gauge .025)
Not just better feeding but also....More bite = better quality of cut.
*of course....Given an ample powerful saw and cedar which is quite soft.

48601594822_248cf221bf_c.jpg
 
BobL , you wouldn't happen to be a hand filer as well . Lol
Since 1964. I tried a grinder for about 6 months around 2007 but I needed too many loops of sharp chain to keep me going for a whole day so found a way to sharpen the chain on the mill so gave it away and went back to hand filing. I can touch up a chain for the 42"m bar faster than I can swap a chain AND my mill is designed so the saw does not have to removed from the mill to swap the chain. I still use a grinder very occasionally if I damage cutters to get them back to the same length. BTW I have not bothered with getting cutters to the exact same length since I started progressive raker setting. If I see a raker getting too long it gets a couple of extra swipes but that's it. As well as optimising the cutting speed progressive raker depth setting removes the need for exact same length cutters. I'm in no hurry when I milling so I touch up the cutters after every tank of fuel and swipe the rakers after every 3-4 tanks. That minimises the amount of pushing required and the load on the powerhead. It also means no worries cutting at 90º.

RE: Andy@clover:
Great looking wood. I ahem only ever milled one cedar and still remember how it was like cutting a knife with hot butter compared to the other stuff I mill.

I notice you are getting a few stripes across your cut.
48567990566_9daa2c75db_c.jpg
This could be a due to loose/sloppy mill, too low rakers, or, when you change your stance and ease up and then increase the forward pressure during that process, or all 3. If you slope the log this will provide a constant forward pressure on the mill even when you change stance and generate a smoother cut.

Instead of referring to just raker depth (eg 0.045") it's more useful to give to raker depth relative to the length of the cutter gullet which is what I call the raker angle. A stock 0.025" on a new stock chain where the gullet has a length of 0.25" this translates to a raker angle of ~6º. This is calculated by basic trigonometry but if this is not familiar to you just use the ratio of the "gullet width to the raker depth" which in this case is 10:1

When the chain is worn and say the gullet is now 0.45" and the raker depth is 0.045 the gullet length/to raker depth ratio will now be 10:1 and cut the same size chips at the same speed at the stock chain

If a raker depth of 0.045" is used on a new chain with a gullet of 0.25" this translates to a ratio of 5.5:1 This will be fine in cedar but will not work in harder woods as the chain will grab and stall the power head on any chainsaw (unless you have a a few tens of HP motor such as on a Lucas mill) When the gullet reaches 0.45", to maintain the 5.5:1 ratio this will require a raker depth of ~0.08" which leaves very little raker behind.

BTW lower gullet/raker ratios increase vibe, increase B&S wear and tear and seriously increase the risk of kickback if used out of a mill, so WATCH OUT.

The optimum ratio depends on many things like; Available power, width of cut, drive pin number, chain type, cutter angles, type of wood etc. On Aussie hardwoods I use ratio of 8.5:1 (880, 60" bar, 7 pin sprocket, full comp chain). When milling with a 441 with a 25" bar and Lopro chain I use a ratio of 8.5:1

Back in 2009 one of your countrymen experimented extensively with determining the optimum ratio for your softwoods while chainsaw milling using a 660 the lumber for a complete barn. He found a ratio of about 6.5 worked best for softwoods up to 24", with 3/8 full comp chain. Above that he found the saw would bog down and also started to generate too rough a cut.
 
Thanks Bob

Cedar is a pleasure to work with. So soft to cut but quite strong and super bug/weather resistant.
These slabs I left at 3 3/4" to use for heavy tabletop blanks. They are 32-38" wide !

The pic you reposted was with the “factory new” chain... hand fed do to no slope.
Yes, it got a bit stripey.

Usually I’ll lift a log up but this one is too big and heavy to even rock a little bit on the soft ground it’s on.

If you look at the second pic, you’ll see the improvement from filing rakers and also, I installed the winch I have but seldom use.
The winch proved to be super valuable in this case.

I finished that log up today. Found an old 16d nail lodged at approximately growth ring 40 of 68.
Did plenty of chain damage. Hand filed it clean and then finished that pass to remove nail.... not much else to do.
My cheapie metal detector did not find it ahead of time.... time to seek an upgrade. Although, It would not have helped much anyway that deep in.
It's the 5th time I've found iron on in the center of a tree on this land.... it's a drag.
48621535572_692960519d_c.jpg
 
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