What's the best blade for for swingmilling?

[Captain]

With respect to the point that was made about the strobe knife slots dispersing water, we've studied and considered this.  The centrifical force and circular motion of the blade dos not allow the water to simply "fall through" the holes.  The water does in essence cool the plate when copious amounts are applied, but is is rather like the mud puddles warping hot brake rotors argument to suggest warping of the blade is possible by applying on one side when it is rotating and in the cut.  It may possibly if poured on a hot and stationary blade.   Water effectively cools by lubricating the cut,and also has positive benefits on some species in carrying/removing chips in some species.  It also keeps the fine dust down  .   We like water, but mill more often without it for one reason or another.

[LOGDOG]

I hope you guys don't mind if I disagree on a couple of points mentioned here.

First I have to say that the notion of my water trickle from my ASM dripping on my blade (which is spinning at 3650 rpm +/- reaching the other side of the blade (migrating through the stobes)in either the horizontal plane or the vertical plane is just flat out unlikely. Physics says no. The water lube system was so inefficient on my ASM that in the vertcal plane it wasn't getting water on it anyway. The drip mechanism was mounted to the armature with the blade. In the horizontal position the water would drip straight down onto the blade. But in the vertical position, that armature swings 90 degrees and now (because of gravity) the water still wants to drip down. Only problem - the blades not under it - it's to the side. A better system albeit more expensive system would be a pressurized system similar to WoodMizers Lubemizer which has the ability to irrigate both sides of the blade under pressure in both the vertical plane and horizontal plane. Then of course you'd have to figure out how to do it without it getting in the way while double cutting. Also I believe that with proper side clearance of the teeth to the blade the need for water becomes less.


As to strobes robbing hp. - I didn't have any to spare. With 27 hp I was already underpowered to pull a full 10" cut well. The rule of 5 hp per inch of thickness is hard to get away from. I know some have said that they could do it. If things were right I could do it in the vertical plane  if I would baby it. But I'd put money on the table that it's not feasible/ practical with that hp and a 10'' blade to pull those full cuts all day efficiently and have any amount of production. IMHO

Also, a rounded gullet (as slightly round as they may get if you're speaking of the edge of the blade where it meets the profile of the gullet) is not near as likely to be at fault for sawdust spilling over onto the body of the blade as is the geometry of the tooth angle changing and producing smaller chips instead of curls that are easily rolled out of the cut by the blade. If you're talking about the actual shape of the gullet changing then that's some cheap steel in that blade. Also, an excess number of teeth creating too much of a chip load can contribute to over loading the blade.

It's also still a material fact that the strobes interrupt the process of roll tensioning and leveling a blade. See the Armstrong website that I posted earlier in the thread. Note the different approaches to roll tensioning. I don't make this stuff up.

Also, if the strobes or slots were the answer why not have all the mills in your line up using them? It's been mentioned here that some didn't have strobes. Just thoughts that come to mind. Not trying to be argumentative I promise.

Here's my thought on R&D. I think we're it. The sawyers that buy mills, identify things that need to be improved, and either do it ourselves or tell the manufacturer about it and then they address it. Woodmizer is humble enough to say that their best ideas have come from sawyers running the mills and having ideas that ultimately endup on a blueprint and then in production on new mills. For progress to occur though someone has to say, "You know what? You're right, there's a better way to do that. Show me what you've got in mind." I think that's one of the good things to come from this thread. Here's a mix of guys using different brands of machines facing similar challenges posed by the law of physics. This kind of brainstorming can lead to progress.

LOGDOG

[woodbowl]

The rule of 5 hp per inch of thickness is hard to get away from.

This is another area that concerns me. If a half pass is made, (3" then 6") or (4" then 8") the second half pass that completes the cut takes the same amount of time, the same amount of HP, the same amount of feed pressure and has the same load sounds comming from the motor as the cut is being made ..... right? .... Or does it? ?

Is there a different geometry within the two process that causes either the first or second cut to be theoretically easier and faster to cut?

[Nate Surveyor]

I know it is more complex, but what about a HOLLOW shaft, with an air & water hole in the center of it. And, a few grooves in the mid portion of the blade, to allow the air and water to escape from the middle, some on one side, and some on the other.

And some 40 psi air pressure, with a little water added in, being fed into it.

Now, we have POSITIVE air pressure and water added to both sides evenly, and making a cushion of air on both sides of the blade. This provides cooling, and better blade tracking.

It might be a hair brained idea, but hey, not all of us are bald!

Nate

[LOGDOG]

Woodbowl,

  In your illustration the chip load on the second half of the cut should be near identical to the first half of the cut because when you come back for the second half there is only air in the first half. Almost as if it's not there. That triangle I described earlier in the thread would illustrate this because it's only the first 3 or 4 " down the tip to tip line (in either scenario you mentioned) that is actually doing the work. There could be a difference to how it feels if there were a misalignment of the blade present causing the first half of the cut to rub and bind on the face of the blade but it would half to be out of whack pretty good to get that. As to sound, motor load may sound the same but the harmonics of the blade may sould different. Liken it to a couple of pop bottles. One filled 1/4 of the way with water and one filled one half of the way. Each will produce a different sound if you tap them or blow into them. In the second half of the cut more of the blade is covered and sound will be produced and escape differently.

Nate,

   I like the idea of adding air to a cut. But then we'd have to address the compressor power issue in the portable application of milling. Stationary would be so hard.


LOGDOG

[Nate Surveyor]

2 gallon air tank on the Peterson, with a small compressor, that fills it, and as you enter the cut, pressing the mill, you activate the air valve, by your hand's pressure, to push it through the log. Seems do-able to me!

(Armchair General)

N

[LOGDOG]

Tagged on to the air idea ...I'm curious to see what DoubleCut has come up with to introduce more air into the cut.

LOGDOG

[Steve]

I"ve been sorta following this thread so forgive me if my input isn't relevant here. I come from a long background operating Mobile Dimension mills, which are essentially a bigger swingblade mill that doesn't swing.
These mills use what might be considered standard circle sawblades that use inserted teeth that are held it with a tooth shank. It is this shank that does the work of pushing the sawdust out of the cut. Has anyone tried to duplicate this in the swingblade design?
Maybe a just a hardened surface brazed into the gullet would help?
With the MD these shanks would lose a bit of their edge and need replaced periodically and it was obvious then how much they contributed to the sawdust removal.

Steve
 

[Captain]

Hey Steve, thanks for chiming in.  I have run blades on the swingmill with standard "B9" bits and shanks.  Honestly, the chips were a bit smaller than I was accustomed to.  Feed speeds were a bit slower and harder to push manually, the angle of the tooth was increased about 5 degrees on the ones that I used.  I should also mention that the kerf was .030" wider as well.

In an application where I was cutting a lot of nail ridden urban timber, It would be the way to go.  I prefer the speed and effort of the standard carbide tip setup to my angle preference, and being more dilligent with the metal detector.

Hey, I found those pics of us on the "big island" again the other day, that was a fun visit.

Captain

[Nate Surveyor]

I come from a long background operating Mobile Dimension mills, which are essentially a bigger swingblade mill that doesn't swing.

Steve
 

My little brother used to ask mom for a peanut butter sandwich, WITHOUT peanut butter!

We all knew what he wanted was a HONEY sandwich! (he was about 5 yrs old, and the baby of the family, and he ALWAYS got pampered!)

Maybe try one of Captain's blades, as he has done alot of research on this, and give us some feedback.

Right now, I'm running a 9" mill, but have part of the equation solved to bring it back to an 8" mill. when I get that done, I plan to TRY a number of different blades, in various woods, and develop my own opinion. One of Capitan's blades is on my list.

I am fascinated with stuff I cannot have!

And, I want a swinger that does it ALL!! He he!

Nate

[Steve]

Hey Captain

Yeah that was a nice visit.  To this day you are the only forum member that I've met in person. Sawmill John was close but I think the beaches got him. If you get out to Oregon you'll have to stop by again. My shop isn't much bigger here but this one has walls!

[NZJake]

Hey all,

Been here in the back ground reading your posts, makes for some interesting reading as always!

Here's what I think...

The first horizontal cut is less efficient because it is establishing a datum cut, the tooth may deflect up or down starving horspower. The second horizontal cut will be guided by the upper and lower surface of the first cut, focusing the horse power in a specific region (making it easy).

The water through the holes?
Sure I agree that the water will not jump through the holes to the other side of the blade due to the RPM, but when the blade is entering its cut the water is collecting at the edge of the entry to the cut, forcing into the hole. Once the water is within this area it can only got 2 places out the top or out the bottom. I've used both blades with/with out. One is definately better at cooling the blade.


The strobes do a great job at first, but then how do you sharpen them? The strobes will take more and more horse power as they get dull. Simply dress the strobe hole edges without using strobe teeth. This alone will emprove the cut.

Yep Petersons really did need that extra nipple at the end of the secondary to get the water to the vertical blade. They do have the nipple as an upgrade if any one is interested?

Cheers guys always reading. Just my thoughts.


 

[Captain]

Good to hear from you Jake, you've been gone too long.
 
Captain

[LOGDOG]

Here's a link for y'all that I came across. Very good stuff. Would be something good to save to your document file for reference.

LOGDOG

http://www.fpl.fs.fed.us/documnts/misc/circsaw.pdf

[Firebass]

Well I've had a chance to do some real sawing since I got my engine running on both cylinders. 

I  have to say it cuts like a dream now.  The only thing I can say about the cutting action is if I push it too fast and hit a knot or stress wood the blade sometimes will deflect a bit but I can shove it through the log at a ridiculously fast rate.    Today I was messing around and shoved the saw so fast in the log it made the Vee belts squeak   I really don't need to go there but wanted to see what "wood" happened .   I know I would have the power to add more teeth.  My guess is more teeth=more Gullet=faster chip removal=faster feed rate, at least till you run out of power???.   Soon as I can I will order one of the Captains blades.  It'll be fun to see the differance.  I don't think I like the Idea of a thin kerf circle blades because of the deflection issue.  In my opinion I think we should let the band saws keep the well deserved title of "Thin Kerf"

Firebass

[wtf]

I retip my blades some of the time( don't have the time to do it all the time) It is patterned after a Peterson jig and it works very well; better than my saw doc. They just bought me a blade because they messed up. I will be retipping all of my blades from now on. I get my tips from B.H.Payne right now and Peterson, anyone have any good sources?

Russ 

[scsmith42]

Russ, Timberpro is a FF sponsor and our resident Peterson expert.  They stock carbide tips, silver solder, flux, retipping fixtures - you name it.

Their carbide quality is a bit higher then the average wood carbide too.

You can get to their web site by clicking the link to the below left.

Scott

[wtf]

Scott, Thanks, I 'll get in touch with Timberpro.

[Drew b]

I've just registered and have read the thread here.  Been milling for about 22 years part time with a band mill and milling for 150 hours with a Lucas.  Western Red Cedar is no problem but the Fir can be tough.  Hate to say it but I'm delighted to see that others are having the same problems with blades having a mind of their own.  About ready to render my mill to the deep six but now have some faith!  Many great posts and hints and am greatful for the effort.  My problems have been in the vertical cut 8" deep and the blade pulling (away from the arbor) and binding.  Seems to be tension related.  Loss of blade tension is inversely related to my tension.  I've read that it takes only a small degree of heat to lose tension.  I agree that it would be interesting to put some water on the far side of the blade and will try some ideas.  Again, great to be here and thanks for all the input.

[brdmkr]

Hey Drew,

Welcome to the forum!