I got a new woodmizer blade today & I ran it for a test run

[Rod]

I thoughtI'd try the 1 1/2'' wide blade and I know it's ony 1/4'' wider but it seems to cut twice as fast as the 1 1/4 ones do.I could bog the motor down with this blade and not get a wavy cut.

[Bibbyman]

We tried our first 1-1/2" blade about 5 years back.  We were cutting big oak logs into 2x6s.  It just kept cutting and cutting and cutting.  Then at over 2000 bf it broke.  I told WM about it and they told me I should have removed it at maybe 700-1000 bf and had it sharpened.  I told them I was happy it broke.  2000 bf and no resharp!  That's 1cent/bf.  Ok by me. (I think the blade was about $20 or less back then.)

We've tried a couple 2-3 1-1/2" .055 on our LT40HDS25E and they cut like a house-a-fire!

We're still runing 1-1/4"x .045s.    We've just got so many 1-1/4" we've not changed over.

[Rod]

Bibbyman,I'd  like to try one of there 2'' bands ,it might even cut faster the the 1 1/2''.Are the teeth bigger,is that what makes them cut faster?

[Bibbyman]

Rod,  you lost me there...    I'm pretty sure Wood-Mizer does not make a 2" wide blade or a mill that is set up to run it.  (Although they make 1-1/4" and 1-1/2" blades for other mills besides WM.)

Not sure why they cut better.  They are thicker for one thing and cut a wider kerf.  The extra width gives them more stiffness.  The teeth look to have the same spaceing and shape.

[WH_Conley]

How do the gas engines handle the 1 1/2 blade?

Do they pull harder than the 1 1/4's?

How does production per hour compare?

Easy to tell I don't know nuthin.

[Fla._Deadheader]

  We have 2--1½" WM Blades. I keep the set at .024 and we use them strictly for cutting Heart Pine or Pitch Pine or Fat Lightered. Cutting rate is the same on our 24HP Honda.

  We use plenty of water and the blades cut very flat.   When they get dull enough, they will still dive, if you go too fast.

[Rod]

OK Bibb,I thought they had 2'' blades,guess not.

[Bibbyman]

For sure no harm done...   I thought maybe they snuck another new product in on me without telling me.  I went out to their web site and looked thrugh their blade selection and didn't see a 2" listed.

An 1-1/2" blade is a tight fit in the LT40 housing.  I doubt if a 2" would fit even if it'd work.  Then would the wheels have to change?  I don't know about the LT70 and LT300.  Their housings look a lot larger and deeper.

[FiremanEd]

Rod,

 We're running 30hp hrs of electric so the power will be different but the longevity shouldn't change much.

 Look at WM's 4degree blades. When we were running 10 degree's we had to change blades out every 2- 2.5 hrs (avg. 800bf/hr) and the blades "needed" changing. When we went to the 4degree blades we were doing that at first and then started noticing that the blades were cutting just as good at 3 hrs as they were when new. After a lot of testing, and a LOT of blades, we found that, for us, the 10deg. cut like a bandit for about 30 minutes and then gradually loose ground till you change it. The 4 deg. blades cut great, but slightly slower than the 10deg for that 1st 30 min, the difference is that the 4deg. continue to cut at the same rate for hours. Woody routinely runs them for 5 or more hours (assuming we didn't hit anything) and they're still cutting great. We cut mostly ties and our rule of thumb is that once down to 9" cants the mill should cut at "full speed ahead" without bogging, when it starts bogging then it's time for a new blade. A lot of guys talk about over stressing the blade by doing this but we're averaging 3 blade runs ( 2 sharpenings) for 12-15 hours of run time off of a blade, financially that's better than getting 6 sharpenings on the same blade if you change it every 2 hrs, you'd get the same amount of run time but would have to sharpen 4 extra times and had the down time of 4 extra blade changes.

These of course are just my thoughts and findings.... everyone has differing opinions but I think a lot of people are missing out by not trying the 4 degree blades. We only go back to 10deg for poplar and pine. All aok, hickory, maple, gum, sycamore and such are cut w/ 4 deg's.

Eddie

[FiremanEd]

Oh yea, Biddy

Tell Mary that was a great article in the WM mag.

[Bibbyman]

A number of people already have....

http://www.forestryforum.com/board/index.php?topic=13730.0

[Rod]

FiremanEd ,i dont know which one i got.But i looked at the 1 1/4 blade teeth and they look the same as the 1 1/2 teeth,so i figure the reason i can cut faster is because the blade is stiffer on the 1 1/2 which makes sence  to me.The invoic says it a .045 so i dont think it cutting anymore  wood then the 1 1/4.

[Gilman]

The pitch is the same on the 1 1/4" as the 1 1/2" WM blades.  I little bit of extra thickness goes a long ways.

The 1 1/4" are something like 0.035" thick right?  If so, a 1 1/2" X 0.045" blade is 2 1/2 times stiffer.

If you doubled the thickness of a blade of same width, it would be 8 times stiffer.

  I got to use my

Grafting Calculator !!!

 

[gmmills]

    WM manufactures 1 1/2" blades in three thicknesses 0.045, 0.050, and 0.055.  All have 7/8" tooth spacing. The 0.050's are made in the 10 deg tooth profile only. The 0.045's are offered in 4, 9, 10, and 13 deg profile. The 0.055's are offered in 4, 10, and 13 deg profiles.

    I used 1 1/2" 0.045's for a long time on the old Lt 40 super with 42 hp kubota.  Tried 0.050's and didn't seem to get as much flex life. With the smaller band wheel the 0.45's gave me the best all around performance.

    I always used these guidelines when choosing blade width's and thicknesses. Going to a wider blade in the same thickness requires more hp. Going to a wider and thicker blade requires even more hp to see real gains in cutting speed and performance. According to the WM blade hand book 0.045' are recommended for mills with engines 16 -42 hp gas/ diesel. The 0.050's and the 0.055's are recommended for 51-62 hp gas/diesel engines.

     I'm using 1 1/2" 0.55's  10 deg and 4deg blades on my LT70 . They work great with the 62 hp engine. The 0.055's are getting good flex life with the 70's bigger blade wheels.

[woodbowl]

There seems to be a separation point in performance between the 1 1/4" and the 1 1/2" blades but only if the HP increases respectively. For instance, my 25hp Kohler produces less bfph with a 1 1/2" VS a 1 1/4". However, some Mfg claim that their mill with a 62hp Perkins cuts at the rate of 800bfph. With my current set up the best days may deliver 300 bfph, and that's cookin'. This is a tremendous difference in production. Can an 1 1/2" blade really cut 800 bfph without wavy cuts and be consistant with 62hp? In order for me to push an 1 1/4" with 25hp and cut straight wood, I have to stay on top of every detail when sharpening and setting. Then there is the occasional blade that just won't do right, never did, even when new.

[Rod]

I have a 10 hp eletric motor on my mill and all I can say is that I can push the blade though the wood alot faster with the 1 1/2 blade.

[FiremanEd]

Woodbowl,

Yes the 1.5" will cut 800bf/hr w/ straight boards. You're absolutely right on the fact that some blades, and I can't for the life of me figure out why, wont cut. New out of the box or resharpened they never do cut as good as the rest but on avg we get 800+ and w/ the 4deg. are averaging 4-5 hrs run time per sharpening.

Eddie

[woodbowl]

FiremanEd,
    What king of mill are you running? How much HP and what engine? The separation point that delivers 500' plus bfph of straight lumber has got to be an inherant stability property associated with high HP. I can push a 1.5" blade with my 25hp Kohler and sometimes it will wave. I think it was Tom that made a statement in a post somewhere about "raw ripping power". This is a very substantial increase in performance. My excuse for not upgrading to a bigger bandmill has always been, If I get wavy cuts now with 25hp, running a 1.5" blade, it's still going to wave no matter how much HP  I have running the same blade................................SOMBODY SET ME STRAIGHT!

[gmmills]

   Ed,

      The reason for some blades to not cut good out of the box or even after they are sharpened and set is the issue of blade body flatness. The blade bodies need to be flat to slightly dished on the roller side of the blade. This allows the blade to be guide by the roller guide across the entire surface of the blade. If a blade is not flat across it's width from edge of the gullet to the back of the blade it will not cut straight. WM has a number of quality control checks in place to monitor the blade body flatness.   Even with all the checks still some come through with blade bodies not flat. I have had boxes of 10 blades that are all flat and run great out of the box. I've also had boxes that two or three blades that wouldn't cut straight. I have a Cooks blade roller to fix the blades that are not flat. I wouldn't be with out this tool. With the guide system on your 300, no roller guides just sandwich guide blocks with a backup roller bearing, the blade flatness issue is important.

Woodbowl,

    A blade needs to run at a near constant speed in order to cut properly. When you push a blade the engine rpm generally drops. This in turn slows the blade speed down. The blade will wave. You might want to install a tach on you engine and monitor the rpm's while sawing. VA Sawyer did this and I think he told me he loads the engine down 100 rpm's while cutting and has good results . You can still work the engine to get the maximum production and the blade will saw straight.

[FiremanEd]

Woodbowl,

We're running the LT300, it's got 30hp electric running essentially the same head as the LT70 w/ the 62hp Cat engine. (30hp of electric is comparable to diesel power in the 60's)  There are some differences in the heads but not major ones.

Waves in the boards, for the most part, come from slow band speed in relation to your feed speed. There are a lot of factors that contribute to slowing blade speed like wood type, cant width, blade thickness, width, hook angle, set and others. When one part of the equation is off the motor starts to bog down and blade speed slows, thus getting the blade speed to feed speed out or perportion. That's when you get wavy boards. This is somewhat a point of critical velocity for that specific mill setup. Increasing HP will allow you to increase feed rate and still maintain blade speed, but the factors listed above, mostly the band it'self, become the limiting factor at a point of increasing HP.

I started w/ a 18hp diesel on our Timber Harvester running 1 1/2 blades, we cut a LOT of lumber w/ that set up but when we upgraded that mill to a 30hp 3-phase we increased production more than 50%, the motor change was the only change made to the mill to get that increse. We later upgraded the hydralic pump to a higher gpm pump to get quicker movements of the clamps, turner & travel speed (on return) and this increased production a little more. On the Timber Harvester the drive motor powers everything. On the LT300 the only thing the drive motor powers is the blade, there are other motors for all the other operations. Therefore we have more torque available to keep the blade speed up and this allows for even faster feed rates.

WM has once again stepped the thin kerf band mills up another step by developing the thicker .055" x 1.5" blades which can stand much higher torque/hp and still cut absolutely wonderful lumber. This blade and the higher HP mills that they now offer are producing lumber at rates that was undoable just a few years ago.

There are a lot of factors that play into what blade is best on what mill. I've found that if you listen to the guys on here who have the same or similar mill as you and your mills manufacturer they'll point you to the best blade types without having to re-invent the wheel.