simonds blades breaking

[sabre_tooth]

hi everyone just started using my free simonds blades.sawed about 1500 feet and broke two blades before ever sharpening .thought something wrong with saw but put on timberwolf have sawed around 1000 so far with no problems.has anyone else had same or simliar problems.any suggestions would be helpful.  thanks

[Tom]

You don't say what your footage has been per blade, but 1000 is a pretty fair amount for any blade to be sawing without sharpening.

Have you changbed your setup?   The folks that sell timberwolf recommend a setup that won't work with a simonds.

Depending on your saw size and horsepower I would suggest that 600 feet would be a good estimate to pull a simonds for sharpening.  Some may run more and some less but they sure will break if you run them dull.

[sabre_tooth]

tom have sawn about 600 to 700 before blade broke

[Tom]

ignoring the fact that the timberwolf's are running ok, check for this stuff.
breaks at the weld = bad weld, misaligned weld....fault the blade shop.
cracks in the back of the blade = blade guides to far back from the blade.
cracks in the gullet = driving blade too hard, running dull

Too little pressure can cause heat that will deteriorate a blade and cause it to work harden

Too much pressure on a blade may stress it and "find" weak spots.

If you are using rubber blade tires (V-belts) a belt that is compressed to the point that the blade strikes the band wheel will cause the blade to break.  look at the band wheel for shiny spots next to the tire where the blade may be striking the metal.
Sawdust buildup beneath the v-belt will cause a vibration that may break a blade.

I can't imagine your having a manufacturig metal fatigue problem so look closely at your mill. If you are getting over a thousand feet on the timberwolf's then maybe you should stay with them rather than the simonds.

I've always had good luck with simonds on a 158" blade.

[Dugsaws]

I have good luck with simonds also I was using 1 1/4 in blades and they were getting dull at around 4-500 bdft and now I use 1 1/2 in and am getting between 800 to a 1000 ft before taking them off and sharpening

[D._Frederick]

S.-T.,

If you are talking about the "Free" blades from Simonds, they are hard back blades and won't give much life if you are running them on small diameter band wheels. To get maximum life they should be run on wheels close to 30 inch diameter.

How many feet per minute are you running them at? Do you stop the blade after each cut to reduce the run time?

[sabre_tooth]

the blades are running at 4800 spf .what type of simonds would be suitable for my mill. band wheels are 18.75 in dia.have been stoping blade in between cuts.these simonds hard backs should give more 600 feet even on small band wheels .should they not.

[Tom]

My experience has been with Simonds Red Streaks on a woodmizer LT40HD.  The blades are usually dull enough after about 600 bf to warrant replacement.  They can still be sharpend.  Pushing them beyond that point, work hardens the metal and they will break.  

Life of your band can be anticipated by the thickness of the metal in the band too.  The thicker the band, the more difficulty it has making the trip around the band wheel.  Bend a coat hanger back an forth enough and it will break too.  You have to find the happy medium between a thick band for accuracy and a thin band for longivity.  The most important thing concerning longivity and accuracy is sharpness.  Let any band cut dull and the stresses will destroy the blade body.

[beerguy]

I have not received mine yet. It has been 5 or 6 weeks since I sent in.  :'(

[gmmills]

I've used a 1 1/2 Simonds hardback on my WM and was well satisfied. I bought it from Cooks along 3 Munks blades. It was sharpened 12 times and was pulled when it became too narrow. Great flex life.  

 I did send for the free blades and received them. They sent me 1 1/4's. I haven't taken time to change guide rollers yet, so I haven't tried them. All things being the same, they should hold up as well as the 1 1/2's.

  I saw mostly hardwoods. A mixture of green and seasoned logs of the same species. I am lucky to get 350-400 bd ft between sharpenings.  Flex-life can be greatly increased by pulling a blade and sharpening before it gets too dull. Cutting with a dull blade puts extreme pressure on the gullets and will cause the blade to fail sooner.

[Gilman]

Speaking of bands in this thread, I'll add another question.  

A newbie here (24 hrs on the mill).  I bought a sharpener and have been sharpening my own blades.  About 40% of the blades had lost a sever amoung of set, down to 0.010" on a 1 1/2" x 0.045" bland.  While others have are running at about 0.020" offset after grinding.  I've been reseting them to 0.022 - 0.024" offset.

Should I expect this, or am I doing something wrong?  I think I pushed a couple too far after getting dull, but I don't think I pushed all 40% this way.

I've been cutting dry soft maple, white oak crotch 28" wide, 40+ year old railroad trusses, poplar and some fir.

[Tom]

That's what is nice about having a gauge on the setter.  You can see what you are doing instead of guessing.

A 21 thous. set is what most manufacturers reach for unless asked to do differently.  I shoot for 22 thou. before sharpening and expect the sharpener to drop the set a thous. on .042 blades. (You can expect to lose one or two thous. per sharpening.)

Sets in the 18 thous range work on hard wood.  The guys up north talk about 13 thou. for frozen wood, I don't use anything that narrow.

I find that sets above 24 thous. are too course, hard on the blade and rob horse power.


Set can be diminished by sawing dull, hitting something hard or running the blade against the guides.  You can also lose set by dropping the blade on the top of the cant.  A blade that is not cutting true is rising in the cut and may be changing the set on one side of the blade.

The most critical thing is to have both sides of the blade set the same, regardless of the amount.  You can play with the amount.  I find 21 thous. to be pretty universal and you may find a set that works on most of your woods too.

[D._Frederick]

Gilman,

Unless your saw teeth are razor sharp and the corners square, hard dry knots will take the set out. I find that the blades start cutting crooked with only 200-300 bdft, the teeth look sharp, but find the set down to the .012 - .015 inches/side. Reduce your feed rate and see if this helps.

[Gilman]

That makes sense Fredrick, I was going through some pretty hard knots, especially on the dry old growth fir beams.

So do you all grind after you've set your teeth to get a square face on the set teeth?  I guess that makes sense too.  Without a square face the tooth would be pushed back toward the blade body.

[Tom]

Gilman,
Most of us will set and then grind.  It saves time because you don't have to worry with the 'burr'.

It also gives a squarer profile than grinding and then setting.

There is a thread on here somewhere, where I drew some pictures to represent it.  I'll see if I can find it.

[Gilman]

I knew I hung out here for a reason.  8)

[Tom]

Here are four threads.  One has my drawing.

There are a bunch more way back but I didn't take time to locate them.  I may later just to prove I can find them.  

A search of things like ....configuration...tooth......face grind....back grind.......gullet........sharpener......set first......sharpen first...   and things like will probably find a bunch of good stuff in the sawmill topic and maybe in the General topic as well.

https://forestryforum.com/cgi-bin/board/YaBB.pl?board=sawmill;action=display;num=1019171666;start=7

https://forestryforum.com/cgi-bin/board/YaBB.pl?board=sawmill;action=display;num=1049699594;start=1

https://forestryforum.com/cgi-bin/board/YaBB.pl?board=sawmill;action=display;num=1068406267;start=8

https://forestryforum.com/cgi-bin/board/YaBB.pl?board=sawmill;action=display;num=1075309869;start=42

[Tom]

.

https://forestryforum.com/cgi-bin/board/YaBB.pl?board=sawmill;action=display;num=1016395382;start=0

[D._Frederick]

S. T.,

The hard back blades will give you more sawing speed if you have the power, because the beam strength  is greater and the blade will not defect in the cut as quick as the flex back blade. The down side is that they have less time going around the band wheels before they work harden and break. So buy one of each and see how they last and keep track of how much they saw. You can figure out the cost of board foot sawn for each blade.

[steveo_1]

I tried simonds and didnt think too much of em.They didnt saw as much as other blades and the teeth were breaking for no apparent reason so i used em all til they broke and bought some munkforsagors  and now no more problems :D