Video-Sawmill Problems - Broken Blades and Wavy Boards

[mikedurland]

Speaking of "hard to watch"...
http://youtu.be/yvIkZh_jNSo

[Delawhere Jack]

Grasshopper, you are learning quickly. smiley_chinese

Checking that the blade was still in  the guides after the bump, I mean. Did the same thing on my last job and did not check. Next cut the blade started to climb...... blade was out of the guide on one side.

[mikedurland]

I've also had problems in the past with pitch build up on the blade, that can make the blade hot and cause it to dive.

Like this?
http://youtu.be/RLPqzrVuxwo

[beenthere]

I'm curious Mike.
Why the uneven feed?  Seems moving steadily through the wood while sawing would give you some sound and feel to the sawing that would be useful. 
Or was it just for picture/video effect?

Watching the band set in the cut like in the video makes me think that a lot of heat is building up in the blade.

[mikedurland]

I'm curious Mike.
Why the uneven feed?  Seems moving steadily through the wood while sawing would give you some sound and feel to the sawing that would be useful. 
Or was it just for picture/video effect?

Watching the band set in the cut like in the video makes me think that a lot of heat is building up in the blade.

I was showing how the pitch accumulates on the blade and how it scrapes itself off when you stop.
I don't know if that is the best strategy or not but it is how I have always dealt with the problem.

[fat olde elf]

Hey Tarheel !  IMHO you would benefit from spending a few hours with an experienced sawyer on a similar piece of equipment, Lots of folks in this part of the country would welcome you and share their knowledge.  Just a thought...
Sharp bands are a must .........Say your prayers...

[redbeard]

Great videos Mike! I have experienced a majority of those mis haps. A rusty blade wont last very long  even after sharpening they are hard to set properly also. Keep them shiny and clean before you resharpen also those cracks are much easier to detect. You can hear a ticking sound when a blade develops cracks the louder it gets the quicker it will break. Plumb guide rollers and a level blade between the rollers with recomended deflection is the key element. How is your tracking? Spin wheels forward and backward at full tension blade should stay true both directions. Norwood made some tough mills especially older ones. Good luck on your milling ventures.

[bugdust]

Good for you Mike, like Bibby said, most of us are ashamed to show our goofs. Photos and videos are worth more than just words .... in certain cases.

[delvis]

Mike
That video will help explain to others how things can go awry, so it will be helpful.

When you put on a band, and bring up the tension, does the band run without touching the backup guides? I believe the band should run free and only touch the backup guides when in the cut. Some have a roller, and some have a ridge on a roller.
Just wondering, as you seem to be getting early band failure.

The bands are not touching the ridge on the back of the roller until cutting. The band failure in the video is mostly due to reusing old rusty blades over and over again. The mill has been in the family for almost 20 years and it has been modified and rigged-up several times so I am surprised it still works as good as it does.

 

Hey there,  Keep in mind that the blade should not run against the back of the roller guides at all even when cutting.  A properly set, sharp blade will actually want to pull itself into the cut.  A blade running agains the roller guide will heat up too much and develop cracks from the back of the blade.  Taking videos of your issues was the best thing you could have done I think to let people see what was going on.  Good luck.

[beenthere]

............  Keep in mind that the blade should not run against the back of the roller guides at all even when cutting.  A properly set, sharp blade will actually want to pull itself into the cut.  A blade running agains the roller guide will heat up too much and develop cracks from the back of the blade.  T..................

That is interesting. Tell us more where you come by this info. I may be misunderstanding ...........wouldn't be the first time.

[5quarter]

Beenthere...Delvis is correct. The flange is only there to ensure the band does not track off the bandwheels. A sharp blade backs up on the roller guide maybe 1/8" while in the cut. if you find the back of the band running against the flange while in the cut, you're feeding too fast, your band is dull or perhaps your tension has dropped off. Some mills, like the D & L double cut, dont have or need a flange on the back of the roller guide. Also, sufficient down bearing on the blade is enough for properly aligned roller guides to obtain full control of the band.

Awesome thread Mike.

[delvis]

............  Keep in mind that the blade should not run against the back of the roller guides at all even when cutting.  A properly set, sharp blade will actually want to pull itself into the cut.  A blade running agains the roller guide will heat up too much and develop cracks from the back of the blade.  T..................

That is interesting. Tell us more where you come by this info. I may be misunderstanding ...........wouldn't be the first time.

Sorry about taking so long to reply.  Been busy sawing.  I learned this from the guy that sharpens my blades.  He has a lot of time as a sawyer and he will tell me when my blade alignment is off based on the 'tracks' the roller guides leave in the blade metal.  I have also heard the same thing from Wood-Mizer and Cooks manufacturing. 

[Chuck White]

Hmmm!  I thought the flange was on the back of the roller guide specifically to "more-or-less" push the blade into the cut.

Live and learn I guess.

Good post Mike.

[customsawyer]

Mike the only thing I might add is that when cutting older logs like the ones in the video the amount of water you are running will make the sawdust start to swell thus causing heat in the blade and lowering your blade tension. ;)

[mikedurland]

Mike the only thing I might add is that when cutting older logs like the ones in the video the amount of water you are running will make the sawdust start to swell thus causing heat in the blade and lowering your blade tension. ;)

Thanks for the insight!