Video-Sawmill Problems - Broken Blades and Wavy Boards

[mikedurland]

 :-[
http://youtu.be/xvpVoVkDcL4

[ladylake]

Doesn't look good at all, is that with new blades.  Does the mill have a movable  guide wheel on the right, it needs to be closer to the wood.  Take some pics of your guide wheels, something is wrong with them or your tension is way low.   Steve

[barbender]

It looks to me like you are pushing a dull blade, there seems to be a lot of rearward deflection. Is there a lot of resistance? 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.

[mikedurland]

It was old dull and improperly set blades.
Everything is fine now I just made a video of all the failures I caught on film so far... more to come!

[petefrom bearswamp]

Glad to hear you figured it out!
Poor sawing can be very frustrating,  been there done that.
Pete

[Bibbyman]

That's a different approach.  I tried hard to not show any problems on my videos

[hackberry jake]

That's hard to watch!

[hamish]

Very hard to watch, was about to sent you a couple of my freshly sharpened and set band, for your Norwood!

[POSTON WIDEHEAD]

was about to send you a couple of my freshly sharpened and set band, for your Norwood!

I was about to send you some business......but I held up.  :D

[kelLOGg]

Prior to the band breadkage you can see the band "jogging" in and out of the cut. That is a telltale sign that the blade is about to break. If you stop the cut and inspect the band you can find a crack probably in the gullet.
Hanging out your dirty laundry is a fast way to learn because you will get lots of feedback. Good for you for showing the video.

Bob

[mikedurland]

Prior to the band breadkage you can see the band "jogging" in and out of the cut. That is a telltale sign that the blade is about to break. If you stop the cut and inspect the band you can find a crack probably in the gullet.
Hanging out your dirty laundry is a fast way to learn because you will get lots of feedback. Good for you for showing the video.

Bob

I filmed a perfect example of "jogging" today. Here is the picture of the crack in the gullet. Video coming soon.

 

[mikedurland]

As you can probably tell I am not a professional, I am just a dude that cuts stuff for personal use.
Thanks for everyone's help and suggestions!

[mikedurland]

Here is the video of the "jogging" blade. It happened when I was cutting old dried out oak.
http://youtu.be/blhYk2QkL_4

[Cutting Edge]

Mike,

Others will benefit from your frustration...always helps for folks to "see" what is going on to understand and troubleshoot their own issues.  If a picture is worth a thouhsand words, a video is worth....................???

[mikedurland]

Mike,

Others will benefit from your frustration...always helps for folks to "see" what is going on to understand and troubleshoot their own issues.  If a picture is worth a thouhsand words, a video is worth....................???

I am happy to be the example of what NOT to do.  8)

[5quarter]

Mike...Steve is right. Your movable guide needs to be moved closer to the log. Make sure your guides are adjusted to keep the blade parallel to the bunks. pull a dull blade the moment you feel undue resistance in the cut. And as you learned, a properly sharpened and set blade is golden. excellent video, btw.

[beenthere]

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.

[mikedurland]

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.

 

[Chuck White]

I noticed that one of the issues was the blade coming off while backing up in the cut!

In the Wood-Mizer book (and probably others) it says disengage the blade before backing!

[mikedurland]

I noticed that one of the issues was the blade coming off while backing up in the cut!

In the Wood-Mizer book (and probably others) it says disengage the blade before backing!

Thanks Chuck... that makes perfect sense.

[grweldon]

Others will benefit from your frustration...always helps for folks to "see" what is going on to understand and troubleshoot their own issues.  If a picture is worth a thouhsand words, a video is worth....................???

I have already benefitted.  In my whopping total of about 10 hours operating a mill I have never seen a "jogging" blade.  Now I know what it looks like and know what it means!  Thanks Mike

[Delawhere Jack]

I would wait until the band wheels stop before opening the cover. A broken or thrown blade might move when you open the door and come in contact with a spinning wheel.

[mikedurland]

I would wait until the band wheels stop before opening the cover. A broken or thrown blade might move when you open the door and come in contact with a spinning wheel.

I didn't even think of that... thanks for preventing a future injury.
Normally I don't open the cover so soon I just wanted to get the spinning wheel on camera.
Definitely not going to do it again.

[Riggs]

Great videos, thanks for sharing

I would wait until the band wheels stop before opening the cover. A broken or thrown blade might move when you open the door and come in contact with a spinning wheel.

+1 once was enough for me as well.

[kgbond]

Mike thanks very much or all your work. It was scary and painful to watch but very interesting.  KGB

[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!