Blade issues

[sawdustmaker123]

Hello all
Ive been having a few issues with my blades, and hope to get some insight.
For some background:This is my second summer trying to earn money with a mill.  Last summer I ran portable on a hd36, and this year I have parked the mill and am running a timberking 1600.  There is usually one helper, and I am looking at edgers. In the winters I go back to school. Loving the hydraulics and roller guides!

I am finding that the resharpened blades are lasting 1/2-1/4 as long as new blades.  I use about 2-3 new blades per day or 5-7+ resharpened. I have tried Morse regular blades and bimetal, they last a similar amount of time and cut similar new, and cut equally poor resharpened.  I don't think the teeth are blued, as I have done that and seen what it looks like.  Trying to just skim the teeth.  
I was wondering if a finer wheel would put a keener edge on the cutting edge.  I also haven't got the profile dialled in, so sometimes the back(gullet side?) of the tooth isn't sharpened.  However, I haven't found it to have a major effect on cutting performance.  
I recently purchased 10 Simmonds blades. They are cutting better in pine(ewp) (can push them harder and they cut straighter) but they wave in hardwoods (red oak).  Im thinking too much hook.

The second issue is Ive been having a tough time setting them. Im using a timberking sharpener and setter.  I find it tough to get a consistent set from one side to the other, and even from tooth to tooth there is variation.  Even on blades I thought were set well, I get wave and dive.
     I would describe wave as slight dips around knots or other defects, but the blade quickly recovers.  You can reduce the feed speed on a waving blade and keep going if needed.  
Diving blades will dive multiple inches, and don't want to recover. I have made the mistake of trying to press on, but they will keep doing it, and I have not found out how to predict it.  I haven't observed any differences in the set or anything when resharpening these diving blades, which makes me nervous to put them back on the mill. 

I have been thinking about taking the time I spend sharpening and simply mill for another hour or two, and pay my local guy to do it.  I think I will send him some and see how they turn out.  However, he has a 4 week lead time which means keeping quite a few blades on hand.



How do you guys who cut for a living deal with your blades?
If this should have been broken up I apologize, and I look forward to your insight.
Thank you, Evan

[Bruno of NH]

I'm not new to milling 
I saw for a living with a Lt 40 wide
I just started sharpening my own bands.
I use profiled cbn wheels dry.
I'm learning to take a little at a time and they cut fine.
I use a single tooth setter and I adjust as I go around the band. I'm finding thev more I use it the faster and more accurate I get at the setting. At this point I try to get 23° to 24° of set.

[Bruno of NH]

I also think you should check you alignment on your mill.
3 new blades a day and 4 re-sharps is alot of blades in a day.
I have been Sawing 12',14'and 16'long pine logs with 40" to 45" small ends with 2 sharpened 7/39 .055 × 1.5 bands a day .

[terrifictimbersllc]

I'm wondering whether the resharpened blades are sharpened correctly.  Red oak is in the top of woods easy to cut flat.  

I use a CBN grinder (with oil) and dual tooth setter (set is somewhere between 025 and 030 usually.  Resharpened blades cut like new ones.

Suggest you compare what your resharpened tooth tips look like under a 10x hand lens, with tips of new blades under 10x lens. Should  look as good or better. Ground square and no shiny area where back of tooth meets front of tooth.

Ps agree that alignment factors should be ruled out. 

[sawdustmaker123]

Thanks for the initial feedback.
I feel pretty good about the alignment because with a good blade the mill cuts pretty good. I do find that maybe 2-3 blades in a new batch of 10 will dive right out of the box.  This could be a sign of poor alignment, but the remaining blades show no indication at all.   I try to keep the blade level with the bunks, I have found that if the blade is not level at all it climbs/dips.  The blade is about an 1/8 off the back of the rollers when not cutting, and I have about 1/4" down pressure.

I may not have made it clear, I meant 2-3 new blades OR 5+ resharpened blades in a day.  Thats very roughly 3-600 bd ft per blade.  (They aren't big days yet, still working out hiccups.)

With the morse blades the oak cut great.  You could push the feed speed until the motor really slowed down, and the blade would stay straight.  Its only with the new Simmonds blades that I have the issue, so I've been thinking about different blades for different wood.  

The 10x magnifier sounds like a good idea, it would be very interesting to compare.

Our Norwood single tooth setter let you be very accurate, although it was also very tedious. 
Thanks

[Southside]

Are you running a debarker? I will normal get 800BF +/- on a new band in logs. I re sawed 5,000 BF of cants the other day on a single new band and only removed it after I knocked it off, she was still sharp and cutting flat.

Bark has an amazing impact on a band.

[JoshNZ]

It does sound like an alignment issue, or tension possibly (do the vernier check)? Pitch buildup? I found oak to really gum up the band and needed a lot of diesel. That's a lot of bands to be duds in each box. The only thing I've ever found wrong with a band out of the box is a rogue tooth, where I've prob snagged it while handling.

If it makes you feel any better I'm cutting overlay flooring in acaica at the moment, no debarker, I get about 100bdft per band...  smiley_cry

[sawdustmaker123]

No debarker.  Was planning on an edger next, but it sounds like a debarker could pay for itself pretty quick.  
The oak doesn't seem to cause too much build up, the blades are usually clean using only water.  

The dud blades may have been my fault, as I had a really knotty oak log when the first one dove.  I then tried 2 more that both dove, and I think in hindsight the blades simply weren't set up to deal with wood like that.  Im guessing that the reason they cut nice in pine is an aggressive hook, and the same hook caused the issues in oak. (No personal experience playing with different hooks, only what I've read)

The Morse blades only dove in the pine, and the Simmons blades only dove in oak.  Ill keep tabs on how the next batch does.  

The vernier check is interesting, looking forward to trying it Monday. Ill try increasing the pinesol as well, I know some of the blades had some minor buildup on them in pine.

When you guys talk alignment, where exactly are you looking? How level the blade is to the bunks? Or just look everything over.

When cutting pine, are you guys able to push the blade until the motor bogs? Or does the blade always wave first?  Im sure bigger motors change things, we have a 27 horse Kohler.
Thanks in advance

[JoshNZ]

Alignment is all in your guides. Band should be level with the bunks when you put a straight edge on the band, across a non-set tooth. Guides should be pulling down ~1/4". And guides should point slightly toward the incoming band direction, i.e. if you look down from above at the flange of the guide there should be a hairline of daylight on the incoming side which ensures that when the band deflects into the flange it contacts the side of the flange that is pulling upwards into the guides wheel face, if that makes sense... If you've got that backwards that will give you grief.

I don't know much about other lubricants but never seen anything diesel won't wipe clean after a couple of drops. Be worth trying in a squirty bottle for your own interests sake.

You should be able to use all 27horses in clear pine with a sharp band, I'd say. Maybe not while going through knots.

[Bruno of NH]

I use woodmizer t7/39.5 in all the non frozen red oak I saw with not a problem Sawing flat.
T7/39.5 has a tall tooth that really bites in .

[Southside]

I have tried every possible concoction of blade lube possible and even went so far as to having a chemical company make up a few different potions in hopes of finding the magic elixir which I would sell for a gazillion $$.  Just like the song about settling just a few miles from home after all of his travels I settled on diesel fuel for band cleaner.  Nothing beats it, I use so little the cost is nothing.  With water / soap / magic potion mixes I would use a WM jug a day, with diesel fuel I use a jug in about three weeks and there is no smell, no mess, no drip, zero pitch on the band, and no band drive issues from build up.  It simply works.  

[YellowHammer]

You should be able to stall out that motor if you get careless and push too fast, and still cut straight.

My guess is that you are not completely sharpening the tooth corners, just the flats.  Use a magnifier or your cell camera to inspect your sharpening.  It's extremely important to visually inspect your sharpening and setting so you can dial them in.  

Also, how many sharpening are you doing, are you out of the heat treated zone of the band and sharpening into softer base metal?

A properly sharpened band should cut faster, straighter, and even last a little longer than a new one.  



 

This is improperly sharpened.  A little bluing and dull corners.  




 

So is this one.  Not ready for prime time.




 
This is a well sharpened tooth.  Which picture does your look like?

No band ever should "dive multiple inches" without there being a serious problem.  Even a dull as a rock, but well set band should not do that.  Even if it did, there should be black smoke coming from the kerf and about to catch fire.  Once that happens, the band is dead.  Throw it out.

There appears to be multiple issues.  A quick test:

With the band off, extend you blade guide arm in and pull and twist it very hard, up, down sideways, every direction.  It should not move relative to the head at all.  It should feel welded on.

[JoshNZ]

I used a brand new band today on the same job/acacia boards I've been working on, it definitely lasted longer than my resharpened bands. Ive got a little 20x loupe, I'll be having a look next time!

I wrote a post out one day with a question then never posted it because it seemed silly but here goes.. are bands that have been resharpened then hung on a wall nail for a month or two as sharp as bands that were sharpened the night before lol. I swear my bands fresh off the sharpener go better than those I sharpened then never got around to using right away.

Is there a microcorosion effect that reduces the keen edge of a tooth?

[ladylake]

 
  Are you sure your getting enough set.  Lately I've been getting new  blades sometimes that come with not enough set, I have to set before using them.  Red oak cuts easy and straight until the blade gets dull.  I can make my diesel smoke and still cut straight, dont be lugging that Kohler down too much as it wont cut straight if you do   .  Steve

[sawdustmaker123]

Thanks for the advice all.  With the morse blades I can do that, YellowHammer.  At one point I was too slow to chop my feed speed and nearly stopped the motor. Whoops! its just these new blades that won't cut as straight.  Im thinking I will stick with the morse blades for oak, and the Simmons for pine.

It is knotty pine, so I think Josh may be right.  The blades are good in the clear stuff but those big whorled knots, especially closer to the centre is where the blade wants to dip.  If I back the feed speed off a little they go straight through.

Ill have a close look at the teeth after sharpening tonight, very possible the corners are rounded.

Ive noticed that about blades Josh, seems like if they sit around for a bit they go dull just from time.

The set may be part of the problem.  I have been setting from about .020-.027, just kind of playing with different sets.  
Thanks

[Geeg]

With the band off, extend you blade guide arm in and pull and twist it very hard, up, down sideways, every direction.  It should not move relative to the head at all.  It should feel welded on.

Noticed mine had a lot of play in it, thought it was normal. Thanks for the info

[YellowHammer]

 

[sawdustmaker123]

Not sure if this counts as reviving a dead thread or not.
Anywho, been incorporating some of your suggestions this week.
The alignment looks good, and the guide arm is solid.  More so than I expected in fact.

With that I propose 3 questions (indented), to which I would appreciate your insight.

I tried to put more time in to the blades, to see if I just wasn't taking them back to 100%.  It took 3-5 trips around the sharpener to get the teeth ground consistently.  It seems the factory sharpen has high and low spots, as my sharpener hardly touches some spots and then blues others.  I haven't decided yet if it is my sharpener or the blades.  
          Have you who resharpened noticed inconsistencies when sharpening new blades?

I then set a few to .023-.025 and a few around .027.  They seemed to cut straighter, but they still dipped around big knots and crotches.  It also took more power to cut at the same feed speed,  and they dulled faster than new.


          Any ideas on why they are still dulling? I sharpened them until the teeth looked nice and square.

Secondly, I did not expect the blades to dip as I have now touched all aspects of the blade performance (as far as I know).  They have been resharpened and reset.
          Is there another aspect of blade performance I am missing? Or do some brands have less stiffness or 'X factor' which resists waving?
I have seen some people mention that the blades need to be hammered or rolled to undo the effect of travelling around the band wheels, but thought this was unnessecary for 1.25" blades.


Thank you for your insights

[KenMac]

From what I understand about the rolling of blades it shouldn't be necessary if at all, until after several sharpenings ( at least three). It supposedly takes a while for the anticlastic curvature to make itself known. I have a Cook's band roller and have tried it, but haven't seen any conclusive positive results. That doesn't mean that it doesn't help when needed, but I'm not sure mine needed it when I rolled them. I kinda doubt that's your issue unless you do have a bad batch of blades, which is doubtful.
 Supposedly you take a straight edge and lay across the blade and check for curvature on the outside of the blade and roll it in two to three positions to relieve that stress and return the blade to nearly flat across it. Cook's had a video about this but it has been pulled apparently when they stopped making and selling the rollers.

[ladylake]

 What hook angle are you sharpening at.  
 Are you sure your at  1/4 down pressure
 Is the clamp on your sharpener holding the blade good, not letting it slide back a little when the push arm goes back or push forward when the stone hits it.
 On the first sharpening is it hitting the whole gullet or just the face and bottom or the face and the top tip

  Steve

[sawdustmaker123]

KenMac: I had thought something similar, I didn't really think it was a factor on the small blades.  Ill check some when I sharpen.

Steve: I believe it is 8-10, I will check when I sharpen.
I haven't measured, so it could be off
It holds pretty good. I have caught the blades sneaking back, but tweaked a few things and believe I have it under control.  
It doesn't hit the whole gullet.  I haven't been able to find a setting that gets it.  Typically the stone lifts up right before the tip of the tooth.  I played a little bit with setting the stone higher, but then it doesn't get into the gullet much at all.  After 2-4 passes it is pretty consistently cleaning up the full tooth.  

I'm thinking I'll try setting a bit heavier.  I used to keep it at .023-.025 because I was scared of cutting too much wood, but i'm thinking i'll try like .030+ and see how that goes.  The latest batch hasn't done any serious diving which is good.  Only some waving around knots, and so far only on the Simmons blades, which waved new as well. How strange.  

It also seems like they are staying sharp longer as I do a better job on getting square teeth, so thank you for that recommendation. 
Much obliged all, thanks

[ladylake]

 
 I'd get it setup so the stone hits the face of the tooth and the tip on the way up. That will make the gullet a little shallower after 2 or three sharpening's  which saws straighter.  Don't worry about the bottom of the gullet on the first or second sharpening.  99% of the time I only run my blade around once with good results..   You might want to try less hook also, that takes a little more power but saws straighter.  Make sure on the down pressure, it's important.
 To adjust it , back off the guide rollers, then with the blade tensioned get the blade level with the bunks.  Then apply 1/4" down pressure.  Steve

[sawdustmaker123]

Right on, good to know.  Thank you Steve.  I was playing with settings and found I can be a little more aggressive with the sharpening, which will speed the process up.  I was worried if I go to shallow the gullets would plug up?
Thanks

[Stephen1]

The first thing I check with wavy cuts is Drive Belt Tension, especially if the mill or drive belt is new.  Then blade and mill alignment. I do not believe setting over 30th will make much difference. 

[JoshNZ]

I've played around with set too, .030 and slightly over. Great way to make a lot of extra saw dust and burn some extra fuel. Not very useful for much else.