bandmill blade questions

[chainsaw_louie]

My band-mill came with 10 blades ,  a electric band sharpener and a saw-blade tooth setter.  All the blades have been sharpened several times by the previous owner.  I've been using these blades  to cut hardwood but have been getting more wavy cuts than I'd like, despite going slow.

- Aside from cutting straight, what are the checks to determine when a band-mill blade is sharpened and set correctly ?

- Is there a way to tell when a blade is no longer able to be sharpened and set so as to give straight cuts and should be disposed of ?

- Is sharpening a band-mill blade to be 'as good as new' or to consistently cut straight and fast ,  difficult and time-consuming to learn how to do?

I'm thinking it would be instructive to order some new blades just to compare them with the used blades I have and learn the differences between old and new blades.

[doc henderson]

I think that all sounds right.  I have a setter and sharpener and still working the kinks out.  did the setter come with a micrometer to check set?  Some new blades will also let you compare the resharpened blades.  Other with experience will chime in, I am sure.  

[woodman52]

As Doc Henderson said... Also there are a lot of reasons for wavy cuts including going to slow.  Some new blades are a way to check if it's your blades.  If not do a search for wavy cuts, there's tons of posts 

[GAB]

CLouie:
Recently MagicMan posted an entry about the width of the gullet on a blade that I think would probably help you.  My thinking is if the gullet is too narrow the rollers might be taking the set off of the top side and that would not be a good scenario.
Also what brand blades are you using?
What brand and model number sharpener and setter are you using?
What is the brand and model number of your mill?
Never having sharpened or set a blade I won't be of much help to you but with answers to the above questions and possibly many more some one has probably been where you are and would be willing to help you and most probably others on the FF.
GAB

[SawyerTed]

Here's a link to Woodmizer's Thin Kerf Bandsaw Blade Handbook.   

Lots of good info about blades and geometry etc.  

https://forestryforum.com/board/index.php?action=dlattach;attach=4532

Much of the info can be used with blades from other sources besides Woodmizer.  

[barbender]

Sharpening and setting blades is even trickier than running a mill. You're shooting yourself in the foot trying to learn both at once. You're dealing with so many unknown variables, you'll never be able to accurately troubleshoot issues. 

Get yourself a box of new blades. That will accomplish a few things. One, it will eliminate one variable and you can isolate issues to the mill itself. 

Secondly, when you are learning to sharpen you will be starting with blades that someone else hasn't already screwed up. 

In my experience, there aren't many poeple that can sharpen and set blades correctly. The majority bungle them. And learning on pre-bungled blades would sabotage your efforts in every aspect. So get those new blades.

[jpassardi]

Good advice from BB above. Personally I find setting to be more tedious than sharpening.

[Bradm]

This is one of those situations where a picture is worth a thousand words.  

All the blades have been sharpened several times by the previous owner.

This is an area of concern (for lack of a better word).  I've lost count of how many bands I see that someone has "sharpened" but can't get to cut properly.  So far, almost all of them have one of the following two things in common (1 is by far the most common):

 1) Improper tooth face grind resulting in either a dubbing effect (lower hook angle than intended due to band being pushed away by the grinding wheel) at the cutting edge or a radius so large that your hook angle is negative
.
2) All the set has been ground out of the teeth

[chainsaw_louie]

The grinder I have is a Woodland Mills Grindlux 4000.

Tooth setter is also Woodland Mills.
Mill is LT40.

I looked along the length of one blade but didn't see a brand name or model number of the blade .

While I wait for new blades , I'm going to set up the sharpener and setter and see how it works and how precisely I can sharpen and set the teeth.

It looks like the setter with its digital dial micrometer can also be used to measure the set of the teeth without moving them.

[doc henderson]

do not fiddle much with the sharpener till it is set up.  Might be nice if it is really close to where it needs to be.

[barbender]

The basics of band sharpening with a drag type grinder (which yours is) is lightly touch the face of the tooth as the stone comes down, and then lightly grind the remainder of the profile. You may or may not be able to get it in one pass, but keep it light. It's better to grind light and miss some of the profile, and do a few passes. I focus on the face of the tooth, and the back of the tooth. Im only worried about the gullet getting ground to maintain the full tooth height and gullet shape. 

Is your setter single or dual tooth? Typically, setters take a bit of fussing with to get them adjusted correctly. Once you do, I would advise you to just go around the blade, only checking an occasional tooth to make sure nothing is out of whack. If you try to watch every tooth, you'll drive yourself insane!

For both operations, your blades need to be clean. And sap build up will mess with indexing pawls, clamps and setter anvils.   

[dgdrls]

https://cookssaw.com/bandsaw-blade-basics-101/

Cooks does a good job explaining blades and their features, etc

D

[chainsaw_louie]

There is nothing like learning by doing, so today I set up the blade grinder and tooth setter.  I watched a video that explained the key points and settings from the previous owner made things go quicker.  I was able to sharpen and set one blade:
Set = 0.020 +-
Angle = 9 degrees

This grinder only cuts the face and gullet. Is there any need or advantage to hand file or touchup the back of the teeth ??

I'm forgot to get a measurement on the thickness of the blade which from the data should influence the allowable blade set. 

My hp = 28

Tomorrow I'll test the blade and see how successful my sharpening is.

[Magicman]

That blade should not have been sharpened & set with that pitch and crud on it.

The best time to clean a blade is before it is removed from the sawmill.  Let it run with a good flow of lube or while being squirted with diesel.  A wire brush is useful then too.

[chainsaw_louie]

Thanks for the clean blade suggestion. 

I've had good results cleaning circular saw blades using oven cleaner.  I'll clean this blade up and re-do the sharpening.  

Any comments regarding dressing the back side of the teeth? 

[ladylake]

With that much crud on the blade it wont saw straight.   Steve

[ladylake]

There is nothing like learning by doing, so today I set up the blade grinder and tooth setter.  I watched a video that explained the key points and settings from the previous owner made things go quicker.  I was able to sharpen and set one blade:
Set = 0.020 +-
Angle = 9 degrees

This grinder only cuts the face and gullet. Is there any need or advantage to hand file or touchup the back of the teeth ??

I'm forgot to get a measurement on the thickness of the blade which from the data should influence the allowable blade set. 

My hp = 28

Tomorrow I'll test the blade and see how successful my sharpening is.

You should set up the sharpener so  it hits the face and the tip of the tooth on the way up. Dont worry about the bottom of the gullet, it will hit that after a couple sharpenings.  20 thousands is not enough set to saw straight, set a least 25 thousands,   30 thousands for pine.    Steve