suffolks troubleshooting guide

[Neil_B]

Been playing with the blades trying to get a decent cut in hardwood cants. I've been using Suffolks guide to figure out what is wrong but nothing seems to be helping.
I was getting a lot of diving and bowing across the board so according to the guide I needed to increase my hook angle and increase the set. I went from 10 deg to 12 and 15 thou up to 20. Still didn't make any difference.



I just can't seem to figure out what's wrong with the cutting.


It's still diving down part way through. Tried slowing down and speeding up.
Everything is adjusted properly.
I'm just about at my wits end with this. I spend more time in the garage than I do sawing anything. In the last 3 days I sawn about 100 bdft (yep, that's one hundred) and wasted almost as much.

Arggg. Please help.  :'(

[Tom]

Diving can be the wood.  It can cause the blade to follow the grain. In this case a real sharp blade is the answer.

Other things that will cause it are:
blade tension too light
set too small
blade lubricant allowing gumming

diving in only one direction is:
Blade dulled on only one side.
set heavier on one side than the other
blade guides misaligned
(sometimes)blade dull

Something else that will cause erratic blade behavior is a loose drive belt.  If the belt slips, the blade speed drops and the blade will quit performing. (I've also had the blade slip on the band wheels and cause it. Check for foreign material buildup or lack of tension)

[Neil_B]

Thanks Tom, but I've tried all that and nothing seems to be helping.

Blade tension at 4000psi, according to the gauge.
Whole new drive set up. Just spent a pile of money I don't have to upgrade everything. No longer slips in the drive, not sure on the wheels though.


Freshly set and sharpened blade.
Keep checking the guide alignment and everything is good there too.

I'll try a slightly heavier set and see how I make out, but the last time I used anything over 20 thou, I start getting a lot of sawdust staying in the cut leading to more problems.

I should mention that I do get a few good cuts before it happens again. Could be that the sharpness is wearing quickly but this is only in a few board feet.

 ???  ???  ???

[smwwoody]

Standing in front of your mill looking at the side of the band that has the teeth on it which way does it rotate?  clock wise or counter clockwise?

[Neil_B]

 Facing the blade is counter clockwise.

One thing I am wondering is how far up, or down the tooth should the set be? The setter is only pushing out the top 1/8" of the tooth.
 I had rechecked the last blade to come off and the set was down a bit on one side. Could be that either it was reduced when it went for a dive or that it's getting knocked down quickly causing the dive.

 ???

[BBTom]

I recently had a problem that comes to mind.  the blade guard got pushed up to the point that it contacted the bottom side of the blade, took the set right out of that side and I couldn't cut anything, blade took off for the sky right away.  makes me wonder if maybe your blade might be riding too far back on the bandwheels, causing the set to be taken out of the top teeth?  Might only happen when it is cutting, so you would not see it happening.  Just a guess on my part.  

Here is one trick that helped me get the blade cutting right,  set your blade 12" off the bed, then set a 12" block at the other end of the mill. now use your eyesight to look across the blade toward the block, line up the side of the blade and the top of the block to make sure the blade is flat with the bed.  I have a laser on mine, and that is what I use, but a block of wood should work just fine.  

Wish I had a magic trick for you, but I know when I have problems like that, it is normally something that I have overlooked a dozen times. Hope you find it soon.

Woodmizer's setter pushes the tip of the tooth, but there is nothing holding the tooth to make it bend at any one point.  the "anvil" that it is bent against is at the bottom of the gullet.  I suppose that makes the whole tooth bend. I honestly have not examined it that close to see where the bend is.

[gmmills]

One thing you haven't told us is the blade specs your using. Seems like you have checked every alignment issue and still having trouble. I've been there. If you are using 1 1/2 or wider Timberwolf  blades and the blades have been run and sharpened a couple of times the problem is the blade.  
  I've used 3 mixed in along with my WM blades as a trial. After sharpening the Timberwolfs 1 time they would dive. Put a WM blade on and the mill cut fine .
   What you need to check is the flatness of the blade.If the blade is crowned toward the log it will dive even if properly sharpened and set. This is what was wrong with the Timberwolf blades I had.  
   I saw hardwoodsalmost exclusively and stay with hook angles between 8 and 10 deg.
   For more info on blade flatness check out cookssaw.com  

[ronwood]

Neil_B,

Recently there was a post discussing the crowning of blades.
TIMBO from Cooksaw talked about rolling the blades to flatten them.

https://forestryforum.com/cgi-bin/board/YaBB.pl?board=sawmill&action=display&num=1081165325&start

Might take a look at this thread.

Ron

[smwwoody]

Timbo has a welth of info on band blades.  I spent about an hour on the phone with him today.  go to his web site www.cookssaw.com  and check out some of his thoughts on bands it is well worth the reading time.

Woody

[Neil_B]

Thanks for the tips.
Funny some of you should mention Timberwolf blades. I'm using Viking blades which are supposed to be from the same steel company that Timberwolf are. Can't seem to get any proof to comfirm that though. May have to do some more digging.
I've been through Cooks literature, I also get their news letter when it comes out. Very good info.
Problem would be trying to find someone up here to roll the blades. Thought of trying to rig up something of my own using a mock up of a hydraulic bearing press using rollers. These blades have been through a lot of trial and error which could explain the problems.

The blades I have are all 2". Some are .035 which don't work at all on my mill, and the rest are .042 and .045.
I've been trying to find a 2" in the .050 but no luck. Have no money to buy more blades right now anyway.
I often wonder if the span of the blades, at least 5', is much of the problem therefore needing a thicker band for better support.
Sent in for the free blades from Simonds but not sure if I will get them or even when. Would certainly give me something to compare with.

I appreciate the ideas, keep 'em coming please.

[Neil_B]

Well back at it this morning. Checking the alignment that is.
I took BBTom's advice and checked the tracking and it may have been a bit too close especially when cutting so I moved the blade ahead a bit on the wheels.
Also went through Timbo's advice. I checked the alignment of the band wheels, top to bottom, and already had the top out 1/8" as he suggests so I'm on track there. I think I did that the last time I aligned the wheels.

I'm going out to check to make sure the guides are still holding the blade parrallel to the bed and to see if I can find any curvature in the blade itself.

One thing that this mill has been like since day one, is that the carraige itself is twisted. On the right hand side, or the blade entry side, it's ahead of the left side of the carraige by about 1/2". This puts the entry of the teeth ahead of the exiting teeth. I've heard of the angled mills but not sure if they enter the cut on the exit side of the blade or the other side.  ???

Anyway, as my subject title suggests, does anyone else use Suffolks troubleshooting guide as a sawing bible so to speak?
I would think there are more variables than the ones they list and it would be nice to find more info somewhere on the subject of blade troubleshooting. In addition to the ones you guys mention of course  ;)

[SawDust_Studios]

We had the same problem awhile back on an old Breezewood mill as BBTom pointed out.  The blade guides where slightly to far forward and with even a new blade, would take some of the set out of the teeth.  This cause some of the same problems you are referring to.  

I have used the Suffolk blades, but never checked out their troubleshoot guide.  If your like me, you eventually find something extremely minor and wonder why in all of this time you couldn't see it.

Hope you solve the mistery.

 :(

[Neil_B]

Well, did solve the mystery.
Thank You Tim Cook and everyone else who offered their advice.

I had gone back and read the previous post Tim left about the curvature of the blade. I emailed him about an easy way to make my own blade roller and he got back to me quite promptly explaining how to do it with just a ballpean hammer.

What a difference, blades are cutting great now. Only thing is that most of these blades have been through a lot of trial and error so they won't hold their edge long. At least I know what to look out for now.

That kind of sharing of info will go a long way when it comes time to look at a new mill.  ;)

Thanks again all.

[D._Frederick]

Neil,

Could you post how to adjust the curvature of a band blade with a ballpean hammer?

[LeeB]

I to would like to know about the ball peen trick. LeeB

[Neil_B]

Oh, I suppose I could share it.  ;D

I hang my blade from the ceiling of the garage and supported on a bench with a piece of flat steel under the blade. Mine are all curved downward so some may have to turn their blades inside out so the hump is up.
Using the ball side of the hammer, tap lightly in the middle of the blade between the bottom of the gullet and back. Tim said to tap it about every inch so I do one behind every tooth.

Trick is not to hit it too hard, you can always go back around and do it again if it's not quite straight otherwise you'll end up curving it the other way.

I just use a exacto knife blade to check for flat from front to back.

He also mentioned that he has band rollers for sale now. $795 US.

Quite simple to do actually. I little time consuming on a 198" blade though.