Hour Glass cuts

[TimW]

The blade tension is built based off of a PSI gauge which i'm running at 3-4k which is how it was made to be run. 

Has he built any other sawmills that are doing what your's is doing?  If not, what is different on the other mills.  My LT40HD has blade tension between 2800 and 3000.
Have you sawn with 3000 on the gauge?

[beenthere]

You can move your photo's to your post by clicking the next to last BBcode (normal) and copying that to your post. 

As I did here

[Magicman]

I did potentially see some belt slip on the clutch so I will replace that and give it a shot.

A belt slipping and slowing the blade down will absolutely cause woes.

[barbender]

If you even suspect that your belt is slipping, I'd  say with a 99.9% certainty that you've found your problem. 

[BT9212]

Belt slippage was the main issue, my technique still needs work as well. They came out today after I changed the blades and we sawed up a few logs they did pretty good. Got some more tips. Appreciate the help as always. It's definitely a lot to learn.

[BT9212]

The blade tension is built based off of a PSI gauge which i'm running at 3-4k which is how it was made to be run. 

Has he built any other sawmills that are doing what your's is doing?  If not, what is different on the other mills.  My LT40HD has blade tension between 2800 and 3000.
Have you sawn with 3000 on the gauge?

Yeah, they have a built a few, they recommend 2500-3k. I was just mistaken. My cuts today were not the best but I was cutting logs with tons of knots and lots of curve so I was happy with what I got from it. My nice clean logs seem to be doing really well after belt changes.

[barbender]

 Drive belt slippage is probably the most missed sawing issue out there.

[GAB]

If you even suspect that your belt is slipping, I'd  say with a 99.9% certainty that you've found your problem.

You aren't leaving yourself much room for error which could mean eating crow without much condiment.
GAB

[barbender]

 GAB, what I meant by that is if you think it's slipping, it's slipping. I've had my drive belt slipping with no indication that it was doing so, other than terrible cuts. You can't hear it, or see it. It's one of those things where you do all of the troubleshooting, and it's the only thing left. So you check it, and adjust it, and whalaa! Your sawing issues are resolved👍

 Said another way, there have been many times where I didn't think that my belt was slipping- but, my belt was slipping. So whenever there are sawing issues, my belt gets checked right away.

 I have also been known to eat heaping helpings of crow from time to time. I prefer it with Vermont maple syrup😁

[Magicman]

What da man just said ^^^^^^

[fluidpowerpro]

Are the comments regarding belt slipping based on higher HP woodmizer mills? I only ask because for us guys with lower HP mills that are manually pushed down the track, if the belt does slip, you will see the blade slow down, and then you slow down the feed to compensate. I also know if the belt is slipping when the blade slows but you dont hear the engine load as much.
Im not saying that belt slippage isnt something to be avoided, however on a low HP manually fed mill, belt slippage is just one of the issues.
Lack of HP, feed speed, sharp or dull blade are I think just as big or more of a factor.

[Magicman]

Higher HP or not, I normally saw with the power feed speed just below the point where the loaded engine speed slows.  If the drive belt slips, then the blade speed will reduce which in turn will indicate that you can increase the power feed speed.  At that point, your total sawing is screwed because you are compensating one thing for what you don't know is happening with another.

I would hate to imagine that I could watch the blade speed and determine that the drive belt was slipping. 



 

[fluidpowerpro]

I can see the band wheel shafts so I made a mark on the end of the shaft to make it easier to see if the speed is dropping. While cutting, I'm actually watching the end of the shaft as much as anything else.
With a low HP mill human nature is to constantly push it to the limit so although constant blade speed is desired, its not easily accomplished.

I should have looked closer at the original post earlier. Based on the pictures I see that the mill is not high HP. Looking at the track, I would vote for bed frame flex as the issue.

[GAB]

Dear @barbender & @Magicman:
Last fall just prior to placing the mill in hibernation I sawed a sticky pine log and was not impressed with the results I achieved.
Then @YellowHammer made a comment, I believe in one of his videos, that got my attention.
My problem was that my blade rollers were not keeping the blade parallel to the bed rails.  Yup there was a bit of a twist.
After what seemed to be a long time I got it to where I felt comfortable with the settings and checked the blade height above the bed rail nearest the hitch end to make sure I had just 1/16" delta recommended.
Last week I sawed for over 5 hours and except for a broken blade and an occurance of plugged blade lube nozzles all went very well.  For this customer I sawed a lot of 5/8" & 3/4" material this time.
So for me the blade not being parallel to the bed I believe caused my problem as I did not change my belt tension setting.
GAB

[Magicman]

I have not read where anyone suggested that a drive belt slipping was the cause to all sawing problems.  Proper total sawmill alignment trumps everything, but even with a 100% properly aligned sawmill, a slipping drive belt will cause sawing woes.  

So will a dull or improperly sharpened/set blade.  So will the wrong blade.  So will pitch buildup on the blade.  So will etc, etc, etc.

[GAB]

I don't disagree with what you folks are saying, and I'm not trying to be arguementative, but I just finally got to the source of my problem after scratching my head on and off all winter.  Yes it is getting thin up there so now a haircut is more costly per hair.  Sorry Mr. Resonator.
I appreciate you folks inputs, however in my case it was a different problem.
GAB