LT 15 not sawing true on the last cut

btulloh · March 31, 2020, 11:12:00 AM

Is the bottom board tapered evenly from end to end like a slight wedge or is it just a bump at the end?

Stacy · March 31, 2020, 11:14:57 AM

It start climbing around 32" from the end.

I forgot to mention in my last post, the blade tension is set correctly.

terrifictimbersllc · March 31, 2020, 11:30:00 AM

Can you post a photo of that last board which shows this? Not your ruler but the last few feet along the edge of the board.

And you don't see any irregularity looking down the side of last two or three boards just above the last one?

Stacy · March 31, 2020, 11:36:10 AM

Yes, I will post a picture when I get free up from my job that pays the bills.

All cuts above the last one look perfect from end to end.

terrifictimbersllc · March 31, 2020, 11:39:33 AM

If so sounds like something on the mill is riding up over something on the bed when the head is down to the last board. Does it matter if the last board is 1" vs 2" thick?

Stacy · March 31, 2020, 11:57:08 AM

Thickness doesn't make any difference, it even does it on 4x4's

Stacy · March 31, 2020, 03:45:49 PM

terrifictimbersllc
here is the picture you asked for.

SawyerTed · March 31, 2020, 03:57:48 PM

So the next to last board doesn't have a corresponding but opposite taper thinner? Is the end of your cant resting on a bunk within a few inches or is it hanging between bunks?

Stacy · March 31, 2020, 04:11:32 PM

Nope, the second to the last board is perfect. It can be resting dead nuts on the bunk, doesn't matter.

dgdrls · March 31, 2020, 06:42:11 PM

Thinking out loud here,
When you're finding this result did you unloading the cut boards before making the cut?
Are you advancing the saw-head differently on the last cut?
~~Did you string test with the saw bed loaded?~~ I see you did

Challenging issue for certain,

D

btulloh · March 31, 2020, 06:56:06 PM

Following this thread and it gets more perplexing all the time.

One thing I'd like to dig into a little bit - you said:

Quote from: Stacy on March 31, 2020, 11:57:08 AMThickness doesn't make any difference, it even does it on 4x4's

How does the mill know you're at the last board? Suppose you were stopping at 4" to get your your 4x4. In theory, the problem would show up because it's your last cut. BUT THEN on the spur of the moment, you decide to saw on and make three 1x4's. What would happen?

terrifictimbersllc · March 31, 2020, 07:02:03 PM

Quote from: Stacy on March 31, 2020, 03:45:49 PM

terrifictimbersllc
here is the picture you asked for.

Not seeing it in this picture.

ps was wanting to sight down the edge of the board to see if there was an "event" at the beginning of the problem.

pineywoods · March 31, 2020, 08:54:35 PM

I'll bet you are overlooking the actual problem. Like the mis-cut is on the FIRST cut, and happens on all following cuts. Try this, load a small log and make your opening cut. Then measure from the kerf of that cut to the mill bunks (all of them). What's going on is happening on EVERY cut, you only see it on the last one. Been there, in my case the problem was guide roller alignment coupled with a bad bearing in the outboard roller. There's 2 bearings in the roller. One bad and the other good will drive you nuts. Worse case, guide roller worn off to a taper will do the same thing...
Here's a sure fire way to see that happening.. Watch closely when the blade exits the cut at the end of the log. If the blade drops you can bet it climbed somewhere down the log..

Woodpecker52 · March 31, 2020, 08:57:44 PM

Stacy on the question is the rails adjustable. My Lt15 head rail is only adjustable in the horizonal axis not the vertical which would cause your problem. Where the seams join there should be no gap or slight bump or uneven area. There should be no slack what so ever in these rails. If all your adjustments are ok then I would open up a face on a log and raise head, the head one notch, pull it back and start at the front again with it off and look at the blade gap and log face and observe the gap variance and mark on rail where it occurs, Then turn the log and open new face and do the same thing. If it occurs at the same spot then it is usually a bed section adjustment problem. If not vary feed rate etc. I have it occur in drier logs vs. wet etc. Even was a problem with stress lifting up the clamps as it was cutting, Since they swing and only hold in one plane and do not lock down the log. When all else fails It usually believe it or not has to do with blade set. I have covered up a multitude of problems by just increasing the set on my blade.

Stacy · April 01, 2020, 07:54:49 AM

I have checked the bolt on rail, the only adjustment is horizontally. All of the bed joints are flush with each other. I didn't make it to the mill yesterday to try some on these great ideas, but I hope to today. I will report back with my findings.

YellowHammer · April 02, 2020, 04:08:52 PM

I think it's an initial cut problem as Piney says. If all the cuts and boards are parallel including the second to last board then it means the misalignment started on the first cut and the saw is cutting consistent thickness throughout the cant. Then the initial misalignment is apparent only on the last board.

Stacy · April 02, 2020, 04:18:00 PM

After the testing I did last night I agree. I took a 6" cant and snapped a chalk line every inch then started sawing. I could see the blade climbing as I got about 2/3rds down. It did it on every cut. But... every board was the same thickness on each end except the last board??? It was a 1/4 thicker.

I then check my blade alignment and its perfect on every bunk.

terrifictimbersllc · April 02, 2020, 04:36:39 PM

Is the end of your board at the last bunk? Or is it overhanging some, if so how much?

Stacy · April 02, 2020, 04:40:46 PM

I made sure it was on the bunk.

dgdrls · April 02, 2020, 05:54:26 PM

Do you have the same results with a brand new, never been to resharp out of the box band?
Are your guide rollers taking some set out of the teeth?

Stay on it you'll find the gremlin.

D

beav · April 02, 2020, 06:58:56 PM

Look at the shield on the moveable blade guide right next to the blade guide roller. If you set it down on a cant or log it might have bent up a bit. This would dull the blade on the bottom if it contacts it, causing the rise in every cut. You would see a shiny spot at the contact point.

donbj · April 02, 2020, 07:57:21 PM

Does your blade snap down a bit when you run off the log at the end of the cut? Is it the blade rising or the whole head? I suspect blade alignment/sharpness/set issues

Stacy · April 03, 2020, 08:16:41 AM

Last night I installed a new blade out of the box. I experienced the same problem. I believe my blade alignment is correct. I attached a pic where I tried to show the front and rear spacing in one shot.

Remle · April 03, 2020, 09:15:51 AM

Are you sawing from the small end of the logs or the large end of your logs ?If you are sawing from the small end of a log with a lot of flair, try sawing from the large end.