inconsistent cuts on lt15 wide

[forrestM]

Hello,

Just getting to work with my new LT15 wide single phase electric. It seems I just cant get the same thickness from board to board, and along the length of a board.

If I cut a one inch board (moving an inch and an eight on the dial) I get 1" at the beginning and end of the cut, and 1 - 1/16" in the middle. I typically get a 1/16" inch belly in the middle of the board. Sometimes though, my one inch board will be 1 -1/16th throughout, or the whole board will be 15/16ths. No consistency - and I can't have that belly - I wont be able to get a flat stack of lumber. 

I have thoroughly aligned the sawhead and the bed rails, and have even bolted the outside legs to the concrete pad it sits on. When I run my strings form end to end of the mill, I can get it as close as the welds will let me, and from bunk to bunk it varies at most 1/32" 

Is there any other big culprit that would cause whack-a-mole boards? Of course I could have missed something. 

I use 9 degree blades, cutting a lot of ash and poplar lately.

My old lt15 standard didnt seem to have these problems.

Thanks,
Forrest

[jaygtree]

i know nothing about woodmizer mills but two things that come to mind are maybe you need a bit more band tension or the drive belt needs tightening.  jg

[forrestM]

good idea with the drive belt. It is a new mill so i assumed it would be tight - a lot of other stuff wasn't quite right, so it probably needs a look!

thanks,
forrest

[SawyerTed]

Have you tried parking the head in the middle then using your string to check the bed alignment?  Then park the head at the end of the mill and check with the string.  There might be some flex you aren't seeing and the weight of the head is causing that flex.  

[ladylake]

 If your blade is sawing straight and no stress in the log with the center being thicker  you need more pressure on the end jacks or less on the middle jacks. Throw away the string and try that.  If it's doing this as you saw though a cant your just dealing with stress in the log.   Steve

[forrestM]

I did have flex when I first aligned the bed rails. With the zinc guide rail on both sides, the rails are so stiff on the lt15 wide that you can't easily get them straight. I would try to get the sag out of the middle of the mill, and it would end up raising the far end. Then, when i bring the head to that end, the other end raises up! So I ended up bolting the outside legs to the concrete pad, and also pinned down 2 of the middle legs. That took care of the flex, and that's why I'm looking to other causes. I had no problems like this on my standard lt15. 

I checked the drive belt tension this afternoon and it was reading at 5lbs at 1/2" deflection!! I cranked it up to 14 lbs at 1/2"  I will test it on a poplar log tomorrow. I am hoping this was the cause of my troubles. I was pleased with how easy it was to engage the clutch before - but i now know it was because I had no tension on the belt. Very stiff now, but I guess that's a good thing. Not sure how that would have gotten past the factory like that?

Will let you know how cutting goes.

Thanks,
Forrest

[barbender]

Stuff wears in. Drive belt tension should be checked weekly IMO. With only 5 lbs of tension, I'd about guarantee you found your problem. 

[forrestM]

tested it and I'm still getting 1/16th thicker in the middle, and sometimes 1/8th thicker. Like tightening the drive belt made it even worse. 

I guess I'll get my strings back out and while I am leveling I'll put the sawhead over every bunk and measure down from the blade? Not sure what else to do. Every single board on every single log can't just be stress. 

Thanks,
Forrest

[barbender]

Hmm. Some of the bed adjustment aggravations can be really tough to diagnose from descriptions. Plus I have an LT40 so I'm not overly familiar with the LT15 bed. Good luck.