Woodmizer alignment

[Olddevonstihls]

I’m using an old LT40 for various milling projects.  When we set it up it was more or less square, but over time it was not cutting perfectly square, so cants were coming out as parallelagrams, each cut being slightly out but over four cuts compounding to something more noticeable.  We didn’t do a full alignment as described in the manual, but checked that the beds were level with one another and square with the side log supports/dogs.  This was slightly out so the side dogs were adjusted on the cam bolts to bring them into square with the beds.  So far, so good.  Levelling the blade to the beds, with the plus 1/16” on the idle  as specified in the manual, didn’t produce a square cut, however.  In fact, to get a square cut we needed to raise the idle side 15mm above the drive side.  This was done by adjusting the nuts and bolts under the bottom rail.  Apart from the blade being out of spec,  this also means that the blade guide alignment arm is also unlevel by about the same amount.  As it is, we are getting perfectly square 6”-8” cants, and boards are uniform thickness (as should be the case when cutting through and through because each cut will be paralell to the previous), but, but… why is the machine like this?  Can anyone suggest where we might look?

[Big J]

How much play do you have in the head? 

 

The issue with Woodmizers is always the single post design. They are designed to operate with a bit of flex in the head, but as the roller bearings on the rail start to wear, you'll have more and more movement. 

 

As the saw bites into the wood, it'll pull the cantilevered side down. 

 

Check the rollers and adjust do that you have as little movement as possible. Then level the bed up to the blade, but perhaps make a slight overcorrection, which will allow for the head pulling down just slightly as it settles into the cut. 

 

We had an LT40 about 10 years ago and always found it a bit of a pig to align. Single post heads have their advantages, but accuracy and ease of alignment aren't amongst them.

Edited February 18 by Big J

[Olddevonstihls]

That’s helpful, thanks.  I had hoped with the beds square with the side support dogs it would only be a blade adjustment but it sounds like I will have to do a full alignment if I get the bottom rollers tight.