Having problems with my band mill cutting out of square. I've checked and done every thing I know to do. The track is square the blade is aligned with the bed. The only thing I can figure is the log rests are out of square. Any one know of any thing else I could check out? It's a norwood mill. :-X
Take a string from one bed rail and extend it all the way to the other end. See if all your bed rails are level. Check it on the ends and center of those rails.
Oh, check your backstop rails with a framing square too!
I would say to that, that square to what? square is a right triangle, so in my mind it is the bed rails to the back stops. But, the bed rails have to be level and square to each other in order for the head to travel true to the log bed rails,, It is an alignment issue, unless the back stops are whacked out of shape some how, heck I don't know, been driving for the last 10 hrs, and just wanted to relax, but hate to here about issues that deal with sawing. give norwood a call, or maybe another owner will chime in with a similar experience. hope to read you got it sooner than later,,
Make sure mill is set up properly. Check your backstops with a large speed square. Put the sawhead so that the back of the blade is above the center of a bedrail. (have full tension on the band) Measure down from the back of the blade to the top of the bed rail on both sides, close to the guide roller. should be the same distance, to my knowledge. The WM mills have you a 1/16" difference because of cantilever head. How far out of square is it?
When you say you are out of square... I am not sure exactly which way you mean... but one thing we run into quite a bit is when we are securing our log/cant/etc... when we "squeeze" the piece, it can often rotate a bit...
Then we bring the hydraulic clamp back "down" a bit to straighten the piece back out...
I am not sure if this is what you are talking about... but it makes a world of difference on our mill!!!!!
HTH,
-Dad2FourWI
Quote from: jdw on May 04, 2015, 06:51:21 PM
It's a norwood mill. :-X
are you getting a cant that is a parallelogram ?
which model of mill is it.
how long have you had it.
has it always done this.
does it do it every time.
Check that the blade is not only parallel to the bed rails but that it CUTS parallel to the bed rails. In other words that the board or cant which is lying flat on the bed and has been cut on the opposite face, is the same height (thickness) on either side. you can't cut square lumber if not.
Then see that when a flat is pressed to the back stops, that the next cut (at right angles ) is square. That should be it.
Excess pressure against the backstops bending than what you wish to use during sawing , lifting of the cant off the bed during clamping, must be recognized and dealt with in the business of keeping your lumber square.
Another way to verify that your blade is parallel to the bed is to open a face and then turn the log/cant 180° and make a cut. Then measure the thickness on each side of the log/cant. If they are not exactly the same, then do some adjusting.
I always keep a level handy. IF the mill is set up level side to side, the flat cut should be perfectly plumb when you clamp it down. Even if the log stops are square, they may not be high enough to give the log enough surface. Once you get the second face square, everything should be square from that point on. If not, use MM's suggestion about rotating the log 180 degrees & looking for taper to check blade alignment. That's a good idea once in a while, even if you think the blade is aligned properly. If none of that helps, send me a private message. Here's a photo of using the level method (I don't usually use a shim, but sometimes it saves time).
(https://forestryforum.com/gallery/albums/userpics/12837/Level_V_s.jpg)
I always set up with the loader side half a bubble high, so when needed, I use a 12" square to verify that the first two face openings are square.
The very first thing to do is make sure your square is "square". I had a sawyer one time spend an hour adjusting the mill to make the post square. When I measured the cant I realized it was geometrically impossible to have 2 corners square and the other two greater than 90 degrees. Thus I checked the square and sure enough it was about 92 to 93 degrees. Got a good square and didn't take long to get the mill proper.
Not saying your square is abused, but it could be a source of the problem.
Quote from: Cedarman on May 05, 2015, 12:39:08 PM
The very first thing to do is make sure your square is "square".
I was thinking the same thought. If it is a new framing square its not square...something to do with Chinese. If it is a good old USA square its not square either...been dropped way too many times. :D
It's the lm 29 mill. Had it about a month or so after I got it put togather I cut about 700 bf of poplar it worked fine with no issues. But I pulled it out to a logging job to cut ties and ever since I moved it I've been about 1/8 out of square. I guess I'll find me a new square and check the log rests.
on your norwood, with the head pulled all the way to the back, look and see if both sides touch the stops equally, same on the other end. its kind of tough to explain but I will try. the back stops that you clamp the cant or log against is riding on a solid bar between the two rails of the mill. if the two rails are not square , meaning if one is different from the other, then your back stops will only be square with the rails in one position only.... who knows where that will be. when I built mine, I did not get the rails square... its out about 3/8 " which makes my backstops not true.... I use a level on the side of the log after the first turn and that makes my cant square.
if I clamp my cant up flat with the stops the cant will be out of square.... not good on house logs or cants....if I am making 1x lumber its really no problem to me.
ps my mill is stationary if I had a mobile mill I would go ahead and fix it right...if/when I tear into mine I intend to fix it correctly.
I'm not familiar with the clamping system on a Norwood, but had this issue with my Hud-son mill. Turned out I was trying to clamp them to tight and was flexing my stops. It did teach me how little you actually need to clamp your logs, how I was doing it a log couldn't have blown off in a tornado.
Framing squares can be fine tuned back to square, if they are found to be out of square.
Here is a video of how to do that.. a bit different than I learned but this is prolly better. ;)
https://www.youtube.com/watch?v=_vDY_p3eilQ
Thanks for the video, BT
Really the only critical cut is the first 90 after that its the relationship between the bunks and the band. My swinging stops are a little out of plumb due to heavy logs rolling agenst them. My mill is level and plumb all ways, second cut I use a level to get close to 90 after that it takes care of its self. Really a little out only matters on timbers and larger dimention, boards don't care. Frank C.