The Forestry Forum

General Forestry => Sawmills and Milling => Topic started by: wbrent on April 08, 2021, 07:40:25 AM

Title: Bandsaw leveling
Post by: wbrent on April 08, 2021, 07:40:25 AM
That time of year again when the frost is coming out of the ground and i spend countless hours it seems re levelling my mill. So a few questions in regards to this. The mill is a Norwood LM-29. As many know this mill comes to you in pieces and you bolt it together. I have always assumed that once bolted together and the bolts torqued the rails are essentially like a solid rail. Meaning any adjustments I make in levelling are in the levelling legs and not in taking sections of track back apart putting back together. So then assuming the sections of track are well together, that would mean the the rails as a whole are bending under its own weight. Do others with solid rails have as much re levelling to do with different seasons of the year?
My mill sits on blocking at each levelling leg and the whole thing sits on crushed rock underneath. I am considering pouring a concrete pad for it. But I know the pads of concrete in my barn and garage go up and down with the seasons as well. Those of you in Northern climates. Do you find you are re levelling just as much with a concrete pad as you did with gravel? The concrete would sure make clean up easier but if I'm still levelling the same amount Im not sure Ill be in a hurry to do it. I live in Atlantic Canada. 
Title: Re: Bandsaw leveling
Post by: arky217 on April 08, 2021, 09:54:00 AM
Quote from: wbrent on April 08, 2021, 07:40:25 AM
That time of year again when the frost is coming out of the ground and i spend countless hours it seems re levelling my mill. So a few questions in regards to this. The mill is a Norwood LM-29. As many know this mill comes to you in pieces and you bolt it together. I have always assumed that once bolted together and the bolts torqued the rails are essentially like a solid rail. Meaning any adjustments I make in levelling are in the levelling legs and not in taking sections of track back apart putting back together. So then assuming the sections of track are well together, that would mean the the rails as a whole are bending under its own weight. Do others with solid rails have as much re levelling to do with different seasons of the year?
My mill sits on blocking at each levelling leg and the whole thing sits on crushed rock underneath. I am considering pouring a concrete pad for it. But I know the pads of concrete in my barn and garage go up and down with the seasons as well. Those of you in Northern climates. Do you find you are re levelling just as much with a concrete pad as you did with gravel? The concrete would sure make clean up easier but if I'm still levelling the same amount Im not sure Ill be in a hurry to do it. I live in Atlantic Canada.
I also have a LM-29 and yes the part that I'm most disapointed with are the rails and bunks.
I don't have the frost heave problem here in western Arkansas that you have but it is a
pain to get the rails and bunks aligned and level with this model.

Even when you get the rails straight and level, that doesn't mean the bunks are also; they
have some play in the way they attach to the rails, so they need to also be level with the rails.

Norwood, IMO, just used too flimsy steel for the rails and the bunks should have sat right on the rails instead of being mounted the way they are.

How much simpler and stouter it would be if they would have just used 3 sections of say
1/4" x 3" x 6" x 6' angle and let the bunks bolt directly onto the rails at the joints.
You wouldn't then have all those bolts nor the need to adjust the bunks also get all the joints exactly right to keep the rollers from bumping at the joints.

I have my rails mounted on treated 4"x6" timbers edge ways which in turn rest on
4"x6" treated timbers flat ways and they rest on solid concrete blocks at each joint.
I have the timbers cross braced to each other but if I'm not careful, a heavy log will
knock everything out of whack.

I just got through raising the mill 10" by putting 10"x8" short beams between the rails
and the treated timbers at each joint. I also did away with those flimsy leveling legs 
and lag bolted the rails directly to the beams using shims to level the rails. Then I angle
braced the 10" beams with each other and I also drove 5/8" rebar into the ground
through the bracing of the treated timbers to keep heavy logs from shifting the whole
thing on the concrete blocks.

For your application, maybe if you made a full length subframe using stout steel such as
3"x6"  or larger rectangular tubing and welding cross braces on it to make it one solid structure, then the frost heave might not affect it. You could even put wheels on it to make it mobile.
Title: Re: Bandsaw leveling
Post by: doc henderson on April 08, 2021, 10:18:03 AM
I can mill 21 feet and have a solid welded frame.  you still have to level occasionally.  I think the slab over your gravel is a good idea.  it will for sure be solid for the big logs. and will move more in mass.  you could also use the cardboard tube and pour 4 foot deep footer to set your legs on.  post hole digger on a tractor .  I currently have 2 x locust beams that run side to side and support my jacks on each end.  3 beams for 6 jacks.  I am considering a concrete slab as well.  my sprinkler system is in the area with a dozen pipes under ground, and worry if I have to fixe something, it would be under concrete.
Title: Re: Bandsaw leveling
Post by: alan gage on April 08, 2021, 12:12:45 PM
You could try insulating under the cement pad to keep it from frost heaving.

Google frost protected shallow foundation.

There are different prescriptions based on climate and whether or not the slab is under a heated building or not.

Alan
Title: Re: Bandsaw leveling
Post by: Patrick NC on April 08, 2021, 05:52:30 PM
I don't have any frost and I still have the same problems with my bed. I have 8 leveling Jack's so the rails stay pretty straight, but the bunks always need adjustment. I also have a problem with the rails having a tendency to toe in at the top when I saw something heavy like white oak. I think it's caused by not enough lateral support. I've been in contact with Norwood several times and no one ever has a solution. I see on their new Mills that they have redesigned the track. No doubt because the old one is so much trouble. Pretty frustrating at times. The rails can be dead level and the bunks be off as much as 3/16 of an inch. I'm going to try adding some bracing and some sort of shims on the bunks to help. 
Title: Re: Bandsaw leveling
Post by: KamHillbilly on April 08, 2021, 09:29:41 PM
Quote from: alan gage on April 08, 2021, 12:12:45 PM
You could try insulating under the cement pad to keep it from frost heaving.

Google frost protected shallow foundation.

There are different prescriptions based on climate and whether or not the slab is under a heated building or not.

Alan
If you insulted underneath you should insulate 4 ft out on all sides to prevent frost from driving under the sides of the slab . Here in northern Ontario it may work if it wasn't trampled to drive frost down .  
Title: Re: Bandsaw leveling
Post by: RAYAR on April 09, 2021, 01:29:17 AM
Hi wbrent, my mill has a solid rectangular frame and welded bunks. Today, I noticed the center legs not touching, so grabbed the level to check things and readjusted the legs down. Good to go. My mill has been set up all winter and used it a few times. Just been making minor adjustments as the frost is going out. Being mobile, it only take a few minutes to re-adjust. My mill is currently set up in Moncton.
Title: Re: Bandsaw leveling
Post by: 711ac on April 09, 2021, 07:09:21 AM
Quote from: wbrent on April 08, 2021, 07:40:25 AM
That time of year again when the frost is coming out of the ground and i spend countless hours it seems re levelling my mill. So a few questions in regards to this. The mill is a Norwood LM-29. As many know this mill comes to you in pieces and you bolt it together. 
My mill sits on blocking at each levelling leg and the whole thing sits on crushed rock underneath. I am considering pouring a concrete pad for it. 
If you "mothball" your mill for the winter, I wonder how you'd do with simply leaving a heavy layer of sawdust covering the ground over the winter?
It's an amazing insulator and the price is right. 
Just a thought before you make an investment in concrete. That stuff kills my knees (and more) spending a day walking around on it. 
Title: Re: Bandsaw leveling
Post by: thecfarm on April 09, 2021, 07:43:39 AM
What about a good base of just gravel? You're going to have bring something in to prep for the pad anyways. I dug some of the topsoil off and put gravel about a foot high than on one side it's about 2 feet. Water is the problem with the heaving.  ;D  I never have mud where I am walking!!