Mobile Dimension question

[mirkaba]

Howdy.....I have been slabbing /flat siding houselogs with a mobile dimension saw. I have been operating the mill for app. 8 years and have a pretty good handle on its operation. I started flattening 2 sides on lodgepole houselogs with the bottem edger blade not long ago and find that the saw climbs app. 1/4-1/2 inch from one end of the log to the other. I have adjusted the end stands, set the lead on the edger down and even angle sharpened the teeth to pull down into the log. Nothing seems to correct the problem. Has anyone else had a similar problem or have any suggestions? Thanks......... ???

[Paul_H]

Welcome to the Forum,mirkaba.

I had similar problems when sawing oversize beams with the edger.On our mill,there were a couple of things that needed adjustment.

Run the edger down the bunks and measure the distance from the bunks to the edger on the operators left side and make sure they are all bang on,then crank the crossfeed over to the right and check again.On mine,there was a bit of shimming to do to get it consistant.

I had good luck sawing accurate beams with the edger(12x16) but when I sawed a couple that were 24' I had a problem. The beam was 12" on the operators end and 12 1/2 on the far end,past the last bunk.(the thickness was12" all the way along the beam,and only climbed the last few feet past the last bunk, by a 1/4")

After a lot of head scratching and fiddling around,I realised that it was because the beam wasn't supported by a bunk for over 6' and was sagging down slightly,so the blade was taking less of at that end.Then when the beam was flipped over to saw the opposite side and sawed,it made that end even thicker.(1/4"+ 1/4" =1/2") And the same happened on the 16" side of the beam to a degree.

The short term fix was a block of wood and a falling wedge to support that end of the beam.The better fix would be another bunk.

Does that sound anything like the problem you're having?

[Frank_Pender]

Welcome, Mirkaba.  Another thing to keep in mind, is that if there is less support at the opposite end the log may well have some timber bind.  I have found that when taking the out edges off like you are speaking of, it releases a great deal of tension in the log and the log will move in a direction with the least about of resistance.  Like Paul indicated, you might have to place a small wedge or sliver under the log at the furthest bunk to deal with the issue.   This is only after you have made sure your carrage track bunks are operating at the same level and are level side to side as well as end to end.  The collars on the end stands will shift sometimes if they are not kept anchored securely.  That has happened to me more than once over the last 15 years.   :'(

[Bruce_A]

Good morning all;  I had a similar trial with MD and ended up putting in another temporary bunk close to the end of the log.  This helped a lot after I had made sure eveything was where it should be.  Shortly after this  the problem started again,  but I happened to notice that one stand was not working properly with the others.  After a good cleaning to remove my very slick bar oil mix that I was lubing them  with, I noticed a balled up mess that I wasn't getting cleaned off when I was doing my perpetual cleaning.  This proved to be the hardest to keep up with.

[DanG]

I've noticed the same problem, especially in the lower half of the log, as I work my way from top to bottom. It seems more pronounced in butt logs where there is some swell at the big end. The middle of the log gets thin, and the butt swell is heavy, causing the middle portion of the log to bow upwards. I agree with the others that the answer is to provide additional support for that end that is hanging over the bunks.

I built a movable bunk to help with this, and to be able to saw shorter logs. Just made another bunk with a 4x6, like the others, but bolted a piece of angle iron to the bottom at each end, to clamp to the rails with a c-clamp. Works great for those oddball lengths.

[mirkaba]

Thanks guys......I feel a little dumb here but you have pointed out the obvious that I have totally missed. My mill is mounted on a rigid frame and the far end of the log can be out there as far as 8 feet. I am rebuilding the feed works

[Minnesota_boy]

I don't have a Mobile Dimension mill, but I have noticed that a big red pine log that extends  feet over the last support on my Woodmizer will sag as much as a half inch.  To avoid the sag, I need a suport within a foot of the end.