Chainsaw mill bow

[Rough Hewn]

I'd remount the whole lot with an engineering right angle and ruler.
[emoji106]

[Gog]

I will do this when I got the bar, I always check for square each time I use it so will do this again.

 

Kind regards

[Rough Hewn]

Let us know how you get on.

[Gog]

I will do, got 44" lime to mill soon.

 

Kind regards

[outinthewood]

Some years ago when I started milling (8+yrs) I found no real problem with a short bar i.e. 36" with my home made mill and then with my Logasol at that size then I moved upto a 60" bar on a 090 with the Logasol and found a bad "bow" downwards at first added a an extra steel tube across the frame and that was better but still not to my liking so re made my own mill and it was only ok. I was using just standard full chisel chain. Recently moved to a Panther double headed on 72" bar with Oregon Hyper skip chain and suprise I was getting a 5ish mm downward bow, did a little head scratching and started to play with the rakers and problem solved. Took them down a little more than I would have before. 

Most of my milling is to ready a stem for a large band saw so finish and to a small degree a bow if not too much is not the end of the world but if I was cutting for a" finished" slab I would use two rails for the first cut side by side to give the most support, think of felling- a 2" thick wedge is like 2' at the top of the tree so 2mm bend on the mill rails will soon become a bigger problem adding in bar flex etc on a milling cut. 

 

[Gog]

Thank you very much for your reply, lots of good points to try. I will let you know how I get on.

 

Kind regards

[billpierce]

I'd also check the cutters are all close in length lefties compared to righties. Don't think this is the bother here but I have had it do funny things with uneven cutter length

[trigger_andy]

When milling with my 48" Bar I find I get a slight sag in the middle no matter what I do. So when the Mill is in contact with all 4 corners and everything is square and true I note the cross bar with the push handle has a slight gap of a few millimeters. Im not sure what causes this? I also thought the weight if the bar, or torque of the motor? i also thought inaccurately and uneven sharpening but Ive been using the Granberg precision grinder to good effect and its not helped. 

[gobbypunk]

Do you think it may be the weight of the power head as I have noticed a very slight bow and taking the weight off the power head solved it , just a thought 

Cheers Mark

[trigger_andy]

11 minutes ago, gobbypunk said:

Do you think it may be the weight of the power head as I have noticed a very slight bow and taking the weight off the power head solved it , just a thought 

Cheers Mark

Ive tried this too as my 088 is a heavy old lump. In fact I have always done this as the Power Head really lifts up the other end of the mill.