Looking for advice on Peterson slabbers

[Fether Hardwoods]

 I have been trying to slab some logs with my Peterson mill but it has been giving me some trouble and can't quite get it straightened out. It tends to rise in the cut some and is actually cutting a crown in the center of some slabs (across the width), I have tried new chains and resharpened chains with very little luck. Any suggestions? 

Thanks

[terrifictimbersllc]

Your bar might be worn out.  

Does the chain "cock" slightly whenever it starts to cut?  This is a sure sign. 

Things to do....
dress the bar perfectly square with a bar dresser tool using a good square with good light to check. 
run your chain really tight to double check
If the chain won't cut with gentle pressure and especially if it cocks slightly then cuts, you probably have a worn out bar (groove gets wider as it gets deeper, maybe helped a little but not fixed by closing up the groove-that works only at the front edge of the groove not down deep).  

Flip the bar over if the other side is unused.  Or get a new bar. 

Worst thing for a bar is to let the chain cock and cut at an angle.  The drive link tip will wear the bar wider down deeper. 

[longtime lurker]

Do all the above about dressing the bar. I usually give my bar a couple swipes with a bar dressing tool every time I put a fresh chain on to keep it flat... its a wear part

Make sure the bar groove is clean. I've had a mix of grease and fine dust pack to one side of the groove before and throw a chain out of square that way.

Check your chain body to ensure the bottom of the chain is square.  Bar wear issues create chain wear issues so if your bar wasn't level there is most likely wear on the chain to match that.

Then check the bar is mounted square. I'm not sure of the exact procedure with a peterson but you need the bolts that hold the bar in place under the right tension. There will be a preload in the bar to stop it sagging. With a Lucas you dial the bar in by adjusting the tension on the two retaining bolts on the sprocket end... it's not just do both up tight, its put ½ turn on this one and a 1/4 turn off that one until its cutting well because you can twist or untwist the bar by where the force is applied. I imagine the peterson will be similar.

Check you mill alignment is level. If the rails arent parallel  it will cut a twist in, and the twist thats not really noticable on a 10 inch wide board can be pretty significant over a 60" slab.

Talk to Peterson. They've got a pretty good reputation for backing what they sell and I imagine by now they've talked someone through just about everything that can go wrong with one of their mills.