ripping 48" fir in half and quarters?

[Matt_Ridgeway]

I own a WMLT40 bandsaw and have some 48" diam x 16'  logs I want to vertical grain cut. So I need to half and quarter these logs. I was told by an experienced ripper that a stihl 066 with a 36" bar and ripping chain with a couple of snapped lines will do the trick. He says he cuts from above as deep as possible and then either rotates the log 90 degrees and cuts a quarter out or returns to the original cut and pries it open enough to let the two halfs drop. Working from above like this scares me and I'm weary of the logs splitting apart while I'm above, however the economy of this simple setup rather than an extra hand on an Alaska mill horizontal system is appealing. Does anyone have experience ripping these size logs with this machine and bar? Safety wise what are all the precautions to be aware of?What precautions should I take not to ruin the wood as a novice ripper? Also what pitch,gauge and raker depth is optimal for the ripping chain? I've already bought the stihl 066 and 36" Oregon bar off of ebay on his advise.

[woodmills1]

If the chain is sharp my 066 will rip white pine with the bar buried into wood.  It is faster if the tip is free but non the less the thing rips pretty fast and straight even buried.  sharp chain is very necessary though.

[Kevin]

Also what pitch,gauge and raker depth is optimal for the ripping chain?
 

You will likely get a couple of different answers on this but I use an Oregon 3/8 pitch RA ripping chain and keep it at factory specs.
Crank the bar oil output way up.
You can also jack the log apart  with a hydraulic jack once your top cut is made.

[johncinquo]

This sounds like a kick back waiting to happen.  Buy borrow or beg a longer bar and chain and cut it in half and then quarter with the bar out all the way.   Your face will thank you for it.  

[Tillaway]

If you bought a used bar, be sure it is in good shape before you try.  If it is worn too much it will try to cut in circles.  

[Frank_Pender]

Matt, I have ripped a number of Sequoia logs that were 6' through with an 066 and a 3' bar.  I have worked both methods of horizontal and rolloing 180 degrees and getting the second side as well as standing the log on end and ripping downward.  In both case I still had 6 to 12 inches left uncut.  I simply placed the forks of the tractor loader in th cut and split the rest.   That worked great. 8)

[Captain]

The "kickback waiting to happen" comment is prudent.  Especially considering these factors.  For ripping a log partially, not through entirely, it is necessary to bury the nose or tip of the bar.  Safety chain with the extra bumper links WILL NOT cut at the nose of the bar along the radius, the bumpers are designed to exceed the height of the cutter on that tight turn.  Therefore, you need a non-safety style chain, prone to kickback, for this operation.  BE CAREFUL.

Sawing on the vertical is easier in my opinion to keep a straight cut than on the horizontal.  I will use a 2x4 temporarily staked to the top of the log for a guide that I rub my saw against.  Do not expect to get to a 36" depth with a 36" bar.  It is difficult to cut and keep the saw truly vertical without rocking it on the bucking spikes or something.  I try to remove the bucking spikes to get more depth if necessary, and it removes the temptation to use them and damage the bar.

For ripping, I like 3/8 low profile chain.  It has a narrower kerf, and cuts faster.  I have a loop for my 32" bar on my 066.  For my shorter bars, I'll take a chain with only a small amount of life left and regrind it to 10 degrees for ripping softwood, or 0 degrees for ripping hardwood.  I call them my "stump chains"  I do not feel so badly about them when they are descimated by tramp metal.

I don't do nearly the amount of this quartering and preslabbing any more since I got the Peterson ;).

Have fun and BE CAREFUL

Captain