Considering chainsaw mill purchase

[woodsy]

I'm considering the purchase of a chainsaw mill, like a Sperber or Granberg, as an accessory to my band mill.  My plan is to use the chainsaw mill for quartering large diameter logs that the band saw mill can't do.  Once in quarters, I would then slice them up on the band saw.  I'm basically looking at 2 cuts with the chainsaw mill to get the logs in quarters and maybe an additional slab or two off each quarter if they need to be whittled down before using the band saw.  I've read a fair amount on chainsaw mills here at the FF and have learned quite a bit but I have a couple questions that concern using bars and making cuts 48-72 inches wide.

Have you ever experience problems with the chain diving or rising during wide cuts? If so, is this do to improper tuning, feed rate, etc, or something else?

Are there any preferences toward using or not using a Sperber or Granberg Alaskan mill?  Any pro's or cons that you care to share?  Can these mills handle cutting a 50-70 inch diameter log in half? It seems they could with a little modification? Is there another chainsaw mill I'm missing that I should be looking at?

Would you recommend double head power for wide cuts (48-72)?

It's not as if I'm going to be using the chainsaw mill every day.  The slabbing mills look nice and enticing but I want to keep costs down and have the mill portable.  I'm not as concerned with slow feed rates, as I am with having the ability to safely and accurately quarter big logs.  Besides, it gives me an excuse to add another, and bigger, saw to repertoire.

Thanks in advance for your advice, input, and suggestions, it's much appreciated.

[terrifictimbersllc]

Not aware of any stock chainsaw mills that will cut over about 48" wide, or which will drop the bar enough (2-1/2 to 3-1/2 feet) to saw through the center of the diameter logs you mention.  If you did build/modify one, you also need to work into your plan whether you are going to be doing this alone or with help.  Have you considered freehand sawing with a big bar, like CustomSawyer has done (thread in the last couple of months)?

[paul case]

woodsy,
i have thought about the same type of a set up to dd to my mill. i have a stihl 660 that would turn it so all i have to do is add the long bar and i was thinking of making a portable wooden track to carry the ends of the saw. just for splitting. the set up might never get used enough to justify having it for me. thats a holdup on spending the money and time doing it. my mill will swallow 40'' and cut 36'' and i only get one bigger than that once in a while. 
what else is already in your repertoire?

[Meadows Miller]

Gday

With what your trying to do Mate you would be better going for a rail type csm where the chainsaws I have seen a couple of good ones over the years and the westford rail mill would suit what want to do and you can use it on your own which is a plus  ;) just buy afew different bars to suit the log dia you want to cut a 44" bar on one would quarter a 72" log easy in four passes  ;) they will run upto a 72" bar but I reckon that would be pushing it even for a 3120 Mate  ;)

Heres the site if you want to have a look Mate   www.vianet.net.au/~jemal   ;)


Regards Chris

[terrifictimbersllc]

Very interesting, the saw head is bigger than the operator in the rail mill picture. Notice that she is not the one running the slabbing mill.   Do you have to roll the log or can the mill be run on the side of the log?

[Kevin]

woodsy;
Have you tried cutting a log free hand with a chain saw?

[mad murdock]

Woodsy, Like Kevin suggests in his question, a evenly sharpened ripping chain on a good sized saw, will quarter a large log handily with a lot less messing around with a mill attachment on the saw, if you are going to mill the quarters anyway, you are not looking for perfect precision on the quarters, you can tack a guide string or some other aid on the log to follow a straight line, and get on with milling, rather than monkey with the CSM attachment.  I have a Granberg Alaskan II, and it does a fine job milling, but it takes time and is rather tedious to get a accurate cant, as it requires some detailed measuring on both ends of the log to make sure the guide rails are equadistant from the log center.  The rise or dive hasn't been an issue I have had to deal with, I am pretty picky about running a dull chain, every tank of gas or so, I run a file on the cutters, just to keep a good edge on the chain.  Only takes a minute, and it gives the motor and the operator an extra minute or two to cool down between work cycles. Check out some of the posts by Jim King, on the stuff he is doing in the Jungles of South America.  The loggers there cut a tree down, then rough mill a cant by hand with the same saw they fell the tree with, then pack the cants out of the jungle on their backs to a mill.

[mtngun]

A Granberg Alaskan can only cut 12" or so deep, so it won't easily quarter monster logs.

However, it is easy enough to fabricate a homemade Alaskan to make deeper cuts.

Single 120cc powerheads are commonly used to drive 72" bars.    It'll need an aux oiler, and the middle of the bar may need some support at the start of the cut, otherwise the bar may sag from its own weight.

If your only goal is to quarter monster logs so they'll fit on a bandmill, you may be better off milling freehand, or making a scaled up version of the Granberg mini-mill (which is not sturdy enough to support long bars).

[terrifictimbersllc]

Eric at Granberg sold me 36" alaskan uprights.   I also modified my Sperber 52 with aluminum extension rods, added to and threaded and sized  to match the originals, to drop the bar up to a similar amount.  Have 3 different length additions for different situations, here's a 36"---46" sycamore sliced through the middle:

BEFORE:



AFTER:

[woodsy]

Thanks for the input.  The thought of a chainsaw mill never really caught my attention until the other week.  I guess the idea of having one to help facilitate in quartering large logs while at the same time giving the option of slabbing them, was/is appealing to me.  Sounds like all the poodling involved to modify one to cut 2+ feet deep may not be worth it in the long run. 

The Westford is interesting, thanks for pointing that out.

P.C. - I've kept it simple with a LT40HDG38, a tractor with forks and bucket, an undersized chainsaw, and an oversized 2 man crosscut saw for when I'm not sweating enough.

Yes, I've ripped logs in half lengthwise freehand, but nothing of substantial diameter (built a cribbed dock one summer in the arctic watershed of Canada ripping more dock boards freehand than I ever care to do again).  I haven't written the freehand method off, just wanted to see what other avenues might exist.

[redbeard]

I found this pic a few years back, I liked the idea but looks a bit scary.