Converting FBM to M3

[Woodlotguy]

Could someone please tell me how to convert FBM into cubic meters. In Canada the logs are sold in m3 but the lumber is in $per thousand board feet . I am trying to figure out what recovery I am getting and what the value of my log is in board feet. Is there a formula I can use
Thanks!

[Jeff]

Well,

Lets look at this logically, which probably is not the right way. By the way, welcome woodlotguy.



Meters3 x 35.31 = Feet3
or      
Meters3 / 0.0283 = Feet3
--------------------------------------
Feet3 = 1728 cubic inches
1 Board foot= 144 cubic inches
12 board feet = Feet3

1000/12 = Feet3 (83.33)

so 1000 board foot is equal to 83.33 cubic feet

So ((number of meter3*35.31)/83.33) = MBF
-----------------------------------------------------------------
or 1 METER3 = .4237 MBF

or 1 METER3 = 424 Board feet.


Thats my Calculations anyhow
                              

[Jeff]

[swampwhiteoak]

Woodlot,
I believe you are asking a complicated question, or perhaps not.  

1000 sawed board feet is equal to 2.36 cubic meters.  Easy as that.

However if you are looking at 2.36 meters of logs and want to know the board footage by log rule it is more complicated than that.  Log rules are set up not as an absolute measure of volume, but more as an estimate of yield.  Log rules vary depending on log size and such.  With a log that is 15" small end and 16' long the conversion factor is 1000 bf = 3.48 m3.
According to: http://www.srs.fs.fed.us/landowners/convert_metric_units.htm

FAO seyz 1 MBF sawlogs = 4.53 m3 or
                 220.7 bf = 1 m3
but they don't say what log rule they're using although one would expect international 1/4"
http://www.fao.org/docrep/x5339e/x5339e0g.htm
                
The conversion factor is going to vary depending on log size and log rule no matter what.  I'll try to find a table or formula in the office next week unless someone else wants to chime in - hint, hint, canadians.

There are probably different ways to scale even using m3 but I don't know anything about that.

[Woodlotguy]

Thanks Everyone!

I think I can figure it out now.

[Ron Wenrich]

Looking over that FAO link also gives a conversion of 3.96 cubic meters of roundwood to saw 1 Mbf of lumber.  

Like all conversions, log size is a limiting factor.  In pine mills, they run a Lumber Recovery Factor - LRF.  These are given as total lumber yield in bd ft/total log volume in cu ft.  

You could do the same with cu meters.