Guidance on bdft calculators and their use

[Nick Walkley]

Hey guys.

I have been asked to take out a line of trees, they are pine and pruned up to 4meters (14ft).

The customer has asked if I could mill them as well, there will be about 200 clear logs and some "others", and wants to know how much timber he could expect to get.

I gave been looking over the calcs in the tool box but don't completely understand how to use them or even which ones to use.

Can someone offer some guidance please, I promise to post pics if the job comes off :D

Nick

[GAB]

Nick:
This is one of those questions which can have numerous correct answers based on assumptions, equipment used and the ability of the sawyer.  The quality of the raw material also is a variable that can have major consequences.
You wrote: "The customer has asked if I could mill them as well, there will be about 200 clear logs and some "others", and wants to know how much timber he could expect to get."
The following is assuming that the trees are down and bucked to length: I would suggest you get a tape measure, or yardstick, and measure your logs inside the bark at the small and and also record the length.  Note: Very few logs are perfectly round so take the smallest dimension across and add to it the largest dimension across and divide by 2, and round of to the nearest whole number.  This is called averaging the diameter.  Then print out the International 1/4" scale and tabulate all the logs.  Then the tricky part comes in.  You need to adjust for log defects such as bends or crooks etc.  Then you need to adjust for your sawing expertise and capabilities as this can greatly affect the end results.  Sawing errors can be costly to the end results.  I know as I've unintentionally made some long tapers.
If you are using a thin blade kerf machine then your yield could be as much as 110 to 125% of the Intl. 1/4" scale.
With mostly straight logs I have on occasion gotten yields of over 125% of the Intl. 1/4" scale.
Notes: How much wane the customer is willing to accept will also affect your end results.
If the trees are still standing: The above is not going to help you and I hope someone else can help you as I am out of my realm of knowledge.
Oh and Welcome.  Gerald

[Nick Walkley]

Thanks for your advice Gerald.
Unfortunately the trees are still standing, my estimates are drawn from a visual assessment of what is standing. What I need to do is estimate the sawn yield from the currently standing trees

Nick

[GAB]

Nick:
Good Luck.
I do not know how you account for hollow trees when they are standing.  Also trees that look straight standing look differently when on the bed rails of a sawmill.  Gerald

[Nick Walkley]

I don't think there will be any hollow trees, they are plantation pine and we'll maintained.

There will be some sweep to account for but generally they look like very good logs(trees). Of course the proof will be in the cutting :D

I wonder, because of the lack of interest, am I asking for information on something that isn't normally done?

I am not trying to get a perfect number but I do need to give the customer an idea before he will commit. I usually have logs delivered and what's comes from them is what I get, I have never had to try and calculate sawn lumber before I start.

Can anyone offer any more advice?

Thanks in advance

Nick

[BaldBob]

Hey guys.

I have been asked to take out a line of trees, they are pine and pruned up to 4meters (14ft).

The customer has asked if I could mill them as well, there will be about 200 clear logs and some "others", and wants to know how much timber he could expect to get.

I gave been looking over the calcs in the tool box but don't completely understand how to use them or even which ones to use.

Can someone offer some guidance please, I promise to post pics if the job comes off :D

Nick

In the tool box, go to board foot volume in trees,set the form factor at 80, plug in the diameter at breast ht.(4.5' above ground) for each tree, plug in the number of 16' logs (to a merchantable height) to the nearest half log in that tree , hit calculate, use the international 1/4 inch rule . if there isn't much defect, this should give you a conservative estimate of the volume that tree will yield. You should get a pretty good estimate if you take a good sample of the trees (e.g measure and calculate every tenth tree) and multiply the sum of the results by the expansion factor. If the trees have little or no defect you will get 10-20% more than the estimate.

[Nick Walkley]

Thanks Bob,

I will go and measure tomorrow night and report back.