rule of thumbs

[Eduard Nemirovsky]

Hi,
do you have a rule how to approximate BF's for a project.
Say, I am planning to build a computer desk - standard size. I need to buy a 45-50 bf of wood. Or for bookshelf( no plywood) I would need 60-75 bf? Or it is impossible to say and I need to calculate exact number for each project?
Ed.

[Glenn Clabo]

Depends on the wood and how you buy it. For example...I buy most of my cherry rough...so I usually add 25-30%.

[Jim Summers]

Hi,
do you have a rule how to approximate BF's for a project.
Say, I am planning to build a computer desk - standard size. I need to buy a 45-50 bf of wood. Or for bookshelf( no plywood) I would need 60-75 bf? Or it is impossible to say and I need to calculate exact number for each project?
Ed.


I usually calculate each time. Then add another 15-20 percent.

HTH

[Paul Girouard]

Hi,
do you have a rule how to approximate BF's for a project.
Say, I am planning to build a computer desk - standard size. I need to buy a 45-50 bf of wood. Or for bookshelf( no plywood) I would need 60-75 bf? Or it is impossible to say and I need to calculate exact number for each project?
Ed.



Most custom WW is just that custom so there is no "standard" size computer desk. There are standards like desk top height , chair height , but as far as width , depth , length they are what they NEED to be or , hopefully, designed / planned to be.

Just like the bookshelf , is it floor to ceiling , 10 long , 5 feet long etc.

So I'd say no unless it's a design you build more than one of. There is no magic rule of thumb .

Once you've figured out "exactly" how much you need , add 10 or 20 % onto that for waste due to sap wood , cracks , split ends misc , and the stuff you just forgot to figure for :o :eek:

So woods have more waste Walnut can have a LOT of sap wood , as can Cherry .

Do it depends :D

[Eduard Nemirovsky]

Glenn, Jim and Paul,
Thank you very much. I got an idea now.:D
What amaze me - this is only forum on internet, where you can get professional answer in matter of minutes.
Thank you again, Ed.

[Dave Falkenstein]

I buy hardwood from a dealer where I can go into the lumber area and select my own pieces. Using a list of the materials I need, I select material that will make those pieces. I check off each piece as I select it. I usually buy about 20 percent more than the plan calls for, to allow for waste.

[Tom Esh]

Really has to be on a project-by-project basis. I'm in the 20% camp, but more if I know I'll be trimming out sapwood.
Then I take whatever number and double it. If it comes out anywhere near nice I guarantee somebody will want you to build another.:D

[Don Bullock]

Most of the time my design for a project is based on the wood I find for it. Yes, this method may be a little backwards, but I find that I can utilize the wood and grain patterns better if I approach a project this way.

[Dave Tinley]

Ed-
I most often draw my project out on Sketchup then figure how many bf I need for that project, plus 20 percent for waste. Thats the amount I use in my quote to the client.
But in certain circumstances I will buy at a price break, like 100 bd ft.
As an example, I am building a armoire for a client out of mahogany, I figured 40 bd ft, but a interent lumber source had 100 bd ft of mahoany on sale, so I bought the 100 bd ft.
As I undersatand it Sketchup has a Cutlist now, so you can print out your materials needed.

Dave

[Lee Schierer]

I draw plans of what I'm making in autocad and then use a spreadsheet to lis each piece by length, width, thicknes and type of material. The spreadsheet will totoal up all the lengths I need and give me lineal fewet of material for each dimensioned lumber size. I then buy that many feet of materrial from by supplier. The material I buy is all F4S and knot free, so I can usually use every inch that I buy.

Once the material is home I measure all the lengths I got for each size of material and put that information along with the lengths of pieces of material I need into an optimization program. The program calculates the best way to cut the pieces from the material I have so I rarely have more than an inch or so of waste from a length. If I am grain matching pieces for looks I can cut those pieces first and then run the leftovers through the program again and generally get every thing I need.

[Eduard Nemirovsky]

what optimization software you are mention?

[Rod Sheridan]

Hi, I normally purchase about 25% to 50% extra by surface area depending upon sizes and grain matching.

By volume, about 50 to 75% more material.

Regards, Rod.

[Lee Schierer]

what optimization software you are mention?
I use Sheet Layout Version 8. The software was originally developed by Don Micoletti (spelling?) and I have used it for many years. It works on either sheet goods or lineal materials. There is a free version you can try and then purchase more advanced versions depending upon your needs. The hobbyist version should suit most home shops. I've found the solutions it presents for cutting to be highly accurate and it has saved me more than one trip back to the lumber yard when I have forgotten a piece in my initial calculations or I make a bad cut.

Sheet Layout (http://www.sheetlayout.com/)