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Forum topic by TMcG posted 06-05-2010 01:43 AM 2546 views 0 times favorited 24 replies Add to Favorites Watch
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TMcG

191 posts in 2466 days


06-05-2010 01:43 AM

I have a question regarding cut lists.

On a lot of the cut list diagrams I see the dimensions are all butted up against each other and I’m wondering how that works with taking the blade kerf into consideration ?

So are they always off by the blade kerf and you need to adjust for it or are they inclusive, so to speak, of the blade kerf ?

Thanks in advance
tony

-- http://wood.mcgivern.org


24 replies so far

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,

2387 posts in 3013 days


#1 posted 06-05-2010 01:49 AM

I am not sure what program you might be speaking about?

-- .

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TMcG

191 posts in 2466 days


#2 posted 06-05-2010 02:14 AM

Oh, not the cut lists generated by certain programs, more the ones contained in plans from Shop Notes, Plans Now, FWW etc…

-- http://wood.mcgivern.org

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a1Jim

115202 posts in 3043 days


#3 posted 06-05-2010 02:31 AM

You would have to check the the program an see if it compensates for the kerf or not.

-- http://artisticwoodstudio.com Custom furniture

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Rick

8287 posts in 2499 days


#4 posted 06-05-2010 02:41 AM

Tony:

I’ve noticed the same thing. I did some calculations on one set of plans from a “PLans” site and it appeared to me that there was NO allowance for the saw cut. One used up the entire width of a 4X8 Sheet and you could NOT cut it that way without coming up Short!

Rick

-- Hope Everyone Is Doing Well! .... Best Regards: Rick

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TMcG

191 posts in 2466 days


#5 posted 06-05-2010 02:44 AM

Umm, it’s not a program, really, it’s not :-)

In a magazine, for example ShopNotes, most projects have a cutting diagram that shows what pieces can be obtained from what pieces of material.

Perhaps I’ve confused everyone, I think I’m talking about the cutting diagram not the cut list, helps to be clear ! Sorry

-- http://wood.mcgivern.org

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Sawdust4Blood

392 posts in 2487 days


#6 posted 06-05-2010 03:11 AM

I consider all of those cutting diagrams to be notional. Aside from the loss associated with the saw kerf, jointing, etc, you have to remember that rough lumber isn’t flawless and there are always characteristics of individual boards that you’ll want to work around.

-- Greg, Severn MD

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PurpLev

8523 posts in 3114 days


#7 posted 06-05-2010 03:17 AM

lol, sorry, it’s entertaining seeing everyone thinking it’s a ‘program’.

yes, you would have to take blade thickness into consideration. basically the ‘board’ shown in a plan with the cutlist is really too narrow based on the diagram and cut lists as you suspected yourself.

good catch ;)

you could always consider the blade cut line within the board size meaning a 4” wide cut on the diagram will really give you a 3 7/8” wide board. as long as you keep it consistent – your project will match up.

this is a good topic. numbers are good to get a starting point, but once you start cutting your parts – you really start to gauge one part to match the other, so numbers may not be used at that point – thats why we use marking gauges and not measuring tapes/rulers. keep in mind this is woodworking -sometimes you cut one part too narrow, and then have to match the rest of the parts to that one, so it never really is a perfect cut per the cutlist, there are usually variations and corrections that take place during the build. as a general rule of thumb – I’ll always cut 1/4”-1/2” wider/longer when milling to give me a chance to stay true to my initial sizing.

-- ㊍ When in doubt - There is no doubt - Go the safer route.

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TMcG

191 posts in 2466 days


#8 posted 06-05-2010 04:49 AM

Rick, what a relief, thought it was just me ! :-)

And there I was being all literal about them, oh well, who’d a thunk it ?

-- http://wood.mcgivern.org

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pmayer

864 posts in 2531 days


#9 posted 06-05-2010 05:08 AM

If a publication has provided a sheet layout diagram without accounting for the kerf, they have made a mistake. They should give you at least a full 1/8 kerf, plus some wiggle room to clean up an imperfections on the edges, etc.

-- PaulMayer, http://www.vernswoodgoods.com

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,

2387 posts in 3013 days


#10 posted 06-05-2010 05:34 AM

I would say any plan or diagram that does not consider the kerf is a poor plan/diagram. I have always enjoyed making my own drawings as part of the fun of building. As amateur as I am I still seem to remember to account for a blades kerf when nesting sheets.

I realize I was confused and wanted to ensure clarity. My program I use spits out cut list (which I do not use)and so that term started me on the program thought process. Plus I actually have not digested much in the way of shopnotes or other publications but hope to in the future. I have been mostly self taught and learned a lot on www.finewoodworking.com.

-- .

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MisterCat

22 posts in 2389 days


#11 posted 06-05-2010 05:50 AM

TMcG, I view the ‘cut diagrams’ as a sort of 2 dimensional parts list for a project. One of the uses that isn’t mentioned above is that they also establish grain orientation as well as listing the dimensions.

They are also useful for helping you determine how much material you need to buy to do the project, and more helpfully what board width makes sense for the parts you need. This isn’t too much of an issue for sheet goods, but for solid wood (even softwood) getting very wide boards can be difficult.

I’ve noticed that the diagrams vary a bit, but most often they will not take kerf width into account. This will sometimes cause issues where you are trying to maximize plywood usage. My rule of thumb is 1” extra per cut.

Lastly, there are computer programs that make cut diagrams automatically, but mostly they are the high end cabinet design. Google around for ‘cabinet design software’ if your curious. I personally have not used any of the programs.

I do use Excel when I’m laying out a project for cutting. I Resize the colums and rows to fairly small squares, and generally use 1 square=1 inch. I use the border drawing tools to create boards, and use the highlighting tools to color in the individual parts. Sometimes I’ll even use formulas to calculate board feet. If you really wanted to get fancy you could make extra thin rows/columns to symbolize your kerf loses. For me its a pretty easy, graphical way to lay things out. Excel also lets you draw shapes, lines, circles ect, but I rarely use those tools as they bring i the complications of scale and proportion, ect.

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wseand

2754 posts in 2508 days


#12 posted 06-05-2010 08:51 AM

Never even thought about using excel for cut lists /design, interesting. I always use pencil and paper but it would be nice to have a more permanent drawing. I use sketch-up for visual aid, can’t draw worth a darn.

-- Bill - "Freedom flies in your heart like an Eagle" Audie Murphy

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degoose

7196 posts in 2820 days


#13 posted 06-05-2010 10:29 AM

I use a bit of timber to check if I have cut it right… remember drink twice cut once… OH LMAO.

-- Drink twice... and don't bother to cut... @ lazylarrywoodworks.com.au For lovers of all things timber...

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Catspaw

236 posts in 3281 days


#14 posted 06-05-2010 04:37 PM

I think maybe the bottom line here is being missed. A dimension on a print, cut list, whatever, is a dimension. That is the size the part needs to be. Kerf is never a consideration unless someone is laying out the materials and is trying get get two 24” pcs. out of a 48” pc. Then they are making a mistake.

No one would know whether you are cutting 4 @ 24” pcs. out of a 10’ bd, 12’, 3’ whatever. If the pc needs to be 24”, then it is cut to 24”.

Cut lists don’t have dimensions butted up against each other. The print might, but, a cut list is nothing more than a list….

4 3" x 24" x 3/4"
2
4” x 24” x 3/4” ...etc.

So unless I missed something in your original question and you are actually looking at the print, then forget kerf…it has nothing to do with it accept for getting the parts out of the material, efficiently, that you have in stock.

If the list says buy an 8’ board and cut 4 @ 24” out of it…they’ve made a mistake. You would not cut them less the kerf, then, try to build the project.

-- arborial reconfiguration specialist

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wseand

2754 posts in 2508 days


#15 posted 06-05-2010 08:24 PM

@ Catspaw excellent point, always check your plans. I certainly wouldn’t want to waste a good piece of wood or change all the dimensions to compensate because someone else messed up. I prefer to make my own mistakes and than blame it on someone else. ;~)
But, an excellent question.

@ PurpLev, you know you thought it was a program at first. :~)

-- Bill - "Freedom flies in your heart like an Eagle" Audie Murphy

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