The Society of American Period Furniture Makers

Books, Plans, Magazines and other media => Discuss plans and drawings. => Topic started by: walter connolly on June 18, 2009, 05:49:33 PM

Title: Furniture plans how accurate
Post by: walter connolly on June 18, 2009, 05:49:33 PM
When you purchase full size furniture plans from a professional how accurate should they be, with in 1/16", 1/8" is there an industry standard? Confused and a little upset. The # don't add up.
Title: Re: Furniture plans how accurate
Post by: frangallo on June 18, 2009, 08:05:24 PM
I don't know if there is an industry standard for reproduction furniture but I shudder to think that one might exist. Whenever I take on one of these masterpieces I do as much research as I feel the piece deserves. For example years of research went into my Newport blockfront while I was quite satisfied with the plans in a book which I used to make a Queen Anne stool. I have found that there must have been many factors that influenced the final dimensions of the original pieces. You must put yourself in the position of the original maker. These folks negotiated with the buyer to finalize the final product. That is why we find, in general terms, variation in the actual dimensions of the final product we see on public display. I believe it is important to get as much information as possible from the experts on the subject but never to assume that anything is written in stone. Many highly qualified persons mention this in their publications and provide valuable suggestions on how to extract original dimensions from photographs of pieces using distortion factors of the camera lens in situations where measuring is disallowed. I myself am quite addicted to Verna Cook Solomonsky's 1953 publication for accurate dimensions of pieces seen in the Metropolitan Museum of Art, but there are many other sources. On the other hand if the plans you are working from literally don't make sense there is always the possibility you spent money injudiciously and would be better off using the plans as a rough guide and the literature extant as the final authority. I hope this has been some help.
Fran
Title: Re: Furniture plans how accurate
Post by: walter connolly on June 19, 2009, 09:15:24 AM
Thanks to all who have answered my post. Clarification,when the table of off sets states that the leg of a table is 14 3/4" but the full size drawing measures 14 1/2" that is what i meant about an industry standard regarding accuracy + or -. This is the first time i have purchased full size furniture plans from a professional. 
Title: Re: Furniture plans how accurate
Post by: cbentzley on June 19, 2009, 10:32:46 AM
Walter,

When I draw plans, I draw them full-scale, as accurately as possible. My print shop scans my drawings as saves them as a PDF file. When they are printed, they are accurate to within +/- 1/16" over 36". The prints are accurate enough to trace patterns directly off of them.

Craig
Title: Re: Furniture plans how accurate
Post by: Tom M on June 19, 2009, 12:50:28 PM
Walter,

I also draw full scale.  If hand drawn there is potential for things to be off a bit (say 1/32) due to pencil wear, etc.  If I draw it in CAD, then for all intents and purposes it is exact - at least on the monitor.  Once printed you can always get a little variation.  It is always good to check several longer dimensions on a drawing with a scale.  For the last couple of drawings, I've drawn 12" scales (x & y) on the drawings so people can have a visual check.

If you find that only one dimension is off, like in your example, it could just be sloppy drafting, or mis-dimensioning (i.e. the drawing is correct but the text is wrong).

I've only made one piece of furniture from a purchased drawing, and spent a great deal of time before starting the project going over the drawing in detail.

Tom
Title: Re: Furniture plans how accurate
Post by: HSteier on June 19, 2009, 04:25:22 PM
I think that obsessing over fractions of an inch is a big waste of time. I mean I too like to obssess over my projects, but not whether it's 1/32 too big or too small. Once I get started I use plan measurements only as a guideline and then individually measure each piece to fit. It doesn't matter to me if the plan says the drawer opening is 32" by 6" and my actual size is 31 15/16 by 6 1/8. I cut to fit.
If you look at multiple pieces by one maker (the Elfe chests come to mind) none are exactly the same; too much time wasted over obsessing about fractions.

Howard Steier
Title: Re: Furniture plans how accurate
Post by: John McAlister on June 19, 2009, 05:06:20 PM
I agree with Harold, Tom, Craig and Fran, you can waste a lot of time and effort worrying about small fractions of an inch. Sometimes, as little as an eighth of an inch can make a significent difference in, say space between drawers; or thickness of a Hepplewhite leg; you just need to make it look right! But overall width, length, leg length, top overhang, etc, a sixteenth or even an eigth wouldn't make any difference. I generally draw my plans (mostly 1/4" scale: full size for pieces I need a pattern for) from photographs  and in making a case piece I feel lucky to come within a sixteenth of what I draw the drawer openings to be! But as Howard says you make the drawer to fit the opening!
Title: Re: Furniture plans how accurate
Post by: bmaus on June 19, 2009, 06:01:35 PM
Was lucky enough to spend a little time with John Bivins when he was at MESDA. He was working on his book "The FURNITURE of Coastal North Carolina" Remember him saying as an aside, "sometimes all 4 legs on a table might be different widths or thickness.  Like John said I can always make the drawer fit.

Bob
Title: Re: Furniture plans how accurate
Post by: Tom M on June 20, 2009, 10:10:22 AM
I agree with all the last comments - starting with Howard's.  My point was to directly answer the question which I think had more to do with the drafting of the drawing.

When making a drawing all four legs of a table will be the same, of course they weren't on the original, or on the part you are making from the plans.

I'm a Design Engineer, and spend a great deal of time going over drawings making sure the designer has gotten the datams right, tolerances right, correct views etc.  Becasue of that I probably over-do the detail on my drawings of period furniture.  But I've look at some one page drawings of a secretary desk and think "how could you ever make that from this drawing?" You would certainly have to be an expereiced woodworker who would have an understanding of construction basics (drawer runners, etc).

I just completed a William & Mary Dressing Table drawing for Olde Mill.  Gene had traced the templates off the original, so things that in my "perfectly engineered world" should have been a radius scribed with a compass weren't. I guess almost 300 years ago the cabinet maker either freehand sketched them  or "poorly" rasped to a marked line.  As the drafter of the drawing I had to decide if they should be drawn as radii or sketched off the template.  I used the template.  If you were to buy the drawing you of course would want to review it in detail and decide for yourself if you want clean symetrical curves or lopsided asymetrical cutouts with flats.


Tom
Title: Re: Furniture plans how accurate
Post by: rococojo on July 21, 2009, 03:30:59 PM
I think that obsessing over fractions of an inch is a big waste of time. I mean I too like to obssess over my projects, but not whether it's 1/32 too big or too small. Once I get started I use plan measurements only as a guideline and then individually measure each piece to fit. It doesn't matter to me if the plan says the drawer opening is 32" by 6" and my actual size is 31 15/16 by 6 1/8. I cut to fit.
If you look at multiple pieces by one maker (the Elfe chests come to mind) none are exactly the same; too much time wasted over obsessing about fractions.

Howard Steier

This is the trouble with the world today; no one can stand still to think (or measure)? Everything is on the rush? Why did Rabone rulers, tool up from a length of string?
To give us accuracy.
I was trained to make, then fit a drawer so that it worked as a damper, (hard to close because of the traped air)   if Howard cannot be bothered to use the segments, Dose it makes sense to receive the correct change, howard. or would you for- go that as well. I'm thinking not.

                                              Joseph 

Title: Re: Furniture plans how accurate
Post by: John McAlister on July 21, 2009, 03:50:00 PM
If you make a drawer that's hard to close (because of trapped air, or for any other reason) you've made a bad drawer! A good drawer closes easily! John McAlister
Title: Re: Furniture plans how accurate
Post by: rococojo on July 21, 2009, 04:59:54 PM
John, I was using that as an example only on fractions? Of course a job would never go out unless a flat penny could fit around the drawer. Sorry if I mislead anyone.

                                           Joseph
Title: Re: Furniture plans how accurate
Post by: frangallo on July 22, 2009, 12:10:24 AM
Joseph, please describe what you mean by a "flat penny"
F
Title: Re: Furniture plans how accurate
Post by: rococojo on July 22, 2009, 04:03:14 AM
Fran, A flat penny?  Is from the old coinage, of puree 1972 decimalisation in England, it a old slang word, deriving from worn down? By rubbing against other lose change in the pocket; the imprinted images on both sides of the copper coin are worn away, leaving the coin 1/16” thick. All coins wore down just the same? It must have sounded correct why this one stuck, accordingly from the very earliest days.   
sorry for creating any confution.
                                                                  Joseph
Title: Another issue...
Post by: awleonard on July 22, 2009, 02:57:40 PM
Paper shrinks!  I have a set of plans from a Phil Lowe class.  I know the drawing was correct.  We measured everything off of the original.  Got it home and hung it on my shop wall to reference and found that all my dimensions in one direction were shrunk by about 3/32"!  I only wish my skills were good enough to fret over fractions!  But as a habit, I rarely worry about matching dimensions and work to fit.  I rarely use plans done by others, and my plans are usually not that great.  I do them all in CAD, so I know I can go back and measure the drawing if needed.  I know a few folks at my level (pretty much rookie) that really put a lot of time into making sure every piece is exactly what the plan says it should be.  Life is too short for that!  For most pieces, it seems like once you get the basic carcase together, its time to start measuring for fit anyway. 

Tony
Title: Re: Furniture plans how accurate
Post by: klkirkman on July 23, 2009, 06:56:22 AM
It is a long standing rule of the drafting profession that plans are NEVER to be scaled in use.

While most draftsmen endeavor to draw an object "to scale", it is permissible for a number of reasons to have a finished print of a drawing out of scale in whole or part, and some preprinted title blocks even contain the note "do not scale".

Accompanying this freedom to have parts portrayed not to scale is a responsibility to show on the plan every dimension that the builder will need to complete the piece, thus eliminating the need to scale the drawing. In cases where a complex shape is involved, this dimensioning is accomplished by using something like a table of offsets.

Karl
Title: Re: Furniture plans how accurate
Post by: awleonard on July 23, 2009, 09:48:31 AM
Something I do a lot is print patterns from my drawings via my $99 inkjet.  I'm amazed at how accurate they are!  Now, I don't use those for joinery, but for things like cabriole legs patterns, scroll patterns, etc., they are very useful  I also will print scale sections or parts just to use as a guide.  I measure from those, but I usually know what they ought to be anyway.  Drafting was never my strongpoint.  I used to design race car parts and my prints were very crude.  Got the job done, but wouldn't have passed muster in a high volume "real life" production.  I only vaguely learned geometric tolerancing.  Got me a few times!  Nowadays, seems like models are the norm and you rarely see a "print" anymore.  Makes the QC guys crazy! 

Tony