Friday, November 6, 2009

Graduated Drawers

This post contains arithmetic in the form of whole numbers, fractions and decimals
some resulting from addition, subtraction, multiplication and division.
*Proceed at your own risk*

    When I was laying out the plans for the dresser on SketchUp I needed to determine the sizes of the drawers. I knew I wanted six drawers in three rows. The width would be the same for all six but I wanted the height to be graduated, that is, each drawer would be larger than the one above. I'm not much in the know about traditional furniture design but I did know that drawers were often graduated to give weight to the design and to lead the eye upward. I suppose with three rows of drawers I could figure it out on my own, eventually, but I came upon an article by Christian Becksvoort (Designing Furniture, Taunton Press 2004) which was very helpful and I thought I would share it with you. If you're like me you learn better with visual explanations so I made some examples on SketchUp so I could attempt to do the article justice.

    To find the dimensions of graduated drawers we need to know the following measurements:
    The Total height of the dresser
The thickness of the top, base and dividers within the carcase
The number of drawers
There is a slight variation in this method depending on wether you want an odd or even number of drawers.

       So let's begin with a dresser carcase with a dimension of 24" wide by 48" high constructed of 3/4" stock. We would like this dresser to have six drawers but in graduated heights.

Step 1. Determine the Usable Drawer Height
            Take the total height of the dresser, 48" and subtract the thickness of the top (3/4"), base (3/4")  and dividers (5 dividers x 3/4" = 3-3/4"). In this example the usable drawer height is 48" minus 5-1/4", or 42-3/4"

Step 2. Determine the Average Drawer Height
             Take the usable drawer height and divide that by the number of drawers you want to find the average height of each drawer. In this case it would be 42-3/4" divided by 6 which equals 7-1/8"

Step 3. Decide how much you want to graduate each drawer. I think traditionally drawers were graduated by the thickness of the dividers. Becksvoort uses 1-inch graduations which is what I'll use here.

Step 4. Find the height of each graduated drawer

Even number of drawers.
            For dressers with an even number of drawers the height of the drawer just below the middle divider would be the same as the average drawer height plus half of the graduation increment. In this case it will be 7-5/8" high. The dresser just below this would be 1-inch taller or 8-5/8". Add an additional inch to each drawer below. For each drawer above you would subtract an inch from the height of the drawer below it. The result in our example would look like this...

For a set with an
Odd Number of Drawers
             For dressers with an odd number of drawers it's a little simpler. The height of the middle drawer is the same as the average drawer height. Simply subtract the graduation increment for the smaller drawers above and add the graduated increment for the larger drawers below.
             Let's say we wanted our dresser to have five drawers instead of six. With four drawer dividers (4x3/4"=3") plus the top and bottom (2x3/4"=1-1/2") subtracted from the total height of 48" we have a usable drawer height of 43-1/2". If we divide this by 5 drawers we get and average drawer height of 8.7" or just under 8-3/4". If we use this to layout our drawers our middle drawer would be 8-3/4". We would add an inch to the larger drawers below and subtract an inch from the smaller ones above. It would look something like this...

          Of course the top drawer ends up being 6-1/2" but if it bothers you then you can make your average drawer exactly 8.7" or 8-45/64" if that's what you're into.
          If you just think about the concept it's not too confusing. This is just one way to layout graduated drawers that I thought was pretty simple as long as you don't get caught up in being exact. It's a good place to start I think but if you know of any other methods I'd like to hear about it.

Wednesday, November 4, 2009

Back in the Workshop

    After a nice vacation in the Florida Keys and a couple days in Chicago for the David Gray show I am back in the workshop. Yesterday I spent some time cleaning up the workshop in the barn, sweeping up and putting away tools. It's hard for me to feel focused on a project unless I have some semblance of order in my space. I'm no clean freak by any means but I do find it easier and safer if I don't have to worry about stepping over piles of scrap lumber and cut-offs and searching for clear bench space. When you have to squeeze-in time for woodworking I work until the last minute which leaves clean up for another day.
    After things were tidy I made some sawdust milling up parts for the dresser sides. I met my goal of gluing-up both sides leaving the top and bottom for today. After all sides are done I'll probably have to re-flatten them a bit and cut them to length. Then the real fun begins: dovetails. Through dovetails, half-blinds, and sliding. I'm definitely planning on hand cutting the through and half-blind dovetails, but I'm leaning toward using a router for the sliding dovetails with the drawer supports. I'm sure I could make it happen by hand, but I've got a busy schedule and I'd like to get this done sooner than later.
    I've finished some plans in SketchUp to show what I'm planning. I wanted to make a Shaker-inspired dresser with six drawers to fit in Ryan's room which has a wall which angles in about four feet up. I wanted to design it so it was obviously made by hand so the joinery includes visible dovetails in the top as well as the drawers. I'm thinking about turning the drawer handles from walnut and then staining them black.

    The part of the design I'm most concerned about is the base and how it connects to the case while at the same time allowing the case to expand and contract throughout the seasons. After researching other designs I decided to construct the base moulding around a frame and then attach it to the bottom of the base by glue along the front only, and then screws in oversized holes toward the middle and back.

    The moulding for the top will be attached using Christian Becksvoort's method shown in an article I read. He suggests using a sliding dovetail in the moulding which slides on to dovetailed keys screwed to the top 's end-grain. It's glued only to the front inch or so allowing the top to expand and retract without being held by the moulding. This will definitely be done with a router. If this sounds confusing I'll go into more detail when I get to that point.
    This may be my most involved project to date so I'm both excited and intimidated by it all. This could be either a big encouragement for me or could prove to be very discouraging. I know, one step at a time right?