Wednesday, January 20, 2016

A Ming-Inspired Cabinet (27)

Before getting to project progress stuff, I guess a few more chisel set pics wouldn't hurt, as the earlier ones shared in the previous post were a bit dark. Hope this gives a clearer view:



The gumi has some nice irregularities, which I like:


The rings are pre-fitted about halfway on, and it did not take long at all to prepare the handle end and drive the ring on:


I fitted 10 rings in a row and it took about 30~40 seconds each. These tools almost set themselves up.

The flat neck allows the chisel to behave like a long paring chisel:


Meanwhile, more legs were being milled on the Zimmermann. The splay on the legs is 0.5 in 10 each way, which is the slightest slope I've worked with when dealing with these type of compound-angled projects. It's challenging.

In this step, the legs and attached bronze leveler foot are being made very slightly out of square in cross section - intentionally so - with but a whisper cut:


There's likely no point in trying to mill such a thin angle, but I thought I would give it a go.

Then the set up was changed and the top of each leg rebated in two directions so as to form a clamping tab:


A minor puzzle to set up:


The clamping nub on the end of the leg:


The c-clamp was tried and then latter found to be unnecessary:


The last couple of days however I've been working a fair bit on the project drawings again, so I haven't been at the shop at all.

As I revisit the drawing time and again I have been allowing the design to percolate. This has proven to be advantageous actually. Some aspects cannot be reversed now as I've already cut the parts, however other aspects - namely much of what will be placed atop the stand I'm currently making - exists in a window of opportunity for change. So I keep thinking about ways the piece could be improved or tweaked.

One area in particular I have been scratching my head on concerns the hardware for the bifold doors. In a past project, the walnut vanity shown back in 2009 on pages here, I overlooked the hardware a bit and it came back to bite me in the ass when I found that the little doors with curved edges were problematic to hinge. I avoided a disaster on that one by slight fiddling with hinge centerlines, but it was a close call and drove home the lesson that sometimes seemingly minor things can have significant effects on a given design. It is all too easy to overlook a minor thing which can in some cases sink a design altogether.

With the bi-fold doors, I have multiple hardware requirements. There are the pivoting hinges, there are the hinges between the door pairs, and there needs to be some means by which the doors can be latched and held, at least in the closed position and possibly in the open position as well. There need to be handles fitted on the front of the bifold door pairs, and these handles should stylistically tie to other hardware if possible.

Intersecting the hardware choices for the bifold doors are the hardware choices for the drawers, along with the set backs for the drawers, drawer dividers and the upper sliding doors as well relative to the back of the bifold doors and their hardware. A certain type of drawer handle, if located in an area where a piece of hardware (like the hinge) for the bifold doors was located, could create a point of interference. That's just one of the potential hazards to be considered.

I was going to go with a piano hinge for the bifold doors, however, strictly speaking the doors are not so heavy or heavily stressed that the piano hinge's strength is especially needed. So I began to consider smaller hinges. Piano hinge quality wasn't all that great for the most part besides.

Then I came across some interesting sprung hinges, made by Bommer. Here's an example:


Between the hinge parts on the upper end you can see a little capstan turret sort of affair. You insert a metal tension rod into the capstan and turn it to add tension to the hinge spring, then move into place a second small pin, into a keeper hole, to keep that tension setting. They are pretty cool, stoutly made and the company has been in business since 1876. They make a small enough model, 3" long, which could work very well I think on this cabinet. They would be largely concealed from view. The springs would work to help the doors close flat and would assist in the process of opening the doors from their folded position.

The thing I want to avoid is a uncontrolled bifold door swinging open all the way or dangling out in space. I want the door to fold away tidily, and store well in both open and closed positions. The bifold doors on the closets in my house use a metal guide track on the lintel, however it makes an unpleasant noise when the doors are opened, and look horrible. That was not an option. For a while I thought of making some sort of wooden track on the cabinet's bonnet support rail, and a sprung pin on top of the doors to follow that track. I think the spring hinges might door the job better, and more quietly, however I don't really know for sure. as a result, I'll do a mock-up and test out a few different combinations of hardware to see what is what. I want the door to feel smooth and well-guided as it is opened and closed, so some experimentation is in order.

A means of latching the doors in the closed position has also been an avenue of investigation recently. I'm leaning at the moment to using a metal ball stud and socket type of catch mechanism:

Receiver left, male threaded ball stud to the right. Ball-Stud Speed Clips were originally developed as spring catch fasteners on aircraft access doors, inspection panels, sealing strips and other similar assemblies requiring repeated disengagement. The conical shape of the receiver means it can accommodate minor misalignments.

Pull-out tensions, depending on the material thickness of the Speed Clip and the stud used, can be provided from 3.5 pounds to 50-65 pounds. Various panel thicknesses are accommodated by varying the stud lengths. I can mount the receiver on the edge of the interior work surface of the cabinet, as that board will be thick enough to accommodate a receiver, fitted behind a piece of bronze plate or something like that.

Then there's the hardware for the drawer pulls. That remains undecided though there are some leading contenders.

Here's a view of the cabinet with doors closed, the normal arrangement the cabinet will have:


There need to be a couple of pulls mounted on the bifold doors, probably on the inner door of each pair, somewhat close to the hinge line.

As I've worked over the past month or three to obtain shop drawing take offs from the main sketch I've also reconsidered the middle section of the cabinet, and have decided to revise it. Previously, I had fitted a 'step-tansu' arrangement of storage, however I came to see that it wasn't a very good use of the available space inside the cabinet, and that since display is one of the functions of a step-tansu, and storage is the primary function of the cabinet, these things were therefore at cross-purposes.

I decided to take the steps out from the middle and reverted the area to an earlier arrangement of having adjustable shelves inside with a central divider. The central divider makes for a configuration where with one door open there is a dedicated shelf space:


You can also see in the above sketch that the drawer detailing has bene fleshed out and modified a little bit. I'm also going to look at placing a tiny low railing along the front of the middle section, an architectural motif, and see how that looks. A lot of Chinese cabinets have them and they look pretty good to me and serve a useful purpose of keeping things contained within.

I made the top and bottom edges of each drawer front a little bit thicker, which makes the top and bottom through-tenoned connections between drawer front, runner, and drawer side even stronger, and adds a horizontal visual emphasis, makes the dividers more clearly demarcated, to put it one way:



The color of the Shedua drawers, etc., is a little off in these sketches. In reality that material will be a bit browner than it is greenish.

I feel that the changes in the middle move it away from being a storage space of a somewhat particular nature (in terms of what sorts of things could be placed on the steps and inside the irregular compartments), to a much more generally useful arrangement with the shelves. The sideboard could serve equally well as a wardrobe I think - it's versatile.

I have shared these ideas with the client and am waiting to hear back from him to see how he likes the change, or not. If he wants to keep the step tansu inside, I will make that for him of course, but for our cabinet in this pair, we're going with the shelving.

All for now, thanks for visiting.

4 comments:

  1. I'm glad you are considering a more utilitarian middle section. Allowing for the shelves to move might also be good. For example, I can imagine the upper left shelf being removed so that there is more height available, if someone wanted to put a vase or a pile of sweaters in that section. (It's a nice asymmetry too.) I've always like this style of shelf support: http://www.sawtoothshelfsystem.com/sawtooth_shelf_support_files/cabnit%20for%20web.jpg

    - jamie s

    ReplyDelete
    Replies
    1. Jamie,

      thanks for the comment. The shelves will be easily removable, but I was planning on using steel pins or similar and not the sawtooth idea. Food for thought though.

      Delete
  2. Chris,

    I find it interesting on your Zimmerman that it appears that the same milling head goes from the wood of the legs directly to the leveling feet. Is that true, same head? Do you have to adjust speeds or anything? Either way it's really cool, keep up the great work.

    John Gray

    ReplyDelete
    Replies
    1. John,

      yes, the same cutter is working both the bronze and the wood, and seems to do well on both surfaces, no speed adjustment seems required.

      Thanks for the question.

      ~C

      Delete

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