Thursday, January 14, 2016

A Ming-Inspired Cabinet (26)

Post 26 in a continuing series, which might be interrupted at any point to dig into other topics, you never know.

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Some reader, in a private communication a bit too sensitive to be shared publicly, has been indicating that I am not dressing sexy enough for these posts, so I thought I'd show y'all a little leg today. Hmm, maybe I'll even go so far as to show a LOT of leg, how about that? Hah!

The first task was to take the leg blanks down in dimension a little bit, not something particularly meriting photography. The next task was to mortise the ends of the legs for the bronze leveler feet. These mortises were 1"x1"x 1.0625" deep, and I wanted to approach the task in two stages, the first being to rough out the mortises, the second to bring them out to dimension. The mortises were to end up square-cornered, so they would be finished by chisel work.

A drill is the standard choice, but drilling into the end of a leg, a task which on the surface might seem easy enough, is in fact a bit tricky most of the time. Unless the leg is short, it won't fit into a smaller size drill press, and if it is long and you have a standing drill press, then you will have to construct some sort of fixture to hold the leg on a line axially true to the drill chuck.

The legs I have could possibly be squeezed into the milling machine in a vertical orientation, however why do that when I can mill at a 90˚ angle, horizontal I mean, with the right angle accessory?:


The right angle accessory, which came with the mill, is a seriously heavy chunk of iron and steel. I use the power z-travel, using the table as a lift to help raise the attachment up into position.

Here, I'm relaxing the tension on a center grub screw which spreads the collar and allowed the attachment to mount more easily - with the grub screw eased off, the attachment will remain in place height-wise on the quill:


At this point the casting of the attachment can still be swiveled around, and I therefore worked to align the accessory to the back jaw of the vise using a transfer punch as a dowel and testing the 'pinch' between jaw and rod with a plastic feeler gauge until I had achieved decent parallelism:


As they say on a certain TV commercial from the 1980's, just a li'l pinch between the cheek and gum will get you where you need to be.

With alignment sorted, the two bolts on the attachment's collar could be tightened to secure it onto the quill.

Next step was to fit a drilling chuck and then working to center the spur of the Forstner to the stick:


Another view of the initial set up:


I made a start with the motor, and promptly realized that the spindle was turning the wrong way on the output end of the attachment. Oops! I went to the back of the mill and flipped the main switch over to reverse motor direction. Then I set a depth stop onto the vise jaw and did a test cut:


The cut was okay, except the drilling chuck allowed the Forstner bit to spin a bit, and the bit had actually come loose. I tried re-tightening it but the same thing happened again.

Not wanting to screw around with that, I removed the drilling chuck altogether and put in a collet chuck instead, which can grab the shank of the bit with the many facets of the collet rather than the three used in the drilling chuck. This solved the problem immediately and I can see why machinists often prefer to use collet chucks instead of standard drilling chucks. I'm going to start using them more often too, and an added bonus is that the collet chuck doesn't stick as far out of the spindle end, so it is inherently stiffer. I'm tired of spinning drills in a chuck and damaging their surface.

With the collet chuck mounted, I took care to recheck everything was coming to the correct point:


The drilling itself was effected using the x-axis power feed for most of the cut, turning the hand wheel by hand the last tenth of an inch or so to the target depth of 0.9":


A while later all 9 legs were rough drilled:


I then made up an MDF fixture which would allow me to rout on the end grain to mill a 1"x1"x1.0625" deep mortise:


The completed mortise:


Checking the fit of the leveler foot as best I could:


I felt like the fit was about right, just a hair snug.

A while later, all the routing was complete:


From there, it was a bunch of chisel work to bring the mortises out to a square:


A first fitting:


It came together well I thought:


Later, all the levelers are fitted to the legs:


Another view:


The levelers are fitted snugly enough so that the parts won't separate simply due to gravity and not so tight they can't be readily pulled apart:


The next step was to mill the combined leg and leveler to dress the all the long faces down a couple of hundredths of an inch:


All four faces on each pair were cleaned up, until I had this tidy pile of parts, of uniform dimension and all square in section:


Making the legs square in section is but a preliminary step - next I'll be making the leg section slightly rhomboidal. Here I've marked out the legs to keep track of which faces get milled at which angle:


All for today my friends. Thanks for visiting! On to post 27

4 comments:

  1. Chris,
    As usually this is one of the best blogs out there. Question, how will the leveler feet actually work? Will there be some sort of adjust-ability added to them somehow? Thanks and keep up the wonderful work.

    John Gray

    ReplyDelete
    Replies
    1. John,

      thanks for that. I will be fitting a few more bits to those leveler feet yet. That's the whole point of them - adjustable leveling. The Square Deal tables also had bronze adjustable leveler feet, and I think in some of the later posts in that series you'll find some pictures showing the mechanism clearly.

      ~C

      Delete
  2. That's some nice leg there, Chris.

    Your wife is a lucky lady! ;-)

    ReplyDelete
    Replies
    1. I was hoping someone would see the humor there. Thanks for the comment!

      ~C

      Delete

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