Ted Burdett
Chicago, USA
This is a simple rack of hooks that can be used for all kinds of hanging needs. We came up with this design a few years back as a simple, wire and wood product. The wire parts are cnc bent and the wood comes from urban trees that are milled into quality lumber by Horigan Urban Forest Products.
This is a simple rack of hooks that can be used for all kinds of hanging needs. Strand came up with this design a few years back as an easy to assemble, wire and wood product. The wire parts are cnc bent in Chicago and we make the wood part from urban hardwoods, trees that come down around the city and are then milled and dried into high quality lumber.
The first step in making the rack is to mill the rough lumber into precise pieces of stock. I use a standard milling operation with a jointer, planer, and table saw. I cross cut the ends of the stock with a miter fence on the table saw.
The bed of the XCP is big enough to mill a number of these racks at once, which is how we batch things for production. First, attach a sheet of MDF or other flat fixture material to the bed of the cnc. Level the bed with a planing bit before applying the fixture material. The fixture can be screwed to the bed or you can mill indexing pin holes into both the bed and the fixture to make the fixture easier to reposition for subsequent uses. That all depends on how much time you want to invest in a fixture and how long you plan to keep it around.
The operations for this project depend on maintaining an absolute zero origin throughout the sequence. So make sure that you are careful to keep the X and Y origin position the same between the operations so that you have consistent reference for all of the files you run.
The first operation for holding the rack blanks is a pocketing operation. Carve shallow pockets into which you can place the blanks. The pocket should be tight fitting so that it constrains the work pieces from moving in either the X or Y direction. I use the dogbone plugin to generate relief cuts in the corners so that the cutting tool fully clears the area where the blank sits.
The second operation is to provide for clamping of the parts. In this example, I cut some quick L-shaped blocks from a plywood scrap and used screws to anchor them into the fixture. This would work fine for a few uses of the fixture, but inserting threaded anchors or installing a few toggle clamps to hold down the blanks would make a longer lasting fixture for repeated production.
After loading the fixture with blanks and clamping them down, I run the slotting operation to make the hook slots. This uses the same ¼” bit that I use to carve the pockets for the blanks but the Z needs to be zeroed to the top surface of the blanks before running the operation. And as always, preview the operation in Easel to make sure that none of your clamps are in the way of the tool path. It is always a good idea to set your safe travel height high enough to clear the clamps anyway.
With the slots all machined, the bit can be changed for a keyhole slot tool and a new Z zero can be established. The keyhole slots are generated with an app within Easel. The depth of the cut and the step down are both set to the full depth of the feature which allows the bit to make one plunge cut before stepping over to create the under-cut slot feature. I like the 3/8" diameter bits for this operation since they tend to work well with a #8 to #10 screw, albeit with a pretty tight fit.
Last, I change out and re-zero with a v-carve bit to carve the Strand logo into the back of the product. The alternative to doing this is to use a heat-brand to burn the logo into the wood.
The rest of the product is finished outside of the machine envelope, freeing the cnc for other things. The edges are radiused on a router table with a 1/4" round over bit and then everything is sanded with random orbit sanders for the faces and hand sanding for the edges. I finish the racks either with General Finishes water based finish or with a modified tung oil varnish.
