The 123WaxRing: wax disk project.
An example DeskProto project to create a wax disk.The 123WaxRing system works using pre-shaped wax disks. The big advantage is that this makes the system very easy to use and very quick, the drawback is that you need to have these pre-shaped wax disks, and these disks are more expensive than standard wax blocks. We feel that the return on investment will easily justify this extra expense, however when you feel differently you are of course perfectly free to create your own wax disks.
This page shows a DeskProto project to create such wax disk. It is to be used as an example: your own situation (machine, cutter, etc) will be different so you will need different toolpaths. Still the tips and tricks mentioned may be useful.
The working area of a Roland JWX-10 without and with the wax block to be machined.
This example project has been made for a Roland JWX-10 machine. On top of the rotation axis unit this machine features a small working area (the orange colored surface), so a three-axis project can be done without dismounting the 123WaxRing fixture. We have used two of the four screws of this orange piece to fixture our wax block: see the illustration above.
The project is for a wax disk of 10 mm thick, and the block to be machined needs to be a bit thicker. We have made it about 12 mm, as the bandsaw that we used is not very accurate. The size in X and Y of course needs to be large enough to include the holes for the screws.
Left the DeskProto Project Tree, and right the 2D drawing for this project.
The project 123WaxDiskToolpaths contains one 3D Operation and two 2D Operations, as shown in the illustration. The zip file that you can download thus contains a DPJ file, an STL file and two 2D DXF files.
The STL file is a very simple square flat surface, build from just two triangles. Then one 2D file is present to create the three holes in the disk, and one 2D file to create the circular outer shape of the disk. Two separate files are used, as the milling depth will be different for both contours.
For all operations the same cutter is used: a flat cutter of 2 mm diameter, as the smallest hole is 2 mm. In most cases such cutter will be a multiple diameter cutter: important is that the flute (the part of the cutter of 2 mm thick) needs to be at least 10 mm long. The cutter that we have used had a cutting length of only 2 mm, so roughing was needed with a layer height of 2 mm max.
Toolpaths for the top surface, in DeskProto and on the machine.
The WorkPiece zero point for this project has been set in the center of the wax-disk, at it's top surface. In the drawing above you can see the blue orientator at the WP zero point, in the center of the square geometry (translation in DeskProto set to Center for X Y and to None for Z). So on the machine you need to set the WP zero point in the center of the wax block (XY) and exactly 10 mm above the orange machine table (Z). We have done this by touching the orange table with the cutter and then moving up 10 mm using the Roland Panel program (the control software of the machine).
The 3D Operation is meant to make the new wax-disk exactly 10 mm thick. It is a flat surface at Z=0, so 10 mm above the bottom of the block. The strategy has been set to Spiral for this operation, as we did not want the cutter to come near the two screws. The Layer height for roughing has been set to 1.8 mm, and in order to force two layers it was also needed to set the Part segment to Custom and to set Z-Max to a value above zero (when the part has no height DeskProto will not generate layers).
After completing the 3D Operation it will look like you machined a large hole in the block (see the illustration above), however this is just the top surface of the disk to be machined.
2D toolpaths in DeskProto: left the holes and right the outer circle.
Next the two 2D Operations need to be done. First the holes (as then the disk still is connected to the rest of the block), then the circle to cut the disk loose. The two small holes are represented by a point entity in the 2D DXF file: a point in the drawing will result in drilling a hole at that location. Note that we have set the Plunge rate to 30%: drilling needs to de done very slowly to prevent heat problems.
The machining level (cutting depth) for the holes has been set to -10.10 mm: a bit below the bottom of the block to make sure that the hole will be completely machined. Note that the cutter now will scratch the orange surface ! For the circle around, the machining level has been set to -9.75 mm: to keep the disk connected to the rest of the block, to be manually separated after milling. For both 2D operations as well a Roughing layer height has been set.
When you closely look at the 2D contour lines to machine the circle, you can see that more than one circle is used and that the contours are no complete circles. More than one circle was done in order to machine a wider channel, for easier chip removal. And the three circles in the DXF drawing were connected to form one 2D polyline, in order to force milling the outside circle first and the inside circle last. The exact outer shape of the disk is not critical as it will be milled off anyway: only the thickness of the block and the accuracy of the holes matter.
The wax-disk now is ready.
The result is a wax disk, ready to be used the 123WaxRing fixture.
The toolpaths used were not yet ideal though: the cutter used had a very short cutting length and a long cylindrical flute, and friction between this flute the wax chips caused some melting. A cutter with a cutting length of 10 mm would be better (not easy to find for 2 mm diameter). The surface quality would even be better when using more than one cutter, like a 3 mm diameter for the circles and drills for the holes.
The wax-disks that we offer are created by a lathe, using wax bars as base material. The efficiency of that CNC lathe when creating a large series of disks will not be easy to achieve using a small milling machine.