Wax Carving Mandrel
Plastic prototype and machined steel wax carving mandrels.
This is the finished mandrel turned from 12L14 steel as well as the prototype that was 3D printed. The steel mandrel will hold the green wax (in the photo) that will be machined into a ring on the rotary 4th axis of the Taig CNC micro mill. A 1/4-20 thumb screw will be fitted into the end for drawing down the cap, acting as a clamp for the wax.
The wax is purchased in a tube with the center hole existing. The wax will be sliced in widths greater than the ring design I will be milling. Then the hole will be manually (by hand) increased to the proper ring size after carving.
That’s the plan. It should work well for thin rings that don’t need side machining detail. Such as wedding bands or rings with engraved designs just on the top surface.
I am now contemplating wax holder designs for other styles of rings, pendants, and charms. Perhaps small LWC figurines. I can utilize the 4th axis on the mill for indexed flip rotation as well as continuous 360 degree rotation.
Steel end cap bored out
DeskProto stopped producing their 123WaxRing system. So I may borrow some ideas from that process. Seems the problem may have been the special wax shapes required were expensive to produce in low volume. I will design around standard available wax shapes, or as I do now, utilize slices off larger stock (bulk) wax. I have already been doing that for years using Freemen Waxes.
DeskProto for 4th Axis
Using 4 axis milling, requires a CAM software system to create the necessary CNC G-code. It’s not something one can easily hand code when doing 3D designs. Simple level surfacing could be hand-coded on a 4thaxis, but probably lathe turning would be far easier.
Aspire, a three-dimensional CAD/CAM produced by Vectric can produce G-code for the 4thaxis. It is one of my go-to programs. However, I don’t design everything in Aspire CAD. Fusion 360 and RhinoCAD are also programs I use for design.
Both these programs have 4 axis CAM built in. Fusion 360 has a built in CAM, and with Rhino5 I have a plugin RhinoCAM 2012 w/4axis. In Fusion the 4thaxis CAM is 2.5D and cannot produce 3-dimensional 4thaxis G-code. I added 4thaxis 3D CAM to RhinoCAM 2012 but find it extremely difficult to produce quality cut pathing. It seems to contain some very strange algorithms producing highly fragmented pathing.
This has led me to another 3rdparty CAM software (from the Netherlands) called DeskProto. It can take input (in the proper format) from any CAD software. (I won’t be getting into describing the process here.)
DeskProto’s claim is that it is CAM software for creative people and not the die-hard machinist. I find agreement to that statement. I find details missing with some lack of particular seldom-needed features perhaps needed by a high powered VMC machinist. For the rest of us common users, making things (on up to 5 axis milling systems), DeskProto gets the job done without micro-managing every single minor detail.
Having made that (limiting) statement, there remains plenty of useful variables that will insure getting the results a user like myself desires.
I will admit I put off choosing this program,… Continue reading
No Mistakes – Making My Point
-
- Spiral Pyramid 0.005″
-
- Ball end 0.005″
I seldom, almost never make mistakes… HA! But I found one in my tool definitions for Vectric Aspire. Um… maybe I do make a few mistakes.
I use a very fine pointed, down to 0.003 tip tapered ball-end milling bits. Tapered ball-end milling bits are defined by their one side taper angle and the tip radius in the Aspire tool table. That was what got me. The tapered bits are identified by the manufacturer with total (combined) taper angle and the tip diameter.
So, what the maker defines as a 10-degree 0.005 tapered ball-mill is defined in Aspire as 5-degree taper bit with a 0.0025 tip radius.
I got the side angle correct but I was entering the full tip diameter as the radius. I realized the problem when I would define stepover as a percentage rather than specified absolute distance. The percentage calculation was showing twice the correct distance.
Therefore, Aspire was also calculating the tool path to be twice as wide as it actually was. That’s because that is what I specified.
Hmm… wonder how long I have been doing that!*
I am trying to imagine how that would affect the milling operation. Probably some dimensional errors, the program calculating the bit to be twice as wide as it actually was. With the tiny bits, there error would not be noticeable or of any importance. Pocket sidewall distance would be a couple of thou’ too small.
I think the biggest issue would be the stepover. If I wanted 20% it would be cutting… Continue reading
Swarf Blower Added to Taig HS Spindle
Wax swarf blower system
The blower that was added to the Taig spindle on the original WAX milling system has been updated to operate on the new high speed water cooled spindle. A full article with pictures can be found here: https://thehobbyistmachineshop.com/cms/projects/wax-fan-v-2-0
This is not a dimensional, How-To article. It demonstrates how 3D printing can be utilized to add accessories to the Taig mill and a high speed water cooled spindle.
More Than a CAD
CNC Milling
S. Whiplash, Typical CAD
It’s been a while since I have run my original CNC Taig Micro-Mill. It’s the one configured for metal work and has the mist cooling installed. There is nothing operationally wrong with it as far as I know. Just haven’t had a project where I needed its services.
I have always used RhinoCAD (Rhinoceros) with RhinoCAM to generate the design and the Gcode necessary to run the mill. I am presently working with FUSION360 CAD with its built-in CAM. FUSION360 has become my go-to CAD for 3D printing because of the very good built-in STL generator. Rhino can do STL too but has some issues (for me) in producing first-time usable STL.
CAM is a whole new layer of complexity after creating the CAD drawing. Of course, the first challenge is the CAD, as what is drawn must be something that can be produced by milling. It is possible to draw parts that can never be machined.
The CAM requires the complete understanding of the milling operation and all the tools that can be deployed on the target milling machine. In the case of the Taig Micro-mill, tool size is limited to the machine’s abilities and speeds. I have no need for things like an automatic tool change. I am a hobbyist, not a manufacturing center.
CNC is certainly not “push the button and go”. The complexity is what I love about the process.
I use two different CNC controller software systems to control the movements of the milling machines. The older mill is using MACH3. The newer WAX cutting mill runs on LinuxCNC controller software. I was very pleased to see what is called a POST processor available in FUSION360 for both controller formats.
The POST processor is a function in CAM that… Continue reading