Ring Carved on 4th Axis
Everything came together for the first real use of the forth axis mandrel for ring carving. It’s nice when the plan comes together and everything works as intended. There was of course far more than just making the mandrel. There is the CAD design stage and the CAM (Desk Proto) for generating the G-code for the 4th axis. Then running the G-code on the micro-mill. I use LinuxCNC and I had to write my own metric post processor for Desk Proto. Not all that hard, actually. I made a USC (inch) version too. One tiny code change.
The first picture is the carved ring blank on the mandrel. I can accommodate a wide range of wax sizes. There will be much more experimentation and determination of the correct wax width for a project. This example worked fine.
The second photo is after the wax master model was hand finished and at this point is ready for casting. Sprue’s were added the ring put into a flask and the investment added. This post is not about the lost wax process. However, I thought it was interesting to show the wax carving and the final result the mandrel helps create.
The last picture is the finished Sterling silver ring shown on my hand (size 11). It really looks great. I will be doing a lot more wax carving on the 4th axis of the Taig micro-mill.
Flight of Fancy
I had a long hiatus (about four weeks paid time off) away from my regular employment, creating time to take a good long at the route I should be heading with my at-home workshop activities. What I do for the rest of my life should be something I really enjoy. I have been making small wax carvings by hand and machine.
I have come to a personal decision about my capabilities in creating precision miniature wax carvings. The results of my experiments have shown that even with my PN, I am capable of detailed hand carving but not in the speed and degree of accuracy that I would like to perform. I suppose that is because I have spent most of my life being very accurate with dimensions and machine tools and maybe six months wax carving by hand. Duh?
My plan at this point is that I am going to continue putting effort into perfecting my CAD/CAM creative effort but not abandoning the hand work. I have discovered both to be very enjoyable. To those of you who follow my “in the shop” ramblings about machines and machine software, you will see that machine carving will continue.
Everything I do in my CNC interests is scalable. That means the effort and skills to do small scale carvings are the same whether one inch high or twenty four inches high. The size of the tool bits and the machine just change.
I am totally blown away by what I can do with small machines and tiny milling bits. This is where I have spent most of my time and money. I presently have what I need as far as the machines capable of doing the detailed work. I will be writing a lot more about how they work and how… Continue reading
Milling Wax Adventure
The year is running out fast. I will soon have to say good-bye to 2011. This is the year (last Saturday actually) that I became 65 years old. Time enough for pondering that event, now to keep moving. Ha!
I did some machining of wax on the Taig CNC mill Saturday. I love machining wax (the hard blue kind). The wax is not good for creating real finished useful items but it makes excellent models for making molds and doing casting.
I spent the morning doing the design work in VECTRIC Aspire software. I was creating a Christmas ornament as a negative. I learned how to mirror and reverse the lettering and other “thinking inside out” processes in 3D design.
The afternoon was spent machining the design into the wax, using the Taig CNC mill. That was an adventure.
I haven’t run that machine for some time. The milling started out OK, but I got a couple of stalls and lost steps in the Z axis. The mill has never done that before so it was a surprise. I wasn’t pushing rapid travel or cutting speeds that hard either. Lifting the spindle and motor is fairly hard work.
The rapids are only set at 65 IPM and I was running about a third of that. So I ran through the software set-up and MACH3 warned me I was pushing the limit on pulses for the pulse generation frequency for which I had MACH 3 set. The Taig has twenty TPI screws so it takes a lot of very short pulses with 1/8th stepping (32,000 per inch) to get any speed from the drives.
That’s 32,000 per inch so at 60 IPM travel (keeping the math simple) that’s 1 inch per second requiring 32,000 Hz (32 kHz)… Continue reading
Grizzly G9955 Dust Filter
I decided I needed to add dust control to my high speed rotary carving. Actually I decided that a long time ago. I have finally taken the first step. The Grizzly 9955 is about the cheapest version I could find as none of them do (that is filter) as well as I would like at a reasonable price.
I can’t fault this machine for that problem as it is the very nature of filtration that the smallest particles are the worse kind for human lung health and are also the hardest to filter out.
This filter says it will filter down to 5 microns but I have serious doubt of that, at least on a continuous basis. Most filters actually become more effective (not efficient) the dirtier they become (up to a point of no air flow or media failure) so where when is the 5 microns determined?
Yes, I am an air filtration expert from over 50 years in the HVAC business and having owned an air filtration service.
My propose here is to test the subjective effectiveness of this unit. I don’t have expensive test equipment to make critical measurements and I also don’t think in my case it is worth the effort to be that critical.
Note Grizzly on the label recommends (requires?) the use of the face mask filter when using the machine. So it is pretty clear the user should not depend on just this filter to provide safe breathing air.
I adjusted the poly carbonate panels to provide a narrow gap at the work area. This produces a higher velocity to the air flow at this point and better ensures the dust will be carried back to the filter material.
The filters are listed as 2 inch. That is a bit… Continue reading
I ran some Lithophanes this evening. I realized I had my iPhone in my pocket so I grabed a short segment of the HB2 in operation.
What you need to note is the quiet operation with the Taig spindle running at 10.600 RPM and the bit cutting at 50 IPM (Inches Per Minute). Most of the noise is the cutter in the Corian solid surface material making the 0.10 to 0.20 depth cut. If you listen carefully you can also hear the higher pitch “chirping” of the z axis stepper motor. I am “eighth stepping” the motors so it takes 1600 steps to make one shaft rotation. You are hearing those steps.
Most folks are running very loud (screaming actually) routers or high speed rotary tools to do this work. It’s hard to even think over the noise level. I have to wear ear protection with those spindles, but not with the Taig spindle. It’s nice…