3D Printing - "It's all about design and quality output. Not how fast the printer can run."
The reason I purchased the Wanhao D7 (WD7) resin printer was a desire for high resolution 3D printing. Resin based printing is the currently the best way to get 0.05MM and less layer height. I have been able to produce prints with 0.035MM layers that are of very good quality with the WD7.
The reason I want high resolution 3D printing is so I can use the technology of three dimensional printing in my lost wax casting work.
The WD7 looked lake the least expensive machine and process (DLP) to reach my intentions. This is still true. Commercial grade machines that can do this are in the $4K to +$10K bracket. There are also a group of printing systems far above this range.
For me, the issue with the WD7 is its low power UV light system, which makes the required exposures very long, especially with castable resin materials. Castable resin is the plastic that will cleanly burn out of the mold cavity in the lost wax casting process.
But there has developed another issue with the castable resin. I have not yet used a castable resin model in a successful, equal to wax, cast item. The resin model burn-out has been damaging the investment (plaster-like) material that forms the mold.
I have produced a couple of reasonable casts, but not one anywhere close to the quality I expect as in a real wax-based model.
The issue is direct casting of the three-dimensional print. The WD7, using standard (non-castable) resin will make quality parts in reasonable time. These parts could be used in an additional process to make a rubber mold. Then the rubber mold used to make wax models that can then be lost wax cast.
For one-of-a-kind silver jewelry, this is not an efficient process. A doable process, but very labor and process intensive. For making a run of identical parts, this is a great way to proceed. My goal is to do one-of-a-kind that I can’t do with hand carving or CNC carving wax.
If anyone and I include myself, has the time and the ability to experiment with 3D DLP printing, then I think the Wanhao D7 is a great low cost starting point that requires a lot of time and ability. It is definitely NOT a “plug & play” 3D printing system.
I think I will be able to make it a useful tool for my purpose. The printer hardware works. But it is a slow, low powered printer. All resin printers are messy and smelly beasts. I have learned how to handle the chemicals, but it isn’t a process for children or with children or pets hanging around. It requires care in operation and clean-up, curing and a host of procedure not required with filament FDM printing.
Think carefully about getting involved with ANY resin-based printing. There are a lot of variables and exposures to UV radiation and chemicals. This WD7 is NOT a toy.
I wasn't sure if I should publish this here or in my KautzCraft jewelry blog. It's here because this part of the project is pure 3D printing. The casting I'll publish elsewhere.
I ran across a test block on Thingiverse. It is a SLA test model created by 3DSLA. I was looking for test items for my Wanhao D7. The picture to the right shows the tiny one in white plastic I printed on the WD7 at 50nm layer height. No clean up on either. They are exactly as-printed.
I wondered how the Cetus FDM printer would handle the test. I knew the original size was out of the question at .2mm (200nm) resolution so I scalled it up five times. The red box is about two inches square and two and three quarter inches tall.
The camera doesn’t know how to manage an exposure using a lot of UV light. It’s close to what it looks like with the human eye. Some colors fluoresce under UV light. This is one of two 10 watt UV lights I am using.
Most of the resin I intend to use with my WD7 printer requires a UV after cure process. The parts could be set out in the sunshine, if the sun is shining. The more controllable process is to use a UV cure box and put the parts inside the box with UV lights to cure. Faster and more controllable.