I realize we have an Elegoo 3d printer in the Jewelry section which can be used for 3d printing a wax subsitute which can be used in the investment for burnout, but I was wondering if this 3d filament is permitted:
There are various reviews with differing opinions about it’s effectivness and burnout capability, too.
I guess I was more curious than anything else.
Just based on what I’ve read here in Talk, we went with the resin printer because you can get finer detail. I’d be asking 3D fab about using the filament. In general, because it’s different.
Agree with the printing part.
But equally important is whether we’d be willing to burn it out in the wax burnout kiln. We’ve found that some so-called casting materials that are more like plastic cause fires in the kiln.
With our capabilities, what would be the shrink % between the 3-D printed pattern and the investment casting in yellow/leaded brass? I also understand that the solid model can be adjusted/scaled during post-processing/slicing to compensate for shrinkage?
We don’t cast brass. Only bronze. If you need to cast brass, you’ll need to find a foundry to do that and calculate the brass shrinkage rate.
I’ve measured about 2.5% shrinkage per axis between the CAD model and my cast bronze. Bronze shrinkage is about 1.56% so the rest is the wax (about 0.9%).
No matter how hard you try, you aren’t going to get it perfect. If the dimension has to be perfect you need to allow extra material to machine off.
Here’s the caveats:
The wax resin is the unpredictable factor. I’ve listed the shrinkage per axis as uniform but usually the Z axis isn’t the same factor.
** X and Y are fairly consistently about 2-2.5%.
** Z varies all over the place depending on the geometry and configuration of the model. Only way to know is to print it, cure it, measure it, tweak your scaling factors and reprint.
** Axes are the print axes; not necessarily the model axes.
The wax continues to shrink until you cast it. There is probably a limit to this but I don’t have a time-sensitive study.
Wax shrinkage rate above assumes you cast within a couple weeks of printing/curing the wax. I have a couple large thin wall wax masters that I printed 6 months ago and they have continued to shrink.
** The uncured master shrank about 2.8% per axis over those 6 months
** The cured master shrank an additional 2.5% over those 6 months
Yes, the Chitubox slicer can do this. I never tried this. I only scaled in my CAD model. I don’t see why this wouldn’t work.
As always, WONDERFUL craftsmanship on that stove!!!
Anyhow, a few topics…
I was recently given a vintage PBL HOT-TIP resistance soldering unit that was modified and has not been used in some time. I am in the midst of repairing it and have some items on order, including the MicroMark Grounding Vise For Resistance Soldering Unit (micromark.com)
I also have the PBL soldering DVD, which is about 1 1/2 hr long. I can bring it to DMS over my holiday break and we can view and discuss together, if you are so inclined.
I have a few brass locomotive projects in queue, including a Kemtron On3 Shay kit and need to rework my Balboa Master Series S.P AM-2.
Painting brass is VERY involved! I would suggest you join the Brass Model Paint and Repair Facebook forum and connecting with Richard Bennett and Hal Maynard regarding painting techniques and just how involved it is. AVOID LOGAN THURMAN LIKE THE PLEAGUE! Brass Model Paint and Repair | Groups | Facebook
All the best!
Will Kutler