dnalot
Project of the Month Winner !!!
Mark's Lost Resin Casting or Old fart learns new tricks.
I have been doing sand casting and lost foam casting for awhile and that works out well for larger parts. But for smaller parts lost wax or plastic works better. I could only do the sand casting when the weather permitted as it needed to be done outdoors on a dry day. I hope to be able to do this bench top investment casting all indoors.
Having sold my 1950 MGTD I found myself with some money burning a hole in my pocket. So I started looking at 3D printers and whatever else was needed to try and do some lost “Resin” casting. Resin printers are now very cheap and they give incredible detail. Today you can get resins that are strong and flexible, resins that can take up to 400 degrees F and resins made for casting that can be burned out cleanly.
To kick off this new adventure I bough an Anycubic Mono resin printer. This is my first 3D printer so I spent hours watching you-tube videos to learn the basics. The first parts I will be making are for an upcoming build. I quickly drew up the parts in Draftsight and then proceeded to make a 3D object in Rhinoceros version 5. And that is where I came to an abrupt stop. Its been years since I used the program and I'm fumbling around trying to relearn it. So I decided sense I was starting over I might as well learn a new program. I will be trying Fusion 360.
So I made a kiln, learned how to use Fusion 360, bought and learned how to use a 3D resin printer and now its show time. I used Siraya Tech Cast resin. It is a wax based resin made for investment casting and is one of the lesser cost resins of this type (but is highly rated). I am simply astonished at the detail my cheap printer and budget resin produced. I used Prestige Optima investment powder. It is formulated for use with 3D printed resin parts.
Despite a comedy of errors My first attempt came out far better than I expected. My impatience was the leading cause of my problems. After waiting weeks for a vacuum chamber I ordered I tried to improvise using a small trashcan. I tested it several times without any problems but when it came time to use it for real it failed. When mixing the investment powder you first put the bowl of plaster in the chamber to remove the air from the mixture. And then after pouring the plaster into the flask you vacuum again. That is where the can collapsed. As I was not expecting to much from this first attempt I went ahead and did the burn-out and pour (brass).
My main failure was tiny little balls of metal all over the parts and some air bubbles blocking the smallest of holes in the parts from filling with plaster. Another mistake was applying the vacuum to the flask to soon during the pour. And my flask cooled down to much before I poured. Despite my problems my parts turned out very well I think. Now I will measure the parts to find out how much shrinkage has affected their size. With that info I can make adjustments to my printed part size to compensate.
I made a considerable investment setting up for this (no pun intended). Now I just need to refine my methods and get my equipment sorted out. For me bench top casting is now a reality. I will be keeping this tree of parts as a reminder of the adventure.
Mark T
I have been doing sand casting and lost foam casting for awhile and that works out well for larger parts. But for smaller parts lost wax or plastic works better. I could only do the sand casting when the weather permitted as it needed to be done outdoors on a dry day. I hope to be able to do this bench top investment casting all indoors.
Having sold my 1950 MGTD I found myself with some money burning a hole in my pocket. So I started looking at 3D printers and whatever else was needed to try and do some lost “Resin” casting. Resin printers are now very cheap and they give incredible detail. Today you can get resins that are strong and flexible, resins that can take up to 400 degrees F and resins made for casting that can be burned out cleanly.
To kick off this new adventure I bough an Anycubic Mono resin printer. This is my first 3D printer so I spent hours watching you-tube videos to learn the basics. The first parts I will be making are for an upcoming build. I quickly drew up the parts in Draftsight and then proceeded to make a 3D object in Rhinoceros version 5. And that is where I came to an abrupt stop. Its been years since I used the program and I'm fumbling around trying to relearn it. So I decided sense I was starting over I might as well learn a new program. I will be trying Fusion 360.
So I made a kiln, learned how to use Fusion 360, bought and learned how to use a 3D resin printer and now its show time. I used Siraya Tech Cast resin. It is a wax based resin made for investment casting and is one of the lesser cost resins of this type (but is highly rated). I am simply astonished at the detail my cheap printer and budget resin produced. I used Prestige Optima investment powder. It is formulated for use with 3D printed resin parts.
Despite a comedy of errors My first attempt came out far better than I expected. My impatience was the leading cause of my problems. After waiting weeks for a vacuum chamber I ordered I tried to improvise using a small trashcan. I tested it several times without any problems but when it came time to use it for real it failed. When mixing the investment powder you first put the bowl of plaster in the chamber to remove the air from the mixture. And then after pouring the plaster into the flask you vacuum again. That is where the can collapsed. As I was not expecting to much from this first attempt I went ahead and did the burn-out and pour (brass).
My main failure was tiny little balls of metal all over the parts and some air bubbles blocking the smallest of holes in the parts from filling with plaster. Another mistake was applying the vacuum to the flask to soon during the pour. And my flask cooled down to much before I poured. Despite my problems my parts turned out very well I think. Now I will measure the parts to find out how much shrinkage has affected their size. With that info I can make adjustments to my printed part size to compensate.
I made a considerable investment setting up for this (no pun intended). Now I just need to refine my methods and get my equipment sorted out. For me bench top casting is now a reality. I will be keeping this tree of parts as a reminder of the adventure.
Mark T
