Projet 1200 - FTX Cast Burnout Tests

[bford903]

Also placing the thickest supports do the trick. Do not use thin supports with this material. - A lot of the work I do has pretty fine detail and the thick supports left lots of cleanup on the piece. Also, because of the delicacy of the material, I found it was prone to breaking as I removed the thicker supports, especially with smaller pieces.

Well the all idea is not to use additional phases like rubber molding. In that case why do I need printer for? I can get the form in wax from designer and just do regular casting than. No point. - The idea is to provide the highest quality product to my customer with the materials and tools I have at my disposal. That's the point. The end result is most important. I also run a wax mill, a Roland JWX-30 4-axis Wax Milling Machine, and milling machines are limited by where the cutter can reach. 3D printers don't have these limitations, allowing for more complex and detailed designs while cutting down on build time and assembly after casting. In the case of mass manufacturing, you will need a master mold anyway for repeated castings. I still use both the 3D printer and the wax mill depending on the job requirements. Same way I have multiple hammers in my bench. One does not replace the other, they both have their uses depending on what the job requires.

The posphate based investment seems to do the trick but it is very difficult to divest. I do it with screwdriver and hammer but.... comeon! should I pay for divesting machine because their recommended investment do not work? - If you don't like working with it, then don't. Platinum casters do it everyday, and I agree it is difficult to remove, which is why I use molds. I didn't want to buy a divesting machine either, so I figured out a workaround using the materials and tools at my disposal to achieve the desired result. Molding allows me to achieve a high quality product, utilizing the complexity 3D printing offers, with the tools already available at the shop.

I tried the recommended schedule for Plasticat - faled with the surface quality. I tried to extend the time twice - no results. I am getting rough surface. - Extended burnouts didn't help for me either. I was limited to a 6-8 hour burnout due to the limitations of the shop I work in. FTX Cast does require extended curing. Thicker pieces usually contained uncured resin inside, which was causing porosity and investment breakdown during burnout. I would extend the curing time of your prints considerably before casting, until the light-green shade of your print is completely gone. It should turn to a pinkish-white color when it's properly cured.

Any ideas on the chemical composition of the materials? this may help getting the correct temperature ladder which may help avoiding that explosive burnout which supposidly ruins the inner surface. - With FTX Green, expansion starts at around 800F (426C). Since FTX Cast is still a thermoplastic, I would imagine expansion will start around the same temperature. As far as the chemical composition, you would have to talk to a chemist on that one.

Don't get me wrong. I'm not singing the praises of the Projet and its materials, but this is what I had to work with. If money is no object, by all means buy the phosphate-bonded investment, the vacuum mixer, and the divesting machine. It cuts down a potentially 10-14hr burnout down to 2 hours and provides a consistent high quality product. But if you're working within a strict budget, like I was, molding was a happy middle-ground allowing me to utilize the complexity and shortened build times the 3D printer offers, using the tools already available in the shop. You just have to decide what's the best use of your time, effort, and expense.

[Tigra]

I found it was prone to breaking as I removed the thicker supports -yes, true. It it is problematic. Now I tend to group those supports as a bunch together and technically use them as sprue base and do not remove them, just break the base layer off and it is ready to be used in the jewelry tree(not sure the english equivalent. Frequently it work but requires additional work at the end.

I also run a wax mill, a Roland JWX-30 4-axis Wax Milling Machine - I do not have them at my disposal as well as rubber molding staff so I have to make this option work somehow

Platinum investment - If you don't like working with it, then don't. - That was a good advice thank you, never thought about that. Just joking. I definitely dont as it requires more effort than the regular investment but for now was the only way I got more or less reliable surface. As I do not want to do additional investments into specialised technology for working with this kind of investment I still want to try make the Plasticast work. By the way I tried to dilute this investment a bit also and seems that Formula also works the best thiker rather than diluted. One clear advantage of phosphate based investments is the possibility for rapid burnout.

It should turn to a pinkish-white color when it's properly cured. - By the way I tried mixing the green and cast materials, added a bit green in it. It basically behaves as cast in terms of curing but was a bit sturdier. Also you do not have to use up the curing lamp resource, direct sunlight does the same trick. Just leave them under direct light for half a day or a day.

FTX Green, expansion starts at around 800F (426C) - thank you for this data. It definitely starts smell plasticky around 300C. The only thing I havent tried is to increase the process of climbing the temperature from 150C to 500C to 3-4 hours hoping that the degrading and oxidising of plastics will happen slowly, fully burn the ash and will ruin less the surface during the burnout. It seems that the rapid burnout ruins the walls inside the mold with regular investments and lives small trash pieces inside. When metal filles in the mold the trash pieces ruin the surface leaving dents in it. For example Sample 1.jpgSample 2.jpgSample 3.jpg

But if you're working within a strict budget, like I was - yes, that is true also. The investment should be justified. The thing is I do not have materials and instruments for rubber molding so I have to buy them as well if I will go that way and for the moment I am trying to avoild it. Actually I wrote to their support asking the questions but have no answer so far. I have a feeling that their advirtisement for a "castable" material was a bit too optimistic.