Transcript:
Hey, guys! I’ve had a few requests to do a Beginner’s Guide to PLA Casting video, covering all the steps the equipment, that’s needed etc. So that’s my aim today. I’’ll also be looking at ways of saving money as this can be a very expensive technique, but luckily, I’’ve developed a few low budget solutions. Lost PLA Casting is, of course, taking ordinary 3D prints and converting them into solid metal castings. An ordinary 3D print is placed within a metal flask then surrounded by plaster. It’’s vacuumed to remove all the trapped air then after resting for a while it’’s baked for several hours to burn away the PLA and prepare the plaster. Metal is then melted and poured into the plaster, which is again vacuumed to remove further air. Once the metal solidifies, the plaster is removed. Sprue’s are removed from the casting and everything is cleaned and polished. The 3D printer is an ordinary one. It’’s nothing special. The better the quality of your prints. The better the quality of casting you can expect to achieve. So print slowly on a fine setting for best results. I’’ve also found rubbing the print with fine. Sandpaper helps remove printer lines and rubbing on sprue wax helps fill any voids and imperfections. There’’s two main sorts of flask perforated and solid Perforated are much more expensive and require costly vacuum systems as I’’ll cover in a moment, but for those on a budget or with smaller needs, these solid flasks are nice and cheap and can be used with my homemade vacuum system, which I’ll mention in a moment. Special casting investment plaster is needed and this. You really shouldn’’t skimp on. This plaster is porous and allows a vacuum to pass through it. This plaster needs to be carefully weighed and mixed, according to the manufacturer’’s instructions. It then needs to be vacuumed quite quickly as the plaster usually sets in under ten minutes. In an ideal world, you’’ll need a vacuum chamber and vacuum pump to quickly pull the trapped air from the plaster. These are very expensive, but I did. Create my own very simple and very cheap vacuum chamber and manual PVC pump, which I have successfully used on dozens of occasions. The manual pump isn’’t perfect, but it’’s better than not pumping at all. My recommendation would be to start with my homemade chamber and pump and later invest in a vacuum pump. That will do a much better and faster job for you, though it is expensive. Depending on how well you build my easy vacuum chamber, you may not need to replace that. Once the plaster has set and rested for a couple of hours, it needs to be cooked in what’’s commonly called a ‘Burnout Oven’. This is a carefully controlled heating sequence taking several hours. The PLA is melted away, and the plaster is baked to prepare it for casting and this is done at very high temperatures. So your kitchen oven won’’t do it. This means you need a burnout oven. Now again, these can be VERY expensive. However, I built my own electric furnace for just a few hundred pounds and it’’s much easier than you might think. Yes, I employed a fancy hoist mechanism to raise and lower it, but you could keep things much simpler and therefore cheaper. But importantly, it does give you perfect and safe control to burnout flasks or even melt metal. Once the plaster flask is almost ready, it’’s time to melt some metal and again. You’’ll need a furnace for this. As the plaster needs to be kept at a high temperature right up until the pour. It actually means you’’ll need a second furnace. Gas is very quick and easy to control. I’ve already reviewed the Devil-Forge foundry, which does a very nice job, but which obviously doesn’’t come free. If you’’re the handy sort, you could have a go at making your own, which I have successfully done in the past – and believe me. It’’s still going strong. But it’’s probably best if you buy the gas burner as these are the heart of a gas furnace. Alternatively, if your casting needs are smaller and with Lost PLA, they tend to be. You could buy one of these table top electric furnaces for a similar price to the Devil-Forge. It’’s much smaller…. This one has a 4 Kg Crucible capacity…, but it’’s, surprisingly quick, clean, quiet and beautifully simple to control. When it comes to the pour again, you’’ll want to vacuum your castings and vacuum machines tend to be expensive. Now, trust me. I tried lots of ways to NOT use a vacuum and none of these achieved suitable results. But then it occurred to me to use my same homemade vacuum chamber and pump. With an easy reconfiguration, this achieves fantastic results. Now again, I’’d recommend when money allows that you invest in a proper vacuum pump as manual pumping is a pain. Now my pump states that it should. Not be used on anything hot. But I’’ve been using it for a while now on with a long hose and I’’ve been watching it carefully. The pipe doesn’’t even get warm and the pump seems to be unaffected. –, but you do that one at your own risk Guys…. These are expensive things to break. Finally, it’’s time to clean up your casting, cutting away the sprues and filing things smooth. After filing sanding with ever finer grades of paper achieves a nice polishing result. But if you want to go a step further, you could use a tumbler. Now I’’ve made a vibrational tumbler which works well. I tend to use this to get rid of any residual plaster and give things an initial fine sanding, but with the proper media, you can polish with vibrational tumblers quite easily. But personally, I opted for a barrel tumbler, which uses water and metal shot to polish metal items to a very fine finish. Lastly, and I know very boringly don’’t. Forget the safety equipment. I’’m not going to cover that in detail here as it’’s largely a personal choice. But you do want something to cover your eyes. Cover your hands and a good mask is always useful. So I think that’’s it. As you can see just like Lost Wax casting –, which is much the same process. – Lost PLA. Casting is not the cheapest casting technique, but it does allow you to create some fantastic things. Other casting styles, just couldn’’t match. I’ve placed links to products in the description for you guys. You may need to shop around if you’re in a different part of the world, but at least you’’ll know what you’’re looking for. If you’’ve got any questions, feel free to drop me a line. So that’’s it for now, guys. Take care and thanks for watching.