Polyurethane vacuum casting is a method for making high quality prototypes or low volumes of parts formed from inexpensive silicone molds. Copies made in this way show great surface detail and fidelity to the original pattern. Have you ever used this process to make your parts?
I used 3D printing together with vacuum forming by FDM-printing a mold, that was used to vacuum cast the end use part. I used a heat resistant, carbon fiber reinforced filament to print the mold. Several vacuum forming suppliers were hesitant to even try, because they thought the mold wouldn't last more than a couple shots. After finding a supplier that was willing to try, they were able to mold all 100 parts needed with the one printed mold. The time it took to get from an idea to finished parts was 9 days, including the design, printing, finishing & shipping of the mold. That's when I noticed how powerful 3D printing can really be in rapid prototyping.
@@trunkki Hey mate. I'm curious to know the exact filament used? There are a number of carbon fiber reinforced filaments. I dont suspect you would have used PLA, PETG or ABS, but maybe something completely different? And did you use polyurethane for the product to be formed in the mold? Cheers
There's a subtle difference here: They're using expensive _equipment_ but not expensive _tooling._ Yes, you may need to use a vacuum chamber for several hours to make your parts. But the cost of the mould is far, far lower.
Argon is optional and just reduces waste/saves money. Vacuum chamber is easier to work with than a simple low pressure pot for $100, but the pot does the job. The ovens are optional for speeding up curing and to allow more consistent results. That leaves the resin and silicone, the latter of which is somewhat expensive at ~$50 per kg. And of course the casually mentioned SLA print, which a DIYer would replace with FDM and hand sanding / vapor smoothing.
You need equipment to do anything. It's not like you can make high quality commercial parts with mud and a straw or something. You get out what you put in.
With simplified technique you only need an old air pump for “vacuum” and two-component silicon and plastic to reproduce parts with amazing accuracy. I know a guy working in a scaled model personal business doing just that. When he needs a set of parts, he produces them basically overnight on his table top. He uses tiny Roland CNC router to machine masters from model board, then pours silicon mold block around as shown on video, puts in a pot and pumps air out to remove bubbles, then when silicon is firm, removes masters then pours two component plastic inside, and again pumps air out. His parts are often relatively small and he makes dozens per mold at once. They look like they go from factory😹. Hopefully my comment is useful for all hobbyists around! Upd: searched for example, similar to this th-cam.com/video/3obngISQ_yk/w-d-xo.html
Instead of pouring the resin under vacuum, you can pour under atmosphere and pressurize in a tank to 50-80 psi. A common technique in the toy-making world, and pressure pots are much cheaper than a complicated vacuum casting machine.
Yes, you can do that. The benefit of vacuum is that you make all the bubbles a lot bigger and they float out and burst during the casting. That doesn't happen with atmospheric hand pouring. There are less bubbles to begin with once the pour is finished compared to hand pouring. Also, you don't get the "pick up" of the surface finish during a hand pour, you only get that with vacuum, and that's why pressure pot castings usually have to be painted after casting. Ours don't. - Gordon
Seeing these things like this made going to uni for engineering so worth it, I only wish looking back that I’d went for mechanical instead of chemical engineering, it’s just so much broader and has a lot more applications.
What you study and what you do don't have to be the same. Switching between many different types of engineering is fun, and if you can afford it I recommend to go for it.
What SLA printer is that that has the print bed coming out of the resin pool, rather than the bed lifting up and out of the resin pool? I'm having a hard time envisioning how that works.
I have been printing positives, given them a clear coat of UV resin (to remove the printing lines), then pour with mold rubber, then pour with resinb to get a positive. This is much quicker and easier as it cuts out one step.
Cool, I'm trying to create an exact replica of the head frame of an animatronic from The Rock-afire Explosion. (which is an animatronic band from the 1980's). I found a copy of the original service manual, which has diagrams and measurements and maintenance tips, etc. Using the service manual in combination with photos, videos, other sourced information , as well as guesswork, i've re-created the head frame almost exactly to original spec, in TinkerCAD. Originally the animatronics' frames were/are mainly made of solid aluminum, and/or square aluminum tubing. Now, it would be cool to make it out of aluminum, but aluminum is a very soft bendable metal. It would also involve welding. So my thought is to 3d print it, and then either use the 3d printed part or do something similar to what is shown is this phenomenal and informative video. I'll probably just find someone/someplace to 3d print the pieces and hope that they print properly. Thank you for creating this video. It's very helpful.
Do you know how the vinyl armrests on the herman miller chairs are made? I would like to use that material to do small scale overmolding for cables at home. It is so very durable. Scratches just wipe off.
Very nice. I do silicone moulding of small parts like knobs and so on for old classic synthesizers. I don't even have a vacuum chamber. I first coat the part to be moulded on one side and let the bubbles rise out. Then I turn the part over and complete the mould. My stuff is not as complex as what you are doing here and I'm interested to improve my process
Just a cheap vacuum pot for degassing is pretty nice and cheap. If you haven't already looked into (and decided against) it, I recommend researching them.
How do you navigate your SLA printed parts inhibiting your silicone? I've found coating my SLA printed parts with InhibitX works but it's a unreliable technique and adds a lengthy and costly step in in prototyping.
if you don´t pour the silicone directly into the mould, but rather let it slide down a Surface (mixing-stick, e,g,) it helps to further reduce the risk of air cavities.
Question: as I know the limitation of vacuum cast caused by low life of silicon mold which is limited to 25 productions and you need to make a new mold to cast another 25 parts and so on.., my question is a 3D printed mold possible to use instead of liquid silicon? This way we can print many molds in stock to use it for production. If not advised what’s the best method to speed up molding it automat it or any thing
Beautiful moulds. How long can you store the urethane without Argon or is that not recommended at all? We never did this step and I do remember some occasional issues with seemingly aerated pockets that could have been it foaming.
Once you've opened a bottle, it is best to use it within a few weeks, with or without argon. You must keep them at 40C, and rotate the bottle every day to stir it, so as not to let it crystallize. The argon stops the absorption of water from the atmosphere which causes foaming.
I agree!! That is not sound production whatsoever!! Must be getting silicone manufacturer kick backs!! I would AT LEAST Rigid Mother Mold over Silicone mold!!
I need to make a highly detailed master with rounded edges in order to make molds using PU and then later cast silicone. Which is the best 3d printing method for making this master? I'm afraid of the typical lines that you usually see in 3d printing. Is 3d printing really the best solution?
Wouldn't it be great if "someone" developed a low cost silicon product that one could use to make molds for aluminum casting that would be robust enough to cast 30 or so pieces. But as far as I know there is not. Which means that my poor 6040 CNC hobby mill is going to have to just suck it up and get the job done as best it can. It is an 8" by 12" (approx) piece to be mounted on a very ornate wooden cross. We have got ongoing power blackouts here where I am But at least we get a 2 to 3 hour notification beforehand so its a bit of a workaround situation. MANY MANY very low material removal tool-paths all shorter than 2 hour run time. Have not bought the material yet but it will have to be annealed to be easily machined. But there will have to be a test run on perspex or something at much higher feed rates to see what goes on. PLEASE SOMEONE - FIND US A CAST-ABLE RESIN THAT WILL HANDLE HEAT... PLEASE...
I'm working on a wood and clay master, to make a silicone mould, to make wax positives, to make plaster moulds, to make silicone parts. It's a bit ridiculous, but actually seems to be the best way.
🤔🤔🤔🤔🤔 If i want to make an HDPE item what resin do i use? Im new and having trouble finding information. I find how to make molds but not the liquid resin to make an hdpe item with that mold.
You cannot directly make an HDPE part in a silicone rubber mold using vacuum casting. You can use UP5690 from Sika (formerly Axson), which is a polyurethane that simulates the mechanical properties of HDPE. To make something out of real HDPE, you would need to make a metal plastic injection mold tool and then injection mold the parts.
You can refer to this case study. This is the case study of the part we show in the thumbnail which has an empty interior. www.starrapid.com/project/okie-talkie-case-study/
I came to see how we can get better throughput, cost effectiveness, and result quality with molding by ourselves as opposed to 3D printing for low volume production. Turns out this method is more complex, slower, more expensive, with sole advantage of production quality. It only makes financial sense for high-value prototyping for clients.
Out of curiosity, whats the benefit of vacuum casting if it only takes 10 hours to complete a 3D printed model? Is the 3D printed model simply too rough to send as a sample to a client?
If a town can do laser-polishing, water-milling, metal-3D-printer, plastic-3D-printer (minus-one usage for paint-dye design printing)... and needs a small production run of things. Start with screw-bolt-nut structure, print on structure(torsional bias preloading), mill, polish, print design. What size and cost machine is applicable.? 3D-optical scanner (mobile phone similar), mould creation for injection-moulding techniques with vacuum-nipples. Vaccum draws injection in vectors(in the mould) to prevent weak corners... additional quicker run.
I've used Star Prototypes for years whenever I need to make very small prototypes at better quality than 3D printing can achieve. They are great when I need 10. But I'd really like a low cost solution when I need to produce 500-1000. At this point, NRE charges quickly go into the stratosphere. There seems to be almost zero cost difference between soft aluminum tooling and hardened steel, despite the fact that machine time should be a lot less. Perhaps you would care to make a video explaining how to make low cost limited production parts. Especially when the parts are fairly large, like a 12" square clam shell enclosure for a PCB. If you need to make 500 of something, and you have to pay $10,000 - $20,000 for tooling, that is $20 - $40 per part. More often than not, this turns out to be the actual killer for small businesses looking to try out innovative products in the market. Any solutions for this segment of the industry?
I'd have to see the specific application, but one way is to use RIM Molding. Paragon Rapid Technologies in the UK are one of the world's best at doing that. Many of the guys there used to work for me in the UK. My old company did RIM molding, but it didn't transfer well into China because of the cost of Air Shipment is huge for larger parts.
The advice is mostly for new product developers and entrepreneurs looking for prototypes to pitch or market-test new products - a silicone mold requires far less upfront investment than a rapid tooling approach. And 3D printing is now a viable technique as well, requiring even less fixed costs. Even when compared to IM equipment which can cost 100s of thousands of dollars, the equipment is a factor 10 less cost-intensive I'd say.
it is not very clear to me what exactly you are offering: the service, the silicone mold material and or the casting resins? I am interested in the resins, SIKA?? do you also sell resins? where I purchase a sample? Thank you so much for the video.
Hello, we don't offer resins. We are a manufacturing company and factory. We offer CNC, injection molding, pressure die casting, vacuum casting, surface finishing, incoming materials inspection, and quality control services.
Hi Gordon, Why you did not create MOLD in SLA rather than PRODUCTS in master patterns part? Would be faster that you created negative mold of the product in SLA and afterward poor the polyurethane? Also did you use RTV silicone for mold? You were curing for 14 hours in chamber? My mold is finished with accelator in 2 hours- perfect condition. In overall, thank you for showing this you are the best teacher of rapid manufacturing. Greetings from Croatia. Also I have question regarding molds, do you know by any chance is there a mold made of silicone that is strong/rigid enough to survive high temperature>? For example I am creating molds in Aluminum and Copper with CNC machine and the price per each mold is pretty high and time per each mold takes 5 hours or more. Basically I need something faster for my Silicone label business. Please help.
how do you propose to take the rigid polyurethane out of a rigid SLA mold ? also there's a large chance that the mold would have defects as even the top end printers have problems from time to time. also you can texture the finish.
@@robot-reboot28 I would use anti static spray for plastic or JElly or Vaseline and see if it works. Look buddy, I did not want to say Gordon did wrong job I just wanted to see if this approach would be feasible nothing else. However, it would be great if you could use your expertise and tell me, is there a way to make molds rigit enought to withstand 300 celsius ? Cheers
I have seen full automotive instrumentation panels done by vacuum casting, but nowadays, those kinds of moldings are done by Reaction Injection Moulding into what are called Silicone Skin Molds. These are plywood framed articulated molds, into which you pour silicone rubber to create about a 20mm skin all over the master model. One of the experts in this process would be Paragon Rapid Technologies in the UK. The owners of Paragon are very good friends of mine, and former colleagues. Read more: paragon-rt.com/rapid-technologies/reaction-injection-moulding/ - Gordon
What level vacuum is inside that huge vacuum chamber? I guess not extremely high given the huge glass or plastic transparent door? Also, why not do everything at atmospheric then only after pouring into the mold use a small pressure pot rather than a huge vacuum chamber, like many other people do?
Two awesome questions. OK, here is how we know if we have a vacuum great enough for vacuum casting and how to test that your seals are good, and your pump is good. We take a small plastic cup of tap water, we put it inside the chamber, lock the door, and start the pump. For everything to be right we must FREEZE at least the first 3mm of the water into ice in less than 10 minutes. Now to do that, you will have reached at least minus 1007 millibar. www.engineeringtoolbox.com/water-evacuation-pressure-temperature-d_1686.html The reason why the vacuum can freeze the water is because each time the vacuum increases to the point that the water boils, energy is lost and cools the liquid. So, once you have reached a vacuum that can boil water at less than 0 degrees centigrade, you have literally frozen it. Not only does the water freeze to ice, but then the ice even starts to sublimate as the vacuum gets even stronger, and you see little flecks of ice explode off the surface. You really should check this out, it’s insane to watch. Don’t ask me how the hell that happens. The second question then is this, by how much does the air expand at -1007 millibar (even though it is deeper than that)? Doing it by vacuum you expand the air by 4 or 5 times, and when you release the vacuum that air collapses by a corresponding amount. So, to have a pressure vessel shrink bubbles by the same amount you would need to go to 4 or 5 atmospheres (bar). Most pressure pots for resin casting are about that. So, if all you are looking for is to shrink bubbles, then a vacuum and a pressure pot will achieve the same thing. One upside to a pressure pot is that the air in the chamber will increase in temperature helping to cure the resin. Another benefit is that you can use a vibratory table as you cast outside of the pressure pot; you can do this in a vacuum, but it is far more difficult, and frankly it is somewhat pointless, read on. The downside to a pressure pot is the danger of an explosion. Boom. The upside of a vacuum is that it further degasses the resin, it thins the air in the silicone mould such that during casting the resin will flow much more easily and into the tiniest cracks and cavities. I know that in North America it is very common to use pressure pots, and in the UK, Europe, Australia, and even South America, vacuum is preferred. In China it is about 50/50. So, in summary, it is a matter of personal preference. I’ve seen really great and really terrible results by both methods. ;-) - Gordon
Have you ever made a copy of a complex plastic blow moulded tube? I have a classic car from 1990 that should have a cold air inlet pipe to the air filter housing - this has a narrow rectangular opening that sits in the grill just inboard of the headlight, this then twists through a couple of angles to take it being the headlight and then rearwards and into the air box itself where the moulding changes shape as the connection is round.The part is not too big overall just complex and the original part was quite weak and either broke or was replaced by an aftermarket induction kit. As part of the owners club I think that I could get sales for between 8 and 10 of these depending on price etc. Thanks for any advice, Iam based in the UK if this matters
The only way that can be done is by blow molding or rotational molding. If we were to do that by vacuum casting, we would have to split the tube into two or more pieces and bond them together after casting. - Gordon.
@@starrapid...... That was my thoughts tbh as its such a tricky shape that is dictated by the constrictions in the engine bay. I could possibly loan an original part but this would need to remain in one piece and returned as such. Would scanning this then splitting into 3 or more models then 3D printing be an option? Wall thickness could be increased slightly to make possible so long as the outer faces are as per the model. What sort of costs would you say this could be for say 1 copy or a run of 10/15? Many Thanks
Fuck man, I was really hoping this was going to be budget shit but apparently I need fucking vacuum chambers, large ass ovens and a shitload of other tools that I just don't have.
I'm not sure how rapid it is, but for sure it need quite a few tools to be done to a very high level of fidelity. Especially if the silicone can only produce about 20 copies, so you need like multiple silicon molds and quite some work for each part it seems. I wonder how it can turn out using hobbists tools. A small vacuum pump is sometimes in the set.
I make silicone molds and epoxy castings. A cheap vacuum pump and pot works well. It's perfectly fine for the silicone. It could be used for the epoxy too, but only in cut molds. It doesn't work for open-top moulds; the epoxy foams up and spills out of the mold. For open-top molds, pressure pots are used instead. Robert Tolone has an excellent series of videos showing how to make silicone molds and then cast with all kinds of materials. All he uses is a large pressure chamber, but you could just as easily use a pressure pot.
The cheese is strong with this one, love it! And I'm considering to use silicone mould for my small project, but i really want good results out of materials that can't be 3d printed
Hi Robert, our factory is located in Zhongshan, China. But we have Project Engineers all over the US and the world. You can take a look at our team's location here: www.starrapid.com/about-us/meet-the-team/
This is very cool! Do you mind sharing the approx cost and time difference to make 15 parts by one silicon mold instead of directly doing all 15 parts in SLA? Also, is there any other material in place of silicon that can produce higher production volume in the same process? Thanks in advance
The problem with SLA is that that it degrades, and is pretty brittle. Unless you use a particularly expensive resin. Polyurethane doesn't degrade as rapidly.
Hi Gordon any reccomendations for reputable chineese liquid silicone/ urethane suppliers? We would like to move away from our mainland vendors. Any insight is greatly appreciated
so.. the difference is that instead of spending 10-20k on the molds and tooling for a production run of injection molding and then pay out the nose for the time on the line (including the setup and tear-down time to get your molds on and off the line) you pay 5-8k for a small volume shop to make some "cheep" silicon molds and do a few resin casts? actually... this seems reasonable. at least if won't look like it came off a hobbyist FDM printer
ha ha, i make very complicated plastic parts, mr, well, on a manual plastic injection moulding machine, i would have adapted the methods you have shown in your video, long time ago, if they are practical.
Star Rapid has been no help and showed no initiative during the manufacturing and quote process. I have not spoken to one English representative. The point of contact I’ve spoken with is an Asian lady that only contacts me on the time zone of China which is night time. She also was not any help when I inquired about DFM feedback and Consultation with an in house engineer.
There are many reasons to Vacuum Cast and not 3D print, including part strength and replicating textures. You can read more about this here. www.starrapid.com/services/vacuum-casting/
Some constructive criticism - if I don't learn something new in 45 seconds of a video, I cut my losses and click away. Don't me that to be insulting, but instructive.
![BOWKYLION - ส่วนต่าง (do it without me) [Official MV]](http://i.ytimg.com/vi/7x-pwcMopzE/mqdefault.jpg)
Polyurethane vacuum casting is a method for making high quality prototypes or low volumes of parts formed from inexpensive silicone molds. Copies made in this way show great surface detail and fidelity to the original pattern. Have you ever used this process to make your parts?
I used 3D printing together with vacuum forming by FDM-printing a mold, that was used to vacuum cast the end use part. I used a heat resistant, carbon fiber reinforced filament to print the mold. Several vacuum forming suppliers were hesitant to even try, because they thought the mold wouldn't last more than a couple shots.
After finding a supplier that was willing to try, they were able to mold all 100 parts needed with the one printed mold. The time it took to get from an idea to finished parts was 9 days, including the design, printing, finishing & shipping of the mold. That's when I noticed how powerful 3D printing can really be in rapid prototyping.
Wondering what plastics types can be cast inside the silicone mold as I am looking to blend in barium sulfate and strontium aluminate.
@@trunkki Hey mate. I'm curious to know the exact filament used? There are a number of carbon fiber reinforced filaments. I dont suspect you would have used PLA, PETG or ABS, but maybe something completely different? And did you use polyurethane for the product to be formed in the mold? Cheers
I’m so glad these processes don’t require expensive, specialized tooling 😉
lol
Yeah!
There's a subtle difference here: They're using expensive _equipment_ but not expensive _tooling._ Yes, you may need to use a vacuum chamber for several hours to make your parts. But the cost of the mould is far, far lower.
Just replace vacuum chamber with old air pump and pot, and pour two component plastic, so you do not need an oven. Done by hobbyists for years.
Argon is optional and just reduces waste/saves money. Vacuum chamber is easier to work with than a simple low pressure pot for $100, but the pot does the job. The ovens are optional for speeding up curing and to allow more consistent results. That leaves the resin and silicone, the latter of which is somewhat expensive at ~$50 per kg. And of course the casually mentioned SLA print, which a DIYer would replace with FDM and hand sanding / vapor smoothing.
You don't need an expensive mold, but you need argon gas, a vacuum chamber, an oven, LOL. But great video anyway to see the process.
😂😂
You need equipment to do anything. It's not like you can make high quality commercial parts with mud and a straw or something. You get out what you put in.
Hahaha it's so true. I'm doing two boutique van builds a yeah and need both metal and woodworking tools, CNC, lathes goes on and on 😅
😄😄
I have all of those things in my house… none of it is too aweful expensive
With simplified technique you only need an old air pump for “vacuum” and two-component silicon and plastic to reproduce parts with amazing accuracy. I know a guy working in a scaled model personal business doing just that. When he needs a set of parts, he produces them basically overnight on his table top. He uses tiny Roland CNC router to machine masters from model board, then pours silicon mold block around as shown on video, puts in a pot and pumps air out to remove bubbles, then when silicon is firm, removes masters then pours two component plastic inside, and again pumps air out. His parts are often relatively small and he makes dozens per mold at once. They look like they go from factory😹. Hopefully my comment is useful for all hobbyists around! Upd: searched for example, similar to this th-cam.com/video/3obngISQ_yk/w-d-xo.html
"The silicone is poured in carefully, from one corner.."
**Pours all around the edges**
Instead of pouring the resin under vacuum, you can pour under atmosphere and pressurize in a tank to 50-80 psi. A common technique in the toy-making world, and pressure pots are much cheaper than a complicated vacuum casting machine.
Yes, you can do that. The benefit of vacuum is that you make all the bubbles a lot bigger and they float out and burst during the casting. That doesn't happen with atmospheric hand pouring. There are less bubbles to begin with once the pour is finished compared to hand pouring. Also, you don't get the "pick up" of the surface finish during a hand pour, you only get that with vacuum, and that's why pressure pot castings usually have to be painted after casting. Ours don't. - Gordon
I just realized I met this guy while visiting Shenzhen. His work pieces appeared to be very high quality.
I tried vacuum for moulding and casting but in the end used pressure, perfect results no bubbles air pockets.
Seeing these things like this made going to uni for engineering so worth it, I only wish looking back that I’d went for mechanical instead of chemical engineering, it’s just so much broader and has a lot more applications.
What you study and what you do don't have to be the same. Switching between many different types of engineering is fun, and if you can afford it I recommend to go for it.
What SLA printer is that that has the print bed coming out of the resin pool, rather than the bed lifting up and out of the resin pool? I'm having a hard time envisioning how that works.
Great understanding the whole process. Thank you so much.!
Very glad. Thanks for watching :)
Would it be possible to extend the 3d printing part of the process to include the all the "support structures" that are hand-made at the moment?
I have been printing positives, given them a clear coat of UV resin (to remove the printing lines), then pour with mold rubber, then pour with resinb to get a positive. This is much quicker and easier as it cuts out one step.
Love it. Great job. Keep up the great work.
Thank you :)
Nice Job done... Amazing Quality...
Thank you :)
Best video ever. Thank you.
Thank you Mike!
Cool, I'm trying to create an exact replica of the head frame of an animatronic from The Rock-afire Explosion. (which is an animatronic band from the 1980's). I found a copy of the original service manual, which has diagrams and measurements and maintenance tips, etc.
Using the service manual in combination with photos, videos, other sourced information , as well as guesswork, i've re-created the head frame almost exactly to original spec, in TinkerCAD.
Originally the animatronics' frames were/are mainly made of solid aluminum, and/or square aluminum tubing. Now, it would be cool to make it out of aluminum, but aluminum is a very soft bendable metal. It would also involve welding.
So my thought is to 3d print it, and then either use the 3d printed part or do something similar to what is shown is this phenomenal and informative video.
I'll probably just find someone/someplace to 3d print the pieces and hope that they print properly.
Thank you for creating this video. It's very helpful.
Do you know how the vinyl armrests on the herman miller chairs are made? I would like to use that material to do small scale overmolding for cables at home. It is so very durable. Scratches just wipe off.
Wow this is amazing
Thank you :)
Very nice. I do silicone moulding of small parts like knobs and so on for old classic synthesizers. I don't even have a vacuum chamber. I first coat the part to be moulded on one side and let the bubbles rise out. Then I turn the part over and complete the mould. My stuff is not as complex as what you are doing here and I'm interested to improve my process
That's great to hear. We will post a lot of Vacuum Casting related content, so consider subscribing and stay tuned.
Just a cheap vacuum pot for degassing is pretty nice and cheap. If you haven't already looked into (and decided against) it, I recommend researching them.
How do you navigate your SLA printed parts inhibiting your silicone? I've found coating my SLA printed parts with InhibitX works but it's a unreliable technique and adds a lengthy and costly step in in prototyping.
if you don´t pour the silicone directly into the mould, but rather let it slide down a Surface (mixing-stick, e,g,) it helps to further reduce the risk of air cavities.
this mold is use for warm plastic? please reply
is it possible to use pourable polyurethane casting resin in an aluminum mold in a vacuum?
can't platinum-cure rubber molds withstand potentially hundreds of resin castings, as opposed to only 15 to 20 for tin-cure molds?
3:40 what's the name of this exact printer? 1st time seeing sla printer with the plate at the bottom
Question: as I know the limitation of vacuum cast caused by low life of silicon mold which is limited to 25 productions and you need to make a new mold to cast another 25 parts and so on.., my question is a 3D printed mold possible to use instead of liquid silicon? This way we can print many molds in stock to use it for production. If not advised what’s the best method to speed up molding it automat it or any thing
vacumm casting machine is expensive , is any diy vacuum casting machine bluprint out ther? i am search and not found any information
Beautiful moulds. How long can you store the urethane without Argon or is that not recommended at all? We never did this step and I do remember some occasional issues with seemingly aerated pockets that could have been it foaming.
Once you've opened a bottle, it is best to use it within a few weeks, with or without argon. You must keep them at 40C, and rotate the bottle every day to stir it, so as not to let it crystallize. The argon stops the absorption of water from the atmosphere which causes foaming.
Informative!
We are glad :)
Wow that really informative, I like it,
Thank you :)
How many uses you get from a single silicone mold if you pump it that full of staples? Wont the rip the sides when you open the mold?😅
You can make upto or sometimes more than 20 copies with each mold.
I agree!! That is not sound production whatsoever!!
Must be getting silicone manufacturer kick backs!!
I would AT LEAST Rigid Mother Mold over Silicone mold!!
I need to make a highly detailed master with rounded edges in order to make molds using PU and then later cast silicone. Which is the best 3d printing method for making this master? I'm afraid of the typical lines that you usually see in 3d printing. Is 3d printing really the best solution?
look into 3d resin printing
lots of details thanks
You are welcome :)
Awesome!
Thank you :)
useful info. thanks!
Glad you find them useful :)
Can you make olive clips with this vacuum molding?
Wouldn't it be great if "someone" developed a low cost silicon product that one could use to make molds for aluminum casting that would be robust enough to cast 30 or so pieces.
But as far as I know there is not.
Which means that my poor 6040 CNC hobby mill is going to have to just suck it up and get the job done as best it can.
It is an 8" by 12" (approx) piece to be mounted on a very ornate wooden cross.
We have got ongoing power blackouts here where I am But at least we get a 2 to 3 hour notification beforehand so its a bit of a workaround situation.
MANY MANY very low material removal tool-paths all shorter than 2 hour run time.
Have not bought the material yet but it will have to be annealed to be easily machined.
But there will have to be a test run on perspex or something at much higher feed rates to see what goes on.
PLEASE SOMEONE - FIND US A CAST-ABLE RESIN THAT WILL HANDLE HEAT... PLEASE...
Whenever I tried molding in UV curable resins from 3d printed, the plastic wouldn't harden at all.
Argon and pouring under vacuum looks like awesome hacks. Thanks for sharing ❤️
Glad to share :)
...er....what was that a prototype of/for?
I want to work for this guy, probably an awesome boss!
Until he spots an air bubble.
You don't need an expensive mold.. proceeds to the Robocop cave for curing
I'm working on a 3D printed mold to make a silicone mold to make a cast resin part right now.
I'm working on a wood and clay master, to make a silicone mould, to make wax positives, to make plaster moulds, to make silicone parts. It's a bit ridiculous, but actually seems to be the best way.
I’d love to see a video on how to apply texture using paint/spray paint.
Thanks for the suggestion!
Love the Monty Python reference!!! 🤣👍
😂
🤔🤔🤔🤔🤔
If i want to make an HDPE item what resin do i use? Im new and having trouble finding information. I find how to make molds but not the liquid resin to make an hdpe item with that mold.
You cannot directly make an HDPE part in a silicone rubber mold using vacuum casting. You can use UP5690 from Sika (formerly Axson), which is a polyurethane that simulates the mechanical properties of HDPE. To make something out of real HDPE, you would need to make a metal plastic injection mold tool and then injection mold the parts.
If we're talking about just a couple prototypes it may also be possible to machine HDPE, depending on part geometries.
if the product you want to make has an empty interior, how do you go about doing that with this method?
My guess is that you would make two parts (with 2 different molds) and then join them together at the end. Hope that makes sense.
@@thecoinbot Exactly. The picture we show in the thumbnail is one such part.
You can refer to this case study. This is the case study of the part we show in the thumbnail which has an empty interior.
www.starrapid.com/project/okie-talkie-case-study/
Excellent 👍
Thanks :)
I came to see how we can get better throughput, cost effectiveness, and result quality with molding by ourselves as opposed to 3D printing for low volume production. Turns out this method is more complex, slower, more expensive, with sole advantage of production quality. It only makes financial sense for high-value prototyping for clients.
Vacuum Casting is cost effective, high quality and relative simple. But it highly depends on your requirements.
i need to cast some hard rubber, but dont know hwat to use, can u help me out?
Out of curiosity, whats the benefit of vacuum casting if it only takes 10 hours to complete a 3D printed model? Is the 3D printed model simply too rough to send as a sample to a client?
If a town can do laser-polishing, water-milling, metal-3D-printer, plastic-3D-printer (minus-one usage for paint-dye design printing)... and needs a small production run of things. Start with screw-bolt-nut structure, print on structure(torsional bias preloading), mill, polish, print design. What size and cost machine is applicable.?
3D-optical scanner (mobile phone similar), mould creation for injection-moulding techniques with vacuum-nipples. Vaccum draws injection in vectors(in the mould) to prevent weak corners... additional quicker run.
Brilliant
I've used Star Prototypes for years whenever I need to make very small prototypes at better quality than 3D printing can achieve. They are great when I need 10. But I'd really like a low cost solution when I need to produce 500-1000. At this point, NRE charges quickly go into the stratosphere. There seems to be almost zero cost difference between soft aluminum tooling and hardened steel, despite the fact that machine time should be a lot less.
Perhaps you would care to make a video explaining how to make low cost limited production parts. Especially when the parts are fairly large, like a 12" square clam shell enclosure for a PCB. If you need to make 500 of something, and you have to pay $10,000 - $20,000 for tooling, that is $20 - $40 per part. More often than not, this turns out to be the actual killer for small businesses looking to try out innovative products in the market. Any solutions for this segment of the industry?
Thanks for your suggestion. Excellent idea. Noted. We will make a video on this topic.
I'd have to see the specific application, but one way is to use RIM Molding. Paragon Rapid Technologies in the UK are one of the world's best at doing that. Many of the guys there used to work for me in the UK. My old company did RIM molding, but it didn't transfer well into China because of the cost of Air Shipment is huge for larger parts.
I need help with making few plastic prototype materials, very simple, but i have no experience, will u be able to help
"release the vacuum"
KRAKEN for the love of God!!
Nice video 🙂
Thanks :)
Listening to grandpa try to force memes into every conversation never gets less awkward.
You might not need expensive molds ^^ but these mega vacuum temperature controlled resin mixing and pouring chambers doesn't look cheap either 😅
The advice is mostly for new product developers and entrepreneurs looking for prototypes to pitch or market-test new products - a silicone mold requires far less upfront investment than a rapid tooling approach. And 3D printing is now a viable technique as well, requiring even less fixed costs. Even when compared to IM equipment which can cost 100s of thousands of dollars, the equipment is a factor 10 less cost-intensive I'd say.
it is not very clear to me what exactly you are offering: the service, the silicone mold material and or the casting resins? I am interested in the resins, SIKA?? do you also sell resins? where I purchase a sample? Thank you so much for the video.
Hello, we don't offer resins. We are a manufacturing company and factory. We offer CNC, injection molding, pressure die casting, vacuum casting, surface finishing, incoming materials inspection, and quality control services.
@@starrapid gotcha! thank you so much. Any chance you can tell me where I can purchase the SIKA resin you showed in the video? thanks for the content.
Hi Gordon, Why you did not create MOLD in SLA rather than PRODUCTS in master patterns part? Would be faster that you created negative mold of the product in SLA and afterward poor the polyurethane? Also did you use RTV silicone for mold? You were curing for 14 hours in chamber? My mold is finished with accelator in 2 hours- perfect condition. In overall, thank you for showing this you are the best teacher of rapid manufacturing. Greetings from Croatia. Also I have question regarding molds, do you know by any chance is there a mold made of silicone that is strong/rigid enough to survive high temperature>? For example I am creating molds in Aluminum and Copper with CNC machine and the price per each mold is pretty high and time per each mold takes 5 hours or more. Basically I need something faster for my Silicone label business. Please help.
how do you propose to take the rigid polyurethane out of a rigid SLA mold ? also there's a large chance that the mold would have defects as even the top end printers have problems from time to time. also you can texture the finish.
@@robot-reboot28 I would use anti static spray for plastic or JElly or Vaseline and see if it works. Look buddy, I did not want to say Gordon did wrong job I just wanted to see if this approach would be feasible nothing else. However, it would be great if you could use your expertise and tell me, is there a way to make molds rigit enought to withstand 300 celsius ? Cheers
What is the largest item that could feasibly be casted using this model?
I have seen full automotive instrumentation panels done by vacuum casting, but nowadays, those kinds of moldings are done by Reaction Injection Moulding into what are called Silicone Skin Molds. These are plywood framed articulated molds, into which you pour silicone rubber to create about a 20mm skin all over the master model. One of the experts in this process would be Paragon Rapid Technologies in the UK. The owners of Paragon are very good friends of mine, and former colleagues. Read more: paragon-rt.com/rapid-technologies/reaction-injection-moulding/
- Gordon
What level vacuum is inside that huge vacuum chamber? I guess not extremely high given the huge glass or plastic transparent door? Also, why not do everything at atmospheric then only after pouring into the mold use a small pressure pot rather than a huge vacuum chamber, like many other people do?
Two awesome questions. OK, here is how we know if we have a vacuum great enough for vacuum casting and how to test that your seals are good, and your pump is good.
We take a small plastic cup of tap water, we put it inside the chamber, lock the door, and start the pump. For everything to be right we must FREEZE at least the first 3mm of the water into ice in less than 10 minutes. Now to do that, you will have reached at least minus 1007 millibar.
www.engineeringtoolbox.com/water-evacuation-pressure-temperature-d_1686.html
The reason why the vacuum can freeze the water is because each time the vacuum increases to the point that the water boils, energy is lost and cools the liquid. So, once you have reached a vacuum that can boil water at less than 0 degrees centigrade, you have literally frozen it.
Not only does the water freeze to ice, but then the ice even starts to sublimate as the vacuum gets even stronger, and you see little flecks of ice explode off the surface.
You really should check this out, it’s insane to watch. Don’t ask me how the hell that happens.
The second question then is this, by how much does the air expand at -1007 millibar (even though it is deeper than that)? Doing it by vacuum you expand the air by 4 or 5 times, and when you release the vacuum that air collapses by a corresponding amount.
So, to have a pressure vessel shrink bubbles by the same amount you would need to go to 4 or 5 atmospheres (bar). Most pressure pots for resin casting are about that. So, if all you are looking for is to shrink bubbles, then a vacuum and a pressure pot will achieve the same thing.
One upside to a pressure pot is that the air in the chamber will increase in temperature helping to cure the resin. Another benefit is that you can use a vibratory table as you cast outside of the pressure pot; you can do this in a vacuum, but it is far more difficult, and frankly it is somewhat pointless, read on. The downside to a pressure pot is the danger of an explosion. Boom.
The upside of a vacuum is that it further degasses the resin, it thins the air in the silicone mould such that during casting the resin will flow much more easily and into the tiniest cracks and cavities. I know that in North America it is very common to use pressure pots, and in the UK, Europe, Australia, and even South America, vacuum is preferred.
In China it is about 50/50. So, in summary, it is a matter of personal preference. I’ve seen really great and really terrible results by both methods. ;-)
- Gordon
Where can I buy the argon blowing tool ?
Compra-se o cilindro com o gás... basta conectar uma mangueira e abrir a valvula...
Have you ever made a copy of a complex plastic blow moulded tube? I have a classic car from 1990 that should have a cold air inlet pipe to the air filter housing - this has a narrow rectangular opening that sits in the grill just inboard of the headlight, this then twists through a couple of angles to take it being the headlight and then rearwards and into the air box itself where the moulding changes shape as the connection is round.The part is not too big overall just complex and the original part was quite weak and either broke or was replaced by an aftermarket induction kit. As part of the owners club I think that I could get sales for between 8 and 10 of these depending on price etc. Thanks for any advice, Iam based in the UK if this matters
The only way that can be done is by blow molding or rotational molding. If we were to do that by vacuum casting, we would have to split the tube into two or more pieces and bond them together after casting. - Gordon.
@@starrapid...... That was my thoughts tbh as its such a tricky shape that is dictated by the constrictions in the engine bay. I could possibly loan an original part but this would need to remain in one piece and returned as such. Would scanning this then splitting into 3 or more models then 3D printing be an option? Wall thickness could be increased slightly to make possible so long as the outer faces are as per the model. What sort of costs would you say this could be for say 1 copy or a run of 10/15? Many Thanks
Maybe model everything in 3d and print them? Or mix 3d modeling to me make an already existing part from other car fit?
Do you want to connect and maybe I can help and send you an estimate?
Fuck man, I was really hoping this was going to be budget shit but apparently I need fucking vacuum chambers, large ass ovens and a shitload of other tools that I just don't have.
In transparent lens part, how to prevent pinholes...?
I'm not sure how rapid it is, but for sure it need quite a few tools to be done to a very high level of fidelity. Especially if the silicone can only produce about 20 copies, so you need like multiple silicon molds and quite some work for each part it seems.
I wonder how it can turn out using hobbists tools. A small vacuum pump is sometimes in the set.
Vacuum Casting is used for very specific applications and needs. You can read more about this process here.
www.starrapid.com/services/vacuum-casting/
I make silicone molds and epoxy castings. A cheap vacuum pump and pot works well. It's perfectly fine for the silicone. It could be used for the epoxy too, but only in cut molds. It doesn't work for open-top moulds; the epoxy foams up and spills out of the mold. For open-top molds, pressure pots are used instead. Robert Tolone has an excellent series of videos showing how to make silicone molds and then cast with all kinds of materials. All he uses is a large pressure chamber, but you could just as easily use a pressure pot.
Typical durations e2e?
Could you use a metal mold for resin casting?
Yes. But as with injection moulding, you can't have undercuts.
Thanks for the response :)
The cheese is strong with this one, love it!
And I'm considering to use silicone mould for my small project, but i really want good results out of materials that can't be 3d printed
Cheese is what we are! Good luck with your project 👍
you should deff split pour to make better lines to seal back upon :O
thank you
Thanks for watching :)
where is your US location/shop?
Hi Robert, our factory is located in Zhongshan, China. But we have Project Engineers all over the US and the world. You can take a look at our team's location here:
www.starrapid.com/about-us/meet-the-team/
Very interesting 🤔
Thanks!
This is very cool! Do you mind sharing the approx cost and time difference to make 15 parts by one silicon mold instead of directly doing all 15 parts in SLA? Also, is there any other material in place of silicon that can produce higher production volume in the same process? Thanks in advance
%60 better
The problem with SLA is that that it degrades, and is pretty brittle. Unless you use a particularly expensive resin. Polyurethane doesn't degrade as rapidly.
@@graealex TRUE
IS THE SILICONE USED HERE SOLD IN FLAT CONSTRUCTION MARKETS? 4:38
Hi Gordon any reccomendations for reputable chineese liquid silicone/ urethane suppliers? We would like to move away from our mainland vendors. Any insight is greatly appreciated
Hi, sorry for the late reply. Try Multiplus for small mouldings
Silicone expands upon injecting plastic due to its elasticity. Rigid molds don't thus have consistent tolorences.
Thanks
Welcome
Do you guys make custom molds? I need something made.
Hi, we do. Please contact our team at enquiry@starrapid.com or request a free quote here.
www.starrapid.com/contact/request-a-quote/
Quite stream lined !
This guy really loves Star Trek.
Yes!
so.. the difference is that instead of spending 10-20k on the molds and tooling for a production run of injection molding and then pay out the nose for the time on the line (including the setup and tear-down time to get your molds on and off the line) you pay 5-8k for a small volume shop to make some "cheep" silicon molds and do a few resin casts?
actually... this seems reasonable.
at least if won't look like it came off a hobbyist FDM printer
great
Why don’t you use the 3D printed part as the final prototype?
"The silicone is poured in carefully from one corner"
*shows silicone being poured everywhere*
that's one gorgeously made toilet brush ;)
Thank you :)
ha ha, i make very complicated plastic parts, mr, well, on a manual plastic injection moulding machine, i would have adapted the methods you have shown in your video, long time ago, if they are practical.
This is cheap and easy?
Compared to Plastic Injection Molding, yes.
this seems to be the more expensive method from the usual model shop approach...
yep poured from one corner, as the guy is covering everything moving around from corner to corner
nice
Thanks
Unbelievable that the state-of-the-art has not evolved in at least 25 years
Star Rapid has been no help and showed no initiative during the manufacturing and quote process.
I have not spoken to one English representative. The point of contact I’ve spoken with is an Asian lady that only contacts me on the time zone of China which is night time.
She also was not any help when I inquired about DFM feedback and Consultation with an in house engineer.
That silicone pour at 5:27 is one of the worst I have ever seen 😀
Just want to make beams to replace wood.
All great advice! It looks like a sci-fi sex toy
Ha! It's a cleaning brush.
why not just model and 3d print one instead of all of these steps
There are many reasons to Vacuum Cast and not 3D print, including part strength and replicating textures. You can read more about this here. www.starrapid.com/services/vacuum-casting/
👍👍👍
You don't need an expensive mold to make plastic parts. Really. you need an expensive machine set up to do that for yah
Some constructive criticism - if I don't learn something new in 45 seconds of a video, I cut my losses and click away. Don't me that to be insulting, but instructive.
Thank you. That's actually very helpful. We will incorporate in the future videos.