Not to underplay the fact that you are a talented craftsman but the part I like best and appreciate Is how you talk through your troubleshooting thought process. It’s something that cannot be taught from a text book and sadly is becoming less common. You remind me so much of my grandfather who taught me how to work with my hands. It’s a pleasant walk down memory lane of working in his shop but in order to make it complete i’m going to need a clip of you going from happy go lucky to calling it every expletive known to man when it goes wrong 🤣😂😂
@@RobertTolone now THAT reminds me of my grandfather…. ROFLMAO…. He was a blacksmith and a farmer… he made all his own tools and taught me how to forge when I was a kid… I miss that old man!
Do you know what is missing from most you tube videos? Honesty. Your videos have it in buckets! Okay, so the castings didn’t go to plan, you’ve learned two ways NOT to do a rotational casting. You are two steps closer to your goal! Thank you!
Maybe helpful, maybe not, but I used to rotocast clear Frankenstein heads back in the day with Crystal Clear 202 that had fumed silica added, using an old Gabriel Monster Maker rotocaster. I’d add the fumed silica (Urefil 9) to the part A, then vacuum degas to get all the air out of the silica crystals. Then mix the A&B, vacuum degas the mix until it rose and fell, then pour into the mold (coated w Universal silicone release) and rotate using the toy rotocaster. Worked like a dream for nice clear hollow heads as the fumed silica thickens the resin and lets it cling to the sides and coat the mold instead of just liquid resin sloshing around. I used a 1A/1B and 1/2 fumed silica by volume back then, adjusting the silica as needed.
Does the urefil stay visible in the finished cast or does it effectively disappear? I'm trying to rotocast something transparent and I definitely need it to "cling" where it doesn't want to
Failure is a better teacher than success sometimes. I kinda actually LIKE being proven wrong sometimes. I've done this stuff long enough to see both the humor in being wrong but also the feeling that I learn better when I fail. Often, we never really know why we win a battle but when we do a post-mortum on a failure we can figure out why we failed.
Thank you for showing the not so glamorous results. youtube and social media in general is full of "Perfect" examples that are unrealistic and highly edited. From personal experience, I know you have to F.A.I.L. (First Attempt In Learning) at some point, but it's always discouraging when you do. Keep up the awesome work!
Thank you. Guy from Denmark here... tried resin for the first time yesterday after a long period of hesitation. I failed 50% and came through 50%. Thank you for your inspiration and talk about learning. I went down hard yesterday, but I'm ready to try again. The problem is that it costs money every time ;-)
I really liked this video. Because I roto casts a ray gun with a closed mold like you did with the globe. And the casts ended up having dimples like yours. I contacted a few experienced molders and casters friends. Including the manufacture of the silicone and resin I used. They told me the heat inside the mold was causing the silicone mold to become more floppy and it was sinking into the casts. They all recommended that the walls of the mold should be made thicker. I know silicone can take a lot of heat. I figured it was the air shrinking when it cooled causing suction pulling in the walls of the casts.
Showing mistakes and failures makes for the best teaching moments! I wouldn’t call any of that a failure… you learned what not to do to be successful….
Two reccomendations: run a vent tube from the fill point to the center of the spherical cavity. Second, re-mount the mold so the center of the spherical cavity is centered on the inner roto frame plane.
I'll suggest to use a cap/plug with a tube that goes to the center of the cavity. This way you can rotate fully and reach all the surfaces inside without loosing any resin via the pouring hole but the air will move freely. You'll have to figure out how to remove the cap with the tube after the first batch of resin (some bees wax may be involved). Regarding the rotocasting machine, you can add one electrical motor for each axis and control them using an arduino or other suitable gadget such that you can program the rotation so it will cover all spots but the ones you don't need to be reached by the resin. You can also move the pouring hole at the top of the ball, use mold for the inside, but with a cavity that you can fill with water in a balloon so it will keep its shape (like a latex glove in a latex glove), then you'll have the cut and polish the top of the ball to remove the resin left in the pouring funnel. Also you'll have to find a way to precisely position the inner mold. Hope it helps.
I feel like the audience would get wise to me if every project was a glorious success. If you are doing custom work you are always on the ragged edge of the unknown and therefore it is an evitable you will fail a certain percentage of the time.
Thanks for the reply Bob. I agree. I am always disappointed in my failures (especially the expensive ones) but I learn a great deal and rarely make the same mistake twice. I am in the middle of a large project right now. I am 3D printing an entire chess set including pieces, support structure, squares, etc. I then plan to mold and cast the whole thing in resin. It's a mammoth undertaking and will take several weeks. I am using a lot of techniques I learned from you. Thank you for making such great content. I'll post a video on my channel when complete. Have a great day Robert!
Super good that you describe the process and how you think when you encounter problems. That is what helped me when I have problems. Thank you for a great video.
Thanks for sharing your issues with rotocasting. I think many are afraid to show less than perfect results to youtube. You make it apparent that it's okay to struggle while finding a new technique to a brand new process. Great videos and great work!
I hate casting thin walled clear resin items unless absolutely necessary. A two part inner and outer mold of the hardest silicone with a solid and precise mother-mold to support both is priceless. Because the slightest deformation under it's own weight will give you occlusions(voids).use a slower setting resin transferred from a very shallow container where the surface area and a few passes of a gas torch will eliminate bubbles. A tube or straw going through the centre and held by the pour spout will allow hot air out and colder back in, with very few drips. Great video all the same
TH-cam recommend this video to me, as I'm also a resin crafter, and I'm so glad they did. I'm gonna bet this gentleman is or was a shop teacher for a high school. Very well spoken, friendly, and very educational. 10/10. Sorry your casting didn't come out well. But I look.forward to seeing you figure this out!
Well, Meghan only partially lost her bet. I taught nature of materials and introduction to painting at ArtCenter College of Design for a couple of years. That is the extent of my formal teaching career. Thanks for your nice comment Meghan!
Very good to see the problems and how you’re solving them, I am no expert at all, so this is really helpful especially as you’re going through a process of elimination it makes me think too. The heating of the resin just seems to be counter intuitive, (accelerating the curing and reducing working time). Anyhow I look forward to seeing how you solve this casting conundrum in the next video.
Great idea for the hot box. I love resin but it's the bane of my existence. My shop is on a non heated garage and in the summer months it's ok but in winter, well you know. I've also just stared doing the rubber mold making stuff. My first mold was my finger and it came out great including the resin part. I'm fascinated but this whole process especially the rotational part. Nice rig man!
This is fascinating, I used to make moulds for a rotomoulding company, which moulded tanks and vessels from polyethylene. They used to heat the forms up slowly in their rotational kilns so the powdery resin can melt, and then coat the forms from the inside, so the resin has a viscosity of honey, and then let the mould cool down slowly so the part can be removed. And they do use a vent pipe so the part can “breathe”. Mostly it is a piece of Teflon tube, so it doesn’t get stuck during the de-moulding. Hope that helps you along.
I once visited a factory where they made kayaks using exactly that process. It was incredibly interesting. The molds were made of metal and were fantastically expensive to produce!
thank you for all your helpful tips I love you show. For poured resin you may want to make the inside of the dome globe out of a second mold as if you were pouring A resin glass there has to be an inside mold and outside mold in order to get the shape right and you would not have to spin anything you would just pour the resin then eliminating any inside problems. So just create the inside of the globe to place inside the outside of the mold and then just pour the resin in the three part mold. You may just have to sand and polish everything when finished. If you want to breathe carbon dioxide to eliminate air bubbles as you go you can do that as you slowly pour in your resin. 🥰
There are two problems here with that. The opening to the globe is very small and so the inner mold would need to collapse to be removed. This could be done by adding a removable core to the inner mold. But the more difficult problem is that the walls of the original part are so thin that if the molds are even slightly misaligned the casting will have a hole where the two molds touch.
Another great video! Thanks Robert. While it was unfortunately not a success, I greatly appreciate you covering the points that you have to learn the material, mold and process. I know when I first got into casting, and, sometimes even now, I get frustrated when things don't turn out. For simple and standard molds, it's pretty easy to just go onto autopilot and churn pieces out, however, when you add some interesting complexities, the fun really starts. Thanks again for sharing. I look forward to seeing how this works out for you.
Not sure if you have done an update video on this or not. I think a slanted rotation is best. Kind like how glass blowers rotate the glass at an angle. I think that would be your best bet. Have a good slow rotation on the first pass to make sure it is covered then slightly even rotation afterwards. Having the mold in a translucent silicone would certainly help. It might be possible to do it without a machine and just hand rotate it, then let it drain through the hole around gel time. Not sure. A two part mold (outer shell and a core) might be the best solution for consistent thickness :) Love the videos including the "mistakes". They all add to our collective knowledge, troubleshooting, and solutions with our hobby/craft
I have never had much luck with that method. I find that if the tube is large enough the resin drips out of it. If it is a small diameter tube the resin clogs it.
@@RobertTolone I would think a .5" id tube inserted half way into the chamber would be large enough not to clog and deep enough to prevent escape of product. A resin with a longer work time will prevent the flow issues but you don't want to stand there for several hours turning the jig. You said you prefer to do it manually but automation may be necessary.
Have made clear casting , rotated by hand and put it in the pressure pot . I forgot the alumilite resin I used I’m sure the right one. For clear. One of the toughest things to do . 👍🏻
Really grateful for the past videos and taking us along on your new endeavour. some ideas that sprung to mind. The way the resin is attracted to the bottom of the mould reminds me of the centrifugal force produced by swinging round a pale of water. To counteract that you could try locking the rotation of the inner axis 90 degrees to the outer, and spin/rotate the outer axis only. All the best from Scotland, James
The resin was viscous and gelled soon after I poured it. I think it was simply too thick to coat the walls properly. Further experiments should yield a better result. 🤞
tip for rotation a lathe at high speed, rotate at a 45 degree downward angle like a spinning globe. the key is high speed so the centrifugal force does all the work.
Good way to show your struggle and you search for the right way of doing it. Shame it did not turn out the way it was planned . I would have bet I would work. Anyway thats the way to find out, just doing it and succeed in the end - as you certainly will. Another great one anyway looking forward to part two and the victory party at the end of it.
The bubbles arise due to the chemical reaction of the catalyst with the resin. So I do the following. I adapted a glass with a lid that closes hermetically. In the middle of the cover I made a hole and introduced a hose duly grouted with epoxy putty. The other inbetween I attached to a 400 watts electric vacuum cleaner. I turned it on and was amazed to see how it sucked out all the bubbles. It took me about 3 to 4 minutes to complete this process. Then it was just putting it in the mold. Solved problem! Hope this helps. Eduardo - City of Pitimbu - State of Paraíba - Northeast of Brazil
Thank you Robert for all your videos they are all great. I have already use some of your techniques to help me develop my own. I particularly love this video where you show failures as it really helps us all learn. Thank you very much
Nice idea and nice effort. I will make the same machine. Instead of manually moving the tire randomly in speed and direction, I'll use a motor to do this job to get a perfectly uniform circular motion.
Then the resin will pool around the circumference of movement and starve the poles around the axis of movement. if you have motorized two axis of movement then you will still have uneven casting. To achieve an even wall thickness the motion must be slow and random. The movement of the two axes must not be synchronized, therefore they cannot be geared together.
i'd try doing it in a very warm environment, I'd expect some heat to keep the resin thinner and get a more even coating until it gelled. then let it sit overnight to harden and get more of a brittle glass hard, than a leather hard.
Just cover the mold with several layers of soft foam and throw it in the drier on air fluff. Simple. Works every time! Or, you can just by one at the dollar store... for a dollar.
Not sure how this channel ended up getting suggested to me, but I'm really glad it did. I never thought I could spend hours watching videos about mold making and resin casting when I usually watch vids about 3D printing and weird sciency stuff. You have gotten me thinking that I can make molds of some of the things I make so I only have to print them once, would save a lot of time I think. Now just need to build a rotocaster and get my hands on a vacuum chamber...lol. I hope you get to a million subs! Looks like you're well on your way. :)
a machine that continuously rotates on both axes will do a better job. changing directions by hand will create thick spots and sometimes globs that bounce around inside. I Use a machine i bought long ago to do a similar mold (hollow sphere) and got acceptable results. obviously the temperature and speed for the size would need tuning for a "production run". for a cheap hand unit i have seen plans online with geared axis so you only crank the one to get both to rotate.
As a small business craftisan, I have so many ideas starting from the first flop. 🎉always thinking of the reuse of bad pours. At 35:00 I thought "JELLYFISH".
Rob, idea for this with the air seal on this. Could you make a short straw of sorts and integrate it protruding inward from the pour hole? The idea is for it to be resin tight around the pour hole but the walls of the straw stick far enough inward to catch any from pouring out.
Bill Catmull -- rather than use a plug for the hole, use a open ridged vent tube that extends through the plug into the center of the sphere. It will let the globe breathe and you can pour in the resin while it is still viscous giving you all the time you need to get a uniform rotation.
In the rotation casting of the 3D-printed part, you made a point to pour multiple shots to build up the wall thickness. With this dome, you're trying to do it in a single shot. Is the difference whether you're pouring clear versus opaque resin, the roundness of the shape, the target wall thickness, something else? (Great video. Seeing the ways something fails is much more instructive than just seeing everything going right.)
With the manual rotation it doesn't get the centrifugal force to push off the dome and basically scatter along the mold and keep displacin the stuff in the center, and maybe there is a way to cut the plug of the mold like your pressure chambers and pressurize it so when it cools down it goes to neutral, not vacuum
There is no centrifugal force involved in rotational molding. As the resin flows around it coats the walls and gels. The trick is to use just enough resin to coat the walls without having a large extra pool of resin inside the mold.
So I love the rig but have you ever (and I'm sure you have) thought about motorizing it? I think a couple of 3D printer stepper motors would work great.....
I might have some things you could try. First of all, is this a polyurethane resin? Then I think the little bubbles come from moisture that take part in the reaction and cause CO2 gas to build up and form little bubbles. You can try to dry the parts before mixing them. Use the vacuum chamber to dry the parts, then mix them at room temp and fill it in the warm mold. So you get a few minutes extra in working time when the material is not warmed up before. It will draw heat from the mold and use it to become more liquid and runny to make a better coverage.
No, I never made a sequel. Couldn’t figure out how to cast the globe. The walls were too thin and the opening of the globe too small to fit the interior mold through. I declared victory but actually beat a hasty retreat!
Not sure if you made it work, but I use a pressure pot to remove bubbles. I'm wondering if you could make a small pressure pot, cast the piece, and then rotate it while it's under pressure. I use approx. 30 lbs of pressure, but also use a slow set resin... Also, maybe use a clear mold. Use a thick resin that sets with ultraviolet light. I'm currently experimenting with that resin now on little egg things I make...
Working with clear resin is a specialty that is very different than my career experience. I am primarily a sculptor for the entertainment industry. Mold making and casting is the final step in turning a wax or clay sculpture into a permanent figurine. So I am not surprised that my little experiment in rotational molding clear resin failed. The fun of my TH-cam channel is that I get to try stuff out that I really don’t know how to do. Many of the suggestions you made are good ones and would probably work. Thanks for commenting.
Hay Robert. got a question, If you gonna cut out the bottom of that part your casting, and you want to keep an open vet ( pour ) hole, can you use a small tube about 1 inch that sticks in side the object? This might keep the vent open and can just be removed as you remove the bottom. Should allow you to do a standard rotation and not have to worry about the vent. Only thing I think might be bad is some strings from that tube to the side. just a thought.
Just an idea but... maybe you can use a straw to close the opening of the hole still allowing the air to enter the silicone. For example, cut 2, 10 cm straws, ensure that the outside of the straws are somehow in full contact with the silicone hole (eg casting a small silicone tap) and then dip both straws inside the ball till their inside ends reach the middle of the ball. This way, it will be really difficult for the resin to come out. Also, I guess that you could also blow some air once in a while to ensure that the resin walls do not collapse and also blow air in one of the 2 straws to ensure they are not clogged.
From a pure artistically point of view, I actually find the second casting quite cool! ^^ It is not what it is intended to be, but I see a lot of potential in this to make a nice little cup, maybe with a little gold leaf covering a side or so ;)
First, again. Thank you for taking on this project for me. I'm thinking. Instead of the manual setup you have. What if you just try making 2 half-sphere molds with smaller sphere molds in each molds to create the hollow portions of the snow globe. Hopefully that makes sense.
In the second attempt I let the resin sit in the vacuum chamber too long and it was very hot when I poured it into the mold. I had a strong suspicion that it was too viscous to rotate correctly. The open time on this resin is 15 minutes. The open time on my usual opaque rotational molding resin is 2 to 3 minutes. So I feel like I have plenty of time as long as I get the resin into the mold promptly. And the vacuuming didn’t work with this particular resin.
If you use a straw or tube that protrudes into mold cavity in place of mold plug you should be able to do full rotation without resin leaking out and allowing air to move freely in and out of mold
If you put a straw in the bung, sticking in to the center of the object and sticking out about an inch you will have a escape route for pressure without any leak of resin. The resin will flow only on the walls of the molds inside and will not enter the straw.
Half of 4 and 1/16, so 2 and 1/8 plus a bit... 😂😂 That's why we measure twice and cut once!! I'm glad you noticed it and drew another circle in time. Some of aren't always so lucky. 😔
One half of 4 and 5/16 is 2 and 5/32, which I described as an 1/8 plus a tiny amount. My math was right but that old compass is loose and wonky and I had to redraw the circle several times, which I edited out.
"Analyse my floppage" is going to be my phrase of the week :P
Not to underplay the fact that you are a talented craftsman but the part I like best and appreciate Is how you talk through your troubleshooting thought process. It’s something that cannot be taught from a text book and sadly is becoming less common. You remind me so much of my grandfather who taught me how to work with my hands. It’s a pleasant walk down memory lane of working in his shop but in order to make it complete i’m going to need a clip of you going from happy go lucky to calling it every expletive known to man when it goes wrong 🤣😂😂
I edit out the screaming, the bursts of profanity and throwing things around the shop.
@@RobertTolone 😂👍
@@RobertTolone now THAT reminds me of my grandfather…. ROFLMAO…. He was a blacksmith and a farmer… he made all his own tools and taught me how to forge when I was a kid… I miss that old man!
Do you know what is missing from most you tube videos? Honesty. Your videos have it in buckets! Okay, so the castings didn’t go to plan, you’ve learned two ways NOT to do a rotational casting. You are two steps closer to your goal! Thank you!
Learning the limitations of the resin is half the battle! Very educational sir thank you for sharing this.
It sure is Marc! I’m determined to figure this out; especially as I have viewer projects coming up that will use clear resin.
The process of eliminating issues.. this is fantastic!!!
Maybe helpful, maybe not, but I used to rotocast clear Frankenstein heads back in the day with Crystal Clear 202 that had fumed silica added, using an old Gabriel Monster Maker rotocaster. I’d add the fumed silica (Urefil 9) to the part A, then vacuum degas to get all the air out of the silica crystals. Then mix the A&B, vacuum degas the mix until it rose and fell, then pour into the mold (coated w Universal silicone release) and rotate using the toy rotocaster. Worked like a dream for nice clear hollow heads as the fumed silica thickens the resin and lets it cling to the sides and coat the mold instead of just liquid resin sloshing around. I used a 1A/1B and 1/2 fumed silica by volume back then, adjusting the silica as needed.
Does the urefil stay visible in the finished cast or does it effectively disappear? I'm trying to rotocast something transparent and I definitely need it to "cling" where it doesn't want to
Failure is a better teacher than success sometimes. I kinda actually LIKE being proven wrong sometimes. I've done this stuff long enough to see both the humor in being wrong but also the feeling that I learn better when I fail.
Often, we never really know why we win a battle but when we do a post-mortum on a failure we can figure out why we failed.
Failure is a great teacher but not a very fun one! 😀
This is possibly the most wholesome channel on TH-cam 🤗
When my friends read comments like yours they laugh out loud. Off camera I am significantly less wholesome.
@@RobertTolone Just do us a favor and maintain the illusion. You've got a good schtick going on here 😄
@@enquiryplay I just didn’t like the way I sounded on video using profanity. The videos were definitely better without it.
Thank you for showing the not so glamorous results. youtube and social media in general is full of "Perfect" examples that are unrealistic and highly edited. From personal experience, I know you have to F.A.I.L. (First Attempt In Learning) at some point, but it's always discouraging when you do. Keep up the awesome work!
Thank you. Guy from Denmark here... tried resin for the first time yesterday after a long period of hesitation. I failed 50% and came through 50%. Thank you for your inspiration and talk about learning. I went down hard yesterday, but I'm ready to try again. The problem is that it costs money every time ;-)
I really liked this video. Because I roto casts a ray gun with a closed mold like you did with the globe. And the casts ended up having dimples like yours. I contacted a few experienced molders and casters friends. Including the manufacture of the silicone and resin I used. They told me the heat inside the mold was causing the silicone mold to become more floppy and it was sinking into the casts. They all recommended that the walls of the mold should be made thicker. I know silicone can take a lot of heat. I figured it was the air shrinking when it cooled causing suction pulling in the walls of the casts.
I've been a professional prop maker for 25 years. I love your channel!! Keep it going!!
Thanks! I’ll keep on keeping on.
Showing mistakes and failures makes for the best teaching moments! I wouldn’t call any of that a failure… you learned what not to do to be successful….
Two reccomendations: run a vent tube from the fill point to the center of the spherical cavity. Second, re-mount the mold so the center of the spherical cavity is centered on the inner roto frame plane.
Two excellent suggestions!
I'll suggest to use a cap/plug with a tube that goes to the center of the cavity. This way you can rotate fully and reach all the surfaces inside without loosing any resin via the pouring hole but the air will move freely. You'll have to figure out how to remove the cap with the tube after the first batch of resin (some bees wax may be involved).
Regarding the rotocasting machine, you can add one electrical motor for each axis and control them using an arduino or other suitable gadget such that you can program the rotation so it will cover all spots but the ones you don't need to be reached by the resin.
You can also move the pouring hole at the top of the ball, use mold for the inside, but with a cavity that you can fill with water in a balloon so it will keep its shape (like a latex glove in a latex glove), then you'll have the cut and polish the top of the ball to remove the resin left in the pouring funnel. Also you'll have to find a way to precisely position the inner mold.
Hope it helps.
Thank you for showing the failures as well as the successes. It's how we learn.
I feel like the audience would get wise to me if every project was a glorious success. If you are doing custom work you are always on the ragged edge of the unknown and therefore it is an evitable you will fail a certain percentage of the time.
Thanks for the reply Bob. I agree. I am always disappointed in my failures (especially the expensive ones) but I learn a great deal and rarely make the same mistake twice. I am in the middle of a large project right now. I am 3D printing an entire chess set including pieces, support structure, squares, etc. I then plan to mold and cast the whole thing in resin. It's a mammoth undertaking and will take several weeks. I am using a lot of techniques I learned from you. Thank you for making such great content. I'll post a video on my channel when complete. Have a great day Robert!
@@Sonic_Ox Good luck with your project, I hope it comes out great!
I have found that failure is just part of the learning process. Thanks for showing your experiments so we can all learn together!
Mr Foot is in production Larry! You’re up next. Let us hope he does not suffer the same fate as the snow globe 😄😄
@@RobertTolone awesome! I am very excited to see how you tackle my sculpt!
Love the way that you learn of your failures with such wisdom and hilarious spirit , you’re a great plastic artist !
Thank you! Cheers!
Super good that you describe the process and how you think when you encounter problems. That is what helped me when I have problems. Thank you for a great video.
The best loser wins.
This is really interesting honestly. Failing. Learning. Not giving up. Massive kudos.
This was really really educational Robert! Thank you for posting it. I think its useful to show the failures!
Great iterative approach. You’ll figure it out. You’re a badass.
Thanks for sharing your issues with rotocasting. I think many are afraid to show less than perfect results to youtube. You make it apparent that it's okay to struggle while finding a new technique to a brand new process. Great videos and great work!
I hate casting thin walled clear resin items unless absolutely necessary. A two part inner and outer mold of the hardest silicone with a solid and precise mother-mold to support both is priceless. Because the slightest deformation under it's own weight will give you occlusions(voids).use a slower setting resin transferred from a very shallow container where the surface area and a few passes of a gas torch will eliminate bubbles. A tube or straw going through the centre and held by the pour spout will allow hot air out and colder back in, with very few drips. Great video all the same
bon courage et plein succès dans vos activités
TH-cam recommend this video to me, as I'm also a resin crafter, and I'm so glad they did. I'm gonna bet this gentleman is or was a shop teacher for a high school. Very well spoken, friendly, and very educational. 10/10. Sorry your casting didn't come out well. But I look.forward to seeing you figure this out!
Oh, Meghan😩 - bet lost.
Well, Meghan only partially lost her bet. I taught nature of materials and introduction to painting at ArtCenter College of Design for a couple of years. That is the extent of my formal teaching career. Thanks for your nice comment Meghan!
Very good to see the problems and how you’re solving them, I am no expert at all, so this is really helpful especially as you’re going through a process of elimination it makes me think too. The heating of the resin just seems to be counter intuitive, (accelerating the curing and reducing working time).
Anyhow I look forward to seeing how you solve this casting conundrum in the next video.
Great idea for the hot box. I love resin but it's the bane of my existence. My shop is on a non heated garage and in the summer months it's ok but in winter, well you know. I've also just stared doing the rubber mold making stuff. My first mold was my finger and it came out great including the resin part. I'm fascinated but this whole process especially the rotational part. Nice rig man!
This is fascinating, I used to make moulds for a rotomoulding company, which moulded tanks and vessels from polyethylene. They used to heat the forms up slowly in their rotational kilns so the powdery resin can melt, and then coat the forms from the inside, so the resin has a viscosity of honey, and then let the mould cool down slowly so the part can be removed. And they do use a vent pipe so the part can “breathe”. Mostly it is a piece of Teflon tube, so it doesn’t get stuck during the de-moulding. Hope that helps you along.
I once visited a factory where they made kayaks using exactly that process. It was incredibly interesting. The molds were made of metal and were fantastically expensive to produce!
Ha ha... never thought I'd be on the edge of my seat during a resin casting video. Great problem analysis... great teaching video ..... carry on!
Thanks Anne ❤️
thank you for all your helpful tips I love you show. For poured resin you may want to make the inside of the dome globe out of a second mold as if you were pouring A resin glass there has to be an inside mold and outside mold in order to get the shape right and you would not have to spin anything you would just pour the resin then eliminating any inside problems. So just create the inside of the globe to place inside the outside of the mold and then just pour the resin in the three part mold. You may just have to sand and polish everything when finished. If you want to breathe carbon dioxide to eliminate air bubbles as you go you can do that as you slowly pour in your resin. 🥰
There are two problems here with that. The opening to the globe is very small and so the inner mold would need to collapse to be removed. This could be done by adding a removable core to the inner mold. But the more difficult problem is that the walls of the original part are so thin that if the molds are even slightly misaligned the casting will have a hole where the two molds touch.
Another great video! Thanks Robert. While it was unfortunately not a success, I greatly appreciate you covering the points that you have to learn the material, mold and process. I know when I first got into casting, and, sometimes even now, I get frustrated when things don't turn out. For simple and standard molds, it's pretty easy to just go onto autopilot and churn pieces out, however, when you add some interesting complexities, the fun really starts. Thanks again for sharing. I look forward to seeing how this works out for you.
Not sure if you have done an update video on this or not. I think a slanted rotation is best. Kind like how glass blowers rotate the glass at an angle. I think that would be your best bet. Have a good slow rotation on the first pass to make sure it is covered then slightly even rotation afterwards.
Having the mold in a translucent silicone would certainly help. It might be possible to do it without a machine and just hand rotate it, then let it drain through the hole around gel time. Not sure.
A two part mold (outer shell and a core) might be the best solution for consistent thickness :)
Love the videos including the "mistakes". They all add to our collective knowledge, troubleshooting, and solutions with our hobby/craft
If you insert a small tube a couple of inches into the vent hole, you won't have to worry about the resin escaping when you rotate the mold.
I thought the same thing but also wonder how much resin it would draw down the straw. Another test to do!
I have never had much luck with that method. I find that if the tube is large enough the resin drips out of it. If it is a small diameter tube the resin clogs it.
@@RobertTolone I would think a .5" id tube inserted half way into the chamber would be large enough not to clog and deep enough to prevent escape of product. A resin with a longer work time will prevent the flow issues but you don't want to stand there for several hours turning the jig. You said you prefer to do it manually but automation may be necessary.
@@imigistx Give it try and let us know how it works for you.
I would also agree, if you get the straw to the center of the pivot point, nothing should be able to get out.
Thanks Cliff Hartle for sending me this way from Adam Savage’s Tested. I hope you get a lot more subscribers Robert. Great stuff
Thank you. Your persistence is inspiring!
Have made clear casting , rotated by hand and put it in the pressure pot . I forgot the alumilite resin I used I’m sure the right one. For clear. One of the toughest things to do . 👍🏻
I love the "Witness Cup" thinking...
ud es un buen maestro y este proceso de investigacion con sus errores es genial
Regardless of the outcome, we all learn from you. Thank you.
I like Mount Everest, I am determined to conquer the snow globe!
Really grateful for the past videos and taking us along on your new endeavour.
some ideas that sprung to mind.
The way the resin is attracted to the bottom of the mould reminds me of the centrifugal force produced by swinging round a pale of water. To counteract that you could try locking the rotation of the inner axis 90 degrees to the outer, and spin/rotate the outer axis only.
All the best from Scotland,
James
The resin was viscous and gelled soon after I poured it. I think it was simply too thick to coat the walls properly. Further experiments should yield a better result. 🤞
tip for rotation a lathe at high speed, rotate at a 45 degree downward angle like a spinning globe. the key is high speed so the centrifugal force does all the work.
Watching this experimentation process is so effective for learning. Thank you.
I’m a really happy that you find it useful Desiree!
Good way to show your struggle and you search for the right way of doing it. Shame it did not turn out the way it was planned . I would have bet I would work. Anyway thats the way to find out, just doing it and succeed in the end - as you certainly will. Another great one anyway looking forward to part two and the victory party at the end of it.
Every resin artist: "Where's my pokey thing/Stick/Stirrer?!?"
Great vid. I was waiting for it.
A quick tip is when you get back to an old project put the name in the title. "Globe"
Good idea. Thanks for the tip!
Ohhh I have that lil Rockwell tabletop saw. 😊
The bubbles arise due to the chemical reaction of the catalyst with the resin. So I do the following. I adapted a glass with a lid that closes hermetically. In the middle of the cover I made a hole and introduced a hose duly grouted with epoxy putty. The other inbetween I attached to a 400 watts electric vacuum cleaner. I turned it on and was amazed to see how it sucked out all the bubbles. It took me about 3 to 4 minutes to complete this process. Then it was just putting it in the mold. Solved problem! Hope this helps.
Eduardo - City of Pitimbu - State of Paraíba - Northeast of Brazil
by far this is my favorite channels cause ive been casting and making molds the past while! always learning !!
Thank you Robert for all your videos they are all great. I have already use some of your techniques to help me develop my own.
I particularly love this video where you show failures as it really helps us all learn.
Thank you very much
You are such an inspiration to me! Thank you for creating your TH-cam channel, and I'm looking forward to your next video. 🥲
I’m glad my videos are useful to you. Thanks for watching!
this project is so interesting.
Nice idea and nice effort. I will make the same machine. Instead of manually moving the tire randomly in speed and direction, I'll use a motor to do this job to get a perfectly uniform circular motion.
Then the resin will pool around the circumference of movement and starve the poles around the axis of movement. if you have motorized two axis of movement then you will still have uneven casting. To achieve an even wall thickness the motion must be slow and random. The movement of the two axes must not be synchronized, therefore they cannot be geared together.
@@RobertTolone
Thanks
You're right, I missed this idea
i'd try doing it in a very warm environment, I'd expect some heat to keep the resin thinner and get a more even coating until it gelled. then let it sit overnight to harden and get more of a brittle glass hard, than a leather hard.
It works theoretically.
Just cover the mold with several layers of soft foam and throw it in the drier on air fluff. Simple. Works every time! Or, you can just by one at the dollar store... for a dollar.
Not sure how this channel ended up getting suggested to me, but I'm really glad it did.
I never thought I could spend hours watching videos about mold making and resin casting when I usually watch vids about 3D printing and weird sciency stuff.
You have gotten me thinking that I can make molds of some of the things I make so I only have to print them once, would save a lot of time I think. Now just need to build a rotocaster and get my hands on a vacuum chamber...lol.
I hope you get to a million subs! Looks like you're well on your way. :)
Glad you found my channel Jim! Thanks for watching.
This popped back into my feed has it really been almost 2 years. 🤪
a machine that continuously rotates on both axes will do a better job.
changing directions by hand will create thick spots and sometimes globs that bounce around inside.
I Use a machine i bought long ago to do a similar mold (hollow sphere) and got acceptable results.
obviously the temperature and speed for the size would need tuning for a "production run".
for a cheap hand unit i have seen plans online with geared axis so you only crank the one to get both to rotate.
Even masters have disasters. I feel much better now, haha
my definition of a Master is someone who never stops learning. The more you learn the more you realize how little you know.
4:20
An excellent channel. Every time I see you use the saw I fear for your fingers.
After 45 years in a shop I still have all 10 of them. The tool I am most afraid of is my X-Acto knife.
Great Mr Robert !! The next week more ...
Thank you. great videos. "Damas y Caballeros!"
😄
Such a great technique, you can do it.
Your work lights my fire!
I’m very happy you enjoy my videos. Thanks!
As a small business craftisan, I have so many ideas starting from the first flop. 🎉always thinking of the reuse of bad pours. At 35:00 I thought "JELLYFISH".
thanks for this lovely video! I've come out with some amazing messes . You share in such a lovely inspiring way!
Thanks for your videos!!!!(from France)
Thanks for watching!
This man is fantastic
I love that you show your failures. Because, those ‘perfect’ channels get really boring, and I don’t learn.
If I didn’t show my mistakes I could basically never release a video! 🤪🤪
Rob, idea for this with the air seal on this. Could you make a short straw of sorts and integrate it protruding inward from the pour hole?
The idea is for it to be resin tight around the pour hole but the walls of the straw stick far enough inward to catch any from pouring out.
Bill Catmull -- rather than use a plug for the hole, use a open ridged vent tube that extends through the plug into the center of the sphere. It will let the globe breathe and you can pour in the resin while it is still viscous giving you all the time you need to get a uniform rotation.
Thank you for sharing! Was curious about this exact thing and learned a lot.
In the rotation casting of the 3D-printed part, you made a point to pour multiple shots to build up the wall thickness. With this dome, you're trying to do it in a single shot. Is the difference whether you're pouring clear versus opaque resin, the roundness of the shape, the target wall thickness, something else? (Great video. Seeing the ways something fails is much more instructive than just seeing everything going right.)
With the manual rotation it doesn't get the centrifugal force to push off the dome and basically scatter along the mold and keep displacin the stuff in the center, and maybe there is a way to cut the plug of the mold like your pressure chambers and pressurize it so when it cools down it goes to neutral, not vacuum
There is no centrifugal force involved in rotational molding. As the resin flows around it coats the walls and gels. The trick is to use just enough resin to coat the walls without having a large extra pool of resin inside the mold.
@@RobertTolone ah alright, would have thought from the turning it would push out instead of sloshing around after the initial coat
A fun video and a good amount to learn from it, regardless of the outcome!
Thanks for watching Rob!
So I love the rig but have you ever (and I'm sure you have) thought about motorizing it? I think a couple of 3D printer stepper motors would work great.....
Your kind of a genius
I might have some things you could try. First of all, is this a polyurethane resin? Then I think the little bubbles come from moisture that take part in the reaction and cause CO2 gas to build up and form little bubbles. You can try to dry the parts before mixing them. Use the vacuum chamber to dry the parts, then mix them at room temp and fill it in the warm mold. So you get a few minutes extra in working time when the material is not warmed up before. It will draw heat from the mold and use it to become more liquid and runny to make a better coverage.
All good suggestions, I will give them a try.
Is there a second part to this video? I keep checking in haven't found it. I really like your videos taught me so much. Thank you
No, I never made a sequel. Couldn’t figure out how to cast the globe. The walls were too thin and the opening of the globe too small to fit the interior mold through. I declared victory but actually beat a hasty retreat!
you could put a box in the inner mold part, which can be taken out first
the best job is the kiss job
Not sure if you made it work, but I use a pressure pot to remove bubbles. I'm wondering if you could make a small pressure pot, cast the piece, and then rotate it while it's under pressure. I use approx. 30 lbs of pressure, but also use a slow set resin...
Also, maybe use a clear mold. Use a thick resin that sets with ultraviolet light. I'm currently experimenting with that resin now on little egg things I make...
Working with clear resin is a specialty that is very different than my career experience. I am primarily a sculptor for the entertainment industry. Mold making and casting is the final step in turning a wax or clay sculpture into a permanent figurine. So I am not surprised that my little experiment in rotational molding clear resin failed. The fun of my TH-cam channel is that I get to try stuff out that I really don’t know how to do. Many of the suggestions you made are good ones and would probably work. Thanks for commenting.
I'm still in trouble like that too. in making souvenir plates .
too thin
Hay Robert. got a question, If you gonna cut out the bottom of that part your casting, and you want to keep an open vet ( pour ) hole, can you use a small tube about 1 inch that sticks in side the object? This might keep the vent open and can just be removed as you remove the bottom. Should allow you to do a standard rotation and not have to worry about the vent. Only thing I think might be bad is some strings from that tube to the side. just a thought.
Preciate your sharing this!
Thanks for watching Tobias!
Just an idea but... maybe you can use a straw to close the opening of the hole still allowing the air to enter the silicone. For example, cut 2, 10 cm straws, ensure that the outside of the straws are somehow in full contact with the silicone hole (eg casting a small silicone tap) and then dip both straws inside the ball till their inside ends reach the middle of the ball. This way, it will be really difficult for the resin to come out. Also, I guess that you could also blow some air once in a while to ensure that the resin walls do not collapse and also blow air in one of the 2 straws to ensure they are not clogged.
From a pure artistically point of view, I actually find the second casting quite cool! ^^ It is not what it is intended to be, but I see a lot of potential in this to make a nice little cup, maybe with a little gold leaf covering a side or so ;)
An artist friend of my already commandeered it!
Thanks!
I wonder if you could hook your drill up and adjust the speed for rotating
What kind of resin did You use? Excelen job
First, again. Thank you for taking on this project for me.
I'm thinking. Instead of the manual setup you have.
What if you just try making 2 half-sphere molds with smaller sphere molds in each molds to create the hollow portions of the snow globe.
Hopefully that makes sense.
it would work but then there would be a wicked parting line in the globe.
Do you need product with a little longer pot time maybe?
Seems like it sets up pretty fast.
In the second attempt I let the resin sit in the vacuum chamber too long and it was very hot when I poured it into the mold. I had a strong suspicion that it was too viscous to rotate correctly. The open time on this resin is 15 minutes. The open time on my usual opaque rotational molding resin is 2 to 3 minutes. So I feel like I have plenty of time as long as I get the resin into the mold promptly. And the vacuuming didn’t work with this particular resin.
If you use a straw or tube that protrudes into mold cavity in place of mold plug you should be able to do full rotation without resin leaking out and allowing air to move freely in and out of mold
If you put a straw in the bung, sticking in to the center of the object and sticking out about an inch you will have a escape route for pressure without any leak of resin. The resin will flow only on the walls of the molds inside and will not enter the straw.
That works but not reliably, at least for me. The resin coats everything inside the cavity and often clogs the straw.
Half of 4 and 1/16, so 2 and 1/8 plus a bit... 😂😂 That's why we measure twice and cut once!! I'm glad you noticed it and drew another circle in time. Some of aren't always so lucky. 😔
One half of 4 and 5/16 is 2 and 5/32, which I described as an 1/8 plus a tiny amount. My math was right but that old compass is loose and wonky and I had to redraw the circle several times, which I edited out.
@@RobertTolone Ahh, I misheard it as 4 and 1/16. And then the extra circle "confirmed"my mistake. Mea culpa.
Was this ever re-attempted? I'm interested in trying something similar.
Amazing video as always!
Thanks Kevin!
Nothing is a "failure", it's a learning opportunity.
Exactly right Martin!
What about rotating a pressure vessel?
Your bamboo paddle stirrer reminds me of the many times breaking my chopsticks apart on my sushi takeout went poorly. :D
Haha - I never get them to break apart evenly!