NEW Making a replica of 3D printed part using a mold

[jimbodeanny]

After one of the 3D printed parts broke for one of my Willy Wonka pinball mods, I decided to try to make a replica using a silicone mold. It ended up working out great and I did my best to document the process. This process could be used in a variety of applications.

Here's the video:
https://www.youtube.com/watch?v=iN802HxUr9I

 

[parism]

After one of the 3D printed parts broke for one of my Willy Wonka pinball mods, I decided to try to make a replica using a silicone mold. It ended up working out great and I did my best to document the process. This process could be used in a variety of applications.

Here's the video:
https://www.youtube.com/watch?v=iN802HxUr9I

Good video, well done. I probably would have used a rubber to rubber mold release liquid when you made the top part of the mold, it works great for two part rubber molds. You can brush that on the bottom rubber mold and the sides of your mold forming case. The spray release is mostly suited for releasing cast resin from a rubber mold. I am not sure if you used the spray prior to casting the resin, it would probably make it easier to release (but it depends on how the mold was made and the complexity of the part).

But, the part looked good! It's exciting!

Paris

 

[jawhn]

Very nicely done! I watched the whole thing. And 30 minutes is a tough sell for a DIY vid.

Alpha-Tron needs to watch this for a similar project he wanted to do that I made a 3D print file for, but couldn't get a good print out of due to it's complicated-ness.

 

[djb_rh]

I watched it all. I learned things that I plan to use. Thanks for that.

Couple tips I noticed, though. For one, you made your fill hole conical, but that was what made it really tough to get your top half of the mold off the part. A cylinder there would have been better. Any reason why you couldn't have used a tiny amount of clay to bridge to a hard cylinder (like a tiny dowel rod or even better, some kind of slick metal rod)? I guess that may not have wanted to stand up easily, but you could have probably run some supports from the sides of your box to hold it. Probably only important if you really *are* planning to use your mold to make a lot of a thing.

Second, an easy way to find out your urethane volume is to get the volume of your part first (duh). An easy way to do that is displacement...fill a measuring cup big enough to hold your part with enough water you can submerge it. Measure the water before and after submerging, subtract, and you know your part volume. Then obviously mix a tad more than that.

I happen to have a 3D printer, and I can see this being a lot faster for folks who want to make a LOT of a part since 3D printer filament is expensive and 3D printers are pretty dang slow. (And you mention in the video that you can get a stronger part, too...but can't you also do *softer* parts out of rubber-like materials?)

I also happen to have a laser cutter, and can see a good use case for:

https://www.makercase.com/

Use that to laser cut an acrylic box of the perfect size for your part. I think I'd try finger style and then still just use Gorilla tape to hold it together. The edges are so clean when laser cut that I *think* the mold liquid wouldn't seep any.

Anyway, good stuff. Nicely done video, too.


--Donnie

 

[jimbodeanny]

I watched it all. I learned things that I plan to use. Thanks for that.

Couple tips I noticed, though. For one, you made your fill hole conical, but that was what made it really tough to get your top half of the mold off the part. A cylinder there would have been better. Any reason why you couldn't have used a tiny amount of clay to bridge to a hard cylinder (like a tiny dowel rod or even better, some kind of slick metal rod)? I guess that may not have wanted to stand up easily, but you could have probably run some supports from the sides of your box to hold it. Probably only important if you really *are* planning to use your mold to make a lot of a thing.

Second, an easy way to find out your urethane volume is to get the volume of your part first (duh). An easy way to do that is displacement...fill a measuring cup big enough to hold your part with enough water you can submerge it. Measure the water before and after submerging, subtract, and you know your part volume. Then obviously mix a tad more than that.

I happen to have a 3D printer, and I can see this being a lot faster for folks who want to make a LOT of a part since 3D printer filament is expensive and 3D printers are pretty dang slow. (And you mention in the video that you can get a stronger part, too...but can't you also do *softer* parts out of rubber-like materials?)

I also happen to have a laser cutter, and can see a good use case for:

https://www.makercase.com/

Use that to laser cut an acrylic box of the perfect size for your part. I think I'd try finger style and then still just use Gorilla tape to hold it together. The edges are so clean when laser cut that I *think* the mold liquid wouldn't seep any.

Anyway, good stuff. Nicely done video, too.


--Donnie

Thanks!

In regards to your questions/responses.

1) The mold was actually pretty easy to remove once I put pressure on the fill hole. The silicone just flexed out. I used a cone because those were the recommendations from the tutorial I watched from Smooth-on.com. It was also what one of their engineers recommended.

2) Yeah, I should have thought of that, and I probably would have been more scientific if the urethane resin was more expensive. Good tip though

As for the strength of the urethane, there is a ton. I opted for something stronger than the original but still containing a little flex, since it needs to flex enough to snap around the rails. When I spoke to one of the smooth-on engineers, he recommended the 65D, but there are plenty of resins that are softer and more flexible too.

If I were to do it again, I'd definitely go with thicker plexi/acrylic. In the tutorial video (the link is in the description of my video), they use 1/2" thick, which I can understand why now. The 1/8" was tricky and obviously caused some issues - although in retrospect, I could have sprayed the outside edges of the first half with Ease Release.

 

[jimbodeanny]

Good video, well done. I probably would have used a rubber to rubber mold release liquid when you made the top part of the mold, it works great for two part rubber molds. You can brush that on the bottom rubber mold and the sides of your mold forming case. The spray release is mostly suited for releasing cast resin from a rubber mold. I am not sure if you used the spray prior to casting the resin, it would probably make it easier to release (but it depends on how the mold was made and the complexity of the part).

But, the part looked good! It's exciting!

Paris

Thanks! The Ease Release spray is what was recommended in the tutorial I watched and by the Smooth-On engineers. It worked well for what it was intended to do - I just messed up with the second half . Although, if I had sprayed it around the outside of the first half, I may not have had to trim as much, but that was mostly due to the reassembly of the box.

Very nicely done! I watched the whole thing. And 30 minutes is a tough sell for a DIY vid.

Alpha-Tron needs to watch this for a similar project he wanted to do that I made a 3D print file for, but couldn't get a good print out of due to it's complicated-ness.

Thanks man!

 

[ArcadeTechGW]

I watched it all. I learned things that I plan to use. Thanks for that.

Couple tips I noticed, though. For one, you made your fill hole conical, but that was what made it really tough to get your top half of the mold off the part. A cylinder there would have been better. Any reason why you couldn't have used a tiny amount of clay to bridge to a hard cylinder (like a tiny dowel rod or even better, some kind of slick metal rod)? I guess that may not have wanted to stand up easily, but you could have probably run some supports from the sides of your box to hold it. Probably only important if you really *are* planning to use your mold to make a lot of a thing.

Second, an easy way to find out your urethane volume is to get the volume of your part first (duh). An easy way to do that is displacement...fill a measuring cup big enough to hold your part with enough water you can submerge it. Measure the water before and after submerging, subtract, and you know your part volume. Then obviously mix a tad more than that.

I happen to have a 3D printer, and I can see this being a lot faster for folks who want to make a LOT of a part since 3D printer filament is expensive and 3D printers are pretty dang slow. (And you mention in the video that you can get a stronger part, too...but can't you also do *softer* parts out of rubber-like materials?)

I also happen to have a laser cutter, and can see a good use case for:

https://www.makercase.com/

Use that to laser cut an acrylic box of the perfect size for your part. I think I'd try finger style and then still just use Gorilla tape to hold it together. The edges are so clean when laser cut that I *think* the mold liquid wouldn't seep any.

Anyway, good stuff. Nicely done video, too.


--Donnie

Good tips! Repped.

This brings back memories of the days I did aluminum sand casting. All very similar principles. Except it's a lot easier with sand - you just pull the molds apart, break out the part, and then clean up the mess.

 

[djb_rh]

Thanks!

In regards to your questions/responses.

1) The mold was actually pretty easy to remove once I put pressure on the fill hole. The silicone just flexed out. I used a cone because those were the recommendations from the tutorial I watched from Smooth-on.com. It was also what one of their engineers recommended.

Good to know. Hard to tell what was difficult versus what was "difficult because it was my first time."

2) Yeah, I should have thought of that, and I probably would have been more scientific if the urethane resin was more expensive. Good tip though

Yeah, didn't mean to sound critical, just an idea for the future or for folks that are doing higher volume parts.

As for the strength of the urethane, there is a ton. I opted for something stronger than the original but still containing a little flex, since it needs to flex enough to snap around the rails. When I spoke to one of the smooth-on engineers, he recommended the 65D, but there are plenty of resins that are softer and more flexible too.

Cool. Can you also add some kind of pigment to get a desired color without painting?

If I were to do it again, I'd definitely go with thicker plexi/acrylic. In the tutorial video (the link is in the description of my video), they use 1/2" thick, which I can understand why now. The 1/8" was tricky and obviously caused some issues - although in retrospect, I could have sprayed the outside edges of the first half with Ease Release.

Half inch? Wow. I was assuming quarter inch would be more than thick enough. That's what I'm going to try when I do this, but that's mostly because that's the thickest my laser will cut.

I have an old Snap-On socket driver (think screwdriver except instead it's got a quarter inch socket drive on the end) that the handle busted off of. I'm thinking of making a mold using a different screwdriver and then doing a new handle using this process, except I'd have to add my driver in before the urethane fill. I feel like it'll work, I'm just guessing it's gonna be pretty hard to make *sure* I get the driver centered well in the mold. I have some ideas I think will work, though.

I also have some surf kayaks that have a removable little block that the grab handle strings attach to. They wear out and break. I've 3D printed some replacements, but they wear out and break even faster. I'm thinking that a slightly new design and then urethane molded parts might be the ultimate answer, though.

Would you mind posting a list of links to the exact products you used? Including the clay? I know with some of the materials there are different choices one might make based on desired outcomes, but it would still be nice to have an exact starting point for the kind of thing you did. Thanks again!


—Donnie

 

[jimbodeanny]

Cool. Can you also add some kind of pigment to get a desired color without painting?

Yes, you can add pigment, but I thought it'd be a heck of a lot easier to bring the part into a hardware store and find a paint that was close, rather than blindly picking a pigment on the website.

Would you mind posting a list of links to the exact products you used? Including the clay? I know with some of the materials there are different choices one might make based on desired outcomes, but it would still be nice to have an exact starting point for the kind of thing you did.

As I said before, all of the links are in the description of the video, including the clay. I also posted a link to the exact tutorial I followed. I used the "soft" Sculptex clay, the Mold Star 30 silicone, and the Smooth-Cast 65D urethane.

 

[djb_rh]

Yes, you can add pigment, but I thought it'd be a heck of a lot easier to bring the part into a hardware store and find a paint that was close, rather than blindly picking a pigment on the website.

Yeah, sorry, didn't mean to imply painting wasn't also a fine option. Just asking if pigment was also an option.

As I said before, all of the links are in the description of the video, including the clay. I also posted a link to the exact tutorial I followed. I used the "soft" Sculptex clay, the Mold Star 30 silicone, and the Smooth-Cast 65D urethane.

Gah, sorry, I could swear I looked but somehow missed it. Thanks.


--Donnie

 

[Hydreigon]

It would be nice to see good reproduction Namco recoil gun shells.