Resin Casting 101

[wazzou]

You are casting boxcars and then you show casting wheels as if they were part of the process.

I know they're not brake wheels. Did I miss something here?

He was using a vehicle wheel mold to use his residual resin after filling his main mold, a common practice.

[randgust]

Yup.   I have certain molds and parts that do better with 'near the edge' resin, so that if I have any leftover material left after my primary casting run, they are ready to accept any leftovers at the last minute.  I nickname them "resin dumps", usually parts without a whole lot of intricate detail and fairly heavy cross-section.

One thing I'd like brought up - because it's an experience thing here from a number of sources - is what people are seeing for shrinkage factors on different materials and practices.   I just did an 85' passenger car shell in resin and it 'looks like' it may have shrunk about 1mm from the master, but it was also a Shapeways master and I've confirmed that painting/sealing those can also have some nasty dimensional effects before you even start, at least in FUD.   I had a diesel shell test I did that by the time I was done (Shapeways FUD, prime painted with Badger,  to Resin part result) it was significantly too short to fit the chassis.    I don't think I have anywhere near the shrinkage issues in CR600 that I've seen other materials do, and Wazzou and I have compared notes before.

[jimmo]

He was using a vehicle wheel mold to use his residual resin after filling his main mold, a common practice.

Yea that's what I do as well, but not what I was inquiring about.

In the middle of a procedural demonstration on boxcar reproduction for those who want to know how, making a vehicle wheel mold seemed kind of out of place, if just to show what to do with residual resin.

[daniel_leavitt2000]

Ah... I get what you are saying.

This is a how-to on resin casting. The actual boxcar is not really the point. I am showing two methods of making a two-part mold. I chose the wheels because that are annoyingly difficult to cast as you can attest to. The side project was just laying around and it is small enough to make if there is only a little rubber left.

[jimmo]

Ah... I get what you are saying.

This is a how-to on resin casting. The actual boxcar is not really the point. I am showing two methods of making a two-part mold. I chose the wheels because that are annoyingly difficult to cast as you can attest to. The side project was just laying around and it is small enough to make if there is only a little rubber left.

Used to be annoyingly difficult to cast vehicle wheels. I have been using a method that injection casts two to four sets at a time (depending on the wheel size) per mold and if I make several of those molds, I can cast up to 10 times that amount.

The only part of the technique that is tedious is setting up wheels, feeders and vents for masters. After that you just cast as many molds as needed. Since I have to make wheel sets for production, it's a time and sanity saver.

With a new-found ability to create wheel sets in 3D, I can either use the printed wheels directly in my kits or make a master and continue to cast them in resin.

If anyone is interested in how I do this, let me know and put together a how-to post.

[peteski]

With a new-found ability to create wheel sets in 3D, I can either use the printed wheels directly in my kits or make a master and continue to cast them in resin.

If anyone is interested in how I do this, let me know and put together a how-to post.

I would love to see a how-to on that (or any modeling technique for that matter)!  There is no such thing as too many modeling techniques.  Knowledge is power!   

[jimmo]

I would love to see a how-to on that (or any modeling technique for that matter)!  There is no such thing as too many modeling techniques.  Knowledge is power!   

Pete, are you inquiring about the creation of the 3D wheels specifically or the use of the technology to create masters?

I agree with your statement that there's no such thing as "too many modeling techniques." If you ever find yourself thinking that then it's probably time to consider a new hobby.

[peteski]

Pete, are you inquiring about the creation of the 3D wheels specifically or the use of the technology to create masters?

YES!  Like I said, I'm interested in learning any new techniques.  I still haven't graduated to anything more complex than an open single-piece mold. I will welcome any additional tutorials on 3D design and mold-making and resin-casting.

[jimmo]

YES!  Like I said, I'm interested in learning any new techniques.  I still haven't graduated to anything more complex than an open single-piece mold. I will welcome any additional tutorials on 3D design and mold-making and resin-casting.

Do you have any CAD experience? Do you have any 2D drawing experience? The reason I ask is that most of the people I encounter on our Facebook page: N3D and other places (like here) are using SketchUp or more advanced CAD systems. What I use is a simple surface modeling program called TinkerCAD by AutoDesk designed solely for the purpose of 3D modeling. TinkerCAD is a free-to-use program that you access online, in other words you never own a copy of it. I found it through Shapeway's "Lets get started" (or something like that) button.

The reason I asked about the 2D drawing is (for what I do) it is an essential tool as the program does not have it's own 2D capabilities. I use Adobe Illustrator for my 2D work. I think I read one time that you use CorelDraw.

[peteski]

Do you have any CAD experience? Do you have any 2D drawing experience?
The reason I asked about the 2D drawing is (for what I do) it is an essential tool as the program does not have it's own 2D capabilities. I use Adobe Illustrator for my 2D work. I think I read one time that you use CorelDraw.

Thus is getting way out off-topic for Daniel's thread.  I will PM you.

[Ed Kapuscinski]

How do I tag something "Best of" again?