Form Cure- Tall, thin Durable parts collapsing under their weight

We are printing extrusion shapes on our Form3, and many have small wall thicknesses and cross sections. We are printing our extrusions straight off the bed because support material can’t reach all surfaces. This leads to a lot of long, tall parts. When we put the Durable parts in our Form Cure, they become very soft and actually collapse under their own weight causing them to be ruined.

Has anyone found a good solution to this? I made a rack to crudely hang our parts from in our Form Cure to have gravity work to keep my parts straight, but it’s very cumbersome and there is very little extra room in the form Cure when printing at the maximum height.

It would be nice if there was a plate to suspend parts from using a vacuum during the curing process.

Any tips or tricks would be appreciated.

Warping during curing is something I battle with sometimes too. I’ve found that sometimes you need to heat the part afterwards in a jig that holds the desired shape, and then let it cool in that jig.

Alternatively you can cure without the heater on. I also do this sometimes, but did that I have to increase cure times by 3X for the parts to feel similarly cured (unsure about impact to mechanical properties though)

Like Leon said, you can cure without heat and also you are on the right track with suspending parts, often when I print thing long parts I will design and print sacrificial frame around part to help with maintaining shape
hope that helps a bit :slight_smile:

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Smart @jantarek!

The other thing I’ve noticed is that parts which print 100% vertically have a higher chance of warping than if you printed diagonally. I’ve seen this for various resins. Might have something to do with internal stresses when the layers are cured in their green state.

In this case though, durable has very low heat deflection temperature, so it’s likely just warping under the heat. Curing them without heat for 3x longer is probably a good, easy first step to try.

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Custom support scaffolding as @jantarek suggested is the way to go. I had some tall Durable prints with the same problem, and generated my own support structure to solve it. If it’s too time-consuming to do in your modeling software, you can try a tool like Formware.

My experience is that for some geometries and resins, even if you have a lot of support structures to hold up the model, parts can still warp significantly when cured under full temp. Durable is the worst for this.
Very dependant on the model, print orientation and material. It’s kind of annoying TBH but also understandable that it’s not a super easy thing to fix.

What I really would like is to see how mechanical properties change over time when curing with no heat, or low heat…but that’s a lot of work to characterize.

Yep, my custom support structures tend to be beefier to hold up a little better.

I agree, lower or no heat is an option as well. IIRC the nice thing about Durable is unlike most other resins, the properties don’t really trade off compromises as it’s exposed to more UV. The Tensile Modulus just reaches an asymptote. In other words, it just keeps sucking up the UV and you don’t really need to worry about over-exposing if you’re trying a longer cure without heat.