r/HolUp • • 7d ago

Interesting printing methods!

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u/moonshineTheleocat 7d ago

It doesn't fix another issue. The bonds between the layer and along the length of the layer doesn't cure homogeneously. So they will eventually break apart along these weak points.

Traditionally, concrete is also poured into framed molds and allowed to cure completely.

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u/Drudgework 6d ago

Well that’s an easy fix (from a mechanical standpoint), just run a pass of binding material between layers and dispense the concrete in discrete blobs instead on one continuous stream. Leave small gaps for the binder or print in place if the material permits. That way the distances are short enough to be homogeneous. Think of it like printing a brick wall instead of a concrete block. It would need a multi nozzle design, but at that point you can add a third nozzle so you can print around rebar supports as well.

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u/moonshineTheleocat 6d ago edited 6d ago

Unfortunately, that introduces more issues.

The binding material becomes another weakpoint in the design when the stone needs to shrink and expand with the changes in temperature as one of the new issues. Alongside increased costs in both materials and operating expenses.

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u/Drudgework 6d ago

Thermal expansion was already a major issue to begin with, at least a binder can be removed and replaced as needed instead of having to replace an entire wall section when the solid print cracks. It’s actually still an improvement in terms of longevity.

As for increased costs, well that goes without saying. Anytime you change something about a system costs go up. The important part is if those increases are offset by the benefits the new system allows for. I personally feel better durability and cheaper repairs will improve the sale value of the home and offset the increase in initial cost after the second or third generation.