Fixing a Formlabs build plate with First Principles

In the past we struggled with some build plates failing on Formlabs machines. The covers on the sides would pop out and no matter what you did they would continue to do so. Admittedly this happens infrequently and must be attributed to some manufacturing or tolerance variability.

However, we were recently reminded of this on a forum post. It seems to be a problem that continues to trouble some users and there have been varying degrees of band-aid solutions proposed, including changing the gasket and/or adding RTV silicone.

One of the things I love about engineering is being able to solve problems using First Principles. If we take apart a build plate and ask ourselves why this happens, we can come up with an explanation and solution.

The design for manufacturing of these build plates is quite clever. They look like extruded aluminum with some end caps and gaskets that prevent resin from leaking in. The cleverness here is that extruding aluminum is cost effective and also allows the build plate the height it needs. I’ve always loved how ergnomic the Formlabs build plates were and how much attention to detail these have for handling and processing.

However, because of this design there’s a large, sealed pocket of air inside the build plate. What happens when this build plate, which is likely assembled at ambient conditions, enters a heated chamber and/or heated resin? Well, air expands of course. This expansion is likely what causes the end caps to pop out.

Therefore, a really easy and simple solution is to allow this pocket of air to vent. This is achieved by simply drilling a small hole at the top of the build plate. No silicone, no band-aids, just First Principles 🤓

Vent Hole

By simply drilling a small hole at the top of the build plate this allows air to vent and prevents internal pressure from building and popping out the end caps. since doing this we’ve never seen any further gasket problems.