Modeling Parametric Hatch based on Drawing and Video Animation

I’m a math and biology major trying to create a 3D printed version of a hatch used for cleanly transferring materials (so mold stops entering and killing my cultures). The design is relatively simple, but I have limited experience with Blender and would like to parametrize it in case design changes need to be made. This type of hatch (DPTE) has been around since the 70s, but I can’t find any full schematics for it (probably because companies want you to buy theirs). I have attached links to a PDF with a basic drawing of the schematic and a video showing a 3D animation of the hatch in action.

Normally I would buy something like this, but since it’s a low-volume item (and from the biotech world): the cheapest hatches sell for at least $750 on eBay.

If anyone could give any advice it would be greatly appreciated, as it would also help Open-source Science and Biohackers. Thanks!

Video animation of DPTE hatch in action (a good cross-sectional view can be seen at 1:22 in the video):

PDF Containing the best drawing/schematic I could find (on page 4):

I should also add that I can write Python scripts and have done some basic modeling in Blender, just not a lot.

Welcome to BA!

Which part do you need?

From the video, i am guessing the opening mechanism is inside a Biosafety/glove cabinet and you only need the part outer part that is on the sample tube side? Or do you need the whole assembly Alpha and Beta?

I need the whole Alpha and Beta assemblies, since they would otherwise cost an arm and leg to buy from the manufacturer.

Since Geometry Nodes hasn’t matured yet, a lot of functionality for readily parametrizing (and editing those parameters) isn’t implemented, so I tried using FreeCAD and the results are going pretty well. I’ll start posting prototypes on Thingiverse when I get the chance. Thanks for the reply!

I take it back: FreeCAD is a cumbersome nightmare that makes something as simple as a polar array an impossible nightmare. But at least it gave me the idea to work on ‘drawing’ the cross section out first before revolving it.

As for the Thingiverse page, here’s the link:

Here is a diagram that shows all of the components interlocking.

Looks doable.

The hardest and most important part will be the seals. Does the the design have to be exactly the same or does it just have to fulfill the same purpose?

Just to fulfill the same purpose.

This is more of a weekend project and i don’t know if 3d printed parts will hold up well.

I made a crude part for joining the outer and inside the of the container.
I still have to make all the other parts like container flange guide, alpha and container doors, mechanism for opening the door and then a method to open the container door without contamination (which is what the unique seals are for)

It’s going to be difficult to design something that will work with normal lip seals to replicate the unique lip seals on the real hatch. Might be able to replicate one of the seals with 3 separate seals.

The 16 holes for bolt and nuts are just a placeholder, 4-6 will be enough and it will just be a one time installation to get the unit fitted to the container.

The most important aspect is that the part of the Alpha hatch that is exposed to the outside will connect flush with the lid part of the Beta container (causing any contaminants on the two to become entrapped. The same goes with the seal between the Alpha hatch’s rim and the body of the Beta container.

This is the current state of the Alpha hatch. I really need to figure out how to cut parametrizable notches into the latches so I can get the timing right.

From what I gathered: the first thing that engages is the rim of the Beta container (called Gamma) with the rim of the Alpha hatch, then the Alpha hatch door with the Beta container’s lid, after that the latch/lip that holds the Beta lid onto the container wall is disengaged.