A (Time) Lapse

Do you ever have something you really need to do but, for whatever reason, can’t quite finish? That’s been this project- a camera mount for my 3D printer so I can take time-lapses of my prints.

I’ve had my 3D printer for almost four years now and a blog for twice that. If there’s anything that I’ve learned about design work and engineering it’s that the finished project isn’t always what’s most important, it’s often the insights and skills you pick up on the way. This is one of the primary reasons I’ve always done my best to document my work and make it engaging, even for people who are less technical. A key component I have always felt was missing was footage of these prints which, to this day, I find inspiring. I am glad to say I no longer have that problem.

The Camera

The first thing I had to decide on was camera/time-lapse system I wanted to use. I’ve seen GoPros, Raspberry Pi cams, webcams, and even DSLRs being used, each with their own pros and cons. Fortunately, I have access to all, however the usability of each is ultimately how I made my decision. I should note that some printer firmware allows for easier camera integration (e.g. Octoprint) however, mine does not.

DSLR

Pros:

• Best image quality

Cons:

• Time-consuming setup
• Some post processing required to turn images into an actual time-lapse
• Requires custom hardware/software to trigger camera from printer
• Can’t use my camera for anything else during what might be a multi-hour print
• Not small enough to be contained within the printer

Webcam

Pros:

• Cheap enough that I could buy an extra to dedicate to my printer
• Small enough to be mounted on the print bed

Cons:

• Still requires a computer/interface
• Also requires custom hardware/software to trigger the time-lapse from the printer
• The government can probably spy on my prints

Raspberry Pi Camera

Pros:

• Cheap
• Self-contained
• Has the smallest/lightest camera module which allows for more flexibility in mounting options
• Would be the easiest to interface with the printer

Cons:

• Still some work required to make the Pi work nicely with the printer
• Questionable image quality from the Pi Camera

GoPro

Pros:

• Self-contained
• Time-lapse features built in
• Good image quality
• Small and light
• Waterproof
• Not being used for anything else

Cons:

• Also requires custom hardware/software to control from the printer

So I settled on using a GoPro. Being able to simply hit the record button (even when the GoPro is off) to start and stop time-lapsed video (with little to no post-processing) is the most convenient.

The Mount

Having settled on a camera/platform I could now go about designing a mount for it. The first choice I had to make was whether I wanted the time-lapses to come from a fixed position (the camera doesn’t move) or to move with the printer (e.g. the print bed). Designing and using a fixed-mount would be easier as there are many places in and around the frame to which a mount could be attached. The drawback is that depending on the size of your print, the framing might be off or inconsistent from print to print. Knowing it would be the easier route, I tried designing a fixed mount first:

However, after thinking about it some more, I decided I wanted I wanted a mount that attached to the print bed so the print was always well-framed. Like I said at the beginning, sometimes insight is more important than a finished product.

I started by taking a look at my printer bed to see where I could attach the camera. It’s a little different than the stock bed as I use a glass sheet held on by clips (making it easier to take out, and for printing ABS). Unfortunately, there aren’t too many extra screw holes or other secure mounting options on the bed so my first though was to add it over one of the clips:

Another important consideration was the backdrop of the time-lapse. If the camera was mounted inside the printer facing the bed, it would be more sensitive to lighting changes in my room and could lead to poor/inconsistent exposure, and any movement in the background would be distracting. It made much more sense to have the camera facing into the printer where the lighting is more controlled and the black casing as a perfect backdrop for the print. With those design choices in mind, I started sketching up a new mount:

It’s always good to start with a prototype to make sure your measurements are correct before wasting time/material on a longer print

Once I knew everything fit as it should I went about designing the rest of the mount:

Unfortunately, I don’t have any photos of the printed mount but it ended up working ok however, there were a few problems with it…

The main one being that the camera wasn’t positioned out far enough and would be hit by the rails. It was also not very well secured as the clip it was mounted to also had some play in it. With that feedback in mind, I set about redesigning the mount:

I changed the design so that the arm attached directly to the bed, which eliminated some of the play that was introduced by the clip. I also moved the mount to the left side of the print bed, which had more room as the center console is offset to the right.

Here you can see the V2 arm being printed using a time-lapse from the V1 arm.

But this arm also had a few issues. You can see the printer didn’t handle the overhang well leaving one side a little stringy:

The mount had a better fit however, there was still too much play. The biggest issue was that putting the weight of the GoPro so far out actually changed the bed level in that corner, and not in a way I could adjust for with a 3-point leveling system (the corner points are on the back side of the bed). This wasn’t an issue for smaller prints however, it became noticeable on larger ones. The last thing I wanted to do was risk a multi-hour print just to get some video. Back to the drawing board.

This time I decided to model the part that attached to the print bed off one of the clips I had been using as it wrapped around the top of the bed and was more stable:

I also switched the mount back to the right side of the printer as I could bring the camera in closer to the print bed, thus reducing its leverage. I also changed the design of the arm so that it could be printed easily, without needing any overhangs:

The result was a much more secure and well-formed arm, which has been put through its paces:

An Echo Dot wall mount (which I cannot recommend)

A bed leveling jig (which I can recommend)

An Apple Pencil holder (which I can also recommend)

I hope you enjoyed the new content as it took me a lot longer than I thought to get. This year I promise to do better. Have a wonderful 2019, and work hard on the things that are most important to you.

Cheers,

Connor