A Cool Look From The Inside

I stuck a GoPro into my Form1 and recorded a little video. It would have been better with more light, but it’s pretty cool none-the-less.

This video would also be cooler if the model was a lot more complicated - this was basically a trial run. Maybe I can find a non-UV-emitting light for a future video.

I recorded a little more later in the print. This one shows an air bubble (well, several really) that has collected under the build platform. Kinda interesting as well IMO.

Wow cool! Any idea what caused all that bubbling? Did it mess up the print?

I’m a little concerned about the trapped air… It would be good if the Form 1 performed a peel process before the first firing to squeeze out any air. [Hopefully the formlabs guys are reading this ;)]

@Vince, it would be because the platform drips straight down, as it is level and the resin is stagnant, there is nothing to cause the bubbles to move off to the side. [also due to natural and manufacturing variations, there may be some slightly concave areas] One option is as I described in my previous post, this would push the air off to the side. Another alternative would be to make the platform slightly convex so the bubbles move naturally to the side. Obviously the former can be done as a software fix, while the latter requires a design change. I prefer the former as you have better control over when the bubbles dissipate, the later requires waiting, and hoping they have all moved off by the time the print process begins.

I’m not sure what to make of the air bubbles. They form when the peel process brings the surface of the resin just below the build platform - when the resin tray lifts back up some of the air is trapped and forms bubbles. Now that I’ve thought about it a little I imagine it would only be a problem if the peel brought the surface of the resin below the cured object.

I’m not sure how far the peel process lowers the resin tank, but I guess it would be prudent to keep the depth of the resin greater than that distance. To say this a different way: let’s say the peel lowers the tank 5 mm, it would be important to keep the resin at least 5 mm deep. That way air could never get between the cured part and the resin surface.

“It would be good if the Form 1 performed a peel process before the first firing to squeeze out any air.”

Yeah, I think that would be a good idea too. Almost all the air bubbles are squeezed out by the initial plunge, but you can see the remainder being pushed up during the first peel.

Oh sorry, I didn’t answer the “did it mess up the print” question…

I’m actually not sure. GoPro has a smartphone app that shows a preview of what the camera can see. I saw the air bubble and freaked out a little. I paused the print, opened the cover, looked in the tank, and somehow got it in my head that I had run out of resin. At that point I canceled the print. Of course, duh, there was still resin left. So far as I can tell the part that printed came out just fine.

the larger bubble in the 2nd video is likely just a result of surface tension as the platform nears and passes the surface of the resin level in the tank… nothing to worry about there, as long as the layer level is well below them. [could be an issue if you are low on resin.]

Argh, I hate not being able to edit my posts!

Let me answer the “did it mess up the print” question a little differently…

I don’t think so. I was a little freaked out by the air bubble (which I only knew was there because I had a camera in there) and canceled the print (read above for a little more info). I checked out the portion of the object that finished but I didn’t see anything wrong with it. I don’t think any air got anywhere that could have caused a problem.

@Mark, the tank is already tilted when the platform first enters, and then as the tank is raised the bubbles are forced out on the right. Are you suggesting another peel after this first pass?

This is awesome! I was going to try this when I get my printer later this week, but I guess you beat me to it.

It would be awesome to set-up the GoPro on a timelapse to capture an entire build, the only issue would be power, and I’m thinking it’s probably not easy to snake a USB cord into the printer.

I don’t think these bubbles are anything to think about.  The clue is in Hirudin’s description.

When the plate first comes down we can all see the plate clear the bubbles before the print process starts.  That’s fine.

Then later in the process the plate will be working it’s way upwards towards the surface of the resin as the model grows.  The peel process will eventually introduce air as it gets closer to the top.  The resin will be at the bottom of the tray and no doubt trapped between the last slice and the tray.   Don’t forget eventually the build platform won’t be in the tray as the model grows so it won’t be dipping in and out of the resin at all.  This video just shows the platform on it’s slow transit to the surface.

We just have to put fauth into Sir Isaac Newton’s gravity to hold the resin at the bottom of the tray and the bubbles to congregate at the top.  Remember the laser is firing at a thin layer at the bottom so the bubbles are well out of the way.

@Gregg: I wasn’t aware that the Form 1 did that already [still waiting for mine]. From the video it looked like a few bubbles remained under the platform, so I was thinking that a peel process would help force them out.