Constructive criticism, Form2 printer design

Hi all,

Having spent a few months with two Form2 printers, I thought that it might be productive for me to list my thoughts regarding how the printer could be easily improved for a future version. Many of these issues below have been discussed in the forums, but I’m choosing to restate them here because I think that they’re easily correctable, and it would be a shame if Formlabs didn’t address them.

  1. Most notably, a resin spill should never be catastrophic. Currently, there is a vacuum-formed plastic tray surrounding the optical window. I see no reason why this tray couldn’t be shaped to include an internal gutter, which would direct spilled resin into drainage tubes, and out the bottom of the printer. This type of treatment is not uncommon for electronics enclosures, and IPX design guides exist for reference.

  2. The optical enclosure is not sealed, allowing dust to enter. The current optical enclosure is designed like a folded paper take-out box. I imagine that it’s very economical to produce, but the large gaps in the enclosure allow dust to freely enter. Both of my printers arrived with specs of dust on the mirrors before my first print. I suspect this actually has more to do with the cleanliness of the Formlabs assembly area, but regardless, it would very easy to design a better optical enclosure. The enclosure should be injection molded or vacuum formed, and sealed with a gasket. In fairness to Formlabs, this would involve marginal increased tooling cost.

  3. Why oh why is the resin tank so shallow? Given the intended resin level, it would be great if wall height was increased to decrease likelihood of spilling. Currently, the wiper comes very close to creating a wave of resin high enough to spill over the edge of the tray. It’s also very difficult to handle a filled tray without spilling. The walls should be higher, and the wiper should have a larger notch to be compatible.

  4. The buildplate is not sealed. The buildplate currently uses plastic plugs with rubber seals. In my experience, these seals are immediately failed on day 1. The result is a leaky buildplate. This is not a huge annoyance, but it is such a silly issue. The plastic plugs should either be glued in place with silicone or epoxy, or a different design should be implemented.

Of course - the Form2 makes fantastic parts, and I suppose that’s the important thing. However, the suggestions above I think represent very low-hanging-fruit mechanical design improvements.

Hopefully this feedback is useful.

  • RC
5 Likes

You’ve done a great job of highlighting some of our main focuses as we continue developing new products :slight_smile:

The tray carrier does currently have a small sump to catch resin that spills outside of the tank, but this is inadequate for some failures. Detecting print failures is our first focus and we agree that more effectively protecting internal components in the case of a substantial spill should be a priority as well.

We did a fair bit of torture testing to verify that the optics were well sealed and there shouldn’t be any significant gaps in your enclosure. Nonetheless, we’re always keeping an eye on the number of tickets associated with given errors (dusty optics as an example) to verify that this is working for users in the field.

The LT Tanks address this issue with a small lip above the resin level. The wiper stops at the lip and doesn’t reach the edge of the tank which makes a spill significantly less likely. We’re looking into porting this to the standard tanks as well.

I haven’t noticed many leaky build plates though it sounds like your experience is different. We’re likewise keeping an eye on this and making manufacturing changes as needed to ensure that build plates are adequately sealed.

Glad to hear your parts are coming out well. We’ll continue working to make our machines increasingly reliable and hopefully achieve far more than what’s on this list.

3 Likes

good idea…

Having the same issue too, but i never had it with old build platforms - just the one i’ve bought last year.
I think the QA on build platforms has went slightly downhill, and i think i know what the issue is - the plugs are slightly bent, leading to a weaker seal.

Additionally, if IPA leaks inside (which is inevitable when using Wash), when the chamber and the resin heat up, the increased temperature leads to the volume of air and IPA inside the platform to expand, which can make a plug pop out in the middle of the print. Best case, ruined print and platform full of resin. Worst case, plug falls into the vat and makes a complete mess.

Formlabs, i know the sample seems small, but please check with your injection molding supplier, or design some lengthwise cross-members reinforcements into the plugs, that might reduce the warping and make the seal better.

@Ante_Vukorepa

My fix was to discard the rubber gaskets and just glue the plugs in with silicone caulk. It seems to have fixed the issue. As you said, hopefully FL fixes the root problem.

1 Like

Been thinking of doing the same.
Just wasn’t sure how well silicone caulk would fare with constant exposure to IPA.

I had the same fear so I checked some data first, it seems that silicone is unaffected by IPA:


http://mykin.com/rubber-chemical-resistance-chart-3

1 Like

Excellent. I was worried about it possibly swelling when exposed to the IPA, or that there could be some kind of plasticizer leeching effect.

For what it’s worth, i sent a request to support and described the issue.
They requested a photo (i provided a video showing… well, nothing, as i reassembled everything back) and offered to send a replacement.

They were also nice enough to send a comprehensive Form2 internal and external resin spill cleaning guide. Luckily, i didn’t need that, as the aftermath of the plug falling out was relatively mild (spills around the vat, nothing on the optical window, and no ingress inside the printer).

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