In my experience, printing anything with sharp angles will create the jello and some needle looking cured pieces in the resin. It was relatively easy to spot them in the clear resin, but in the grey resin it’s almost impossible.
In my opinion the only way to avoid the jelly and the particles, is to design the model in such a way, that no part of it, and no edge, no hole is smaller than the smallest feature size possible with the printer. Which is 300nm I believe.
Hi Andy,
Thanks for reading!
I have not seen any contamination of IPA affecting the resin yet. I tend to shake off the IPA from the comb briefly before using it, and give it a wipe with a paper towel. You do want to avoid getting IPA in the resin, though, so this is a good point.
With regards to the fluorescent strip, I believe we’re primarily concerned about the UV wavelengths of light that activate the resin - indoor light is not that big of a problem, but you don’t want your resin tank hanging outside of your printer for more than a minute or two. I can’t give you a dead certain time for affecting the resin - it depends on the intensity of exposure, as well as the type of light in each case. Sunlight is generally the worst.
I’m also affected by blob like prints. I’ll look at my resin tomorrow to see if I find some jelly inside.
Will: speaking of the resin exposure to the light and indoor light. I’m not sure I understood you about the time that you can put the resin outsinde of the printer. Our printer is located in a room with tube lights (neon). How long I can let the resin outside of the UV protection of the printer?
And the room have several large windows but with window shades on them, but never with direct light in the room or on the printer. How much does it affect the resin?
Hi Thomas,
There’s no hard and fast rule, because each lighting situation is different. Our print farm is located in a fluorescent lit room with moderate light and we generally try to avoid exposure of more than 1-2 minutes at a time. But we cannot make individual recommendation because we don’t know what each individual user’s lighting situation is…
Generally speaking, if you need to remove the resin tank from the printer (after removing the build platform, of course), I recommend storing the resin tank in a cabinet or drawer. This should keep it safe until you are ready to use it again.
Will: I’m always taking care to limit the time when my resin is outside of the printer/bottle, but sometime, removing a failed print from the resin tank may take more than 2 minutes, especially in low light condition.
We will move our offices soon, I’m trying to prepare a specific location to reduce at a maximum the light.
Thank you!
Had number of consecutive failed prints so filtered out the same resin may be 3 or 4 times exposing it to some light for 15-20 mins each time while it was slowly dipping from the vat through the filter. Finally did test print of Formlabs butterflies test model from the resin without any issues. So resin photo sensitivity to luminescent lightning shaded by some carton box is not that big from my experience.
Just a thought - what if a feature was added to Form1 software that allowed the user optionally to “decimate” a model to eliminate any sub-300nm features on the model? Would that help to minimize the jelly/particles?
I just figured out a pretty cute way to filter the resin: Pour it into a plastic tub and clean out the vat.Put the Resin Tray back into the printer and reinstall the Build Platform. Pour the leftover resin through a Paint Strainer (~10 cents a piece) back into the vat. You can hang the strainer on the build platform using rubber bands and let it pour through while you run the Preform software for your next job. Given the cost of the resin, value of my time, I’m going to strain the resin prior to every run.
I’ll post pics of the strainer setup soon.
Happy Printing!
Oops! Here’s a link to Grainger’s Paint Strainer. If you buy them in a box of 100, they should be 6 cents a piece. Might try a local paint shop.
http://www.grainger.com/product/DEROYAL-Cone-Paint-Strainer-41U065?functionCode=P2IDP2PCP
I highlighted this issue with Mark when he had issues way back on the Kickstarter comments, great idea Andy and it works well to minimise print failures an issue with this form (no cross referencing or search) as this technique has been mentioned already. Although I recommend this filtering technique never do it on your machine unless you what to drip resin into/onto the optics. Use paint shop dispoisble pots instead. John nice idea however the quality of the laser spot and cure of resin to a greater depth than requred at overhangs is a bigger issue.
Another thought: Two new machines recently introduced the Xeed from Leapfrog and the Xede from Envisiontec could you not have been more original guys?
Oh and the Envision Tech machine scant IPR after my email over a year ago to Formlabs.