# Minimum Feature Size Test **URL:** \ **Category:** General Discussion\ **Created:** [February 26, 2015, 4:39pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805 "2015-02-26T16:39:21Z")\ **Posts on this page:** 15\ **Page:** 4
**Author:** ![KenCitron](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/kencitron/32/1741_2.png) [@KenCitron](https://forum.formlabs.com/u/KenCitron)\ **Post date:** [March 4, 2015, 6:11pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/61 "2015-03-04T18:11:15Z")
Actually the blobby surface on the support side is due to extra exposure on the draining resin as the laser passes beyond the blockers. The smooth side is always the pdms side where the layer is compressed and the laser first hits the surface. slightly cloudy pdms probably does not help and especially with lasers that have large flares. Wonder if it is possible to develop a resin that uses a dye blocker instead of a pigment based blocker reducing the settling effect and chance of uneven grind of pigments. Of course no flare on the laser would be nice too. ---
**Author:** ![Monger\_Designs](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/monger_designs/32/181_2.png) [@Monger\_Designs](https://forum.formlabs.com/u/Monger_Designs)\ **Post date:** [March 4, 2015, 7:14pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/62 "2015-03-04T19:14:20Z")
> [@KenCitron](#): > > Actually the blobby surface on the support side is due to extra exposure on the draining resin as the laser passes beyond the blockers. The smooth side is always the pdms side where the layer is compressed and the laser first hits the surface. I’m talking about the tall tower prints. There is no support side on those, except the bottom. ---
**Author:** ![KenCitron](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/kencitron/32/1741_2.png) [@KenCitron](https://forum.formlabs.com/u/KenCitron)\ **Post date:** [March 4, 2015, 7:44pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/63 "2015-03-04T19:44:54Z")
On the tower prints that is determinately from the flare and as you mentioned condition of the pdms. I wonder if a resin that blocked better allowing for more precise exposure on each layer with so light doesn’t refract through would help? ---
**Author:** ![Monger\_Designs](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/monger_designs/32/181_2.png) [@Monger\_Designs](https://forum.formlabs.com/u/Monger_Designs)\ **Post date:** [March 4, 2015, 9:55pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/64 "2015-03-04T21:55:41Z")
A resin that has lower viscosity and higher pigment should give better results. Unfortunately, for large prints, if there is no mixing going on, then the pigments will settle and that opens up a new set of problems. ---
**Author:** ![Ante\_Vukorepa](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/ante_vukorepa/32/18125_2.png) [@Ante\_Vukorepa](https://forum.formlabs.com/u/Ante_Vukorepa)\ **Post date:** [March 4, 2015, 11:35pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/65 "2015-03-04T23:35:30Z")
> [@Monger\_Designs](#): > > I have a theory about that tall object and why the back is so bad and every other side is perfect. That’s an interesting hypothesis, but already disproved pretty well. @KevinHolmes demonstrated quite clearly the flaking side changes with the orientation of the laser (by rotating the laser). > [@Monger\_Designs](#): > > I imagine if you twist that model and make it more like a helix, it will print just fine. It’s worth a try. That would make the test useless for what it’s supposed to show. Namely that the flakes are due to repeated exposure of same volume of resin to the lower intensity, unwanted parts of the beam, that - over time - accumulate enough to cause curing or partial curing and end up as a flake hanging off the print. Making the object helical would remove the repeated exposure of the same area to the flare from the equation, making the test useless. ---
**Author:** ![JoshK](https://avatars.discourse-cdn.com/v4/letter/j/4da419/32.png) [@JoshK](https://forum.formlabs.com/u/JoshK)\ **Post date:** [March 5, 2015, 6:12am UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/66 "2015-03-05T06:12:18Z")
Yea I agree that Kevin’s testing with rotating the laser proved the flare was the source of the very bad side. But it’s quite possible that always peeling in one direction has some negative effects too, good point. But probably not enough to warrant a hardware change though. This thread has been very interesting so far. I hope a few more pics get posted from printers we haven’t seen yet. More printers will better represent typical. Both of my jobs are on the brink if the busy season, so I won’t be around my computer as much. ---
**Author:** ![Annino](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/annino/32/2925_2.png) [@Annino](https://forum.formlabs.com/u/Annino)\ **Post date:** [March 5, 2015, 12:21pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/67 "2015-03-05T12:21:58Z")
I should be able to get these tests going this afternoon, I’m pretty curious how my printer performs. ---
**Author:** ![KenCitron](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/kencitron/32/1741_2.png) [@KenCitron](https://forum.formlabs.com/u/KenCitron)\ **Post date:** [March 5, 2015, 4:35pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/68 "2015-03-05T16:35:08Z")
Here is some pics of the test print done at 25µ. Note: I used the 3rd party resin so back side is bad, possibly from the combination of blockers and my flare. Fine detail did hold up though but the smaller holes are plugged where the support side is muddled. I also used an alternative cleaner to the IPA baths. Next batch of resin I get will be the Formlabs so I can test again with that. ![](http://forum.formlabs.com/uploads/formlabs/2933/26cf01d95fbb6f3f.JPG) ![](http://forum.formlabs.com/uploads/formlabs/2934/1fe5a547a4271fcf.JPG) ---
**Author:** ![Ante\_Vukorepa](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/ante_vukorepa/32/18125_2.png) [@Ante\_Vukorepa](https://forum.formlabs.com/u/Ante_Vukorepa)\ **Post date:** [March 5, 2015, 9:46pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/69 "2015-03-05T21:46:10Z")
> [@KenCitron](#): > > I used the 3rd party resin so back side is bad, possibly from the combination of blockers and my flare. It’s bad because it’s facing the platform and the laser is overshooting. It’s not because of the pigment (i assume that’s what you mean by “blockers”) it’s due to _lack_ of pigment. ---
**Author:** ![Annino](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/annino/32/2925_2.png) [@Annino](https://forum.formlabs.com/u/Annino)\ **Post date:** [March 5, 2015, 10:17pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/70 "2015-03-05T22:17:49Z")
Ok so now I have the problem of not having a camera with a macro lens… I am utterly amazed at how well this came out though. The brick w/holes is all skewed because the base didn’t attach, but I was more interested in the pillar test anyway. Not the best picture but you get the idea: 50um, Black setting ![](http://forum.formlabs.com/uploads/formlabs/2939/3cb97a602ea92d74.jpg) ---
**Author:** ![KenCitron](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/kencitron/32/1741_2.png) [@KenCitron](https://forum.formlabs.com/u/KenCitron)\ **Post date:** [March 5, 2015, 10:49pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/71 "2015-03-05T22:49:25Z")
Correct on lack of pigment. I agree it is a bad print. As I mentioned I’ll re run the test with Formlabs resin when I get more. ---
**Author:** ![Alex\_Vermeer](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/alex_vermeer/32/2491_2.png) [@Alex\_Vermeer](https://forum.formlabs.com/u/Alex_Vermeer)\ **Post date:** [March 6, 2015, 9:45am UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/72 "2015-03-06T09:45:15Z")
just leaving this here: [http://3dprint.com/48922/3d-printer-calibrating-test/](http://3dprint.com/48922/3d-printer-calibrating-test/) Probably this would be interesting to print when scaled down 10 times. Making the holes .3 .4 and .5. I like the idea of the wave part ---
**Author:** ![Ante\_Vukorepa](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/ante_vukorepa/32/18125_2.png) [@Ante\_Vukorepa](https://forum.formlabs.com/u/Ante_Vukorepa)\ **Post date:** [March 6, 2015, 11:22pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/73 "2015-03-06T23:22:18Z")
This might be interesting/useful too: > **[DLP/SLA minimal slot test cubes by TimYoshi](https://www.thingiverse.com/thing:202313)** > > Here is quite simple test to try how small slot/hole your printed can do. Most likely it will be actual only for DLP/SLA printers and not for the FDM. But you are free to try! Why not? :) It is very small so that will not pose a problem to throw in... In particular, it’d be interesting to see how orientation (around the Z axis) influences the minimum gap width (due to flare, astigmatism etc.) ---
**Author:** ![ChristopherBarr](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/christopherbarr/32/645_2.png) [@ChristopherBarr](https://forum.formlabs.com/u/ChristopherBarr)\ **Post date:** [March 6, 2015, 11:57pm UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/74 "2015-03-06T23:57:34Z")
> [@Ante\_Vukorepa](#): > > Fine \<------ Universal ------\> Coarse Also build-platform z-height step would need to change in relation to slider position as well, and it may not be a linear change, which ups the complexity a bit. But you’re right on about the ‘variable’ slider kind of control mechanism. Analog feeling, not with clunky steps in the slider, and where clicking anywhere in the slider path moves the slider there, not flipping surprisingly it to a preset spot 😄 Actually, your idea was mostly already requested a plugin to this feature request: > [@Mark slice layer ranges for various optional behaviors](https://forum.formlabs.com/t/mark-slice-layer-ranges-for-various-optional-behaviors/3033/2): > > Throw in the ability to tweak the curing (laser power +/- percentage) as an advanced option somewhere (Fine Tuning?) and i might not look at another SLA printer again Maybe they’re working on it as we speak. ---
**Author:** ![system](https://us1.discourse-cdn.com/flex025/uploads/formlabs/original/3X/5/b/5bc2bdf993ff27c2e0eecab5010b25626fbb327a.png) [@system](https://forum.formlabs.com/u/system)\ **Post date:** [March 21, 2015, 9:24am UTC](https://forum.formlabs.com/t/minimum-feature-size-test/3805/75 "2015-03-21T09:24:03Z")
Closed on March 21, 2015, 9:24am UTC This topic was automatically closed 14 days after the last reply. New replies are no longer allowed. [Previous page](https://forum.formlabs.com/t/minimum-feature-size-test/3805.md?page=3)