# Calculated Volume Bug? **URL:** \ **Category:** Form 2\ **Created:** [June 17, 2016, 4:15am UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630 "2016-06-17T04:15:57Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![3DTOPO](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/3dtopo/32/6361_2.png) [@3DTOPO](https://forum.formlabs.com/u/3DTOPO)\ **Post date:** [June 17, 2016, 4:15am UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/1 "2016-06-17T04:15:57Z")
The reason why I chose to go with a Form 2 instead of the alternatives (including building my own SLA printer) is I thought Formlabs had the most professional software. But the first thing I want to print shows the volume to be only 34.02 mL. There is no way this can be correct. Calculating the volume accurately is an important aspect of having a pro workflow, so this is a serious issue to me. Is this where we file bugs? I am using PreForm 2.5.0 but the same issue was apparent with 2.4.1. ![](https://us1.discourse-cdn.com/flex025/uploads/formlabs/original/2X/2/28b9c3208578eb0ea8417c0c71e0e62c0f22f60d.png) ---
**Author:** ![Zachary\_Brackin](https://avatars.discourse-cdn.com/v4/letter/z/4da419/32.png) [@Zachary\_Brackin](https://forum.formlabs.com/u/Zachary_Brackin)\ **Post date:** [June 17, 2016, 3:53pm UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/2 "2016-06-17T15:53:02Z")
Your mesh does not look like it’s solid, though it’s hard to tell. ---
**Author:** ![3DTOPO](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/3dtopo/32/6361_2.png) [@3DTOPO](https://forum.formlabs.com/u/3DTOPO)\ **Post date:** [June 17, 2016, 8:15pm UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/3 "2016-06-17T20:15:07Z")
According to other software it is a watertight solid model. Despite that, PreForm asked me if I wanted to repair the model. I choose yes, and no errors were reported. It actually has numerous shells, but I think having manifold bodies inside manifold bodies should be valid printable geometry. I guess what is most alarming, is PreForm didn’t report any errors and clearly something is not correct. ---
**Author:** ![Zachary\_Brackin](https://avatars.discourse-cdn.com/v4/letter/z/4da419/32.png) [@Zachary\_Brackin](https://forum.formlabs.com/u/Zachary_Brackin)\ **Post date:** [June 17, 2016, 8:28pm UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/4 "2016-06-17T20:28:31Z")
The mesh might be too far gone for it to fix, but it’s really hard to tell-like I said it’s really complex so I can’t tell what it actually looks like. There’s some shading which could be an issue with flipped faces or it could be z-fighting with the faces too close together. ---
**Author:** ![DavidRosenfeld](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/davidrosenfeld/32/3570_2.png) [@DavidRosenfeld](https://forum.formlabs.com/u/DavidRosenfeld)\ **Post date:** [June 17, 2016, 8:58pm UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/5 "2016-06-17T20:58:31Z")
Can you take a screen shot with the layer slice around 500 - 700. This will show us what the inside of your model looks like and how thick the wall is (assuming it is hollow). ---
**Author:** ![3DTOPO](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/3dtopo/32/6361_2.png) [@3DTOPO](https://forum.formlabs.com/u/3DTOPO)\ **Post date:** [June 17, 2016, 9:18pm UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/6 "2016-06-17T21:18:33Z")
Here you are. ![](https://us1.discourse-cdn.com/flex025/uploads/formlabs/original/2X/0/04945a88be77266e06c1036ad27823886ee01b0e.png) ---
**Author:** ![DavidRosenfeld](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/davidrosenfeld/32/3570_2.png) [@DavidRosenfeld](https://forum.formlabs.com/u/DavidRosenfeld)\ **Post date:** [June 17, 2016, 11:10pm UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/7 "2016-06-17T23:10:09Z")
Based upon your picture, your model is not a single solid. I believe each separate piece is being seen as a solid (maybe). If you post up (if you are willing to share) the .stl, some of us can take a closer look. Another test to prove my theory, generate supports for the part. I believe the model will be littered with internal supports. Re-reading your post, I think your problem is “It actually has numerous shells, but I think having manifold bodies inside manifold bodies should be valid printable geometry” You want 1 solid model or 1 solid shelled model. Not many manifold bodies. From my experience, you will not be able to print this part as it stands. It is not a problem with PreForm but a geometry issue. I understand you think it should be valid printable geometry, I believe you are incorrect. ---
**Author:** ![3DTOPO](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/3dtopo/32/6361_2.png) [@3DTOPO](https://forum.formlabs.com/u/3DTOPO)\ **Post date:** [June 17, 2016, 11:36pm UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/8 "2016-06-17T23:36:14Z")
So you are suggesting it isn’t possible to print a part within a part? For instance, one could not print a chain link on the form? Or a printable ball bearing? Those are parts with more than one valid shell. ---
**Author:** ![3DTOPO](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/3dtopo/32/6361_2.png) [@3DTOPO](https://forum.formlabs.com/u/3DTOPO)\ **Post date:** [June 17, 2016, 11:38pm UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/9 "2016-06-17T23:38:19Z")
Also, my issue is that it doesn’t report its not a valid geometry and instead reports a incorrect volume. It acts like it “fixed” it and is ready to print. How do I know for other parts that the volume reported is in-fact correct and not due to some unsupported geometry? ---
**Author:** ![DavidRosenfeld](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/davidrosenfeld/32/3570_2.png) [@DavidRosenfeld](https://forum.formlabs.com/u/DavidRosenfeld)\ **Post date:** [June 17, 2016, 11:48pm UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/10 "2016-06-17T23:48:27Z")
Yes, a chain can be printed. Maybe a ball bearing. I think someone here tried it. I do not know if it was successful. Your model is not a chain or a ball bearing. I should have been more thorough with my response. What does your cad software say the volume of the part is? If you feel the part should be printable, give it a try. I would not print it as I do not believe it would be successful based upon the 2 images you provided. I would open a support ticket and send FL the file. They can tell you more about the embedded repair tool and how it is configured to repair models. ---
**Author:** ![3DTOPO](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/3dtopo/32/6361_2.png) [@3DTOPO](https://forum.formlabs.com/u/3DTOPO)\ **Post date:** [June 17, 2016, 11:57pm UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/11 "2016-06-17T23:57:06Z")
Of course my model isn’t a chain or a ball bearing. My point is those types of geometries have more than one shell - that aren’t connected which is the same as this part. It was not created with CAD software so I couldn’t tell you. I guess it is about a liter though. Thanks I guess I will do as you suggest. Again - my concern is how do I know when to trust the volume or not and if it is a valid geometry or not if PreForm reports that everything is fine. Seems like cause for concern. ---
**Author:** ![BenFrantzDale](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/benfrantzdale/32/6064_2.png) [@BenFrantzDale](https://forum.formlabs.com/u/BenFrantzDale)\ **Post date:** [June 18, 2016, 3:10am UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/12 "2016-06-18T03:10:15Z")
Something is wrong with that geometry. The light blue chunk in the back and the dark blue chunk in the front indicate that something is amiss. I suspect that as you flip through the layers you will find that fill line jump around. I agree it probably should be something PreForm should catch. ---
**Author:** ![3DTOPO](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.formlabs.com/3dtopo/32/6361_2.png) [@3DTOPO](https://forum.formlabs.com/u/3DTOPO)\ **Post date:** [June 18, 2016, 8:38pm UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/13 "2016-06-18T20:38:57Z")
Yeah - the blue does flip around. I thought this model was a solid, but I actually loaded the wrong version (I have many of them). Meshmixer is able to repair this geometry and then it comes into PreForm fine. I hate having to rely on free unsupported software however, and I still am concerned PreForm didn’t report any issues. Just let me know if you might like me to test or beta test anything of if I can do anything to help. ---
**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:** [July 2, 2016, 8:44pm UTC](https://forum.formlabs.com/t/calculated-volume-bug/8630/14 "2016-07-02T20:44:05Z")
Closed on July 2, 2016, 8:44pm UTC This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.