BTW, I tried to print the fireman example above in the face down orientation, and it failed miserably, about 1/4 of the way through the print, as some of the supports broke off or dislodged  ruining the print.

update:
http://meshmixer.com/forum/index.php?topic=2360.0

Here is an explanation. It makes sense that it is ignoring flat surfaces as it's mainly focused on support optimization. I have some objects that don't have flat bottoms that this is great for.

actually, it looks like if you adjust the overhang angles, you may get the result you are looking for. I'm still messing with it.

But you see this is algorithmic orienting.

Yeah, well... about that...  It's nice that it TRIES to do something like that, but its algorithms leave a lot to be desired.

Here is a a sample of what it does.  The model on the left is in it's normal orientation, with supports for all the overhangs.  Then on the right is the orientation it decided to put it in when you click Optimze Orientation. 

What it apparently does, it optimizes the orientation so it can generate the shortest, simplest and arguably strongest supports.  Without any consideration to the model itself and how it would affect the surface quality.  Not exactly what I would do.

Here is another example.  This time using a piece with flat surfaces (Solidoodle 3 "X" carriage, end block).  This piece should be clearly oriented flat on it's back, and the only thing needing support (barely) is the inside of the large bearing hole.  ON the left, the piece as it should be oriented, and it generate supports pretty much as expected.  On the right is the orientation MeshMixer chose. 

I think it's reasoning here was to print everything at printable +/- 45° angle, but then it didn't take in consideration the fact that the support now need to be rigid enough to support the weight of the object and the fact that the surface quality would suffer.

All things considered, I wouldn't let Meshmixer make the decision to orient an object for "better support and printability".  It's decisions are questionable at best.

carl_m1968 wrote:

metaldrgn wrote:

Easy, youtube and the Features page. $150 is a lot for software that doesn't even have a demo version and meshmixer is FREE (even though I would pay for it if they charged).

One thing I mentioned that apparently everyone overlooked is that meshmixer optimally orients the model for best printing depending on a 4 factors. That actually makes a huge difference (more so in non-flat objects).

If you did a little digging around the net you would find there is an older cracked version of sd3 out there if you wanted to try it.

But since this site is not about piracy I will not go into detail about it. But is is out there if your persistent enough.

I'm sure I could but there's nothing it really offers that the others don't.

Your choice, your loss. I have been printing for 8 years and I can assure you I have tried every host and slicer out there and I can say with full confidence that S3D will blow away any and all of them when it comes to final print finish. Trust me there is more to printing than where you stick your supports. I had one model and S3D was the only one that would print it without issues. Plus it comes pre configured with most of the popular printers. Trust me, I didn't feel any software could be worth 150 but once I tried it I could only ask myself why I waited.

metaldrgn wrote:

carl_m1968 wrote:

If you have not used S3D then how can you even form an opinion or disagree? I have used it, and it does everything you just listed. You can also remove generated supports, move them, control the pattern of the actual support, adjust the interface layer, the distance from the model body, the density, and many others settings just for supports alone. I won't even get into the other abilities of the program like per layer temp and speed control through out the entire model. Controlled infill f\density through various parts of the model. and so on.

I can understand 150 bucks is steep for a program, but don't knock it or say another is better unless you have actually tried it.

Easy, youtube and the Features page. $150 is a lot for software that doesn't even have a demo version and meshmixer is FREE (even though I would pay for it if they charged).

One thing I mentioned that apparently everyone overlooked is that meshmixer optimally orients the model for best printing depending on a 4 factors. That actually makes a huge difference (more so in non-flat objects).

If you did a little digging around the net you would find there is an older cracked version of sd3 out there if you wanted to try it.

But since this site is not about piracy I will not go into detail about it. But is is out there if your persistent enough.

I'm sure I could but there's nothing it really offers that the others don't.

metaldrgn wrote:

jagowilson wrote:

Just going to note that Simplify3D is the king of supports. If you print supports all the time there is no better slicer.

I don't agree. I haven't used simplify 3d but from what I see on the site the meshmixer support system is way better. You can even add and remove your own supports. It also allows you to orient the model for best possible printing which drastically improves the quality. The supports also break away with incredibly nice results.

I use RH with Slic3r and always adjust/orient model for best print-ability and strength

But you see this is algorithmic orienting.

jagowilson wrote:

Just going to note that Simplify3D is the king of supports. If you print supports all the time there is no better slicer.

I don't agree. I haven't used simplify 3d but from what I see on the site the meshmixer support system is way better. You can even add and remove your own supports. It also allows you to orient the model for best possible printing which drastically improves the quality. The supports also break away with incredibly nice results.

I use RH with Slic3r and always adjust/orient model for best print-ability and strength

carl_m1968 wrote:

metaldrgn wrote:

I don't agree. I haven't used simplify 3d but from what I see on the site the meshmixer support system is way better. You can even add and remove your own supports. It also allows you to orient the model for best possible printing which drastically improves the quality. The supports also break away with incredibly nice results.

If you have not used S3D then how can you even form an opinion or disagree? I have used it, and it does everything you just listed. You can also remove generated supports, move them, control the pattern of the actual support, adjust the interface layer, the distance from the model body, the density, and many others settings just for supports alone. I won't even get into the other abilities of the program like per layer temp and speed control through out the entire model. Controlled infill f\density through various parts of the model. and so on.

I can understand 150 bucks is steep for a program, but don't knock it or say another is better unless you have actually tried it.

Easy, youtube and the Features page. $150 is a lot for software that doesn't even have a demo version and meshmixer is FREE (even though I would pay for it if they charged).

One thing I mentioned that apparently everyone overlooked is that meshmixer optimally orients the model for best printing depending on a 4 factors. That actually makes a huge difference (more so in non-flat objects).

If you did a little digging around the net you would find there is an older cracked version of sd3 out there if you wanted to try it.

But since this site is not about piracy I will not go into detail about it. But is is out there if your persistent enough.

metaldrgn wrote:

jagowilson wrote:

Just going to note that Simplify3D is the king of supports. If you print supports all the time there is no better slicer.

I don't agree. I haven't used simplify 3d but from what I see on the site the meshmixer support system is way better. You can even add and remove your own supports. It also allows you to orient the model for best possible printing which drastically improves the quality. The supports also break away with incredibly nice results.

If you have not used S3D then how can you even form an opinion or disagree? I have used it, and it does everything you just listed. You can also remove generated supports, move them, control the pattern of the actual support, adjust the interface layer, the distance from the model body, the density, and many others settings just for supports alone. I won't even get into the other abilities of the program like per layer temp and speed control through out the entire model. Controlled infill f\density through various parts of the model. and so on.

I can understand 150 bucks is steep for a program, but don't knock it or say another is better unless you have actually tried it.

Easy, youtube and the Features page. $150 is a lot for software that doesn't even have a demo version and meshmixer is FREE (even though I would pay for it if they charged).

One thing I mentioned that apparently everyone overlooked is that meshmixer optimally orients the model for best printing depending on a 4 factors. That actually makes a huge difference (more so in non-flat objects).

I don't have all the controls the new version has, but I pretty much figured out most of them now, and with your help I now know how to add or remove support.  So here is a snapshot of my support options along with a model with support. 

I added a few extra supports around the nose, as well as a few braces to support the back supports, basically reinforced the supports themselves.

Still working on refining it, but here's an explanation of what I've figured out so far (at least for the important stuff that isn't self-explanatory)-

Y-offset = z-offset - This is useful if you have a non-flat bottom so you get a good surface that's totally supported. I like 0.6mm and I end up using Kisslicer's supports up to the first few mm to get all the low parts that meshmixer doesn't get at the moment.

Density - how closely packed the support tips are. 91 was too much and made supports too hard to remove and I actually broke the model trying to remove it. I can't recall what the default was, maybe 71is and was easy to remove except it sags a little more which is expected.

Post Diameter - I like 2mm posts, but they need to be reinforced by other supports (easy to do and depending on the height) and I will post a picture later of exactly what I'm talking about. Also I found using a 0.3mm Z-lift makes the end quality better and less likely to break off the supports or thin items.

Tip Diameter - I played with a little and needs more experimenting along with Solid Min Offset so the slicer only leaves a one layer gap.

Solid Min Offset - This offsets the model and trims the supports. The default 0.02mm seems to be too small, but you don't want it to far off either because the supports actually partially attaches to the model.