Todderman wrote:
I found SLA printers required some mental rewiring after becoming accustomed to deposition printers w/ support matieral.
Never thought about it. But now that you mention it, no there's no rethinking. There are thinks I wouldn't try to achieve with FDM printers or for that matter
my SLA printer.
There are details that differ, but I wouldn't call it a different thought process.
Todderman wrote:
I was looking at a pic of a freshly printed model and noted that you lay them flat with tons o' supports, rather than do the typical tilt-on-two-axes approach. This probably helps get all of the rivet details on the sides, but does it cause any unwanted side effects?
You can fill a cold winter's evening discussing that question.
Basically I get the best quality/highest resolution in the plane that is parallel to the build platform and facing away from it.
The orthogonal planes are next.
The plane opposite the first one ist usually of the worst quality.
Main reason is that light doesn't stop at the layer, but will bleed into the layer above.
Also the supports keeping the machine on the build platform connect from this direction.
The quality of all other planes can be interpolated from that.
Nearly all of my models are abstractly box shaped and probably even more important, have a distinct top and bottom. Even soldiers can be pressed in a box shape, and top and bottom can be identified. Top and bottom relative to the final pose.
And usually the bottom is a "blind side". I just do not care what's on the underside of an tank.
The blind side will face towards the worst quality plane i.e. facing the build platform.
Luckily the side we are most interested in when playing or looking on an army - in contrast to inspecting a single model in front of your nose - is the top. So all is well.
If there is no blind side or I have for whatever reason to increase the quality of a facing, I will rotate the model accordingly. About 45 degree relative to the build table plane, will give the best average quality on all faces. In
this case the part of the box closest to the build platform will be a line (an edge) instead of a plane (side).
Sometimes you will have to rotate it in a second direction, so the closest part will not be longer a line, but a point (corner of the box)
If you have small open circular structures that you can not support you might want to lay them parallel to the build platform or at least have them not orthogonal to the build platform to ensure that they are really round.
You may also counter some of the light bleed or deformation by increasing the pigment in the resin. It will increase the exposure time needed and might get a bit more brittle, you just have to decide what's more important.
Rotating the model relative to the build platform will increase print times, that's also something to consider, so I might do the sample "flat" and the real model at an angle.
Sometimes, you can save a large number of supports by printing the model at an angle - or not.
So basically it depends on the model - but more often than not I print in the "natural" orientation - because it's "natural" for us to ignore/not see the underside of things.
I also print on the build table, if I can - i.e. infantry on their 5mm disk - saving the supports an getting a guaranteed plane bottom.
I also save supports, by designing features with an slope. This will only work if the model is oriented accordingly.
Flyers are one of the types of models, where the underside might be of interest. Mainly because it might be mounted on a base at an angle. Or photographed from "below". So I usually print them at an angle.
In this special I printed the flyer as I did, because it was the fastest way to print and I didn't care about max. usability, I just wanted to see what it looks like.
And it looks like the pilot didn't realise that he crashed into a knight when reverse parking, and flew off with the wreckage attached.
Have you made similar observations and do you have others to add ?
Todderman wrote:
And a follow up question - do you hollow out your tanks to save on material, or make them solid?
Again, depends.
On small models I usually do not care.
On large models like the KOW Ogres (28mm miniatures, so they are really 55mm, because they are larger than men), the models are hollow.
There are three pages on my website just about the Ogres.
The first one for those interested:
http://brumbaer.de/index.php/3d-printing/44-ogres-kowDepending on the printer you will have to be careful when hollowing out small models, because the walls may sag or shift as soon as the inside gets hollow or filled again.
How do you handle it ?