3D Printing - Losing Detail At Supports

[regme]

Hi

 

I print this model using the Anycubic Photon, basically it was printed vertically with a 10degree slope.  The problem is the detail on the ends.

 

Where the supports are placed its dull (top pic- it's also been sanded abit) while the other end (bootom pic) is good, excuse the focus.  I tried placing heavy supports on the bottom edges of the raised parts and used light supports for the lower areas to reduce pitting when I tried to remove the supports.

 

I'm thinking about printing the model vertically, that way I don't have to place the supports right on the edges of the model, it's 35mm by 20mm in area, but I'm not sure if that would make it worse due to the suction forces.

 

So any thoughts would be appreciated

 

Cheers

 

[Adam FW]

17 minutes ago, regme said:

Hi

 

I print this model using the Anycubic Photon, basically it was printed vertically with a 10degree slope.  The problem is the detail on the ends.

 

Where the supports are placed its dull (top pic- it's also been sanded abit) while the other end (bootom pic) is good, excuse the focus.  I tried placing heavy supports on the bottom edges of the raised parts and used light supports for the lower areas to reduce pitting when I tried to remove the supports.

 

I'm thinking about printing the model vertically, that way I don't have to place the supports right on the edges of the model, it's 35mm by 20mm in area, but I'm not sure if that would make it worse due to the suction forces.

 

So any thoughts would be appreciated

 

Cheers

 

 

 

Can you show an image of how many supports you used?

 

I used to have similar issues and moved to a higher density of thinner supports placed close to edges which seems to work much better but mostly I try to make it so that the support are always on a hidden face as it never looks good and always needs sanding

 

[justin1985]

Its hard to judge the size of your model from these pictures, but I only ever use "light" supports for the smallest of objects - even a T Gauge coach I'm working on now I use "medium" supports for, otherwise I get distortion. The key is to place supports strategically though - always on the "bottom" edge of any shape etc, and never on a face of a model that will be visible on the final thing, if you can avoid it at all - the auto supports rarely work well.

 

Also key is making sure the "Lift" from the bottom is quite big - I've found anything less than 7 or 8mm and you're likely to get distortion on the bottom edge of most objects - the price is obviously extra time taken to print all those layers of supports!

 

There is a diagram doing the rounds online of the optimum angles to use at different layer heights on the Photon. I always use 0.02mm layer height on the Photon, and I remember the angle for that is 22.49deg. The idea is to ensure each "pixel" ("voxel" in 3D, I think) is a cube - if you use an angle that is more or less than optimum for the resolution and layer height, you'll get jaggedness where layers don't match up neatly to the design. 

 

As Adam says, a screenshot from Chitubox would help judge what might help most. 

 

[regme]

Hi

 

Here is a screen shot, I'll have a search this optimum angle/  I'm print with 0.05mm layers and the model starts at 7.5mm above the build plate.

 

Cheers

[Adam FW]

10 minutes ago, regme said:

Hi

 

Here is a screen shot, I'll have a search this optimum angle/  I'm print with 0.05mm layers and the model starts at 7.5mm above the build plate.

 

Cheers

 

I'd experiment with a few changes to the model, I won't get into layer height and exposure as that's a separate can of worms to look into

 

Firstly if possible I'd move to a horizontal rather than vertical orientation to keep the face with the most support material hidden on the underside. Currently the most supported face is also one of the most visible. If you can re-orientate the print to be horizontal you may want to look into angling the bracing detail on the wagon to not need any support, ie: if you angle the print at 10 degrees add a 15 degree chamfer under any overhangs to remove the need for support material entirely, if the detail is shallow you won't notice the chamfer.

 

Secondly I'd use a lot more thin supports and get rid of the the thick ones, use them for corners or distant features only maybe. If nothing else the thin supports come away far more easily and mark the surface less so theres less clean up needed.

 

Finally it could be the pictures but your orientation appears to only be angled on one axis so the lowest point on the model is an edge rather than a corner. I tend to use 10 degrees on 2 axis' but vary it depending upon the specific model, as @justin1985 said there are some ideal angles that could be used but these may take up too much space or take too long to print depending upon the model

 

[justin1985]

https://github.com/Photonsters/anycubic-photon-docs/blob/master/temp/slice_angles-van_kesteren.jpg

 

Edit - there is a really good summary of how to set up your design for printing on the Photon here: https://github.com/Photonsters/anycubic-photon-docs/blob/master/FAQ.md#model-setup--settings

 

The linked document on designing supports seems to originate with another random manufacturer, but contains lots of good advice:

https://github.com/Photonsters/anycubic-photon-docs/blob/master/Resources/AddingSupportsForSLA3DPrinters-v1.pdf

 

Justin

Edited August 14, 2020 by justin1985

[regme]

Thanks for this, yes the model is only rotated on one axis, I might try rotating on two axis.

 

I might also rotate it so the supports are on the underside of the wagon.  A bit reading also.

 

Cheers

[regme]

Thanks, well I ended up rotating 30deg and placing the supports on the bottom and it came out much better. 

 

Not sure what happened with those tiny holes, just might be somethin in the resin, a little bit of fine turning and should be ok.

 

 

 

 

[justin1985]

12 hours ago, regme said:

 

Not sure what happened with those tiny holes, just might be somethin in the resin, a little bit of fine turning and should be ok.

 

 

Small holes can be caused by all kinds of things - air bubbles in the resin, corrupt pixels in the file (often caused by dodgy USB sticks - especially the notoriously cheap and nasty one supplied with the Photon!), or insufficient support / an unbalanced cross section of model at that point allowing the model to flex a little bit as its printing, therefore little bits being missed.

 

On that model (I think you're planning to use as a master for casting?) I'd just fill those little holes by hand - either with modelling putty, or drip in little drops of liquid UV resin and use a handheld UV light to cure them in place (a UV "laser pointer" is really useful for this). That method also works as the best "glue" for repairing snapped 3D printed parts, or gluing together printed components!

 

J