Understanding how to implement supports  

RE: Understanding how to implement supports

Using supports is an art, not a science unfortunately.

PrusaSlicer, or any widely used slicer software, will only attempt to put supports "where they're needed" when you turn them on, yes.

You'll eventually understand what your printer is capable of even better than the slicer: you can inhibit supports by using a support blocker modifier mesh, and you can force supports even where they wouldn't be generated by using a support enforcer modifier mesh. That's what "for support enforcers only" is in reference to - you're ignoring the slicer's decisions and forcing it to support the areas you specifically choose.

"On build plate" means supports will only be generated if they would rest on the build plate. Supports that would rest on the model itself are ignored. This probably is something you'd only choose for functional parts; more organic and complicated shapes tend to need "supports everywhere".

Until you have more experience and confidence using supports, choose "Supports Everywhere" - the slicer is smart enough by default to not support bridges (short gaps that are supported by the model on either side), it'll only support overhangs that actually need it (angles closer to vertical can be printed just fine), and it does an acceptable job out of the box without intervention, nowadays.

One last note: If you do print a model requiring supports, you should always consider whether rotating the model would reduce or even eliminate the supports needed, for quality reasons, and print speed too. For example, for an ordinary bust of a person's face, looking forward: rotate the model so the nose and chin are pointing more vertically, if you can.

RE: Understanding how to implement supports

Practice!.

First get a rough idea what you can print without supports.

https://www.prusaprinters.org/prints/3025-extreme-80deg-atom-3d-overhang-printed-on-a-prusa-

(I'm not in front of my home computer so don't have slicer available) There is a setting in overhangs for angle which will exclude all angles that your printer can print without supports, hence the reason for the first test.

You can improve your overhangs by increasing the cooling, but this leads to weaker layers so again it depends on what you are trying to print, decorative you can probably afford to have weaker layers, therefore try increasing the cooling, functional, you can probably sacrifice the finish a little, so can use supports more.

Then try some of these prints: https://www.prusaprinters.org/search/all?q=overhang

And see how overhangs towards you, away from you etc print, the cooling nozzle does not blow equally around the print, then you will get an idea which way to orient the print for best results.

Adjust the overhang contact distance / spacing / settings to see what you can get away with, I find orientating the support angle to 45 Deg so it does not run the same way as the printed layers helps with removal, try this.

Play with a model and use the layer preview to see what happens when you change support pattern and look at each layer to work out how much contact there will be, try support enforcers and change their size, slice and check layers, but above all, practice. There is no magic button that will provide perfect support for your prints, also search the forums and see what other people have done and ask.

As mentioned above, face or statue prints, tilt them back maybe 40 degrees, the underneath will be supported and the face will have better detail, and once the supports are removed, you wont see any scaring as this will now be underneath, so sometimes you have to think a little about how you can get away with things.

RE: Understanding how to implement supports

Play with slicer, maybe leave the printer off for a day and just concentrate on slicer, try different settings and slice the model and study what difference it has made to the preview, use different infills, see if layers are supported by infills, if it appears to be printing a layer above an infill mostly into thin air, try a different infill or % infill or rotate bridging layers, you want to try and get most support where necessary, this is the same for supports for overhangs, try the different options, support from buildplate etc and see what happens in slicer, rotate the preview, zoom in, try a support enforcer / blocker, change it's size etc.

Once you get the hang of slicer and have practiced, it becomes a lot easier.

I too just dived off into just printing initially just staring in awe how one layer at a time created something in front of my eyes, but then came complicated prints and failure after failure until I stopped, spend a few days with slicer understanding it's foibles and nuances, went back to the failed prints and now can print them without any issues. It's well worth it!. 😀 

RE: Understanding how to implement supports

I get good results with these settings:

• 0.25mm nozzle for miniatures
• 0.15mm layer height
• 0.25mm contact z distance
• 3mm pattern spacing
• 4 interface layers
• 0.2mm interface pattern spacing
• No interface loops
• 75% XY separation between object and its support

Try tilting the model back 45 degrees or rotating it to a degree that reduces the need for support.

RE: Understanding how to implement supports

thx for the detailed explanation.  I've already tried the different orientations but the part is too complex to solve it that way.  we'll go with 'supports everywhere' first &  see how it goes ...

RE: Understanding how to implement supports

Posted by: @i-am-allin

thx for the detailed explanation.  I've already tried the different orientations but the part is too complex to solve it that way.  we'll go with 'supports everywhere' first &  see how it goes ...

These settings are what will be used when you select supports everywhere. Just look under Print Settings->Support material for the settings.

RE: Understanding how to implement supports

Well the straight forward ‘supports everywhere’ worked but it used a lot of extra material relatively speaking and of course added 2 hrs to the print.  Since I have 13 of these to make I’m going to play around with the enforcer option and hopefully get a good idea of what it will look like with the layers view and then try another print.

RE: Understanding how to implement supports

I believe (Havent tried it yet) that you can use supports everywhere then use support block enforcers where you believe you can get away without any supports, also remember, the printer is quite capable of printing overhangs up to a point, so no need to support these.

This might be an easier option rather than put supports everywhere you think they are needed.

RE: Understanding how to implement supports

There is an open prusa-slicer issue on github regarding this: https://github.com/prusa3d/PrusaSlicer/issues/4128