Time for an update on the first print I made on the Form 1+, the lid of a casing we spoked about in this thread.
Here’s the result of the print:
The print came out very nice, but the ventilation slots (the ‘grid stripes’) are partially wrecked. I don’t know if it was during post processing the print, or during printing. So I decided to alter the ventilation in many tiny hexagon shaped holes. I guess that’s much easier to print, right?
So here’s the new lid, the orientation and support structure for the new try:
What do you think, would this work? I know, I chose to leave the outer surface of the lid as clean as possible, but will this work?
Supporting the ventilation holes (stripes) a little more will help them stay straight. I think they got borked during the peel cycles, not during the post processing.
Hexagon holes is a good idea. However. Every hexagon will need at least 1 support if you don’t want it to fail. So it will cost you a lot of resin!
I would say dividing the original slots in 2 or 3. They will still need supporting but it’ll make the structure more rigid.
Thank you for your reply, Alex. Why does every hole need one support? In this orientation that’s not mandatory, at least if I check everything in PreForm? Or is there something I’m missing right now?
If there isn’t anything floating in limbo on each layer, then you could try it. I thought, each top part of the hexagon might need a support because it gets printed before touching the model (if you know what I mean). But if not. I might work. Though the areas between the holes are probably less than a mm thick which might cause issues.
Prints with a lot of holes in them (templates for instance) are often very hard to print because they consist of tiny parts which need to resist the peel cycle. This doesn’t mean it won’t work. It just means that you should be cautious and check everything thoroughly before you start.
I’ve been printing a lot lately, here’s my general strategy.
For your first print: trust the auto orient, use the default supports. You might turn off internal supports and manually delete / reposition any supports that are touching important surfaces. If there’s no red shading or visible overhangs after you’ve made adjustments you’re probably fine. I think it’s better for morale if you go conservative on your first print - at least it will print well, and at worst you just have a slow cleanup process but this will help you reflect on which supports were helpful and which were overkill.
More advanced: I usually always reduce touch point size for general purpose resins and lower density if it’s a light piece. If it’s a chunkier / heavier piece I might increase density (keeping touch point small). Alternatively for thicker / heavier prints I’ll auto generate supports at a low touch point then manually go in and apply thicker supports on any initial layers or “islands” to ensure they’re well secured and the part will build effectively from those points and beyond. This is usually on the first corner or on any overhangs. You can use the slider tool while doing the manual editing, it’s a nice feature that while manually editing supports you can actually vary the touch point in the process. I sometimes do a few thicker ones at the important initial point and then dot a few lighter ones around it.
I also strategically try to reposition supports onto flat surfaces, where I know I can sand them away. If it’s a show piece for a trade show or event, I might decide not to put supports on a detailed surface even if PreForm wants me to and let the printer try it’s best rather than attempt to clean supports from a surface where the features are smaller than the touch points would be.
For delicate pieces with lots of overhangs I use internal supports at the finest touch point and a knife to get them out, but removal can be tedious so I use internal supports sparingly. While you can control where they attach to, you can’t pick where they build from so they can also be a little fiddly to set up. If you’re a real pro you might build fine internal supports into your model - we suggest this a lot for fine jewelry pieces that require serious thought about support placement.
One exception to all this is Flexible! This material requires thicker touch points to print. If you set a form file up as a general purpose resin and then load it and change the material properties to flexible you can kind of trick PreForm into allowing you to print with touch points as low as 0.4. However the minimum and suggested defaults for Flexible touch points are a lot thicker. You can’t be as sparing with Flexible as you might be for standard resins, you have to imagine the print flexing as it prints and be generous in adding supports fairly regularly to help anchor the part.
So to the case in the discussion, I would probably lean to @Alex_Vermeer’s sentiments and put the supports on the outside flat surface [generate defaults - manually remove any that are on the curved edge, non-flat areas, manual supports off during generation] knowing I could sand those away to a flat finish pretty easily, and then manually add a few fairly light internal supports for the rib features on the other side just to make sure they were anchored.
From what I have read and used on my own if could be anywhere from 250-800 grit you may also sand it and use mineral oil to get rid of the sanding marks. I mainly sand the clear so not sure what others have used for the standard flat color materials.
Fantastic result @Jolmer!
For sanding I use 800/1000/1500/2000 in stages. I don’t prefer sanding lower than 800 because of the sanding marks that appear easily in places you don’t want them to be. Always waterproof sandpaper btw!
Since I am a newbie, I really can’t answer the most of your questions. Perhaps there is someone else who can?
I rinse my printed parts in IPA first (two minutes of rinsing, ten minutes of bathing) and aftwards I wash the items with water. I noticed that - without the washing with water - some small parts of an object can trap the IPA, which results in slower evaporation and a sort of jelly like finished surface. This effect occurs more and more after the IPA contains more resin residu, I guess.
I’m sorry you feel insulted. I’m just trying to help you, as new posts in dead threads often don’t get noticed.
Since making a new thread appears to be difficult:
Materialse Magics Structures should work.
The base is so the model sticks to the platform. You can adjust this thickness. These layers are printed with higher compression than the rest of the part.
