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So I bought a 3D printer about 6 months ago and I am able to print out test prints and diagnostic prints no problem. I have been trying to print some terrain pieces from thingiverse, so no official supports. Here is what I am trying to print:

https://www.thingiverse.com/thing:2932919

More specifically the barrels for now. Unfortunately what I get is in the pictures below. Can anyone help me in figuring out why the barrels are not printing out inside the supports? I have about eight barrels on the plate, but I may get at best one deformed barrel, but the last time all that I got is what you see. There are circular blobs that stick to the bottom of the vat like it was trying print out the barrels but stacked up on each other. Basically this was a failed print, and I am not sure what the problem is given my novice level of 3D printing.

It looks like you're trying to print them straight up and down. Tilt the parts on at least one axis 30-45 degrees. There's probably too much suction for the supports to hold it, or not enough exposure.

also share settings and resin used.

In addition to PondaNagura's comments, looks like you're using lots of small supports. I would recommend trying 2 or 3 large supports on the underside somewhere hidden to give a solid grip on the print. You can then use small or medium supports everywhere else to enable the overhang details.

If you also tilt it, then you will need many fewer supports as you remove many of the overhangs.

Thanks PondaNagura and Flinty: Question though, in my estimation the overhangs on these barrels seem to be significantly less than say the Phrozen Rook that I printed in a test print. I would say that the bands are about the size of the stairwell if not smaller. Likewise I did try larger supports and that did not work out either, but I will make some changes. Speaking of the Phrozen Rook, which prints straight on the plate, should I even use supports?

I did find some of the barrels only larger that what I am trying to print, while using larger supports. It is not easy to see but they do list to the side. This is what I mean by deformed especially on the bottom view

the sample rook is more for calibrating resin settings and to let you know the machine is working in case you don't already have files on hand.
it's also an example of how parts can be designed to be self-supporting and hollow, takes up minimum footprint so it scrapes off easy.

you could possibly print barrels flush without supports but they'd need to:

have long enough exposure for the initial layers to adhere to the build plate, but also cure the full thickness of each subsequent layer

have no sudden overhangs that are parallel to the build plate, rather they do so with a gradual slanting/round beveling of some kind.
for instance the reinforcement bands around the middle of the drum, if they're boxy instead of round, could have issues without supports as they'll get stuck to the FEP and either tear off or deform; which then messes with future layers

be hollowed. and if so have drainage holes that allow uncured resin out and UV light in during post-processing.
otherwise depending on the size you're using a lot of resin and adding longer exposure time to the process. And in the case of trapped uncured resin, they'll eventually expand and leak semi-toxic goo

space them out on the build plate, cluster them too close together and it'll be a darn hard time finding leverage to scrape off the build plate without nicking the print and/or the plate.

Some people print bases flush to the plate but there's something called "elephant foot" that happens

TinyLegions wrote:
Thanks PondaNagura and Flinty: Question though, in my estimation the overhangs on these barrels seem to be significantly less than say the Phrozen Rook that I printed in a test print. I would say that the bands are about the size of the stairwell if not smaller. Likewise I did try larger supports and that did not work out either, but I will make some changes. Speaking of the Phrozen Rook, which prints straight on the plate, should I even use supports?

I did find some of the barrels only larger that what I am trying to print, while using larger supports. It is not easy to see but they do list to the side. This is what I mean by deformed especially on the bottom view

That's not unusual when printing vertically, as the bottom is printed all at the same time and kind of "gets in the way" of itself.

Ideally, this kinda thing you'd print at an angle so that each individual slice is smaller and strains the fep less, which will make it easier to separate and... well, everything else really.

You'd also want to hollow it out (for the same as above, and so that you use less resin), but you'll also need to add holes at the bottom and top of the print (the former to avoid creating suction cups that will strain the fep, the latter so that the resin has somewhere to get out of the print and for ease of cleaning afterwards).

Thanks PondaNagura and Albertorius. I have been thinking of hollowing out the barrels, but this does spark one question concerning draining the resin out of a hollow barrel. Does that affect other items out there that are hollowed out? Should I expect say a miniature that is hollowed out to also have holes in it as well?

I kind of want to have an enclosed barrel as I feel that they look better personally.

Here is the settings that I currently use, and subject to change:

You have to print them at an angle. What you're seeing at the "bottom" (technically the top during printing) is the result of the resin pooling on top of a surface parallel to the ground due to inability to "roll off".

While there may be pooling on the top of this surface, I can tell that the bottom of the barrel is being pulled(I guess) during the printing. I can see the bands on the bottom have a longer distance between bands on one side and the bands themselves are not uniform around the barrel.

Nothing in the settings can improve the issue on your bottom layer. Just have to adjust the printing angle.

One option is to just print directly off the bed, but you're going to end up with a slight lip.

I did a batch last weekend, and it was significantly better. I had only one failure and one deformed barrel, so that is a lot better than what I was originally getting. I certainly need to had a few more supports to get this working all the time, but apparently tilting the angle was it.

Thanks guys.

One problem that I am noticing is that my prints are "bowing" on me. Meaning the barrels are not flat on the bottom, and I see a list on the ones that are flat, but slightly. I also was trying to do a few panels for a shipping container, and they are noticeably bowed.

Best guess on how to fix this is to add supports on more of the edges. Like the corners of the panels if I am printing is what I am thinking. Does anyone else have any brighter ideas than that?

So I grabbed an example of presupports on a base to show how you can presupport something to help avoid bowing/bending of a part.

This assumes that you've used a calibration print, such as the Ameralabs Town, to calibrate your exposure. If you are under-exposing then that will likely increase the chance of bowing/bending with a given resin. Very high temperatures (30C+ for most resins barring those that need 30C minimum to print) can also cause resin to become softer during printing.




I set it to only show the tips of the supports to make it easier to read. Here you can see the tips following the edge of the base and in the area closer to the build plate at the bottom you can see that supports come from both sides to try and reduce the chances of the front edge bending/bowing during printing and increase the hold on the base itself.

As above, likely culprit is under exposure. Prints can warp based on its geometry during curing.

Check your prints for warping after the wash before curing, and then check again after curing to pin point the issue.