I’m trying to print a handle for something. The handle has a round cross section, about 12 mm. I need to print it flat, as otherwise huge amounts of support are required (and I need to print a lot of these).
No matter what I try, I end up with a wide (maybe 4 or 5 mm) flat area where it lies on the plate.
I’m printing, PETG, with supports (using either PLA or Support for PLA for support interface). Tree supports if that matters. Even tried printing in PLA, same result (not unexpected).
I’ve cut a section of the handle and printed it vertically, and it does print as a correct cylinder, no flat side.
As another test, I’ve just made a simple cylinger and printed that lying down, with supports and setting all as above. Worked fine. So, as far as I’m concerned I’ve shown my H2D can print a cylinder without a flat spot.
I’m absolutely stumped as to why this is happening. Does anyone have any ideas? I’ve uploaded the model for if anyone wants to look closer.
I’m sure it’s something I’m stuffing up, or have with the model, but just can’t work out what.
Handle.3mf (89.6 KB)
Hi, I think the flattened bottom/top are due to a combination of chosen layer height and also resolution of the original model (to some extent).
Of course it’s never going to be as round when printed flat as when standing up. You could improve that by reducing the overall layer height, and/or adding height range modifiers to top and bottom which adjust the layer height to something finer, like 0.08mm, but keep the rest of it with a taller layer height, for speed.
In terms of overall model resolution, I can see the flat edges on the model even before slicing – it’s not really round but a series of flat sides, essentially (which is true with any mesh, to some extent, but in this case could be a lot finer). I recommend exporting with a higher resolution mesh (or adjusting the STEP format import sliders in Studio if you’re going that route).
Another slicer setting which helps maintaining resolution is Quality → Precision → Resolution. I like to reduce that to something like 0.008 or even lower (but it can slow down slicing, depending on your computer). It won’t “cure” layer height issues of course, but it can make curves much smoother in general (depending on original mesh resolution of course).
HTH,
-Max
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You can do that with pla as support. Totally doable with low artifacts on the bottom of your device is calibrated
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It’s already set up for “Support for PLA” as the interface filament.
Though the interface is doing some funky stuff… probably worth trying to adjust that out if possible. I didn’t play with the support settings.
-Max
Thanks for your excellent, and in-depth, reply there Max.
With regards to the resolution of the actual model. I made it in Fusion 360 just export it as an .3mf. I had no idea about the resolution thing but, thanks Google, found it and have adjusted. Will see if that helps. I’m not worried that overall it isn’t perfectly round, it’s just the large flat spot I’m trying to improve.
Haven’t ever used, or considered, the variable layer height thing. I’ll give that a go, as I will the precision setting.
Your other reply about the support interface you said “adjust that out”. I’m not sure what you mean there.
I’ll set that off now and report back.
Thanks!
Thanks Blaster.
I happen to be using the support PLA, as I have a roll, but yes, I have found standard PLA great for PETG supports (and visa versa). I got the support PLA before I learned that trick.
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Yeah I always use the “Save as Mesh” options in Fusion vs. the “Export” since it provides a lot more control (and preview!). Hopefully that’s what you found by searching… Autodesk also has a free “3D printing essentials” Fusion plugin which adds a bunch of features… but the most useful one really is a “Save As Mesh” button right on the toolbar. 
Variable height is often recommended for getting smoother rounded/domed tops, but rarely for doing the same at the bottom (that I’ve seen). When adding the layer modifiers in the object tree, keep in mind that the slice preview shows heights of each layer as you scroll through them – very useful to figuring out which layers should be affected (took me an embarrassingly long time to notice that).
Yea I’m not really sure either… I just meant “play with settings,” nothing specific. Perhaps interface density or pattern or the support type entirely… 
With something like this I often just end up changing stuff to see what happens and follow up on anything that improves the situation. (I also always have “develop” mode enabled because that gives more stuff to play with.)
Cheers,
-Max
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Ok, after many little test prints I’ve come to what I think is a valid conclusion. I did tests with just a short 2cm, 15mm diameter, solid rod, laid flat.
This may be obvious to many, it sort of is to me now I’ve come to it. I’ll share it here though for others who encounter this.
I used the suggestions above and it didn’t solve the problem of the flat spot.
I’m really grateful for the help, though, especially your input Max, as they did result in a higher quality rod as it did become a smoother round … but still with the flat base.
Reducing layer height, to 0.08mm, was the givaway. Still had the flat spot but it was thinner. Extrapolating from that, I think, explains it.
Imagine the layer height on your print could be a ridiculous 1mm (even take that to 5mm, same applies). The top of that layer is 1mm up the cylinder, which means you’ve sort of cut off anything below that and made it the same width. With my 15mm diameter circle, if you had the 5mm layer height, you’d lose a third of the cylinder as being flat. You don’t lose that bottom section, but it’s no longer curved.
OK,I’ not explaining it well, so I’ll add a diagram.
Hope this helps others that stumble over this as well.
Thank you Rusty35, that illustrates it far better than my diagram did.
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You should just try full raft.. I would try that. Do you have vision encoder ? You did all the stuff ? belt tightening ? advanced noz cal ? if you remove a nozzle you should redo all the calibrations. (If you think I do exaggerate on this please just tell me 
)
I think the preliminary is to print a sphere on a full raft. When It comes good try the model. just to don’t waste tries on a big model
