Can a toggle be introduced to either enable or disable the consideration of support features being influenced by slice post processing parameters?
Attempting to use a -0.1mm XY Offset to get my part dimensionally accurate. The XY tolerance has a negative influence on my supports, as they reduce the first beam contact diameter. Artificially increasing the beam diameter to compensate will not work in my situation.
Please let me know if there is a workaround to this issue.
Hi,
Yeah good idea i think.
But why wont’ it work in this scenario to just increase the support diamter a little?
Elco
I too thought about just increasing the support diameter to compensate for XY reduction, but that negatively impacted the automatic support generation function. (Unless there is a way to increase the support diameter after support generation.)
Increasing the contact diameter (0.5 -> 0.7), first beam tip diameter (0.4-> 0.6), and first beam diameter (1.5 -> 1.7) would cause the automatic support generation function to place supports in a more sparse arrangement. (Because it maintains the same distance between edges of support members?)
I was just expecting to need to change the part contact depth to compensate for the XY reduction.
Just to expand on the issue. I’ve attached images which show the issue I’m running into. I adjusted my support settings to compensate for the XY reduction, but I still run into strange artifacts when viewing the sliced file.
Part with attached support:
Same plane, but showing the exposure:
There are more examples I can show, but they all seem related. The tolerance compensation calculation isn’t continuous. Some other sections show more erroneous issues where the contact points are entirely missing, even though there is plenty of ‘material’ to still form a connection once XY tolerance is factored in.
For a sanity check, I configured Chitubox with the same support settings and tolerance compensation parameters. (I wasn’t able to perfectly reproduce the beam angles and direction.) Upon viewing the sliced result, there appear to be no obvious defects.
Yes you can actually change it afterwards at the moment;
Just right click ‘edit support’ on the generated structure.
Then you can change for the entire support: tip and diameter beam at tip.
In the general support settings you can increase the diameter of the support by 2x * -0.1.
This is the diamter of the first highest node. Furthremore the pole-width multiplier can also be used to futher tune the widening.
I can’t exactly see what is happening in your image.
It looks like an entire part is taken out of the model? Or is there an inner disjoint part inside?
Is the mesh error free?
You can also toggle off the black in the slice preview (icon next the job name, in the job list).
That makes is easier to see the slice on top of the part.
Just checked the code as well. So the order in which it’s computed:
So yes you do have to keep in mind that if you have small tip sizes then those will be made smaller.
I agree this should be made an option to skip this. Doesn’t make sense to do it for the support.
On the other end; 100 micron correction seems on the upper end to me. Is your exposure high?
I agree that the need for a 0.1 correction is rather high. I’m experimenting with some pigments in my resin and my exposure calibration parts are all coming out with a slight increase to their dimensions. I’m now trying to mitigate it with the XY tolerance feature.
Sorry I wasn’t clear about where the issue is in the attached images. The red box in the image below shows what I see when I enable XY tolerance. The support tip sphere has an irregular shape. Other areas, the tip becomes a narrow eclipse or crescent shape. I usually use a 0.5 mm tip diameter with 0.4 mm beam tip size. Enabling XY tolerance, I’ve increased them to 0.7 mm and 0.6 mm, respectively.
Thank you for the tips about adjusting support parameters and better visualizing the slice preview.
Yes this is correct behaviour mathematically speaking… it gets an offset inwards after being unioned together.
I’ll have a look at how we can exclude the supports from this offset.
The reason we’re doing the offset first and then the union is that the offset can generate new overlapping curves.
I guess we could just skip the XY offset on the supports. That would solves this and it would only be 1 if statement extra.
mm another thing occured to me when adding this option to skip supports.
In theory you should have the growth of your model on all pixels. So also the supports. Especially at the point where they are intersecting with your model; as it’s the same ‘large’ surface.
If that is not the case; it seems more likely to me that you are trying to correct expansion instead (relative). So it’s growing relative to your model instead of absolute.
Or do you measure a consistent offset independent of model size? say a cube of 20mm had the same difference as 10mm?
using a lot of pigment is tricky btw… we did a lot of that back in 2014. In the end we never got accurate results as we had to over expose way to much in order for the penetration depth to get large enough. This let to much expansion because of the exothermic reactions…
i’ve added the option anyway; so it will be there in next release in 1-2 weeks.
kind regards
Elco
Just wanted to say thank you for adding the option. I plan to quit testing/using pigment in my resin. The benefits don’t outweigh the drawbacks.
I tested tolerances using cylindrical shapes which varied in diameter from 1 to 6 mm (1 mm increments). In each case, the diameter of each column was greater than expected, and consistently by the same value (within error). I expect to drop the need for such extreme XY tolerances once I use more standard resin formulations/settings.
ok cool thx for that info.
I’ve just updated the installer on our website with a new file format.
But just realized this extra option (added last weekend) is also in there.
So if you want to play with it; it’s online.
I’ve tested it as well in the output of course; but it’s just 1 IF statement if you switch it on. . so not much could go wrong 
…
May I ask if this change was pushed to the 1.0.4.2 release? I’m using the latest release but don’t see the option. I did also notice that the download page showed that the latest change was posted 09/02/2022. I believe I installed my version before this update. Was there no incremental increase to the version number? Sorry for the annoyance.
Yes it’s in the file from 9/2/2022.
I’ve not increased the version number as it was just a minor thing only affecting your request. Not bothering other users with this.
We’re working on a new build/release system to better manage this numbering.
Elco
