Harry_D
Posts: 13
Joined: Mon May 08, 2017 2:28 pm

Just curious... WHY is the bridge layer in this supported model?

Sat Nov 07, 2020 7:14 am

Please see attached .factory file - I'm printing a cover for a filtering module & there's no issues so far....

However, I've sometimes wondered why I'm getting a bridging layer in situations like this & I figured, it's time to ask? 8-)

In this model, even though the flange is fully supported (normal support & 2 layers dense support at 50%). S3D is still putting a bridge layer in & I seem to get that quite often... But I don't think bridging is required here...?

I know, I can switch bridging off, by increasing the value for the threshold to "99999" - but the current value (50 sq mm) should be enough to prevent it from occuring in this model. (By the way, increasing the value to 500 or 1000 sqmm still results in the bridge layer being added - so the threshold value doesn't appear to be driving the decision?).

I've also tried setting the dense support to 100% & the separation layers to 0 - but the bridge layer is still being inserted.

Why is that, please? :?:
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S3D forum - bridge layer question.factory
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parallyze
Posts: 217
Joined: Fri Jun 05, 2015 4:18 am

Re: Just curious... WHY is the bridge layer in this supported model?

Sat Nov 07, 2020 9:19 am

Hi,
Harry_D wrote:
Sat Nov 07, 2020 7:14 am
I know, I can switch bridging off, by increasing the value for the threshold to "99999" - but the current value (50 sq mm) should be enough to prevent it from occuring in this model. (By the way, increasing the value to 500 or 1000 sqmm still results in the bridge layer being added - so the threshold value doesn't appear to be driving the decision?).
hmmmm... looking at your factory file I'd expect the threshold somewhere about ~2600-3000mm².
bridging.JPG
The bridged areas are roughly 8mm all around. The part is 110mm x 90mm = 9900 mm². The area on the
inside is roughly 94mm x 74mm = 6956mm². 9900mm² - 6956mm² = 2944mm²... (including the area of the holes, so
threshold is probably below that).

Can't tell you why bridging on a layer like this will occur even when setting seperation layers to 0. But the threshold seems to work
as expected.... ^^

Edit: Threshold in this case is 2846mm² ^^

User avatar
dkightley
Posts: 2283
Joined: Tue Mar 10, 2015 4:09 pm

Re: Just curious... WHY is the bridge layer in this supported model?

Sat Nov 07, 2020 10:34 am

I'd worked out similar figures...but a tad larger.

Setting the threshold to 3500 sqmm works as it should

And the reason for getting bridging...is because there's no on/off switch...and its on permanently. But as you've found, you can set the threshold to a rediculous value to force the feature off.
Doug Kightley
Volunteer at the National Tramway Museum http://www.tramway.co.uk
Railway modeller and webmaster at http://www.talkingtgauge.net

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