Slow down above bridges

[stefansjs]

Is there an existing issue for this feature request?

• I have searched the existing issues

Is your feature request related to a problem?

I would love to have a way to print N layers above a bridge slower without having to slow down the whole print. Even without needing to decide geometrically, just slowing down some speeds, e.g. inner walls for one or more layers above the bridge would be very helpful.

Which printers will be beneficial to this feature?

Marlin

Describe the solution you'd like

Ideally I would have a "slow down above bridges" setting that allows me to specify the number of layers above bridges, and speeds for at least inner walls, outer walls, and internal solid infill.

For example, my settings currently include: 300 mm/s inner wall, 100 mm/s outer walls, 150 mm/s internal solid infill, 15 mm/s external bridges. With 20 mm³/s filament most things print fine, but bridges are still difficult. Adding 100+ mm/s moves on the next later above the bridge often times ends up shredding the bridges themselves. My hypothetical solution would be to slow down outer/inner walls and solid infill to 25 mm/s for just the next 2 layers above a bridge.

Describe alternatives you've considered

No response

Additional context

I'm working with a difficult filament that doesn't print bridges well. I've found that I can get the bridges themselves to print ok sometimes, but then the layer above will go too fast and end up shredding the bridges. Since these are sometimes inner and outer walls, but other times solid infill layers, I find the only way to fix it is to slow down everything.

Here's a photo of a bridging test. You can see the overall geometry is roughly correct, but the underside shows the bridges being shredded by subsequent layers

[stefansjs]

Oops, I guess there is already a PR for this