Feature Request: Print Multiple Layers per Feature

[ClownTrigger11 1]

I was watching a print today that had my printer hopping around between lots of separate areas on each layer and had a thought that it would save a bunch of time if it would print a few layers before traveling to another spot, so I thought about how that might work.

 

Similar to print sequencing for multiple parts, a large amount of print time could be saved through reduced retractions and travel by keeping the printing area at the same place for multiple layers. This wouldn't be applicable for objects without towers of some sort or horizontal holes. For those having layers with multiple printing areas or, islands, multiple layers could be printed per island at one time without retraction or travel.

 

Like the print head keepout zone used for multiple parts, the keepout zone could be defined by nozzle diameter at a certain height above the bottom of  the nozzle. For example, from a quick eyeball with calipers, my standard full taper nozzle is about 7mm diameter at  about Z +3.0mm from the bottom of the nozzle. Part cooling ducts and hot end socks would need to also be taken into account into these keepout zones, probably by keeping the +Z below the bottom of such attachments.

 

For a 0.2mm layer height print, even a Z +1.0mm x 4mm diameter keepout would reduce retractions and moves between feature islands by 80%. Increasing Support X/Y Distance to > the keepout radius would allow all supports to be considered their own island(s) as well, allowing multiple support layers to be printed at once. In multiple part printing scenarios, parts could be placed substantially closer to one another while still gaining most of the speed benefits to one-at-a-time printing.

 

Consider the attached model. If sliced at 0.2 mm layer height, the first 10 layers would be printed at once, then on layer 11, the L-shaped corners would be started. Each layer until the arches were closed would have at least four travel moves and retracts if printed traditionally.

 

My suggestion would be to print multiple layers of each of those L-shaped corner islands at once before retracting and traveling to another. If the +Z range was set to 2.0 mm with a 5 mm keepout diameter (2.5 mm radius), each corner could be printed 2mm Z at a time until the keepout would force single layer printing to resume at around layer 33. This would reduce the minimum number of travels / retracts of those 23 layers from 92 to 12.

 

I know this would take some substantial modification, but I think that it would be worth the effort.

Island Test v1.stl

[GregValiant 1,318]

My cooing duct is just about 1mm from the bottom of the nozzle.  As a consequence - four 0.2 layers would be the max for me.  Ten 0.2 layers is a definite crash.  The duct is my own design and works quite well.  I can't move it up because of the design of the hot end.  I can only make the opening shorter.  Not a good option for me.

[ClownTrigger11 1]

Even if you only did one extra layer, that still cuts the number of travels/retracts by half during applicable portions of the print.