Suggestion for PVA settings features

[gaunten]

I have been struggling with water soluble PVA recently.

I'm starting to get good results, but there are some features missing in Simplify that would make the print time significantly shorter, and the results better.

1. There should be a separate setting for Dense support underspeed, alternatively a speed setting for extruder 2.
PVA prints good at about 10mm/s, where PLA works fine up to 60mm/s or more depending on printer and model. Having to set the whole support structure underspeed to 25% on a 40mm/s print makes the print take several hours or more longer depending on size and support.

2. There should be an option for dense layers before the dense layer with extruder 2, so that if you for example would have 10 layers of support, you could have 6 layers PLA in 20% infill, 2 layers PLA in 100% infill, and then 2 layers of PVA 100% infill. Printing PVA directly on a 20% PLA support works if it's a big area, but for smaller parts of the print this could be useful.

3. Temperature settings. As it is now, I have to go through the sliced model to see which layers use PVA, and set the temperature manually for all those layers for extruder 2. As PVA doesn't like being heated up for longer periods, this is a must. There should be a setting where the PVA extruder automatically cools down to a rest temperature if it is not going to be used for X amount of time/layers.

4. Fan settings. Printing with PVA works best if the fan is set down to 50% speed, otherwise it solidifies before it has time to adhere properly. The problem I'm having now is that I can only adjust fan speed on a per layer basis, meaning that on every layer with both PVA and PLA, the PLA will also get printed at 50% fan speed. As with the previous point, there should be a setting so that all operations with tool/extruder 2 uses X fan speed.

5. I don't know if this is me doing something wrong, but when I set the temperatures manually, even though I enable the "relay temperature between each layer/loop" options and "wait for temperature controller to stabilize before beginning build", the printer will switch to extruder 2 and start heating up, but it starts the printing instantly, meaning it doesn't extrude for a good portion of the layer, until it starts reaching the set temperature. My current solution is to set the temperature one layer before extruder 2 is in use, but that does not feel optimal.

[zemlin]

I've never worked with PVA, but on the temperature issue, this thread might be helpful.
viewtopic.php?f=8&t=5942

[gaunten]

Thanks, I have some studying to do! I guess for now I'll have to learn some basic G-coding, but I guess I was going to have to do that sooner or later anyways. I'm really hoping features like these will become more commonplace in the near future. I'm most likely starting on a project soon to make a sort of guide for a certain printer, like optimal settings for different layer heights, materials and support etc. and it would be really cool if I could do it for PVA as well without including G-code changes.

[b-morgan]

I agree with most of what the OP said. Using the Tool Change Script can handle the temperature problem and maybe the fan problem (if the variables exist and their names are available) but point #2 about dense layers for each extruder is going to be difficult without help from S3D.

[ranqizhu]

Agree with OP
+1

[DavidSG]

I heartily agree with OP. However, "by layer" setting are no good for the PVA interface if you are supporting say a horizontal cylinder - there is some PVA on every layer. So the separate settings have to be by extruder. And there needs to be a way to reduce the PVA extruder temp when not in use.