Ooze shield problem

[pcman]

I have a downloaded model that is a single piece but I would like to print it in two-tone. I created four processes, each specifying a start and stop height accordingly and everything seems as expected in the preview. However, when I try to add an ooze shield, it appears to only work with the first process. I have ooze shield enabled on all processes but it always stops after the first one. Could somebody please tell me what I am doing wrong?

[CompoundCarl]

The ooze shield only works if you're printing 2 colors at the same time. If you're just printing one color for the first section of your model (i.e. from 0-10mm) and then another color for a later section (10mm and beyond), you don't need an ooze shield. The easiest (and highest quality!) way to do this is to only use a single extruder. Only heat up one extruder and leave the other one turned off so it doesn't ooze on the print. Then you can just pause the print at whatever layer you need the new color and manually change the filament in the nozzle. That's how I prefer to do it. S3D already has some nice features where you can automatically pause at a given layer, so it's really easy to tell it to do something like pause at layer 50, 100, and 150.

If you really want to use 2 extruders, then you can still do it, but you can't use the ooze shield since that only works for prints with both colors at once. Just heat up and cool down the extruders as you use them, that way you don't have to worry about oozing.

[pcman]

Thank you for the reply.

Ooze isn't particularly a problem in this case, I just wanted to use it to ensure the nozzles are primed. Of course, the same problem occurs when using a prime pillar or a skirt. I will try your suggestion but it will require an actual print to evaluate it rather than just an examination of the preview. I suspect that turning the hot ends off until they're needed will make priming even more of a problem and obviously I cannot print a skirt in mid-air.

I have printed many pieces of my own using the dual-extrusion wizard where I have created the model in sections for each colour. Many simply switch extruders at a certain height and have worked well, so I was trying to achieve something similar. I cannot use the dual-extrusion wizard in this case because it is a single object. If your suggestion fails, I will take the model into Netfabb and separate it into appropriate pieces so I can then use the dual-extrusion wizard. I know I can make it work, but it's a very convoluted solution.

Thanks again!

[horst.w]

But it is the same problem with a skirt.
I want to use skirt or oozeshield for protecting the object to avoid the quick cooling out of ABS. Doing so, I have no warping.
Creating a 2nd process the skirt also stopps with the first process.

I can't see a plausible reason for this.

In version 2.2.2 this was possible but there was an other issue, it lets a gap between the processes, but not on level of the change-value, the end of the first and beginning of the second process in the attached picture is 5 mm.
The old version is history but I expect that S3D will fix this new bug as soon as possible. I need the multi processes for changing a lot of things as infill, speed and other parameters to improve the print-quality.

Skirt V 222 5 mm.jpg (6.55 KiB) Viewed 8708 times

[pcman]

I tried the suggestion of turning unused hot ends off, but it didn't work out well. I set the extruder to heat up when it was needed and checked the option to wait for the temperature to stabilise before proceeding. It appears that this took too long and in the meantime the previous layer cooled enough that the bonding wasn't sufficient because it caused delamination at the colour boundaries. I could adjust the settings to have the hot end start to heat sooner but that would seem to require a lot of trial and error to get right. This one failure already took 5 hours and 23m of filament. Even if I found an optimum setting, it would only be applicable to this particular model so it would be more of a workaround than a solution. Manually changing filament in the same extruder is not an appealing method either because this could later be an issue with an object that I wanted to print multiple times.

I took the model into Netfabb and split it into four pieces. This is a quick and easy process and I was confident that I would now be able to make a successful print. No such luck. It did solve the problem with the ooze shield but it created another one. S3D produced hundreds of unnecessary supports. I think this is probably an anomaly with the .stl files that Netfabb generated, although S3D does not detect any errors in the models. I checked each section and they are all the correct height, but S3D produced supports for each one exactly as if they were unsupported by the pieces below. I tried manually dropping each section by 0.01mm (and then more) but it didn't help. If S3D allowed marquee selection to remove supports it wouldn't be so bad, but having to click each one individually is tedious. So I then tried exporting the supports from my original single-piece model, which were correct, and importing them into the four-piece model. That didn't work either.

For the time being, I have given up. This isn't something that I must print, it was just part of the learning curve because I'm quite new to this. I am now thinking that I will have to write a post-processor that will correct the generated g-code by extending the ooze shield all the way to the top.

I don't accept that this 'first-process-only' limitation is by design. It seems to be a serious shortcoming of the software, if not an outright bug. I bought S3D the very day my printer arrived because I had read about how much control it allows and that's what I would like. If an option is enabled and selectable, it seems reasonable to expect it to do something when I select it. There must be many scenarios where a dual-extrusion group is not the lowest-Z process and an ooze shield is desired at a higher Z than zero.

Edit: After a little experimentation, it has become obvious that Netfabb's .stl files are not to blame for the unnecessary supports. I will investigate further and submit a bug report if appropriate.

[Fabface]

I have the same problem, I need either ooze shield or skirt to be printet in more than only the first process, I as well don't need it to prevent oozing - this should be possible if the users wishes to and not be disabled by default just because it doesn't fit the definition of skirt or ooze shield
It is not even possible to use ooze shield and skirt in the same (first) process, only if the skirts offset is greater than the offset of the ooze shield (but i need the skirt to be printed with 0 offset) it is quite disappointing...

[Kingdom3d]

I have the same problem, how do I print with multi-processes and a prime pillar and ooze shiled?

[DarthRevan]

As far as I remember multiprocess prints with any additions won't have the additions applied if the process includes a start at X height.