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Retraction and Z hop for supports

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Hi everyone. I've been printing increasingly complex models in the past few days and I came across a problem when using supports. There is no retraction between the towers thus causing lots of stringing. This is a problem for me as it tends to break small towers and pull them to one side due to the weight of the added plastic. The print head also tends to rub against previously printed supports during travel and caused print failures a couple of times.

The rest of my print is fine and I don't have any problem with stringing or anything on the object itself.

I think a feature to enable retraction and Z-Hop when printing supports could be really useful.

What do you think?

PS: There was already a similar thread here: https://ultimaker.com/en/community/23443-cura-23-release-bug-massive-stringing-on-supports

Pictures here:

https://goo.gl/photos/rhxT1JpzmSJXQe1x9

https://goo.gl/photos/e2THGPtEm6TYALwR6

Edited by Guest
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Cura already has all these features. First of all if it's not retracting look at all the retraction settings. There's one called something like "minimum extrusion before retraction" and "minimum travel before retraction". Setting those both to zero will greatly increase how many retractions you are getting - possible to the point where you get filament grinding but that's another issues. Or in cura 2.* one of those is something like "maximum retractions on same filament". Set that to 20. Any more than 20 and you definitely will get grinding filament.

Which version of cura is this?

Also in cura 15.* and 2.* is "z hop on retraction" which is what you ask for but I strongly don't recommend it. It creates even more stringing.

Also you can reduce speed and temperature to reduce stringing.

Also there is an "avoid part distance" or something like that in cura 2.* which will avoid those towers if it's moving to another tower far away so it doesn't knock over an existing but I don't recommend this feature either.

So I think everything you mentioned exists in cura already.

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Hi, I do have retraction and Z hop settings activated. The printer does it on the model itself without any problem. I do have most of the settings you talked configured to make the best quality prints. The problem happens only on the support towers where no retraction is done. I'm using Cura 2.6

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I have a similar problem.

I have a part with supports and sometimes my nozzle catches the support when travelling over the support and dislodges the part from the bed. I have enabled z-hop but it only z-hops over the part itself and not the support. It would be great to have a enable z-hop over supports option.

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I'd like to add my notes here also.

Using Cura 3.0.3 and 3.0.4 I get the same issue. This is more obvious for issues when printing the first layer. When the gcode prints one support island then moves onto the next, there is no retraction and it leaves a string or globs of filament across the bed. This then also proves difficult to actually stick the first layer of each island as some of the pressure is lost during travel.

Retraction Minimum Travel is set to 0.8mm, the support islands are a good 30mm apart.

https://gyazo.com/94167280deee003c84b9e4fd3debd055

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