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Remove built in supports from printed parts
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Due to the built in supports limiting the available layer height selection for parts, this often complicates the slicing procedure because in order to get good quality, @EricNugent is removing the supports in blender in favor of CuraLE's built in support abilities.
The request is to remove built in supports from printed part models and add something about the need for supports to the filename.

Event Timeline

logan created this task.Nov 27 2018, 1:57 PM
logan created this object with edit policy "LulzBot Hardware Products (Project)".

@logan are the built in supports easier to remove than the generated support from Cura? If so, why not modify the height of the built in support for the layer height desired?

logan added a comment.Nov 28 2018, 7:15 AM

@Steven Based on the feedback from Eric, no. In order for the built in supports to be effective he has to use a layer height which allows them to break away cleanly which isn't always the best layer height for that part. @EricNugent may be able to explain a little better.
My thought was if the CuraLE supports work well we could avoid having to make multiple adjustments to those parts before we find spacing that works. As of the moment I believe it would be too time consuming to accomplish that based on the current state of the Slicing Queue and the urgency needed to get the Alpha builds complete. It seems to me would be a more efficient workflow for everyone involved if we just remove them.

The general problem is the spacing on the built in supports is heavily influenced by the layer height. When we utilize the built in support in Cura there are settings which allow me to treat the support as its own entity, not to mention this allows testing for those features in Cura in house. Using the support feature in gives more control for print order and speeds. Where the modeled in support will over produce structures that are wasted material. In short, it is easier to slice without modeled in support.

the built in support is not more difficult to remove than the cura supports and works better (in my opinion) if sliced properly. To my knowledge all built in supports are made for .38 layer heights. If the desired layer height for production is different we can adjust the distance from the built in support to the model.

If the consensus is that we should remove built in support, we can do that too.

logan added a comment.Nov 28 2018, 8:38 AM

I am tossing my vote in the hat for removing the built in supports. I trust @EricNugent's level of experience, as he does ALL the slicing for our printed parts and has for some time. If he says its better not to have built in supports, he's probably right.
From personal experience, Cura supports are better. This may not have been true with legacy cura, but CuraLE has many more capabilities.

@logan it is not a problem if he uses .38 layer height on the parts with built in support. the biggest problem i have encountered with cura supports is that they often have trouble adhering to the bed and then break free mid print and spaghettify. They usually build enough spaghetti to correct the supports and it often works out, but not without loss of print quality. Also i have seen the parts warp off of the cura supports a lot

tutley added a subscriber: anolen.Nov 28 2018, 9:19 AM

@anolen any opinions on this?

Ok, there are many pros and cons to both options here, some of which have already been stated. Concerns raised about using the Cura generated supports are that the supports do not have the ability to have retractions and this could prove to be cosmetically negative, also smaller support areas have a higher tenancy to pop off the bed causing print fails. Cura supports could also effect the geometry of the part very slightly, I don't mean that it actually changes the model but when it prints and cools it may shrink at a different rate or direction than we are used to for our geometric precision needs. The positives of using the Cura generated supports are the ability to ensure support coverage throughout the model as needed and this would be another way to ensure our Cura generated support process is working appropriately. Built in supports allow for consistent expected geometric results since its what we have been using thus far but it also limits the cluster production slicing ability which I think only cluster and data from production should be effecting. One of the advantages of 3D printing is our ability to rapidly discover and implement improvements to our product, having the support system built in by the original design team limits productions ability to perfect it through their production process. This being said, absolutely ANY support style changes should each be rigorously tested before implemented into production parts, accounting for geometric accuracy, strength accuracy, etc. I cannot stress this enough, DATA! My conclusion is that we use BOTH and we allow @EricNugent to determine an individual parts support needs upon arriving to him for initial slicing. Some models will benefit from a built in support that Eric could build and add using FREECAD (it has to be in FreeCAD), and other models will benefit from using a Cura LE generated supports.

@anolen i like your response. I agree that both options should be on the table. Lets not remove any options because sometimes it may be the better choice!

AFAIK, Eric is not familiar with FreeCAD. He uses blender anyway to arrange parts on the build plate for parts where multiple are printed on the bed at the same time. He also is usually quite busy with slicing, having to modify those supports (model changes) would increase the bottleneck.
I know what you mean about supports adhering to the build plate, I struggled with this until I found the settings governing support speed, especially with the first layer. I hated Cura supports until I tried it in CuraLE.

the supports do not have the ability to have retractions

What do you mean by that? It does retract after completing the support portion of a layer before going back to the part and while moving between support sections from my experience. Otherwise it would have drag-overs across outer walls.

Do we even test supports while developing profiles or do we just roll with the defaults? Based on the behavior of default profiles with supports, I'm guessing the answer is no?

alexei added a subscriber: alexei.Nov 28 2018, 12:12 PM

@logan: FWIW I needed to tune support parameters too much from default values to get a decent support structure. So my guess is also that the answer is "no".

We are all supposed to be using FreeCAD for consistency. If @EricNugent makes changes in any way to a model it needs to be in FreeCAD. Most parts may not need built support changes at all, many will probably be fine using the generated support, which could save some time. If we keep built in support and keep doing that in R&D then Cluster can't change the part print orientation, layer height, or support preference. I feel like learning FreeCAD (yeah, i know... its FreeCAD, I'm sorry) would be worth it in the long run. I am not saying that we now make it mandatory for Eric build all the supports, I am saying we keep built supports open as an option on a case by case basis, we don't yet know how the generated supports will effect production quality and if it will increase or decrease production material waste. @david.hall thoughts? We will have to hear more from Eric when he is back but giving him parts that don't have set supports that force him to slice it certain ways that work around another persons idea might also save him time.
@logan , I mean that the supports do not retract when going from one area of support to another, only at the end, so if there are two areas of supported material it could string across the part. Yes, I have been testing all of my support settings for newly submitted profiles for a while now. If you would like to know which have been tested and which have not, it may take me a while to get you a list.

oliver added a subscriber: oliver.EditedNov 28 2018, 12:49 PM

@anolen AFAIK Eric is not using blender to build the parts but to focus on orienting the parts for loading into cura. It's easier for him to orient the parts in blender than doing it in CURA.

we don't yet know how the generated supports will effect production quality and if it will increase or decrease production material waste.

From my understanding he's been manually removing the supports in blender for some time in favor of CuraLE's capabilities.

I feel like learning FreeCAD (yeah, i know... its FreeCAD, I'm sorry) would be worth it in the long run.

Depending on where/how in the model tree the support gets added can make modifications difficult.
I could be wrong but I don't think Eric has time to handle all of the slicing in addition to what you're requesting. Nor do I think he should have to.
The efficient option here as far as I see is to leave built in supports out of the model, if generated supports are proven to be insufficient he can request built in support be added if necessary on a part by part basis. I wasn't suggesting a ban on built in supports, it will always be an option.
This would save him time, that's the bottom line.

kent closed this task as Resolved.Dec 17 2018, 3:09 PM
kent claimed this task.

From @logan comment above

leave built in supports out of the model, if generated supports are proven to be insufficient he can request built in support be added if necessary on a part by part basis

I think this is a good resolution to this ticket. If there are any models that do not meet these criteria, please create a separate ticket for them.