Look for advice on the best way to print this part

[DadOfThree 0]

Hi Folks,

 

I'm still learning some of the more advanced features in Cura, and I have very little experience with supports.   I installed the "Auto Orientation" Plug-In as sometimes it puts things in a better position.  When I import the attached part, the way it's placed doesn't make sense to me that it would be the best way to print.  The Auto Orientation plug-in also keeps the part on it's side exposing gaps that I think would be hard to print.  I manually moved the part upright and I think this should be more efficient, but I'd like some advice before I try it.  Attached are some pictures of what I'm talking about.

 

Any advice would be much appreciated.  

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zTensioner_Bracket.STL

[Enigma_M4 119]

Hi,

if you attempt to avoid using supports, the upright position ist the best, because the arcs don't need any support. But regard that your adhesion surfache on the print bed is VERY small, so you need at least a good brim.

If you've a dual extrusion printer and can use dedicaded support material, such as PVA or Breakaway, you shouldn't look for avoiding support but best position of print object, especially needed strength (layer adhesion is the most weak point of a printed object).

Regards

[DadOfThree 0]

Thank you.  I'm not necessarily looking to avoid using supports.  I guess my inexperience is getting the best of me and not understanding how a 3d Printer will handle those gap / arcs.  After slicing with supports enabled and having the part on its side, I didn't see any difference in the preview.  I was expecting to see something in the middle, where that gap is.  

[Enigma_M4 119]

Handling overhangs is part of a steep learning curve and often result of trial and error. I'm still surprised of the ability of my printer to handle overhangs I just regarded as impossible.

For round arcs and overhangs angled less than 45° you definitively don't need supports. Many objects are designed to avoid need of support in just this way.

In Cura preview, you should be able to see the generated support. But of course the color sceme for "helpers" and the related extruder must be activated.

 

[GregValiant 1,243]

Next to the "search" box at the top of the settings is an icon.  Click on it and select "all" so unhide all the Cura settings.

There are a lot of settings under "Support".  One of them is an option called Support Placement.  If "Touching Buildplate" is enabled then those gaps won't be supported.  Change it to "everywhere" and the supports will show up.

 

That is a fussy model.  The small features on the ends of the legs would print best as your second photo shows.  If the sides were parallel instead of at a small angle it would print best laying down with a support blocker over the horizontal holes.  This looks like a case where the part is designed to release from a mold, rather than be FDM printed.

 

I like it like this.  When you open a 3mf file it will have all the settings and the printer (Ender 3 Pro in my case).  You will need to switch back to your printer and look carefully at the settings to assure that they will work for you.  There is one support blocker to keep support from the small horizontal holes.

zTensioner_Bracket.3mf

[DadOfThree 0]

Sorry for the late response.  Thank you both for the suggestions.  Going to work on this next week.  

[geert_2 557]

I would probably use the vertical position, and indeed use a very wide brim for bonding to the glass. Or design a custom brim in the CAD model.

 

If you want to make custom supports in CAD for a single-nozzle printer, you could try free-hanging supports. Without supports the arcs might look a bit like grapes.

 

These below are free-hanging supports. Note that this is a very small model: the opening where the supports are hanging in, is only 5mm wide. The ribs on top of the supports are 0.5mm wide and high. Between support-ribs and the underside of the roof is a tiny gap between 0.2mm and 0.5mm (adapt this to what works best for your model: narrower gaps give more accuracy, but support is harder to remove).

 

 

The supports attach to the side-walls by the stringing alone. This is enough to keep them in place, but makes it easy to remove them later on. The 1mm staircase underside improves stability and reduces curling-up of the support while printing (compared to triangular undersides).

 

The tiny connection-tabs on the side-walls (shining through the supports) improve connecting to the walls, make removal easier, and minimise damaging the walls. These tabs are ca. 0.2mm high and wide, and 0.5mm long. It took me some time to come up with all this, but it works well for my designs.

 

If you have a dual-nozzle printer, maybe you can still use this concept: make the supports in the same material as the model, and provide a support-layer in-between this support and the model. So that would fill up the gap that is present here. Then you get a nearly perfect underside of the model, without using too much support material. See the support-sandwich below.

 

Try-out and optimise these concepts on a small test part only, before doing the whole print, so you don't waste too much time and material. You may need to adapt them to your models and dimensions.

 

[DadOfThree 0]

On 12/29/2020 at 8:02 AM, GregValiant said:

Next to the "search" box at the top of the settings is an icon.  Click on it and select "all" so unhide all the Cura settings.

There are a lot of settings under "Support".  One of them is an option called Support Placement.  If "Touching Buildplate" is enabled then those gaps won't be supported.  Change it to "everywhere" and the supports will show up.

 

That is a fussy model.  The small features on the ends of the legs would print best as your second photo shows.  If the sides were parallel instead of at a small angle it would print best laying down with a support blocker over the horizontal holes.  This looks like a case where the part is designed to release from a mold, rather than be FDM printed.

 

I like it like this.  When you open a 3mf file it will have all the settings and the printer (Ender 3 Pro in my case).  You will need to switch back to your printer and look carefully at the settings to assure that they will work for you.  There is one support blocker to keep support from the small horizontal holes.

zTensioner_Bracket.3mf 235.71 kB · 1 download

Well, I tried printing and it was going so well, and then this happened.  I just don't see how the folks on Thingiverse got this part to print.  I don't have enough experience yet with supports and all the other options available to help with this.  I clearly need to practice.   

 

[DadOfThree 0]

On 1/5/2021 at 10:35 AM, geert_2 said:

I would probably use the vertical position, and indeed use a very wide brim for bonding to the glass. Or design a custom brim in the CAD model.

 

If you want to make custom supports in CAD for a single-nozzle printer, you could try free-hanging supports. Without supports the arcs might look a bit like grapes.

 

These below are free-hanging supports. Note that this is a very small model: the opening where the supports are hanging in, is only 5mm wide. The ribs on top of the supports are 0.5mm wide and high. Between support-ribs and the underside of the roof is a tiny gap between 0.2mm and 0.5mm (adapt this to what works best for your model: narrower gaps give more accuracy, but support is harder to remove).

 

 

The supports attach to the side-walls by the stringing alone. This is enough to keep them in place, but makes it easy to remove them later on. The 1mm staircase underside improves stability and reduces curling-up of the support while printing (compared to triangular undersides).

 

The tiny connection-tabs on the side-walls (shining through the supports) improve connecting to the walls, make removal easier, and minimise damaging the walls. These tabs are ca. 0.2mm high and wide, and 0.5mm long. It took me some time to come up with all this, but it works well for my designs.

 

If you have a dual-nozzle printer, maybe you can still use this concept: make the supports in the same material as the model, and provide a support-layer in-between this support and the model. So that would fill up the gap that is present here. Then you get a nearly perfect underside of the model, without using too much support material. See the support-sandwich below.

 

Try-out and optimise these concepts on a small test part only, before doing the whole print, so you don't waste too much time and material. You may need to adapt them to your models and dimensions.

 

This is a lot of information, and thank you.  I need to work on this.

[GregValiant 1,243]

You can open the Cura 3mf file I posted and just change the printer to your own.  Then slice it.  The supports will show up.

[DadOfThree 0]

On 12/29/2020 at 8:02 AM, GregValiant said:

Next to the "search" box at the top of the settings is an icon.  Click on it and select "all" so unhide all the Cura settings.

There are a lot of settings under "Support".  One of them is an option called Support Placement.  If "Touching Buildplate" is enabled then those gaps won't be supported.  Change it to "everywhere" and the supports will show up.

 

That is a fussy model.  The small features on the ends of the legs would print best as your second photo shows.  If the sides were parallel instead of at a small angle it would print best laying down with a support blocker over the horizontal holes.  This looks like a case where the part is designed to release from a mold, rather than be FDM printed.

 

I like it like this.  When you open a 3mf file it will have all the settings and the printer (Ender 3 Pro in my case).  You will need to switch back to your printer and look carefully at the settings to assure that they will work for you.  There is one support blocker to keep support from the small horizontal holes.

zTensioner_Bracket.3mf 235.71 kB · 1 download

Oh, I imported your .3mf file wrong, I'm going to try this again.  

[geert_2 557]

A tip: while slicing, always verify the model in layer-view mode, before starting a print. Then you can see all nozzle movements, and you can see layer by layer what is going to be printed (like brim, supports, model) and what not (too thin parts). Then this issue would already have come up during the slicing.