Best orientation to print large stand?

[markus555 0]

Hi all,  I'm new to the Ult 2 and have a large print but before I waste 24+ hours and 200+g of material I am wondering which is the best orientation to print this object.  I was thinking just like it would normally be used in real life, upright with the 4 legs on the base.

but then I was worried about tipping and thought maybe to orient it on its long side as the base?

any recommendations?  Thanks again

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Edited April 20, 2017 by Guest

[DidierKlein 729]

Hi and welcome,

It's hard to say like that but personnaly i would choose the orientation that will leave less visible marks from the supports so probably the second orientation.

Also if strength is an issue you have to think about the orientation (prints usual weak points are following the lines)

[gr5 2,168]

Unless you are driving a car over this I don't think strength is an issue.  A 200 pound human should be able to stand on that I think if it's made out of PLA.  

I agree with Didier though that the second orientation is probably best.  Make sure you look at the part in slice view.  Make sure the bottom layer is squished well and even push with a few pounds of force sideways on the 4 supports to make sure they won't come loose during the print.  You want those 4 legs to stick like hell.

I would use zero support on this part.  Will save you a day or so.  the underside of those arcs will be ugly but you can just file that off in a few minutes.

Consider printing a 1/10th scale version as a test.

[geert_2 557]

If I had to print this for myself, and it was my own design so I could edit the design files, then I would create custom supports as in this quick and dirty Photoshop image:

Pink = thin solid layers of 0.5mm height.

Blue = support columns.

The 0.5mm solid bottom layer (covering the shown area or maybe even the whole area that is now dark grey) is to get a good grip on the glass plate for this high model. When printing overhangs, the molten edges of the print sometimes curl up, causing the print head to hit them hard on the next pass. So you need a very good bonding to the glass to withstand these impacts, and to distribute the force over a large area. Otherwise the thin legs might be knocked over.

The 0.5mm pink top layer support would sit a little bit below the actual surface it supports, with a gap of 0.3 to 0.5mm (test what works best for this size). Sometimes I use a flat top surface on such supports, but usually I design small ribs into it of 0.5mm wide. Like an anti-slip floor mat. This makes the support easier to remove, and it gives a better bottom surface on the model. See this test model:

And the tree-style supports would be strong enough, easy to remove, and not consume too much material and time.

[markus555 0]

Unless you are driving a car over this I don't think strength is an issue.  A 200 pound human should be able to stand on that I think if it's made out of PLA.  

I agree with Didier though that the second orientation is probably best.  Make sure you look at the part in slice view.  Make sure the bottom layer is squished well and even push with a few pounds of force sideways on the 4 supports to make sure they won't come loose during the print.  You want those 4 legs to stick like hell.

I would use zero support on this part.  Will save you a day or so.  the underside of those arcs will be ugly but you can just file that off in a few minutes.

Consider printing a 1/10th scale version as a test.

 

Thanks for all the support! I think I will go for the 2nd orientation.nn

Anyone can direct me on how or knows how to easily add a few of those "tree" supports in Blender? I basically just took that model and modified the scale so am a little useless with adding/designing.

Or what about the 1st layer thickness idea but also/or adding brims to the 4 legs, would that would better?

If I print at 0.30mm layer thickness, the 1st layer thickness should be about 0.27mm thickness right? from what I was reading?

Thanks again, you guys are awesome!!!!

[geert_2 557]

I can't help with Blender, as I haven't used that yet. But if the design is an STL-file or STEP-file, you could open it in free editors like DesignSpark Mechanical (requires registration) or FreeCAD, and design the supports there. But expect a serious learning curve and study time. DesignSpark Mechanical can not edit STL-files, but you can edit supports (and other stuff) around it, and save that combination again as an STL.

Brim will certainly help the legs to stick better, although I can't say if it is going to be enough, but will not improve the overhangs of course.

If the first layer is set to 0.3mm in Cura, then I think a real height of about 0.2mm in the print would be best. But this is only an educated guess, not the holy thruth. :-)

You will have to experiment, and if it fails, consider that part of the learning cost.

[gr5 2,168]

Try it without any support. It will be okay - just need a few minutes with a file. If you really want to do support with the simplest tool then definitely go for meshmixer. Tutorial:

http://www.extrudable.me/2013/12/28/meshmixer-2-0-best-newcomer-in-a-supporting-role/

pay particular attention to how to rotate your part in the "annoyances & limitations" section and also note that there is a small error where he set layer height to "0.5" mm and it should be the layer height you print at e.g. .2 or .1mm.

[markus555 0]

Try it without any support.  It will be okay - just need a few minutes with a file.  If you really want to do support with the simplest tool then definitely go for meshmixer.  Tutorial:

http://www.extrudable.me/2013/12/28/meshmixer-2-0-best-newcomer-in-a-supporting-role/

pay particular attention to how to rotate your part in the "annoyances & limitations" section and also note that there is a small error where he set layer height to "0.5" mm and it should be the layer height you print at e.g. .2 or .1mm.

I'm having it printed by my local college and the person in charge of printing won't do it without supports so instead of messing with designing stuff and adding supports what about this orientation? Then no bridge, supports, etc?

Only question gr5, the printer is more than big enough to print 188mm high but is there any stability issues you can think of by printing in this orientation?

[gr5 2,168]

I don't think it can print the top two legs. That looks worse. They are just hanging over nothing.

[gr5 2,168]

Well if you don't want to figure out how to follow that meshmixer tutorial and if the guy who is in charge of the printer refuses to print without support then I suggest you just let cura print the support. Cura will do an okay job of supports automatically.

[markus555 0]

Well if you don't want to figure out how to follow that meshmixer tutorial and if the guy who is in charge of the printer refuses to print without support then I suggest you just let cura print the support.  Cura will do an okay job of supports automatically.

Yeah as soon as I looked at that orientation further I realized it was was ridiculously worse than the previous. The project part that this print is due next week but I will try and fast learn the MM tutorial, if cant figure it out then the stock Cura supports it is. Preview looks like this.

Again GR5 and everyone else, thanks for your help, you guys are awesome.

[rowiac 53]

Have you tried flipping it over 180deg (legs sticking up)? It'll only take a minute for Cura to tell you if that's better or worse. With supports touching the top, however, you will get some marks on those surfaces, but a little sanding could take care of that.

[gr5 2,168]

You can reduce the cura supports by quite a bit by setting the support angle such that it only supports the center 3cm or so of the arc. I forget if you need to set it to 80 or 10 to reduce support to the "almost level" areas.

[MechDesigner 3]

Mark,

Do you have to use the .4mm tip?

it will reduce your print time by about half with a larger tip. A large part like that I would use the .8mm tip.

What might happen on a 2 day print, is all that support will act like a heat

sink and the results are not good, I had a 2 day print that was doing well till about half way thru and the center collapsed about .25in. That part was only about 3 inches tall. I even created my own supports on the sides and center with thicker material. This is with ABS.

[rowiac 53]

You can reduce the cura supports by quite a bit by setting the support angle such that it only supports the center 3cm or so of the arc.  I forget if you need to set it to 80 or 10 to reduce support to the "almost level" areas.

 

@gr5,

It would be 80°. I believe the default is 45°, but I have mine set to 50° all the time and go higher sometimes as you suggest to reduce unnecessary support. Maybe at some point Cura will allow modification of support directly. I'm not ready to cough up the dough for S3D yet. Cura is so good (and getting better all the time) it is hard for me to justify.

[markus555 0]

You can reduce the cura supports by quite a bit by setting the support angle such that it only supports the center 3cm or so of the arc.  I forget if you need to set it to 80 or 10 to reduce support to the "almost level" areas.

@gr5,

It would be 80°.  I believe the default is 45°, but I have mine set to 50° all the time and go higher sometimes as you suggest to reduce unnecessary support.  Maybe at some point Cura will allow modification of support directly.  I'm not ready to cough up the dough for S3D yet.  Cura is so good (and getting better all the time) it is hard for me to justify.

Im using my college library printer so have limited access to nozzle size and stuff. the 1st print failed 3/4 way through. they said the the nozzle was moving but no filament was coming out, but was not clogged. It could have been tangled filament from spool. any suggestions if its not?

[Swissengineer 25]

Look at the back of the printer to see if the filament has any grinding marks on it...

[Swissengineer 25]

as for the orientation I would print it up side down. With the legs up. I think you would gain in print time, check it and let us know

[kmanstudios 1,120]

I'm having it printed by my local college and the person in charge of printing won't do it without supports.......

Yeah....I was highly frustrated with the printer people at the college I used to teach at. After a few bad prints, I asked what slicer they were using and could not tell me.