Solidworks to Cura - without STL?

[herzla 3]

hi there

I'm using SolidWorks since years and got a 3D-Printer some weeks ago

may I'm wrong but to me STL look like a bitmap-stack without knowing that curves exist
I don't know if Cura (internal) knows about curves and roundings but my printer does and my SolidWorks also!
sure I use the SolidWorks-Plugin but in background this also just creates an STL and not in best quality (event I didn't got it done with absolute minimum tolerance-settings)
if I export the STL from SolidWorks with minumun tolerace-settings it looks round in Cura (but i know it is not and my STL grows to 250MB)

so to come to a point I would like to be able to import STEP-Files into Cura :-)
or is there any other file-type between SolidWorks and Cura?

[gr5 2,240]

What kind of printer did you get?  How much did you pay for it?

 

The most common technology right now is you convert those beautiful solidworks curves into triangles.  Sorry.  But it works pretty well.  And you want a pretty low resolution because if you have too many points on the curve your printer (with it's wimpy arduino style processor) will probably freak out and stop and stutter as it tries to process too many points in too small a distance (too short of time).  So paradoxically, if you want good looking curves on the final print you should have fewer points.

 

There are some tricks to put curves in the gcode but I recommend you DO NOT do that.

[herzla 3]

 i thought my coreXY does beautiful roundings..

..and now I see none of my gcode-files contain a G2 or G3 command 😞

[nallath 1,124]

Cura only handles tessalated surfaces. Even with STEP importing, it will probably still just convert it internally for the moment.

[ahoeben 1,992]

7 hours ago, gr5 said:

There are some tricks to put curves in the gcode but I recommend you DO NOT do that.

Can you elaborate?

 

@herzla: There's a plugin named "ArcWelder" in the Marketplace, which will take the gcode as created by Cura from the tessellated model and will try to fit curves to multiple subsequent tessellated movements, replacing them by G2/G3 arcs. Your printer firmware will then re-tessellate those arcs to linear moves. So it would be a quite round-a-bout way to get curves to print. Perhaps that is why @gr5 recommends you not to use it.

[wjbdesign 1]

13 hours ago, herzla said:

I use the SolidWorks-Plugin but in background this also just creates an STL and not in best quality (event I didn't got it done with absolute minimum tolerance-settings)
if I export the STL from SolidWorks with minumun tolerace-settings it looks round in Cura (but i know it is not and my STL grows to 250MB)

@herzla In my experience it is best to manually export files to STL within Solidsworks. This gives you maximum control over your STL properties. To adjust STL settings you should go to system options > Export > file format STL. Make sure the Binary option is selected, since ASCII files can easily be 6-8x the size. The preview option really helps to identify the different parameters. After the export you can open the file in Cura. But remember @gr5’s advice about having to many points. 

[GregValiant 1,361]

Only God can make a circle.  The rest of us have to use 2πr and so there will always be facets even with π calculated to 31 TRILLION decimal places.

[gr5 2,240]

6 hours ago, ahoeben said:

So it would be a quite round-a-bout way to get curves to print. Perhaps that is why @gr5 recommends you not to use it.

Yes.  It's both complicated to learn how to do this and buys you potentially nothing and may actually make quality worse.  It also creates MORE work for your printer firmware which for 99% of printers is bad but I have to admit there are very special cases (and this will happen more in the future) where that's a good thing.  I guess the only case I can think of is:

Klipper firmware

 

That's partly why I asked about your printer.  Klipper is really amazing.  Hopefully it's the future.  But I suspect less than 0.01% of printers are using it.  I haven't tried it.  It typically runs on a powerful multi core with floating point computer (e.g. a raspberry pi or beagle bone black) combined with a slower computer such as an arduino.  It handles G02 (arcs) natively.  It may not handle them well at this time - I don't truly know - but it probably already performs better than Marlin on arcs.  It's the only firmware I can find that smoothly clocks all axes independently (no bresnehan crap like in redeem firmware.  No fixed rate interrupt crap like in Marlin).

 

I also asked about your printer because if you got a $200 Chinese printer but are using $4000/year cad software there might be a mismatch in quality expectations between the 2 products.  From an engineering point of view this is almost a meaningless point but I tried to make a point anyway: yes STEP is a better format but most 3D printers are running Marlin firmware which, although it's pretty amazing, it has issues and is kind of limited on how well it can handle G02 gcodes.

 

[ahoeben 1,992]

57 minutes ago, gr5 said:

complicated to learn how to do this

It is as simple as installing a plugin and checking a checkbox.

 

58 minutes ago, gr5 said:

buys you potentially nothing and may actually make quality worse

It also potentially buys you quality improvements. The truth is it differs per printer type and firmware variant.

[herzla 3]

7 hours ago, GregValiant said:

Only God can make a circle.

yess, that's the point 😔

I'm dreaming of an analog computer since over 25 years

 

8 hours ago, ahoeben said:

There's a plugin named "ArcWelder" in the Marketplace..

looks nice on the first view
first little test-cylinder got printed without explosions or a burning printer

the gcode-file of my model comes down from over 200MB to almost 70MB (6,607,713 lines to 2,048,472)
I'll have a look at the acr-settings in my marlin and will do a ~20h testprint

 

7 hours ago, wjbdesign said:

In my experience it is best to manually export files to STL within Solidsworks...

I'll check if there is any way to get it done with one click like SolidWorks-Plugin does - just i high-quality

here you see the diffrent resolutions:

right is 'coarse' - 0,05788cm and 30 degrees (450KB)

middle is 'fine' (:rofl) - 0,022304cm and 10 degrees (1.4MB)

left is minimum tolerance - 0.00241187cm and 0,5 degrees (235MB)

the SolidWorks-File (SLDPRT) has 1.1MB, the STEP has 5.5MB

so at this point thanks for your replies

I think we're a bit away from the point i wanted to reach

but first I have to try Klipper Firmware and learn about G2/G3 commands

 

 

@gr5

yess I'm unhappy with marlin somehow - so Klipper will come next as my board can handle it or the new will arrive

I'm unsure if a $500-dollar Tronxy 400 Pro is much better than an $200-printer but I needet 400mm and liked this coreXY-stuff (after I saw my fried's printer shaking) so I had to choose if I pay 7-8 hundret Euro for a chineese printer and some tuning or invest over 10 thousand for a project that is more like a hobby or a passion-test and may not be realisable at all 😉
and honestly I saw the diffrence between 200 and 500 or 900 dollar but I didn't saw the real diffrence to a 10k$ printer (except the case)
and yess, I'm a newbe in 3d-printing but I'm great in imagination and optimasition and as I see a world full of STL-Files I just wondered..

[GregValiant 1,361]

Well @herzla, I cut my teeth on analog computers.  Then it was punch cards and an IBM 360 (1000mm diameter memory discs stacked 5 high and each disc held a whopping 720kb!!!).

 

3D printing is like owning a boat.  You don't get it right until you spend enough money on it.

 

I don't trust my Chinese printer.  I probably have as many hours troubleshooting as I do printing.

[gr5 2,240]

1 hour ago, herzla said:

but first I have to try Klipper Firmware and learn about G2/G3 commands

Ooh!  If you do please post what you learn and also direct message me as I get so many forum notifications I'm bound to miss your postings.  So I would really appreciate some DM message simply saying "hi gr5, I posted something you might want to read".  I can then easily and quickly look up your most recent posts by simply clicking on your name (just as you can look up mine - don't bother - nothing  worth reading, lol).

[herzla 3]

okai, after 2 attempts I will not install Kipper on my Chitu3DV6 tonight..

 

but thank you all! 😄

 

sometimes I wondered why I bought a RSP 3 B+ just for a WebInterface and why my ordered board will not be shipped

 

now I found PandaPi (again) https://www.pandapi3d.com/product-page/pandapi-2-8 and ordered

 

so I'll give an update about the future of my chinese printer within 2-3 weeks 🐔

[herzla 3]

haha, great, I found this forum again 😄
guys, klipper is awesome, absolutely abesome!

 

@first request: the convert from curve to pixel to g1 to g3 became more complex ~~
so implementing step & arc direct into Cura would be great 😄