1 Topic by stenci

  • stenci
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Topic: How do I print a shape with thin cylinders?

I just got a Da Vinci Duo, my first 3D printer.
I know how to make a 3D model (that's my job), but I don't know how to tweak it to improve the quality of a 3D print.

I printed two small easy shapes just to see how the printer works, then I tried to print my first real model. I was afraid I would have some problems, and the problems showed up.

The model doesn't have a flat part to lay on, so I decided to put it with as many vertical faces as possible. The shape has 2 vertical thin cylinder touching the bed and tons of support to reach other surfaces.

I imported it in XYZware, I set it up with excellent quality and slow print, I clicked Print, I waited 4 hours (is that normal???) for the slicing to be finished, I started the print, and after a few minutes 1 of the 3 vertical shapes disappeared.

Here there are photos of the result and the stl model (I wasn't able to create a link in this post): drive.google.com/folderview?id=0B6Eyi7du69LQY2p0X3lpdWU1SlU&usp=sharing

Is it possible to get that model printed with good quality?

Thanks, Stefano

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2 Reply by skywiselh

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Re: How do I print a shape with thin cylinders?

That is a complicated print. First you want to run a calibration on your printer - forget what the manual says, the thing is not calibrated from the factory. Second, look into a better solution to stick your print to the print bed. I recently started using "ABS Juice", which is simply acetone with some ABS dissolved in it - it works better than the glue.

Beyond that, check and fix your belt tension, check your white pulleys, if they are moving you need to install spacers. Check the right brass bearings of the build platform, if they are loose in the plastic you need to glue them into place. After all that the machine is actually reasonable precise.

Finally, make sure you model is working. https://modelrepair.azurewebsites.net/index.php can fix models.

3 Reply by stenci

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Re: How do I print a shape with thin cylinders?

Thanks for the precious advice.

I did check the calibration and the belts, it was good.

I used the glue that came with the printer. In my previous tests I had some problems with it, especially on the corners, especially on the starting corner, so I focused on making it very smooth (no lumps) and making sure that I was covering the corners. The raft looks good to me and it is well attached to the bed. I had to push hard to get it out.

I started the print twice, and both the times the tip of the left cue fell at exactly the same time. I have two identical cue tips. The first time I stopped it. Right now it is two hours into printing the rest of the model.

I will check the pulleys and the bearings after it has finished. And I will also try with the fixed model.

The fact that it failed twice exactly in the same way makes me think that it is either the model (but I have made hundreds of STL models and never had a problem) or the slicer (which I just used for the first time).

Right now I wanted to slice the fixed model while the printer finished the print, but... it's impossible. I am very disappointed by the software. I like the printer, but a software that takes 4 hours to slice a model and only works while the printer is idle and connected to the computer makes the printer usable only for simple things.

Do you think I can find a better software? Am I too worried?

4 Reply by skywiselh

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Re: How do I print a shape with thin cylinders?

stenci wrote:

[...] Do you think I can find a better software? Am I too worried?

There's a number of ways to get the unit to work with different software (Slic3r, Cura, Kiss, anything that outputs gcode pretty much). I personally did a hardware modification and moved an internal SD card in the back of the unit to the front - that way I can just upload gcode as the demo print files and have the machine print that way. Another option is to create a gcode, add the proper header and base64 encode the entire file in something like Notepad++. Once in base64, you can just save the base64-gcode in 3W and the XYZWare will import it pre-sliced and send it to the printer. Another option is to install an open source firmware (Repetier) on the unit and you can just upload gcode via USB.

5 Reply by stenci

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Re: How do I print a shape with thin cylinders?

I searched for the different options with the slicers, and I decided to try with Cura, because it seems to produce the best results.

I downloaded Cura, played a little with a small model and I was able to get something out of it. I haven't tried to print yet, but it did produce some G code.

Then I loaded my model (and the one fixed using the link you gave me), but either Cura hangs and needs to be killed by the task manager, or stays there doing nothing (the task manager says the CPU is 100% idle) and the save button is grayed out.

This is the first model that I try to print and I can't find a software to print it. Is there something wrong with my model?

Are my expectations to high, and the slicers out there only work with simpler geometries?

6 Reply by Weekend Avenger

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Re: How do I print a shape with thin cylinders?

stenci, is your stl looking gray or yellow in Cura? If it's not yellow, you did not set the bed size which defaults to 100 X 100. If it's gray, Cura won't even attempt to slice it.

7 Reply by stenci

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Re: How do I print a shape with thin cylinders?

It is white.

I set the working area to 150 x200 x 200, and it worked with a small object.

This model is about 120, much less than 150.
Why doesn't it become yellow?

Also with the smaller model I noticed that there was a large area around the object that prevented them from being placed close to reach other.

8 Reply by Weekend Avenger (edited by Weekend Avenger 2014-08-25 05:35:35)

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Re: How do I print a shape with thin cylinders?

stenci wrote:

It is white.

I set the working area to 150 x200 x 200, and it worked with a small object.

This model is about 120, much less than 150.
Why doesn't it become yellow?

Also with the smaller model I noticed that there was a large area around the object that prevented them from being placed close to reach other.

Does your space settings include calculating for the raft that isn't part of the model? A large brim or even the 1 line border it normally makes around an object will also make it go over the size that it thinks the bed is and Cura will just sit there and not slice. I'm adding a large file that I printed on my DaVinci. If you turn on things like brim or raft, you'll probably find that it will go from yellow to the gray color and won't print.

http://ppl.ug/XBx47jY31WM/

and I apologize for not noticing yours is a duo. That model is for a 200x200x200 type bed that the 1.0 has.

9 Reply by stenci

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Re: How do I print a shape with thin cylinders?

Thanks, It was the brim.

The slicing was done in 1 minute vs 4 hours with XYZware, and it looks much better.

Tonight I will try to figure out out to print it.