Nozzle marks on top layer & warping

[edible3d 1]

Hi everybody

Im Bernie and a newbie to the Ultrimaker 2+ that I received only today and been having fun running a few tests. The reason for the purchase is we are starting a business that designs and make custom cookie stamps for special occasions like birthdays etc.

I designed the initial model in TinkerCad which was fine and easy to do and then printed it on the UM2 for the first test run. Basically looked great although I noticed there were a few nozzle marks on the top layer that may be an issue when selling as a final product as you can see in the photo.

Basically I had issues with extruding filament initially (Using PLA) at the standard 210 deg. however when increased to 230 degrees it flowed well.

The settings I used in Cura for this particular print are shown in the following photos:

I feel that I may need to increase the top / bottom and shell thickness to maybe 1.2mm? Would really appreciate any feedback you can provide.

Also another observation on the first print is the based seemed to warp on one side so I assume the filament didnt attach enough to the buildplate so maybe use a raft next time or increase buildplate temp ? I also attached a photo for that too.  

Im really enjoying the machine its amazing and the quality of the build itself is really solid. Cant wait to learn more and more! Im really honored to be now a part of the Ultimaker community :-)

I thank you all for your time.

Bernie

Edited May 19, 2016 by Guest

[Nicolinux 288]

Hi Bernie,

and welcome to the forum.

The marks on the top surface are a "software issue". The printer moves the head over the (pretty) top and leaves a mark. I don't remember how this can be prevented, maybe someone else can chime in.

The warping of the piece is a sign that your bed is not leveled properly. Go into the material settings and start the bed leveling wizard again. Make sure that when you are asked to move a sheet of paper between nozzle and bed, you don't push down on that paper because it pushes in turn the bed down a bit. Grab one edge and slide it between nozzle and bed.

[edible3d 1]

Hi Bernie,

and welcome to the forum.

The marks on the top surface are a "software issue". The printer moves the head over the (pretty) top and leaves a mark. I don't remember how this can be prevented, maybe someone else can chime in.

The warping of the piece is a sign that your bed is not leveled properly. Go into the material settings and start the bed leveling wizard again. Make sure that when you are asked to move a sheet of paper between nozzle and bed, you don't push down on that paper because it pushes in turn the bed down a bit. Grab one edge and slide it between nozzle and bed.

 

Thanks so much Nicolinux I did level the plate so that part seems ok now the issue of the 'smooth' finish im after really want to resolve that :-(

Thanks again.

[StephanK 30]

Getting a perfect top layer ist difficult. You usually end up with scratches and lines deposited during travel moves or both. Z-Hop and Retraction Settings, Extrusion rate, printing speed all needs to fit for it to work. To dial this in properly takes a while.

Here's a start: http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#scratches and heres some more: https://www.simplify3d.com/support/print-quality-troubleshooting/#scars-on-top-surface..

Hope this helps a bit.

I do wonder, how does the bottom of your object look, would printing it upside down help? First layer on naked glass usually comes out looking great..

Edited May 21, 2016 by Guest

[JohnFox 25]

I use wet and dry emery paper when I want really smooth top surfaces, Start with 180grit and move up grade by grade to 400 or 600 grit. Make sure you do it on a flat surface such as a work top.

If you want to avoid those straight edges on the sides of your stamp, specify a large number of segments, ( I use 99 ) when drawing the circle.

[edible3d 1]

I use wet and dry emery paper when I want really smooth top surfaces, Start with 180grit and move up grade by grade to 400 or 600 grit. Make sure you do it on a flat surface such as a work top.

If you want to avoid those straight edges on the sides of your stamp, specify a large number of segments, ( I use 99 ) when drawing the circle.

 

Thanks so much JohnFox ill do some sanding and see how that goes! I understand its just something that happens on 3D prints so post finishes are required. With specifying segments is that in a software ? Im using Simplify3D at the moment.

Thanks again

Bernie

[edible3d 1]

Getting a perfect top layer ist difficult. You usually end up with scratches and lines deposited during travel moves or both. Z-Hop and Retraction Settings, Extrusion rate, printing speed all needs to fit for it to work. To dial this in properly takes a while.

Here's a start: http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#scratches and heres some more: https://www.simplify3d.com/support/print-quality-troubleshooting/#scars-on-top-surface..

Hope this helps a bit.

I do wonder, how does the bottom of your object look, would printing it upside down help? First layer on naked glass usually comes out looking great..

 

Thanks for that StephanK appreciate it yes it isnt easy to get it perfect but I guess some post finishing work like sanding will need to be done. I did try printing it with the top layer flat to the glass however it didnt build layers well when trying to extrude over long distances without any support underneath once it got past the layers that involve text. Its all about experimentation I guess !

[edible3d 1]

Ok. So I recently printed a stamp again and it turned out pretty good except the very top layer looks really rough.

Heres a photo:

Besides sanding, is there anything I can do here in terms of settings. Im using Simplify 3D but any suggestions would greatly help.

Regards

Bernie

[neotko 1,417]

1. Separate the base, text and star on 3 objects.

2. Drop them on s3d and group them (autocenter off)

3. Assign 1 process for each object

4. To get clean text measure a text side and adjust the nozzle size so it's a number in proportion to the width but if you use 0.40 don't go bellow 0.32 or you will have problems.

Edited June 2, 2016 by Guest

[geert_2 558]

Also, try printing such fine details cool and slow.

I recommend making a small test piece with similar text, and then printing that at various speeds and temperatures, to get a feeling of what to expect.

For example, in my experience fine text (character Caps-height of 5mm, line-width 0.5mm, and 0.2mm raised, layer height 0.1mm) prints much more beautiful at 190°C and 20mm/s than the default 210°C and 50mm/s, when printing in colorFabb PLA/PHA.

For other materials the best settings will be different, but the general rule should apply too, I think.

But it will not be perfect, so you may need to cut off any defects with a knife or fine scalpel, and to very gently sand it. (A scalpel is a small, very sharp surgical knife, and blades come in various sizes and models.)

[zerspaner_gerd 383]

1. Separate the base, text and star on 3 objects.

 

I am a little curious @neotko, do you mean by "separate" different stl files or just different Layer modifications Process.

[neotko 1,417]

I always work with separated stl and then group them ctrl+G.

This way you can select a model for each process. You can fine tune the top layers, improve how each part it's printed, etc. it's a matter of how well you want to print the object. S3D works very well if the stl it's in peaces. Ofc you must desactivate the autocenter to keep the original x/y/z position of the object so when group it stays as you designed it.

[gr5 2,234]

Are those rough surfaces showing up in the cookies? it seems hard to believe. I'm wondering if you really need to make the top look perfect visually in the stamp as long as the cookies look perfect. Getting the top surface perfect is quite hard.

The advice about leveling was to avoid the part lifting off the bed. I'll give you simpler advice. The problem is your are printing too high off the glass on the bottom layer so it's not sticking well. So rotate all 3 leveling knobs about 1/2 turn counter clockwise as seen from below. This will raise the bed closer to the nozzle so that the next print you make WILL STICK BETTER. Also keep your glass clean if you aren't using glue on the glass. Oils from your fingers (or cookies?) on the glass makes it not stick so well.

Again the other advice about flipping your part over 180 degrees sounds smart also - if you really need the letters to look better you can try printing them upside down on the glass. It should work out nicely. Please don't use raft. That's very old technology and not needed since 2014.

Finally consider lying to Cura and telling it that your nozzle is 0.35mm (and similarly make shell a multiple of .35 such as .7 or 1.05). The letters will probably come out a little nicer.

[Nicolinux 288]

 

@edible3d: The last photo looks like there is something else wrong. The top is not tight so it might be underextruded. I don't know S3D well, but as a quick test, increase the flow and see what happens.