GregValiant

When you open a model in Cura and the popup says "The model is not watertight" it means the model itself has errors. In your case, a lot of errors. When a surface is red in X-ray view it is facing the wrong way and Cura can't figure it out. Here are two models. On the right is the one you uploaded and on the left is the same model repaired at NetFabb (where you have to create a free account). Just upload a model and download it when it's been processed. Here they are sliced. Missing pieces in the right model. The repaired model looks pretty good. Notice how the missing pieces in the right model coincide nicely with the red areas in the Xray view. BTW I think this needs to be printed on a fair sized raft. Its so tall and has very little contact with the build plate. Trying to print this fast could cause the model to fall over of it's own accord. I'd have accel control enabled at about 250 as well. Nice soft starts and stops are the way to go.

Yes, but you are an honest man who has been known to laugh at my jokes. I did notice that you jumped right in to defend Make Overhang Printable. It wasn't perchance added at your request was it? You can admit it if it's true. Your among random people you met on the internet here. Enough stealing the thread. I'd like to thank @humaneel for the nice PM he sent.

OK I'll give you that. But I see more OP's with buttresses filling their horizontal counterbored screw holes and it's a head scratcher until "Oh Yea, turn off Make Overhangs Printable". I'm staying with my tooltip idea.

If possible post the STL and also use "File | Save Project" and post the 3mf file as well. It will contain your settings. Some models just don't scale well and you are pushing it down a long ways. Features can disappear because Cura knows the printer can't print them with the current settings. Why it says it can print at 100mm but not at 210 is odd though.

If you have Special Modes | Print Sequence | "One at a time" enabled then it's the area your print head takes up. You can't put another part in the gray or the print head will hit it when it lowers to print the next part. That's actually true for people who bother to keep the Print Head size and Gantry Height up to date in the settings. Disallowed areas for brim/skirt are around the periphery and if you have them shut off then the gray doesn't show. With that piece you're printing another model would have to be the shape of a piece of linguini. (I was going to say spaghetti but that's a bad word in 3d printing.)

Thin walled models present unique problems. Not being watertight on such thin walls...I don't know. You can try uploading to service.netfabb.com. It's free and pretty good. Making it watertight gets rid of one issue. If you were to remove the side mirrors (make them glue-ons - you're going to knock them off all the time anyway) you can eliminate one problem area. If you can alter one half of the body so it has a centerline flange that fits under the other half, it will make assembly much easier. Even with tabs glued here and there, it won't fit well unless it has the support of the other half. As far as print supports go, you'll need to play around. It's so thin that the roof is going to be a problem. Remember that the supports will need to come out. If you sweep a shape across the top of the front window to the top of the rear window it would add layers to the roof. I think that would print better and hold up better during support removal as well. I would suggest a dense support interface of 50 to 60%. I've had better luck removing supports with dense interfaces without hurting the print. When you slice it, make sure to look very closely at the preview so you can pick out problem areas before you print. You'll have a lot of time invested in this.

3 blades .8 wide by however long and tall Top, bottom, and middle. Much easier to print. If you still get movement of the filter then increase the blade count.

Larger features and less density. You are going to take a hit on flow. Minimizing the size of the hit is the trick. If I may ask, what direction is flow? BTW the first experiment on vertical extrusion failed.

Wow. Nice job getting that tall. You might have invented a new calibration print! It looks like they did well to about 7-8mm and then they pretty much all failed one way or another. Time for an experiment.

I have a Creality Ender 3 Pro and I'm up to 17 different slicers now. A couple are really useless, most are fair, several are Cura knock-offs. I much prefer Cura as developed by the Cura team at Ultimaker (although I have the SmartAvionics branch as well). The one thing all those slicers have in common is they were free. The Creality slicer is an old version of Cura. Within the newer versions of Cura there is a drop down menu next to the "Search Settings" box and one of the setting visibility options is "All". Something like 300 different printer definition files are included with Cura. I don't think that Supports are mentioned in any of the Creality definition files (as opposed to Max speed, Jerk, Accel, etc.). The Creality definition files were written by "Trouch.com" and submitted to Ultimaker for inclusion in Cura. Trouch got some things wrong (like totally overstating the resolution that the printers are capable of). In regards to the Supports - as @gr5 says, you need to experiment and look closely at the preview. One of the nice things about Cura is the huge number of options. That huge number also makes for a steep learning curve. I'm not criticizing you because how would you know, but if you had posted the model and what you were trying to do, there are people here who are quite good at coming up with a plan. Right now looking at your print, I'd say that a little pair of nippers (like the ones that Creality supplies with their printers) would be a good place to start. I'd start by nibbling away at the mid portion of the cab supports but you are right - it ain't gonna be easy and it's gonna take a while. Whenever I visit my dentist I bother him about tools with a broken end. Dental picks are good at support removal. I've even used the little mirror. There is a setting in Cura that I could almost term idiotic..."Make Overhang Printable". Somebody must have asked for it or it wouldn't be there. The tooltip should be "Do Not Touch".

@curasurf, @fvrmr is looking at it on Github. That particular file shows the movement of the mesh modifier on any printer. When I put together a similar project file (2 models and a mesh modifier on the bed) I can't duplicate the movement. So at this point the problem appears to be just with that specific file. Could you go HERE and post what operating system and version of Cura are you using? Thanks.

I'm a self-taught Visual Basic coder. Unfortunately for me, knowing VB in the Cura world is like knowing Latin. It's not real helpful. Moving from my very dated knowledge of "Visual Basic for Applications" to "VB.Net" and Visual Studio was enough of a problem. I have created a modest little Windows app (Greg's Toolbox) that among other things will switch between, and control, up to 10 printers. Reviewing some post-processing plugins (PauseAtHeight.py and SearchAndReplace.py in particular) helped me to understand a bit about how they work to find something in the gcode stream, and then to insert new code. It gave me just enough of an understanding of Python for me to customize them to suit my needs. For myself and what I do, writing post-processors in VB.Net didn't require any knowledge of Python or Cura as I just deal with gcode files after they are generated. Splicing two files together and creating the transition code, altering retraction distance in a file, removing Z-hops, changing a file created for 2.85mm filament to 1.75mm filament (or vice versa) are some of the utilities in the app. Not stuff that would be terribly useful to anyone else, but I've been stuck in the house a lot.

Done.

When it's part of a group it's OK. When it's a separate mesh it jumps by exactly -25 in the Y every time it's saved and re-opened. Save and open it 4 times and it's moved -100mm. Good luck Nallath!

All that time typing and all I had to say was thank you.

Thank you sir. Occasionally I've thought it would be nice to be able to collapse the bar to the right (to give the model area more screen space). I'll settle for drag and park off-screen for now. It's my bad that I never thought to mention it.

Something to play with in the morning... Printed with 4.8 and horizontal expansion at .02 on the left. Arachne with line width at .35 on the right. .4 nozzle at .2 layer height. Ender 3 Pro. Measuring thickness - the Arachne print is .65 and the 4.8 print is .91. It's hard to measure due to the bulbs on the ends of the lines. The Arachne print has a line missing about 2/3 up and isn't as neat. That could be the printer's fault as there isn't much material flow in that part. The 4.8 print with more material in it and does look better. Minimum layer speed 5mm/sec. Using "Lift Head" made a mess. PS: @gr5, @ahoeben, Horizontal Expansion of .02 makes the wall .44 thick. Scaling 102% makes it .408 thick. Line width changes and Print Thin Walls didn't have any effect. It's a fussy little bugger.

Surface makes it thicker (0.8?). I haven't been happy with any setting combinations. Scaling it to 102% worked. Remember to set the bottom back on the build plate.

The model is good. I suppose you have a reason for not printing them lying down. @gr5 - take a look here. I get the same results as Curasurf and am unable to get the tree supports to support the slot roofs on the other side of the model.

I wonder if there is a problem with the model and Cura thinks the tree supports should be from that side when in fact they are growing through a wall? If it isn't a proprietary part - post the STL.

That is a very odd result. The tree should grow from the build plate and not the part.

In "Special Modes" you have "One at a time" selected. Change that to "All at Once". If you use One at a Time, Cura checks the height of the model and if it is taller than the "gantry" height it won't slice it. Cura figures that the X beam will crash into a part. The blue rectangle about 25mm above the build plate is the clue.

You can ty it with tree supports to see how it looks. Without support that roof won't print correctly.

It happens sometimes with Blender and with Sketchup. Inventor and Fusion don't seem to have the issue. I don't know Blender, but it's possible there are options for the STL Export Utility.

In Blender, double check the scale you are modeling at. It might be 1 meter instead of 1mm. If you see just a shadow then the model is WAAAYYY up in the Z. Right click on the build plate and select "Select all Models". Select the "Movement" tool at the top of the left toolbar and change all the dimensions to "0". The model should drop to the plate and be centered.