Can't slice model - used Push/Pull tool's "new starting faces" option

Hi all,

I am at a loss here and kindly ask for help: I designed an ice scraper with SketchUp by drawing the outline and then pushing it to a width of 99mm. I then added curved lines on the surface using the push/pull tool’s “new starting faces” (Option key on MacOS) feature to create kind of handles to get a better grip.

When I export this model to STL and try to slice with either Cura or Slic3r everything looks garbled. I have holes and a plethora of missing layers (in layer view).

Using I could get a fixed STL that slices nicely. But I would very much prefer to design models in SketchUp that correctly slice in Cura.

The *.skp might help: It can be downloaded here

What is wrong with my model? What is missing?

Your help is kindly appreciated!
Many thanks in advance

A picture is worth a thousand words, they say.

Unfortunately there’s so much wrong, Solid Inspector3 can’t fix all of it automatically.

Yeah it is a bit of an issue, mainly it’s all the internal faces not really intersecting properly.
If you select it all and intersect the faces the Solid Inspector will fix it.
Plus a little bit of Fixit101 and all is good.


Eiskratzergriff14.skp (328.2 KB)

I redrew it from a copy of the end and made a solid component of it. Your model has a bunch of coplanar edges near the scraper edge that wouldn’t be useful in a 3D printed shape. Perhaps you want some additional detail there?

I think when you get to printing this, you should make sure Box gets one. I bet he doesn’t have an ice scraper in his car. :smiley:

Hej Box!
Ok, wow, awesome! I could reproduce the fixing process and … it worked!
(Tried before with “CleanUp3” but to no avail. A fool with a tool is still a fool.)
Many, many thanks for your help!
Best wishes

Hej Dave,

you are absolutely right about the coplanar edges! These will make up the holder for a copper inlay. There is nothing better than copper for scraping ice (at least on windscreens:-). My old copper scraper broke so I have to build a new holder for the copper piece.

Now I know how to fix the wrong model. But I do not know what went wrong during construction. Since you redrew it you might point me in the right direction: My model is fine (=slicable) until I add the bars. I used the push/pull tool with “new starting faces” to the get lines along the shape. This seems to mess up the model. How did you do it?

Many, many thanks for your help!

Best wishes

Axel, I think what went wrong was the Push/Pull with creating new faces. I avoided most of those internal faces and the reversed faces by using a different process to create the shape. I’ll try to outline the method.

First, I copied the end face from your model.

I used Offset to create the outer rim of the ribs.

I copied that offset edge along with the edge from the end shape into position for the first rib. Then I deleted the offset edge. You could move the offset edge over and then copy the edge from the shape. Fewer clicks the way I did it and less chance for error. then I drew line segmets to connect the curves and create a face.

I used Push/Pull to make the rib 5 mm wide and then use Move/Copy to make a linear array of ribs.

Next I used Push/Pull on the large end face and extruded it to 99mm.

There are a few internal faces–the inside surfaces of the ribs shown in white and selected–but those are easily removed. I hid the bottom surface (don’t fat finger it and hit Erase in the context menu), selected the internal faces and hit Delete.

Then Unhide>Last, select all of it and make it a component. Check to see that it reports as solid in Entity Info.


Hi Dave,

thanks a lot for taking the time to outline your method! :slight_smile: I just followed your step-by-step instructions and -voíla- everything shiny! :-)))

Thanks again and merry christmas!

PS 3D print already started. As soon as the ice scraper is ready I will post a picture.

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Hi guys,

to correct a mistake: The metal part of my old, broken scraper is brass, not copper. However, the ice scraper was finished in due time since temperatures started to drop below zero here in Germany.

Here is the readily assembled scraper. Thanks again for your help!

SKP/STL files available on Thingiverse Heavy Duty Ice Scraper. I also added a version without brass mount. Pretty unlikely that someone has a brass plate like the one from my old, broken scraper. :wink:


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Thanks! This was only possible with the help from Dave and Box! Great community! :slight_smile: