Is there a more appropriate place to be asking this?
I can’t figure it out. I’ve created a bin to fit into a corner of a drawer. The drawer has side walls that are angled 18 degrees outward.
I have a cube and cut the corner walls exactly 18 degrees. I created a rounded corner “hole” and have it angled exactly 18 degree. But if you see this photo you will notice it doesn’t line up?
I’ve tried this multiple times. There must be something I don’t realize about how to go about this.
I may have missed what you are aiming for, if you are hoping the cylinder leans into that corner…
It only looks like it is leaning left, did you also tell it to lean backwards?
Thanks Malc. The cylinder to round the corner is leaning 18 degrees into that corner in the same way as the block. Here’s some photos to show it’s 18 degrees in both the X and Y axis. But it isn’t lining up the same way for some reason.
Actually, I’m not sure if I exported this correctly, but here are the two pieces. It might be simpler to see it on your end.
hole.3mf (1.1 MB)
block.3mf (1.1 MB)
UNBELIEVABLE!! Man, how did I do that so many times in a row! I was trying to learn the protractor method in Tinkercad but gave up and instead took the screengrabs where I didn’t notice the 18 vs 15.6.
15.6 was the original angle from the design I was copying. I was afraid there was some other step I wasn’t aware of, but in the end I’m just not that experienced and made a stupid mistake!
Thanks so much for finding that for me. You probably saved me hours of troubleshooting.
If you’re jamming that cylinder in to the corner to give the corner a rounded edge, there are better ways to accomplish that by actually rounding the edge… I don’t use TinkerCAD so I don’t know the specific commands to use, but TinkerCAD is enough of a CAD program is must have that capability and it’s probably just a Google search away.
If on the other hand the rounded cylinder is supposed to stick out of the top, there is no requirement that it extend all the way to the bottom. A much shorter version of the cylinder, inserted just a fraction of a mm in to the top of the box, will produce the exact same print as one where the cylinder goes all the way down to the bottom of the model. The interior overlapped regions are ignored by the slicer.
Ugh.. I’m still having issues.
First off, RocketSled, I’m new to Tinkercad, and it appears I can only apply rounded edges to whole objects (in this case I only want one edge). But I guess I could make a copy and cut the section I want.
I think I know what you mean about using a much shorter version - but to clarify my next step is to make this block a bin, so I would want it to extend all the way down.
I may start from scratch and try the rounded edge version of the block (and cut that edge onto a non-rounded corner block). But after correcting the angle that u/blchandl2 pointed out, I’m still stumped with an issue. These “SHOULD” be all exactly 18 degrees, but it’s still not overlaying?!? Here’s screenshots with the ruler showing both options are at the ruler point. Also a shot showing the alignment. And just showing how it looks. 
I’m going to attach the objects again in case someone wants to take a look. Thanks!
Glorious Allis.3mf (24.4 KB)
Glorious AllisAA.3mf (27.1 KB)
(regarding how I’m still having issues)
It appears like by rotating it 18 degrees in one direction, and then 18 degress in another direction, it creates an addition rotation somehow?
I thought this could be due to the pivot points for these rotations somehow causing an issue?
Also, I don’t perform both rotations at once (I’m not sure how to do that if it’s even possible), so I have to do them independently one after the other. Is there some unwanted effect from it being compounded?
I was curious, so I searched “TinkerCAD fillet”:
Methods to Create Fillets in Tinkercad:
MetaFillet Tool: Search for “MetaFillet” in the Shape Generators panel for a customizable, pre-made fillet shape
Manual Subtraction: Use a cylindrical hole and a box hole to create a rounded corner shape, then align and group it with your model.
Fusion 360 Export: For complex, precise fillets, use the “Send to Fusion” feature to transfer your design to Fusion 360, which has built-in filleting tools.
Using Basic Shapes: For cylindrical objects, you can use a cone or torus from the basic shapes to create a rounded, chamfered edge.
So creating a “hole” is actually a correct method, but I would recommend the third choice: use a more capable program.
In Fusion, you would select specific edge(s) and/or face(s), press “F”, then specify a radius, or simply drag until the fillet looks right. It even works on curves. Much fewer steps than making a hole and a box and then fiddling around to adjust sizes and angles. If you change your mind later, you can edit the feature to change sizes, add/subtract edges, etc.
Fusion looks more complex, but is easier to use once you learn the basics.
Huh. I guess TinkerCAD is less of a CAD program than I thought. 
This took about 2 minutes to model in my CAD software. Which isn’t even actually CAD software, it’s CGI software. Admittedly, I’ve been using it for decades and know all the tricks. But all I used was a box primitive, which I hollowed out using CSG Subtract. Then I selected the edges I wanted rounded and picked the “Rounder” function from the menu and bam! done. 
If TinkerCAD makes it harder than that, then a different program is probably in order…
I used up my free trial with Sketchup with no idea how to do anything before then switching to Tinkercad. This was only a month ago and can say I’m finally figuring it out. I’m definitely ready to move up to a better program. Except I can’t afford an expensive subscription at this time. I downloaded FreeCAD awhile ago and assume that’s free. Does anyone have any suggestions (bonus if it’s free! I’m not doing anything crazy, but want these obvious tools which are useful)
And did anyone figure out what the heck I’m doing wrong!?
Is this what you want? I think you are rotating the fillet in X & Y which is causing the problem. I only rotated the fillet in one axis.
This is done in TinkerCad in about 5 minutes.
And in most other CAD systems in a single click. Tinkercad has its place but not when filets are involved.
Fusion has a free version for personal use. There are a few limitations, but most of the missing capabilities are not needed for 3D printing. It is also an Autodesk product, so I think a TinkerCAD user/password can be used.
Onshape can be free, if you don’t mind that your models are available to the public. (That is what led me to choose Fusion, but I don’t think anyone would be interested in my models anyway.) Because it works in a browser, my grandson can use it on his iPad. I’ve helped him with some of his projects and have been impressed with Onshape.
It has been a few years since I was looking for a free CAD program, but I remember FreeCAD was very confusing to use. The interface was quite inconsistent, so you had to remember different selection methods for different operations; some operations could be reversed, some could not. Changing a dimension could require going back several steps, deleting features, and starting over. I’ve read that there have been improvements since then, but I only remember wasting a day building a simple model in FreeCAD, with lots of Googling and YouTubing, before realizing I would have to start over. I downloaded Fusion and was done in an hour, because it just made more sense to my brain. YRMV.
Fusion, 1 minute, 11secs, to add two interior fillets, two exterior fillets, and a complete top edge fillet. Would have been much quicker with keyboard commands instead of mousing into menus, but I was trying to make a GIF that turned out too large to upload.
The base model took less than a minute. A parallelogram sketch on the XZ plane, a rectangle sketch on XY, and a sweep of the first sketch around the rectangle.
You could also try shapr3D; I think it’s pretty intuitive.
Yeah, but how?!
So, now that people keep using the word Filet I’m realizing that was it this piece is (and not some fish). Appreciate all the responses, and I will definitely take up the recommendation to move over to Fusion (knowing there’s a free version). Absolutely impressive it only took blchandl2 5 minutes to do that in TinkerCad (or Ikraus it in 1:11 in Fusion). It’s a little frustrating though since I’ve been attempting to do it for 48 hours now and still no one has explained how to me.
blchandl2 did mention it was my rotating it in X & Y which is the problem, and that’s what I suspected and tried to explain. But come on then. How does one rotate an object in only one axis which causes it to move in what would otherwise take X & Y?
So… Will someone please tell me how to actually do it or do I just waste another 12 hours?
In case I’m not being clear. It appears I’m trying to create a filet against a block, except the corner of the block itself is cut 18 degrees in the X axis AND 18 degrees in the Y axis.
This is a bin I want to sit in the corner of a drawer, and the drawer’s sides all lean in 18 degrees. So this filet needs to be leaning in two directions 18 degrees in both.
How?
Yes, I’ve been trying for the past hour since last posting. Others have proven they can do it in as little as 5 minutes. No one has actually told me how. Forgive me, that’s a little frustrating.
I found one way to tilt the fillet in two axes, but I hope a real “tinkercadder” knows a more efficient way.
I did not take the time to make a box with tilted walls, so you are ahead of me there.
On the right, next to “Basic shapes”, use the magnifying glass to search for MetaFillet.
Drag the fillet into the model, select hole or solid, adjust height and radius.
Depending on the viewing angle, you should see one or two curved, two-headed arrows above the fillet.
Click an arrow, and then click the angle number above that.
Type and enter the exact desired angle.
If you only see one arrow, rotate the model with a right-click-drag to see the other.
That is as far as I went, and I’ll be stopping there. Playing with fillet movements, I discovered that the angle values are always measured from the current position, not the orthogonal workplanes. So if I were to tilt or rotate a shape by dragging, and dropped it at 15.7°, I have no (apparent) way to know that a 2.3° adjustment was needed. There are probably commands to make two shapes snap to each other, or to redefine the workplane, but I don’t want to invest the time in learning them.
