Please help on drawing some very simple rectangles and circles

sketchup
advice

#1

I’ve spent a day pulling my hair out on trying to use Sketchup, and I still can’t figure some extremely simple things out, and after 7 hours I can’t do this anymore.

I’m trying to draw a simple rectangular speaker box with some circular holes. Here are the things that I want to do but I can’t no matter how much I Google.

  1. I’m trying to cut a hole in the front and back side for every circle I’ve drawn, but push/pull just will not cut a hole.

  2. I’m trying to draw a circle with the top and bottom truncated. Basically I want to turn a circle and truncate it to look like this

However I can’t draw a straight line from a point on the circle to the other point on the circle. It would snap to a different point that makes it a slanted line, but not straight line. I want to do this for the outer circles in the “tweeter” and “midrange” group.

  1. How do I find the center of a circle?

  2. How do I move the center of a circle to exactly say 1 cm to the right and 2 cm to the bottom of the top left corner of a rectangle? I need to draw a to scale model, and I need high accuracy. For example, the two circles on the front and back needs to be in the exact same spot so they’re perfectly back to back.

I’d really appreciate any help for this. I’ve uploaded what I have so far.

Speaker.skp (56.5 KB)


#2

Your model consists of a number of groups. To use a circle to push a hole in something else it needs to be part of “something else”'s geometry, ie, draw the circle inside the group.

To get the centre of a circle you just hover over the edge until the centrepoint is recognised. It can take a bit of trial and error.

What you want to do is actually quite simple if you are familiar with how SU works. I recommend you take some online tutorials such as those on Youtube.


#3

Going through some relevant videos is a must.
You may want to start here: https://www.youtube.com/user/SketchUpVideo

Your model shows grouped geometry. You can only modify chunks of geometry when being in the same level, inside their group environment.
To enter a group for editing, double click on it to open it.
To close it again (to edit other geometry), click outside the group.
Explore what is offered in the ‘right click’ context menu. it is context sensitive. Each click may show a different set of options depending on what you ‘right clicked’. Find center is one of them for clicking a circle, (since SU16)


#4

Save yourself untold hours of frustration.
Invest a modest amount of time in learning and practice.

SketchUp Video Tutorials by Trimble


SketchUp Skill Builder Tutorials by Trimble


SketchUp for Dummies Videos by Aidan Chopra


#5

I did watch 10+ YouTube tutorials for Sketchup. Without it there is no way I could have done anything when nothing in Sketchup is intuitive, not even move that sticks to random things. I had to watch a tutorial or Google something to do every single little thing because Sketchup is so unintuitive. I wouldn’t know about making precise dimension shapes or making groups or push/pull.

Please, could you just show me how to do these extremely simple things. This is supposed to take one to two hours max. I ended up spending 7+ hours to do the same 2D stuff that took 30 minutes on CorelDraw, both softwares I’ve never used before, or any other similar software. Difference is, I only had to just Google a few things for CorelDraw, but I’ve watched 1.5 hours of tutorials on Sketchup just for the absolute basics that should have never required a tutorial. I haven’t even started on the 3D parts that I can’t do in CorelDraw.

@simoncbevans, what do you mean by “draw the circle inside the group”?

I apologize for my little rant, I’ve just never used a piece of software so unintuitive, frustrating to use and so inflexible that I can’t change the dimensions of a shape by an exact amount after I created it, or something that can’t even draw a perfect circle.


#6

I’m not too sure you should be using SU if you are so unhappy with it. All I can say is that I have used a number of CAD systems over the years and SU is way ahead of them in intuitiveness. It does have some quirks and some annoyances but overall I think it is excellent, especially as there is even a free version.

If you click on one of your circles, you will see that a blue box appears around it signifying that it has been grouped. In short, the lines that make up the edge of the circle and the surface created inside them have been joined together into a single unit. If you right click on it, you have the option to explode it, which will turn it back into raw geometry. If the circle is then placed on a surface that is also raw geometry, you will find the push-pull will work.

If you are going to spend any time on this forum, there are a couple of things you should know. People don’t much like being asked simply to do someone else’s work for them (though there are many kindly souls here who will!). Also, you have to be very careful criticising SU, even in a positive way, as for some it is like telling them their daughter is ugly!

Good luck. It is worth persevering.


#7

Ahhh. Exploding it worked! Thank you! But I seem to lose the original circle as a group, so it seems like if I want to move the circle later, I have to make a new one?

Yes and that’s why I sucked it up and kept pushing through with Sketchup because many people say Sketchup is one of the easiest ones (gulp). I asked because I know people here can do what I did for 7 hours in 5 minutes. I look at some of the photo realistic models and just wonder how in the world can someone do that when I’m having trouble drawing some simple shapes.


#8

“Intuitive” varies widely from one individual to another, depending on their experience and also their basic cognitive processes. Whereas a 2D drawing program such as Corel Draw is essentially patterned after drawing with pencils on paper (which essentially everyone has done at some point), a 3D modeling program is quite different. Unless you have used one before, you have no experience from which to draw intuition and therefore, yes, there can be a steep learning curve. Many people who have tried several 3D modeling programs agree that SketchUp is easier to learn and use than most of the competition.

Possibly the most important thing about SketchUp that you should study while starting out is its “inference engine”. This is the “snap” system that it uses to infer where in 3D space the cursor on your 2D screen is trying to indicate. There is not just left-right and up-down to deal with, but also near-far, which requires additional info to make it unambiguous. The SU inference engine flags existing items in your model that can provide that extra info and offers to snap new items to them.

So, to answer one of your questions, at least on up-to-date versions of SU (your profile just says Pro, not what year) if you hover the cursor over a point on a circle the inference engine will find and indicate the center of the circle. If you then move the cursor near that location, it will provide a snap to the center.

To answer one of the questions in your original post, the push-pull tool “extrudes” a flat face perpendicular to its surface. It will not cut a hole in a circle. To do that, you draw a second circle and erase the face inside it.

Groups and Components isolate geometry into their own contexts so that it can’t interact with anything outside the Group/Component. Otherwise SketchUp always assumes you are extending what you have drawn and causes new geometry to “stick to” the rest. Components also add the benefit of enabling multiple copies (“instances”) that are magically tied back to the original “mold” so that editing one propagates the same changes to all the other instances.

Yes, exploding a Group releases its geometry back into the wild where it can interact with other geometry. That doesn’t mean you can’t subsequently move it (use the move tool) or copy it (use the move tool and press ctrl to move a copy), but exploding kills the isolation provided by the Group so any interaction with other geometry becomes permanent. But circles are so easy to draw, why not just do another one at the new location?


#9

Glad to have been of service!

It’s difficult to answer your question without knowing what you are trying to achieve. If you don’t want to lose the original grouped circle, you could make a copy (Ctrl-C followed by Ctrl-V), then you will have two grouped circles in exactly the same place. You can then explode one of them to use for the push-pull exercise leaving the original exactly where it was. It will help if you hide the grouped circle while you do the extruding and then unhide it after.

And finally… A lot of the photo realistic models (if that’s what you really mean) will have been post-processed. SU’s native tools for that are good but basic. A learning curve is hyperbolic, steep at the start but levelling off with time. Keep on truckin’…