Join Gabriel Corbett for an in-depth discussion in this video Problem 2 Review, part of Cert Prep: Certified SOLIDWORKS Associate.
In this movie, we're going to be reviewing sample exam number two, question number four. You can see here I've got three different sheet metal brackets-- actually, three sheet metal brackets, they're exactly the same, and two pins which are the same. So we're going to go ahead and start building those parts. Notice the bracket is made out of aluminum and the pin is made out of titanium. Alright, jump over here to the assembly. You can see this is what it's going to look like when it's done. And let's go ahead and open up one of these brackets, and go through how we created that part. So down at the bottom here, you can see I have millimeter, grams, seconds selected.
My material is 6061-T6, and notice on the sample exam, they only specified 6061, they did not specify the temper. So if you right click and take a look at "edit materials," you can see here there's a lot of different types of material. And there's actually 6061 alloy by itself. There's a T-0, a T-4, and T-6. So you can choose pretty much any one of these. They all are going to weigh exactly the same. Now, you could have created this part as a sheet metal part if you wanted to, but I chose to just create it as a basic extrude.
So back to sketch number one, let's take a look at that. So 30 by 30, two millimeters thick, with an outside radius of three millimeters. And I'm going to do a Boss Extrude here of 20 millimeters. And then do my first cut. The circle here, 10 millimeters, 10 out from this face here, and 10 out from that face there. Pretty straight-forward, just cut through. Same thing with the secondary cut. There they are. And then finally this little notch in the side.
So pretty straight-forward part there. And go ahead and save that part and take a look at the pin now. So here's my pin. I chose commercially pure titanium on this one. Again, there's a bunch of titaniums and none of them happen to be exactly just pure titanium. So this is what I chose and a basic circle extruded out 5 millimeters. To build the assembly, let's go back here. Get my parts. I'm doing basically coincident mates on the front face here to this face here.
As well as concentric mates on the pins and just making sure we've got a one millimeter gap in the center here. So as long as this face here and this face here are both coincident, that should end up the right way. Now I did want to point out here, these angles on the drawing are specifying these at 45 degrees from this face here to this face here is 45 degrees. However, when you go to create these inside a SolidWorks, it does not allow you to put in a 45 degree there, it's actually asking you to put in a different value of 135 degrees, and that's what you're going to have to accommodate.
So, first things first, take a look at this here. To get them to be in that right orientation, notice my angle's 135 because it's thinking it's 180 degrees minus the 45, which gives you the 135. So you might need to specify your angles slightly different inside of SolidWorks than you actually see on the drawing. But in the end of the day, it still is 45 degrees from here to there, as shown in the drawing. Same thing with this other angle here. We're having to specify it differently inside of SolidWorks than it's done on the drawing, but that's okay. We can get the final angle being exactly the same.
So again, 135 for those. Now, when I go to find the center of mass of this item, notice if I click on "Center of Mass," here are the values. And that's relative to generally your coordinate system. But take a look at where my coordinate system is. If you look at the origin here, it's right here in this back corner. And that's really not the right location, is it? If you go back and take a look at the drawing, you can see that the very front corner here, with the X, Y, and Z, so you have an X positive going into the page.
You have a Z positive going to the right, and a Y positive going up. So we want to make sure we've got a coordinate system in exactly that same location with those same orientations and directions. So let's jump back over to part. And let's take a look at this little triad down here. So the X positive is going to the right, the Y positive is going up, and the Z positive is coming out. So that's looking pretty good. So what I want to do is I want to create a new coordinate system. So here it is. And I'm going to edit that.
I chose that front corner right there. You can see I've got Y going up, I've got X going into the page, and I've got Z going over here to the right. Again, let's verify that those are the right values. So Z going to the right, Z going this way, X going into the page, and Y going up. So that's exactly what we want to duplicate in our corner system. And these do match. Click okay. And now I have that new corner system with everything going their right directions. Then go over here to Mass Properties. And make sure I report the coordinate values relative to, not the default, but this new coordinate system that I just created.
So coordinate system number one. And notice that will give you massively different values here. So center of mass here, if you go back to the default, those are going to change. So make sure that we've got the right coordinate system here and we're getting the right values based upon those. Now, take a look. When I go to my center of mass, I've got 40.234. And notice I have a three-place decimal. That's incorrect as well. So go up to Options and make sure I use only a two-place decimal for my values. So now I have 40.23.
Let's take a look at the answers and verify. 40.24 is one of the answers, but I have 40.23. So something might not be totally correct. So let's go ahead and verify some of the materials. Notice I specify titanium with a density of .0046. Now, let's go back to our part. Let's go ahead and open up this pin, and find the mass properties there. Now, notice here it says 0045.
I'm supposed to be choosing material that has a 0046, so there is my error right there. So let's go ahead and choose a material that has the right values. So you notice we have a lot of different titanium alloys here. And as I flip through these different alloys, they all have different values. So I want to make sure that I choose a value that is as close as possible to what they're specifying. I'm going to go ahead and choose this one and close. And that should give us a little bit closer value. Now we're at 27.
So, again, we haven't found the exact value but we're close enough because we need to be within one percent to get to the right values. But if you look back at the part, itself, on question number four... So these values are the only ones that are even close. So let's go ahead and choose "C" for the answer to question number four. Now in preparation for the exam, I would definitely recommend going and creating each one of these parts, and building this assembly. And then making sure you have the correct coordinate system established. And then find the center of mass of the assembly, and verify you're getting the same values, or very similar values, to what I have.
Along the way, he'll cover creating effective sketches, using equations to modify parts, weighing parts, building assemblies, assigning the correct materials and units, and creating drawing views. At the end of the course, there are two sample exams to practice what you've learned.
- CSWA requirements review
- Working with sketch entities (Line, Circle, Rectangle, and Arc)
- Making offset, convert, and construction lines
- Reviewing the boss and cut features
- Sweeps and lofts
- Smoothing corners with Fillet and Chamfer
- Creating linear and circular patterns
- Dimensioning techniques
- Setting mass properties
- Selecting and using materials
- Inserting components
- Setting up reference geometry
- Establishing standard drawing views
- Annotating your drawings