Join Tanya Staples for an in-depth discussion in this video Measuring the part, part of 3D Printing & Modeling Household Parts.
- So the first stage of our project is, we need to take our part and translate it into a 3D model, so that we can take that 3D model and send it to the printer. So, there's a couple ways, Greg, that we could do this. We could 3D scan it, take some photos and translate that into a 3D drawing. Or we could model it directly in something like SketchUp. Tell us about each, and what's best for a part like this. - 3D scanning is great for organic objects, say, like this couch. You can take pictures and then create this really neat model.
But it won't be accurate with its dimensions. And it might take a lot more time to create an accurate dimensional model from a 3D scan. For this towel holder, you need very accurate dimensions to make sure your towel holder doesn't fall off the wall. - Right. So, so speaking of that, I mean, we've gotta really focus on the functionality of this little part as we think about how to measure it and model it, right? - So when you look at a part - Right. like this, what do you think about, in terms of how you model it? - Well, the first thing that I'll start thinking about is why it has what it has.
So it's actually got a couple different holes, and then it's got a tapered edge, and it has a couple support struts around here. With the actual holes here, when you put it into the actual part, you can see how the center hole lines up with the center screw of the towel holder. That's probably for space for that actual screw to fit in. So we'll wanna keep that hole and center punch that out. This, ultimately, goes against the wall, so it needs to be mounted to the wall in some way.
So these two holes on the outside, most likely, are for screws to fit through. So we can set up in our model two holes on the outside of this center hole in order to screw this plate to the wall. This third area that I look at is the taper. And we see here that there's an actual set screw on the bottom of the towel holder, which, when it's screwed in, will actually latch onto the plate and keep it from spinning or falling off the wall. - Okay. So how do we approach measuring something like this? Do we use a ruler? You got some other tools here.
How do you measure, and what are the important things to measure in this case? - Measurements are really important. When I get into the 3D modeling, I need to see the measurements from the top, from the side, to accurately get all the extrusions and the size of the holes and the size of the overall product. With using different measuring devices, we can get all the measurements that we have here. The easiest way to do this is with a set of calipers.
It has three different ways to be able to measure. We can measure the exterior of a part by using this side of the caliper. We can measure the interior, say, of a part by using the back side of the calipers. And then it also has the ability, on the bottom here, this little spike that comes out, you'll see how it moves up and down as I open the calipers. I can actually measure the depth of this inside wall, so I can tell how much to extrude from the bottom up to where this actual plate is at.
I can find out that measurement. I'll then jot them down in an actual drawing. It'd be really simple, but it helps me translate all of these measurements into the final 3D model. The outside dimensions, the height and width of the product, as well as where different holes are set. - And so, if I didn't have a caliper and I was using a ruler, what would I need to think about? - I think the biggest thing to think about is that you wanna be sure that the overall size of your plate or product that you're modeling is dimensioned.
So if you're dealing with round objects, you may wanna lay it down on graph paper, trace it out, and find the very top and very bottom of that circle, so that you get the overall dimension. - Got it. Now, there's a few little parts of this that I've questions about, like, these four little circles and this little lip. Are those things that we need to put in our final part? - On this part, I don't think you need to. What they did here was, this was an aluminum cast, an injection mold.
And so what they did was, created a bottom mold and a top mold and then injected the aluminum into the mold. These support struts help for structural integrity of the side walls. These little holes along the side are just from the vent holes that they actually poured the liquid into, and they just broke them off at the end. And then this little lip on the bottom, I think, might have just been to the idea of making sure that the product didn't spin. But because we're doing two screw holes on the side of this main hole in the center, I think we'll be just fine to have a flat bottom.
- Okay. So it looks like we've got all of our measurements. Now we need to go right into SketchUp and model this? - Yep. - All right.