Join Chris Reilly for an in-depth discussion in this video Modeling the wooden base, part of Rhino for Mac Essential Training.
- [Presenter] Now that we've finished modeling and importing all of our metal parts, we can focus on the wooden parts. These are the pieces of the musical instrument that will be the most detailed, and that will require the most custom fabrication. First, let's do a little bit of layer management here. I'm just gonna go ahead and shift-select these two blank layers, those just came stock in the layers panel. We don't need those for now. And since we're making wooden parts here, I'll be working under this wooden parts layer, and I'd like to make a new sublayer, so I'll just right-click on wooden parts, and say create new sublayer.
And this one will be called 'base.' So remember, we have two main wooden parts to the instrument, we have a larger base, and we have a smaller top, so in this video we'll be working on the base. And I'll set the current layer, that base sublayer I just created, and I'll go ahead and hide that hardware layer. We don't need that for now. So working from the top view port, I'll just go ahead and sketch out a rectangle, that will start to flesh out the shape of our base. And if you remember from the previous video, when we plan for how much wood material we would need, we used the same rectangle.
So, from Curve, I'll select rectangle, corner to corner. And I've got my grid snap on. I'll start an origin. And I want this to be seven and three quarter inches long, so 7.75, I'm just typing that into the command line. And then, an inch and a half wide, 1.5 for the width. Okay, so this is kind of the overall footprint of the base of our musical instrument, and we'll use this to build up the three-dimensional version, and to build up the cut profile that we'll send to our fabricator.
Now let's go ahead and make some holes. So I'd like a series of three holes, centered along the horizontal center of the instrument, and these are each gonna be 11/64ths inches in diameter. And the place that I'm pulling that number from, is actually my industrial supplier. If you remember in the previous video, we imported all that hardware, one piece of which was the T nut, and that slides into the base of the instrument that we're building right now, and it needs a hole that's 11/64ths inches in diameter.
So before I get started here, I'll make sure that my center object snap is active. And from the Curve menu, I'll make a circle, with a center and radius. So for the center of my circle, I want to snap to the center of the rectangle I just created. So that's gonna center it, both vertically and horizontally. And again, I want the diameter to be 11/64ths inches, so in the command prompt here, I'm gonna switch to diameter, and just type in 11 over 64, and hit enter.
Okay, so that's one circle. So the other two circles, I want one right about over here, and one right about over here. Each are gonna be 1 5/8 inches from that center point. So I can take that first central circle, and use the Copy command, to move that over an inch and 5/8ths, and another one an inch and 5/8ths to the left. So if we transform, I'll go to Copy, and I'll copy from that center point, and I want to copy to an inch and 5/8ths over this way, so, in the command prompt, I can just type in, one dash five over eight.
That's gonna give me an inch and 5/8ths distance. And then I can also use ortho, to constrain it horizontally. I can also just use grid snap, you can see I'm snapping right there, but if I had grid snap off, I can just hit shift, or click ortho, on the constraints, and that's gonna constrain it to either, perfectly horizontal or perfectly vertical. Okay, so I've set my first circle over to the right there, and I'd like to set another one, over to the left. Copy has this nice little feature here, I could say, use last distance.
I'm gonna select that. That's gonna set my distance again to an inch and 5/8ths, and this time I'll be clicking off to the left. And because I have ortho selected, it's constrained to either horizontal or vertical. Okay, and I'm done. So these three circles represent my through holes, and this is what's gonna allow the machine screws and the T nuts to sandwich together all of the parts of the instrument. Now I'd like to take a look at the ends of this base profile here. I don't want these to be perfectly square. I'd like to round those over.
That's gonna make it a little bit more aesthetically pleasing. It's gonna make it a little bit easier to play. So we can do that really easily with the fillet command, and I'll just type that into the command line. We'll do fillet, and for the radius, I'd like to set it to half of the width of my base piece here. If you remember, the width is an inch and a half, so I want my radius to be half of that, which is 0.75, or three quarters of an inch. I'd like to join and trim the lines that I'm filleting.
So then I'll just go through each corner, and click on one curve, and the other curve, and I get that nice round over, hit space bar, to activate that command again. We click on one curve, and then the next. I'll do this one, and then finally, that last set, and then I'm just gonna hit space bar, to bring up that fillet command again. Okay, now I'd like to draw some lines, and these are gonna represent the tracks, that my frets will sit inside of, so they'll kind of snap into these little hibbets.
They won't go all the way through the base of the instrument. They'll just be kind of like a shallow groove that are gonna allow the parts to line up with each other. So to make those, I need to draw two lines, one, right about here, and the other, right about here, so they'll be spaced about three quarters of an inch apart from each other, and centered horizontally, along the base of the instrument. And there's a few different ways I could draw this, so I'll show you a couple here. One's a little bit more complex, but quite automatic. The other is a little bit more manual, where we just need to kind of think through the steps that we're doing.
So the first technique I'll use relies a lot on snapping. So I'm gonna look at my object snaps here. And I'd like to turn on quad snapping. And I don't need center for now, so I'll turn that off. Okay, I'll go ahead and activate the line command. I'm just drawing a horizontal line from one end to the other here. Okay, and Rhino's prompting me to pick the start of the line, so to pick that point, I'm gonna use a one shot object snap, along with my persistent quad snap.
So click on one shot, and I'm looking for this option called 'tangent from.' Okay, so Rhino's asking us to select a curve for tangent tracking. So, basically what I'm looking at here is, I'd like to use the end profile of the base here. I want to grab a line that's tangent from that arc, and then set a distance from that tangent point. Okay, so I'll click on this curve to select it for tangent tracking. So you can see as I move the cursor, Rhino's constraining that point to the end curve there.
So I need to pick some point on this curve, and the point that I want is specifically that quad point. So, now I'm back into the line command, and I'm still being asked to set the start of the line, and my one shot object snap is constraining that start point along the tangent line of that profile curve. So I know that I want my two horizontal lines to be 3/4 of an inch apart. So this top one needs to be 3/8 of an inch away from the center line, which is right here, where the quad is.
So I can just use the grid snap to set that, or I could type that into the command line. I'll just use grid snap, in this case, so I'll click here, and I'll say, so for the end of the line, I'd like to have it extend beyond the boundary of the profile there, so for the end I'll just type into the command line, the original length of the base that we started with, so that's 7 3/4, and I say seven dash three over four, and there I have my line, I just need to click once more, to finalize that point. Okay, so that's maybe a little bit over-complicated way to set that line.
Let's look at a simpler way to do that. Now, since I already have this one, I could use the mirror command, and I could just mirror this line over the horizontal axis of symmetry, of this base piece. I could also simply activate the line command again, and by paying attention, and using grid snapping, basically just figure it out. So, if I zoom in here, I know that this is the center line, and I want it to be, one, two, three eighths of an inch away from center.
So at the first point, and down here, it's at the second point. And part of what makes that so easy, is that, I sort of, ahead of time, done the work of setting up the grid system to an increment that makes a lot of sense for this project, so I can do little operations like that, without a lot of extra work, and going into all sorts of snapping routines, but it's just important to know that there's lots of different options for setting lines like this in Rhino. They're usually not right or wrong. Some are just a little bit faster than others. Let's switch back to our four view here.
And we are actually ready to start extruding some of these profile curves. So I'd like to extrude just the curves that are closed, so I'm not gonna be extruding these two lines. So I'm gonna go ahead and select those. I can manually go through and shift-click on things. I can also use the selection filter, so I'll say sell, sell closed curve, and Rhino grabs all of the curves that are closed. And from the Solid menu, I'll select extrude planar curves, straight. Okay, and I'd like to extrude this 3/8ths of an inch, and I want to set that distance below the construction plane, so I'm actually gonna type in negative three over eight, and the reason I'm doing that is so that we can continue to do some work here on these lines, and those'll line up right with the surface of the base.
So that's looking pretty good, so we have a closed solid. That's a pretty close representation of our base, and it's already got the through holes down the center there. Next what I'd like to do is, carve out these tracks for the frets. So, I'm gonna take, so I'd like to select both of those lines, oops and I just accidentally selected the base there. So I'm just shift-selecting both of the lines, and I'll use the pipe command to turn those into cylinders. From Solid, I can select pipe.
And so I'd like to make cylinders that are 0.125 inches in diameter, so I just type that in, 0.125. And I actually want to click diameter, not radius. And we've got some other options here. We can set a cap. I don't need a round cap. I'm just gonna leave this flat, and just make sure we're setting the correct diameter, which is 0.125. Click done. Okay, and you can see that Rhino's now created some nice little cylinders that are intersecting with my base.
And let's maximize perspective there, so we can see just exactly what's going on. So that's looking good. In a couple more steps, we'll use those cylinders to sort of carve out a little track, from the base. And that's where the frets will align, and sort of sit in, as we sandwich all the parts of the instrument together. Before we do that though, I'd like to fillet the edges of my solid base here, and that'll give just a nice little round over. It's gonna be aesthetically pleasing, make it a little bit easier to play, and it's a step that doesn't add a lot in terms of the fabrication, cost or expense or labor intensity.
So let's use the fillet edge command. And I'd like to do kind of a couple of different sets of fillets. For these straight edges along the side here, I'd like a larger radius fillet, so I'll do an eighth of an inch radius. As we get to these rounded ends here, I'll use a smaller radius, so 1/16th of an inch radius. That's mostly just for visuals, and again, it's something that doesn't add a lot of cost or labor intensity to the fabrication. So let's set our first radius at 0.125, and I'd like to select, just these straight edges here.
So just those four, and click done. So Rhino's gonna give us a preview here, with the handles, and if we needed to we could adjust these, either up or down. And I'll just click that one to reset it back to 0.125. And click done. Okay, so you can see that looks a lot less clunky to me. I like that visually, quite a bit. And let's go ahead and do that second set of radiuses, so we'll do the fillet edge command again, and this time our radius is gonna be 0.0625.
We're just selecting those rounded arcs, on the top and the bottom. And let's see how the preview looks. Pretty good, and click done. Cool. I like how that looks much better, much more appealing. All right, and then let's take a look at these pipes that we created here. And we're gonna use a Boolean difference command, to carve out those tracks from the base. So under Solid, we'll select the difference option, so that's a Boolean difference operation.
So we're first prompted to select the surface that we're subtracting from, and in this case that's the base. Done. And now we'll select the surfaces or polysurfaces to subtract width, so that's our two pipes there. And we do want to delete the input. I'll click done. Okay, very cool, that's looking pretty nice. I'm gonna change my render mode here to rendered, just to get rid of all those isocurves, so we can really, start to look at the form a little bit more closely.
To me, that's looking really nice, nice form for a musical instrument, and we have some very important functional aspects to the design here. So we have the tracks that the frets will slide into, we have the through holes that the hardware will bolt into, and this is all set up in a way that is pretty easy for fabrication, so the fabricator can start by just chopping off a rectangle of our hardwood, rounding over those corners, then using some router bits to knock off the edges, to make the tracks, and then probably a drill press, to do those through holes.
So the last step we'll do here, is just a little bit of layer management. So under, my base sublayer, I'll make two new sublayers. So I'll make a new sublayer for curves, and a new sublayer for solids. Then on the command line, I'll use a couple selection filters. So I'll say sell curve CRV. Select the curves. Right-click on curves, and say move objects to this layer.
So we have curves in that layer. And then I can just select the solid base. Right-click on solids, and move objects to this layer. And now we have those separated, and that'll by really helpful, so again, the 3D object will go into our rendering, and into our 3D print. The profile curves will go into our measured drawing for the fabricator.
- Installing Rhino for Mac
- Preparing a design
- Modeling metal parts
- Importing models
- Modeling parametrically with Grasshopper
- Extruding objects
- Modeling curves, surfaces, and solids
- Creating diagrams, 2D drawings, and layouts
- Preparing for fabrication: cutting and 3D printing