So like I said, in this step we will deal with the part that slides over the main part we just finished modeling. First, we need to create cross section of that part so we can extrude it. Lets start
In Right Viewport, anywhere, create one little perpendicular line from top to down long 0.15cm. That will be your reference line for later mirroring. You’ll get what I mean little later. Start from the end of it (the bottom) and create polyline to the right with first segment long 1.05cm, next segment is 0.6cm, and third one is 0.15cm.
Next polyline will be made of 3 segments also. So now, start from start of that little reference line (upper) and type in as length 0.75cm, then go to right, then type 0.3cm go up, and type 0.2cm and go left… Connect with line or polyline both ends of these two polylines with 3 segments. Like on the image below. Yellow line.
Now, select all those lines, except the little one we said is for reference for mirroring. Input mirror command, and select the start and end of of the line that will be for mirroring. Just point and click on the start of little reference line, and then on the end of the same line. After mirroring, you can delete that little reference line. Don’t forget to join that cross section to be the closed curve. Next, we need to position it well.
Extrude the line by 5.3cm, and position it according the background image.
You can see from the video, that I have put everything except this selected yellow object in Red layer, so I have easily hide that layer so it doesn’t get in the way. You can do that as well.
On the inner edge of this extruded part, start polyline, make one segment 0.6cm long and other one perpendicular to the first one (you can use Ortho, and just create the line straight up) and make it go outside the object. Lets say it goes in the line where that little arc part ends (according to background bitmap). You can make two more segments just to close that polyline in a closed curve. Like on the image below.
You can extrude that closed line, make the height a little over the height of the model. Next, from Top Viewport, move the extruded object down a little. Just enough or over to cover edgy part (use Ortho, so you are sure it goes straight down).
Using Boolean Difference command, make the hole on your model with this chunk.
Please note, maybe this isn’t the happiest solution but it does what you need. Also, you could have done this in various other ways, like creating the rectangle and then extruding it.
Ok, next, we’ll make a base for our screw wheel. First, make a line 0.6cm long, and a curve with InterpCrv command according to background bitmap. Check the image below:
Mirror the curve, join those 3 and position in the same plane where the lower edge of this object is. Using trim command trimm off the curve with the object, and delete the parts that are inside the object. Next you can make a line from start to end of this 3 joined curves like I did on video, or you can simply use CloseCrv command to close this automatically. Extrude that closed curve by 0.6cm up. And using Boolean Union connect it to the other part. Create a circle 0.12cm radius, and extrude it, and with Boolean Difference make a hole. Check the image below:
Now, we’ll deal with copying the parts we already modeled on the first part of our slide rule. So, copy the entire part (the one we hid in red layer). Now, the part we are modeling now, from the bottom edge (looking from Top Viewport) start a line, and move to the left, just enough to go through “nose” of our first part. Use trim to trim off the other part. We just need the nose. Check the image below.
Now, mirror the trimmed part, and move it to its right position.
Using Boolean Union, connect those two into one. Next, we’re going to create that arc part. We will use mirrored closed curve we used creating the first part, so mirror it…
Next, we need to position it well. This is really important part. Note the red line.
We, now, need to adjust that a little. So, create 1/2 of circle with arc, radius 2cm (anywhere in the Top Viewport). And using the Mid option in Osnap toolbar, with move tool find where the mid is on the 1/2circle is, and click there and move it to the upper edge of mirrored closed curve.
Now, explode the closed curve, and delete the parts you don’t need, and create a polyline to close that, and using trim trim off the parts you don’t need, and you should have couple of lines like on the image below, and just join them in a closed curve.
Next, extrude that by 0.15cm (you might need to input -0.15 as you need it to extrude in the opposite direction). Boolean Union that part to your big part. Now, similar to what we’ve done to the same part but mirrored, we need to create a line we will use for trimming.
And again, trim that. And join the surfaces. Position the second part to fit the first, so it looks like the slide rule is closed.
Now, we will use some of the lines we used for creating the hole for slider. Best way is to loft those 4 curves, just select Straight Sections in the Style dropdown menu, and Check Closed loft. Next, trim the end of it to fit the length of the first part.
Close the trimmed surface, and you’re done. There are some little details that are made in the video version of tutorial, like that screw wheel, and other. So be sure to check that too, and there is some little detail that isn’t made, so you can try that on your own.
Ok, I hope this tutorial was helpful, and stay tuned for new ones 😉
If you have any questions or suggestions don’t hasitate to contact me, or leave a comment here!