What I learned is that designing a bolt in Cubify Invent is actually EASIER than in many well-know CAD packages. That's probably because they have a legacy interface. I was surprised how easy it was to not only cut threads; but, to do so with precision.
Of course, the drawing is going to be a lot more precise than any extrusion printer can currently deliver. But, that's OK. 3D technology that is expensive today will, one day, be affordable to home users. So, all that precision will NOT go to waste.
Creating the bolt took place in steps.
STEP #1: Create the Bolt Shaft
The first step in creating a bolt is to precisely create a blank shaft at the OUTSIDE specification for the bolt size you want. In this case, the OUTSIDE of the threads would be .427". Since we wanted a bolt having 1" length for the threads, we created a cylinder that was 1.276", allowing for the head depth.
|Step #1: Bolt Shaft Extrusion
STEP #2: Create the Bolt Head
The bolt that I measured as the model for the tutorial had a head that was .609" across and was .276" deep. The MAKE DIMENSION option makes getting the sizing precise very easy.
|Step #2: Bolt head Extrusion
STEP #3: Chamfer the tip
Chamfering is the process of cutting an angle along an edge, By, putting an angled edge on a bolt, it makes it easier to start. In this case, we picked a random measurement of .075".
|Step #3: Chamfering the Bolt Tip
STEP #4: Use REVOLVE CUT to shape the head.
This was actually the toughest process to design and implement. The process involves designing a cutting tool that trims the top and bottom of the head as it is REVOLVED around the head. The depth of this cutting tool had to be great enough to clear the pointed edges. The great thing about Invent is that you can EDIT the cutter after you try it, so that corrections can be made with automatic updates to the result. Nice!
|Step #4: Forming the Head with Revolve Cut
STEP # 5: Create the Thread Cutting Tool Shape and Reference Line
Thread specifications include DEPTH and PITCH. The depth is controlled by the size and shape of the tool used to cut the threads. In this case we used a triangle that was .040" deep. This number came from one of the many specification sheets that can be found on the Internet.
At the same time, we created the reference line around which the Helix will revolve. Creating a Helix, either BOSS or CUT, always involves a shape and a reference line. The distance between the reference line and the cutting object determines the circumference of the Helix sweep.
|Step #5: Create Thread Cutting Triangle & Reference line
STEP #6: Cut the Threads using HELIX CUT.
Cutting the threads turns out to be extremely easy. When Helix Cut is selected, a dialog asked for a number of parameters. In this tutorial, all we needed to enter was the length of the Helix (1") and the PITCH of the cut. The bolt modeled had a pitch of .060".
|Step #6: Use Helix Cut to create the Threads
STEP #7: Finished Bolt.
Here is a picture of the finished result.
VIDEO OF THE PROCESS
I hope this tutorial video shows that using HELIX CUT is relatively easy if we remember we need and object AND a reference line. It was actually quite interesting to see how much easier this process was in Cubify Invent as compared to some other, more famous, CAD programs.