Tuesday, September 4, 2012

Cubify Invent - Tutorial #10: Bolt with Helix Cut

Before attempting to learn how to create a bolt using the Helix Cut tool, I scoured the Internet to see what it takes in other bigger name CAD packages.  I also scoured the Internet for information about bolts and thread specifications.  So,  others unwittingly helped me as I tacked learning Cubify Invent's techniques for creating a bolt using actual specifications.

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.

Finished Bolt

 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.


5 comments:

  1. Praise, problem, and a question,
    This is the first time I have actually understood anything useful about CAD. Five days into using the trial software, repeatedly watching your tutorials, and I cannot put it down. You sir have taught an aged dog new tricks, thanks so very much.

    I have been trying the Helix Cut on and off now for a day. Sometimes it works, sometimes not. All of the failures seem to be due to the reference line not being referenced or not staying in existence once I exit the sketch plain. Will continue to practice.

    I have also been trying to get the Helix Cut to follow a curved spline reference line. No success yet.
    Have you done this?

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  2. Cubify Invent is a good product at a good price. But, it is NOT perfect and sometimes it drives me crazy when I hit a wall with little or no explanation. Your observation that "sometimes it works and sometimes not" is something that I've also experienced.

    I'll try to chase down what is happening if I can duplicate it.

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  3. Cubify Invent is a very buggy piece of software and needs a fixed update. I tried making internal threads with no success and have had reference lines and features disappear. A good price means very little if you can't use it!!!

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  4. My preference is certainly Moment of Inspiration. And I agree that Cubify Invent needs to be friendlier. But, with some patience and experience it CAN be used quite effectively.

    Invent is based on Alibre and that has been around, and successful, for a long time. So, I hope, and expect, that Invent will become more consumer friendly over the next few months.

    I see my responsibility as learning the flow of the application to avoid the pitfalls that prevent accomplishing what we want to do.

    I do, however, think Moment of Inspiration is far more intuitive and, for those that can afford it, a better design experience.

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