Merry Christmas!

I hope you found a Cube under your tree!  If not, I still hope you found a 3D printer.  Because, there is nothing quite like a 3D printer to begin another year of wonderful creativity.

If you were one of those lucky individuals to receive your own brand new 3D printer, let me point you to the Cubify web site where you will find some great apps to get you started.

Recently, I was privileged to be invited to introduce 3D printing to a great group of young people at the Freestate Challenge Academy in Aberdeen, Maryland.  And, one of the things they enjoyed was making there own ring designs using the Cubify Ring App.

Cubify Ring App - Step 1

Each student was able to create their own personal ring design.  When they return to pick up their certificates, the ring will be there for them. 

Mentioning the  Ring App is a great time to point out that one of the design goals for the Cube was to make it portable enough to be carried to friends homes for 3D printing parties!  Of all the 3D printers of which I am familiar, the Cube is the most appropriate for these kinds of social gatherings.  And, having apps that require absolutely no 3D CAD skills is a great way to begin enjoying 3D printing for everyone!

So, here's wishing you a magnificently creative year with your new Cube or other 3D printer.  Now, the fun begins! :)

Christmas Eve Gift - Thread Cutting Tool

Before I left the house this morning, to visit my grandchildren, I finally created that long promised thread cutting tool tutorial for Moment of Inspiration.  And, before retiring this evening, I edited the video and posted it on YouTube.

I have NO idea why it took me so long to get it done because it is a piece of cake to do in Moment of Inspiration!  Maybe I was just waiting for a grand occasion, like Christmas Eve to release it.  Whatever the reason for the delay, I hope that the second part of the tutorial on designing bolts and threads in Moment of Inspiration will come a LOT faster.

Have a GREAT holiday/  And, for those of you that will be fortunate enough to have received a Cube 3D printer for Christmas, I want to welcome you aboard and hope that you will find these pages helpful to you.  This is going to be the start of a wonderfully creative adventure!

Cube Features I Have Most Appreciated

I probably should have gotten around to this post a lot earlier, when parents might have been considering a 3D printer for their child or themselves.  (It's OK to be self-serving on this one!)

It's no secret that I continue to love and appreciate my Cube 3D printer.  But, I thought it would be useful to list specific reasons why I continue to believe that the Cube 3D printer is not only a great buy; but, a great long-term investment.  So, here is a list of things I most appreciate about the Cube's design and function.

1)  The Heated Printing Table

Those who have a Cube and another 3D printer can relate to why I REALLY appreciate the fact that the Cube has a heated printing surface.  With my Cube in the hands of the staff of Freestate Challenge Academy last week, I tried printing some hangers the students had specified on a printer not having a heated bed.  My basement is colder in winter and while I had not problems printing PLA with my second 3D printer during the summer months, I had to abandon the task due to warping.  Even in summer I was unable to print in ABS on my second printer due to warping.

Warping is very rare with the Cube since the bed is always heated to the optimal temperature to reduce it.

2)  Compact Size

I love the size of the Cube.  It travels well.

In fact, it is the perfect size to carry around in a fabric rolling cooler that I'd purchased at Costco or Sam's Club.   It looks something like this one... without the beer and soda, of course!  LOL!

 


The Cube and 2 cartridges fit perfectly.  The padded sides of the cooler are more than enough protection.  The rolling function is convenient; but, the Cube is light enough that even with the added weight of the cooler, it's easy topick up and carry.

3) Ruggedness

Unlike some personal 3D printers, the Cube is ruggedly built to withstand the rigors of travel.  I can confidently loan it out to people that have no experience at all with operating a 3D printer.   It can be carried from home to school or to friends homes with little likelihood of a breakdown.  In fact, in just this past 6 months, my Cube has traveled to in 3 states to1 museum, 2 conferences, a fundraising event, a school setting and at several homes... outside of my control and without a single failure.  THAT is an impressive record for a 3D printer.

4) Printing in ABS

Most personal 3D printings use either PLA or ABS as their source material.  PLA is easier to use.  But, it doesn't quite have the strength of ABS.  The fact that the Cube prints in ABS is a HUGE advantage and a very big deal to me.  In fact, I have used the Cube to print parts for my other 3D printer since my other printer does not have a heated bed and ABS warps without that feature.

5) Reliability 

The only difficulties I have had with the Cube are an occasional clog when changing cartridges due to my own impatience. And, that was only in the early stages of my learning to use it.  They have changed the messages on the LCD screen related to removing old filament and installing a new cartridge and those additional directions have helped to reduce the potential for clogging.  The only time I had a print job fail in the middle of a run was when I let the outside studio temperature get too high on a hot summer day.  Other than that, this printer has been a flawless performer.

From time to time, I get emails from new users telling me about some issues they have with a newly arrived Cube.  But, invariably, the Cubify team has been able to sort out the issues early.  There have been one or two users that have unreasonable expectations for a 3D printer.  But, for the most part, I get very positive feedback from users about their Cubes.  So, I am confident that I can tout the Cube's reliability not only from my own point of view; but, that of others who have contacted me.

While these are the 5 major things that I most like about the Cube, I can assure you that there are other things that make this little 3D printer a real winner.

Growing the Brain in 3D!

Before launching into the real meat of this post, permit me a moment to rant about one of the claims often made by personal 3D printer manufacturers.  I cringe every time I hear a 3D printer manufacturer claim that their product can "replicate itself".  First, the claim is demonstrably false.  At present, all any personal 3D printer can do toward the goal of replicating itself is to print out a few plastic parts.  Secondly, it is such a narrowly inferior goal that it actually demeans the value of 3D printing rather than enhancing it.

Now having declared the "replicate itself" claim as false and puny.  I am going to go W-A-Y out on a limb with a claim of my own that will surely invite declarations of FALSE or MISLEADING.  I'm going to claim that a 3D printer, while not able to replicate itself, CAN contribute to something FAR more important... GROWING OUR BRAINS.

Of all the recent discoveries that should be meaningful to all of us... from youngest to oldest... it is the understanding that we can, literally, GROW our brains.  

For most of my life, it seemed to be believed that we started life with a finite brain structure that deteriorated in old age as we lost brain cells.  But, in recent years, there seems to be a growing consensus that our brains structure is NOT static and that we can actually grow our brains!

This remarkable fact first came to me through the writings of Dr. Caroline Leaf, a South African learning specialist.  Her writings launched me on a quest to either validate or repudiate her claims.  And, that turned out to be a true and remarkable adventure.  

In my last post, I alluded to the fact that I believe that the Cube 3D printer is much more than a simple gadget builder.  At some level, it is a key that helps us unlock the potential of our brains by allowing us to realize, in concrete form, the ideas that used to tantalizingly fly fleetingly by. 

Just visit the Cubify blog and scroll through some of the latest articles to witness the power of ideas made real!

How do I think the Cube (or any 3D printer) helps us grow our brains?

First,  let's start with a fun article, by Lulu Miller, that introduces the concept.   A more academic description of the new field of neurogenesis can be found at this link.   

While my own observations about the link between 3D printing and neurogenesis are completely anecdotal, I'm convinced that the link is there.  Now, that could mean that I'm simply crazy.  But, it may also mean that my own personal experience, and the experience that I've seen in others can be explained by neurogenesis in action as the brain finds a feedback path in the real world of tangible objects.

The DREAMS LAB - Virginia Tech

Now, I'm not sure that the professors at Virginia Tech would go as far as I do in claiming that there may be a connection between a 3D printer and personal neurogenesis; but, it sure is interesting that they named their Additive Manufacturing center, THE DREAMS LAB.

It's also interesting to me that every single person I met, during a recent visit to their facility, would fit my personal description of being a "Renaissance Person".   By "Renaissance Person", I mean one that has remarkably wide ranging interests and accomplishments.  While they are rare, I have been very fortunate to have been surrounded by such individuals... Dave Nutting and Bob Ogdon  while I was with Astrocade,... Don Komai with Time Life Software (Time Life Books) and Frederick "Mike" Slay with my current employer.   But, the world of 3D design and printing seems to teem with them.

The Dreams Lab - DreamVendor Kiosk

Perhaps nothing demonstrates the professor's confidence in the value of 3D printing to the creative process, for all students, than the DreamVendor kiosk which allows any Va Tech student to print out their designs completely for free.

I'll let you read more about this terrific idea on Gizmag.  Be sure to watch the video!  Very Cool.

Inviting Cube Owners or 3D Printer Users to Chime In

If you own a Cube I would love to hear if you believe that owning and/or using a 3D printers has unleashed your creativity and grown your brain.  I know that it has been true for me.  I've certainly witnessed it in others.  But, Has it been true for you?  

This should be interesting.

The Cube in Review - 2012 at 6 Months

This is going to be a very short post.  That is because it's being typed on my granddaughter's iPad.  The iPad is terrific.  But, my skills at typing on a screen are not.  However, I thought that this post was important enough to give it a try as I travel.

BOTTOM LINE - The Cube is Every Thing I'd Hoped it Would be and MORE

It's been almost 6 months since I opened my Cube's box.  In the subsequent months, between then and now, it has performed extremely well, traveled well and spawned lot's of creative ideas in myself and others.  And it is the latter idea that I want to communicate this morning.

Right now my Cube is in the hands of the staff of Freestate Challenge Academy.  I had the privilege of introducing 3D printing to 9 eager students and witnessed exactly what I'd expected to witness... An explosion of creative ideas that always seems to happen when individuals finally grasp what they can do with a 3d printer, and the Cube in particular.  The clean design of the Cube seems to remove any barriers or intimidation and invite an almost instant free flow of ideas.

Ideas came quickly.  but, actually printing those ideas takes a bit more time than a single day.  So, the Cube stayed for a while as I returned home.  There was NO way I was going to deprive those students of the chance to see their designs printed.

Parents.  This past six months with the Cube has convinced me, beyond ANY doubt that there are few gifts that you could give a child that would spark their creativity and grow their brains like a Cube printer.  I.know that it's not cheap.  But, six months of watching it work it's magic with scores of people tells me that it is well worth the investment!

I have more to say on Freestate Challenge Academy and their YouthQuest project when I have an actual keyboard to type.  You are going to love what they have planned.

Designing a Thread Cutting Tool

A good place to start, if one wants to understand design characteristics of bolt threads is the venerable Wikipedia.  There, you will find that most; but not all threads, are based on an equilateral isosceles triangle whose tips have been truncated.  I'll let you explore the referenced article for a deeper understanding that is needed for this article.

Instead, we'll just focus on the 8 simple steps required for the tool that will be used to 'cut' the threads in our making of the bolt for 3D printing.

To create a thread with a 3D design application, like Cubify Invent or Moment of Inspiration, requires creating a "Cutting Tool" shape that is used with a Helix tool ((Coiled Line) to make the threads. 


STEP 1: Create the Primary Reference Triangle at the Thread Pitch size

While it is not absolutely required that the triangle used to form the thread cutter be an equilateral triangle, it is the most common form.  What is required is that the height of one side of the triangle is exactly the length of the desired "Thread Pitch".  In our case, this would be 20 threads per inch, or 0.05".  our starting triangle would look like this sample.

Equalterial Triangle with 0.05" Sides

 

 STEP 2: Create a "Tip Triangle" to Aid Truncation

Each of the tips of the base triangle will be truncated for reasons explained in the Wikipedia article.  To facilitate the design of the trucation, we copy the primary triangle and then scale the copy to 1/4 the size of the original.  We then place that second triangle right into the tip of the first as shown below.  We'll call this the "Tip Triangle".  It's colored red in this sample.

Create the Tip Triangle at 1/4 Scale of the Base Triangle.

STEP 3: Create a "Corner Triangles" 

We next make two copies of the "Tip Triangle" and scale them to 1/2 the size of the Tip Triangle.  Each of the copies is moved into either the upper left tip or lower left tip of the primary triangle.  All of these triangles are merely reference objects to help us actually draw the cutting tool itself.

Back Triangles 1/2 Scale of the Tip Triangle

STEP 4: Create a Truncation Arc inside the Tip Triangle

The goal of this step is to create two 90 degree reference lines that intersect the side of the Tip Triangle at a point that is 1/4 along the side of the triangle.  We then draw an arc whose center is at the center of the back line of the triangle and that extends from the points where the lines intersect the triangle.

Adding the Trucation Arc

STEP 5:  Add Reference Lines that divide each back triangle.

These lines will aid us in drawing the final cutting tool by giving us snap-to points.  

Add Reference Lines to Facilitate Drawing

Step 6:  Using Continuous Lines Draw the Cutter Outline

Notice that we do not draw to the tips of the primary triangle.  Beginning at the intersection of one end of the arc we draw a series of connected line (Blue Sample) until we get to the intersection of the arc on the opposite side of the triangle.   We then JOIN the arc and lines to form a single object.

Using the Reference Lines, Draw the Cutter Tool Outline

Step 6:  Remove the Reference Lines (Invisible) to Reveal the Cutting Tool

As we make the reference triangles and lines invisible, the outline of the cutting tool is revealed. The front tip is rounded and the back tips have been truncated to result in gaps so that the final thread will not be too pointed.

Remove References to Reveal the Cutting Tool

Step 7:  Add References to Aid Connecting to the Helix

The final step is to add a line and a point, which we have exaggerated for clarity, to aid in positioning the Cutting Tool relative to the Helix path.  Notice that it is NOT attach the cutter to the Helix along the back side of the cutting tool.  We move the attachment point forward to a point along a line anchored at the tips of the small back triangles.  This means that the thread is slightly more shallow then the thread pitch.

Add a Reference to Center the Attachment to the Helix

Thread Result

As the cutter moves around the shaft of the bolt, it removes material to form the threads.  The thing to note is that the tips of the thread ends up being somewhat flat, rather than sharp.  And, the valleys of the thread are also not sharply pointed.  This makes for a stronger, smoother turning thread with less potential for binding up..

It's been very interesting, to me, to explore the more technical aspects of thread design.  Once grasped. it allows us to design any sized threaded bolt or accessory.  But, knowing how to design it is not enough if we are to use a 3D printer to realize those designs.  And, this is going to take some experimentation in scaling, etc.

As usual, it's going to be fun!

General Design Dimensions of Bolts and Threads

Wow!

It sure has been a while since I've updated this blog.  But, lest you think that is because I have lost interest in the Cube or in creating tutorials for Cube owners, I want to assure you that is NOT the case.  I simply got hung up.

Writer's block?  Fear of leading you astray in what I wanted to convey?  A busier than normal schedule?

Well... a little of all of those things.  But, mostly, I think, a fear that I might lead you down the wrong path as you are learning to use the software package of your choice when it comes to exploring making threaded bolts.  There was also the fact that I try to limit the length of my tutorials to around 10 minutes and this is a reasonably big subject.

So, I have decided to break it into three blog entries.

The first will focus on the general dimensional characteristics of standard bolts and threads.  In this case, we will be looking at a 1/4"x1"x20 standard hex bolt.

The second will focus on design characteristics of the "Cutting Tool" that will be used in conjunction with a Helix to actually create the threads.

The third will be in the form of a video design tutorial, first in Moment of Inspiration and then in Invent.

I am also going to create a companion video tutorial for this blog entry.  But, it will use this blog as the script.  So, it will add little additional information.  It's simply a second available format for those that prefer to watch video tutorials.

General Design Dimensions of Bolts and Threads.

A bolt or screw is generally described by four features.  The first is the HEAD TYPE.   For the purposes of these tutorials, we will be designing a HEX BOLT having a hex shaped head that requires a wrench to tighten it.  Then there is a three element description, such as 1/4"x1"x20.

We will be using the SAE system for describing our bolts.  But, the METRIC system is similar.

The first element, 1/4", tells us the nominal diameter of  the shaft of the bolt.  The next number, 1", tells us the length of the entire bolt shaft, whether it is threaded or not.  And, the last number, 20, describes the THREAD PITCH.  This is the number of thread peaks in 1" in the case of SAE (United States) bolts.

But, this is only the beginning of describing our bolt.  Let's start at the very beginning and work our way to the complete dimensional description.

A)  The Bolt Diameter

The most critical of the dimensions is the diameter of the bolt shaft.  It tells us that this bolt will fit into a 1/4" hole.  It would be a very tight fit, to be sure.  And, usually the hole meant for a 1/4" bolt will be slightly wider than that.  But, that is the diameter of the shaft. 

1/4" Shaft Diameter

B)  Bolt Length

1/4" bolts come in many lengths.  So, it's important to know exactly how long your bolt shaft should be for your particular application.  This is the length from the bottom of the head to the opposite end of the bolt shaft.  In this case, we will be designing a 1/4" that is 1" long.

1" Bolt Length (Shaft Length)

 C)  Thread Length

Descriptions standard thread lengths can be confusing.  Each reference that I explored claimed that the thread length for 1/4" bolts under 6" was 75% of the shaft length and those over 6" were 100% of the shaft length.  BUT, I could not find a single bolt in a hardware store that followed that "rule".  So, I have simply chosen to define the thread length in my design as 90%-95% of the shaft length,  This gives us an opportunity to show how to taper the thread leaving a bit of the shaft without thread.

.90" Thread Length

D)  Thread Pitch (Threads Per Inch)

SAE bolts come in both COARSE and FINE threads.   I'm not even sure that a consumer 3D printer can effectively resolve fine thread pitch.  So, we'll settle on the standard Thread Pitch that we're most familiar with... 20 threads per inch.  This translates to a distance between thread peaks of 0.05".  This is very important to know; because, it is the basis for creating a cutting tool that we will use, in conjunction with a HELIX, to create the threads.

20 Threads Per Inch Thread Pitch

E)  Bolt End Chamfer

While, theoretically, you could create a straight bolt, it's very helpful to taper the very end of the bolt shaft to make it easier to thread the bolt into a nut.  So, we are going to CHAMFER the end of the shaft with a 45 degree slope that begins .025" from the end of the shaft.  Aside from making it easier to begin threading the bolt, it also gives the thread a more finished look.

0.025 Chamfer at the Bolt End

F)  Head Height

1" bolts are actually longer than 1" if you include the height of the head.  While it is true that head height can be thinner or fatter different applications, there is a specified standard for a 1/4" bolt and that is 5/32" or 0.163".  The head shape is actually more complex than we typically think.  The edges slope slightly and the corners are FILLETED or rounded.  There is also a raised area, also called a FILLET that we will discuss later.  The HEAD HEIGHT only includes the head itself and not the FILLET.

5/32" (0.163:) Head Height

G)  Head Width Across Flats

While  we might play a bit with the head height without too many adverse ramifications, that is NOT true of the width of the head from one flat side to the other.  If we are to claim that we have printed a standard 1/4" Hex Bolt, then those who try to use it, expect to be able to use a 7/16" wrench to install it.

This probably presents some interesting hurdles for the home 3D printer.  What we design may or may not print exactly at our expected dimensions.  It could be that reducing the width of the head to an acceptable print width will cause our threads to be too small, etc.  So, we might find that we have to adjust the head width and the shaft diameter separately!

It is possible that this is an individual printer characteristic that can only be guessed in a global tutorial such as this one.  So, we'll simply stick with the standard for now.

7/16" (0.438:) Across Flats

H)  Head Width Across Corners

While the SAE standard calls for a distance of .0.505" from corner to corner on the top of the head of a 1/4" bolt, we really don't have to worry about it too much.  It just happens if we get the distance across the flats right.  And, of course, the converse is true.  If we get the corner distance right, the flat distances will be correct.  It all depends on your preferences as you create your hex shape for extruding into the head.

0.505" Across Corners

I)  FILLET DIAMETER

The specifications for a hex bolt call for a spacer just under the head that acts like a washer so that the head itself is not absolutely flush with the surface into which it is screwed.  While it might be a bit difficult to see in this illustration, the nominal diameter of this spacer is 13/32" or 0.406".

13/32" (0.406") Head Fillet Diameter

J)  FILLET HEIGHT

The height of spacer under the head is nominally 0,0125".  But, we are, in fact, limited to the minimal layer height of our printer.  Even so, whatever difference there might be is inconsequential.  But, since we are aiming at a standard bolt size, we need to try to design the bolt as tightly as we can to the specifications.

0,0125" Fillet Height

 BOLT DIMENSION SUMMARY

These are the dimension specifications we will be using to design our Hex Bolt

Summary of Hex Bolt Dimensions

 In our next blog entry, we will explore the dimensions and characteristics of the
Cutting Tool" that we will use to remove material from the shaft to complete our Hex Bolt.

As usual, if you spot an error or think something needs some clarification, please feel free to comment!