Learning to print objects 101

[LePaul 312]

So I have a co-worker who is a very dedicated STAR TREK fan

He has been after me to print an original series phaser

We found great CAD files on GrabCAD

http://grabcad.com/library/star-trek-phaser

Using Solid Works I converted the STEP file...

It looks very very cool!

I saved it as an STL and fired up Cura I had to move it around a lot to fit the platform but having never done anything like this, have no idea of this would print

Clearly a lot of the print would have issues printing....

So, guide me! How would one tackle something like this?

 

[illuminarti 18]

I haven't studied it... but at first glance, I'd probably try printing it angled, with the bottom of the grip, and bottom back corner of the body touching the build plate. Then use lots of brim to stick it down at those points. That way its mostly 45º overhangs.

 

[calinb 11]

>So, guide me! How would one tackle something like this?

I have much experience printing prototypes of training guns used by my company's customers (large police departments in the U.S.). The orientation you selected in Cura is probably the best choice, given no modifications to the model. However, I would split the model horizontally (near the height of the muzzle) such that I could print it in two pieces with no level overhangs and full footprints on the bed to obtain the best possible bed adhesion and retention. Then I would mix up my own ABS cement by dissolving ABS in MEK (just like what's available in the plumbing section of home improvement and hardware stores in black only) and bond and clamp the two parts together.

If you are using PLA, there are several threads here and on the reprap forum, as I recall, suggesting methods for bonding this more difficult to join material.

I would post photos of my company's printed prototypes and also injection molded products, but they look too much like real guns (scary!) and would likely be deemed non-PC by many members of the "maker community!" :(

-Cal

Update: Just to be clear--my suggestion is to bisect the muzzle and print the top piece right side-up and the bottom piece upside-down (orientations are from the shooters perspective when presenting the gun, which is standard in the firearms industry when referring to directions like up/down and right/left, BTW). It should not require any support using this method but the two pieces will need to be joined. If you have an aversion to bonding the pieces together, you could use hardware (drill for screws, tap threads, use nuts, etc.).

 

[gr5 2,005]

Certainly print a test one at half size first.

Do you plan to paint it? If so you could consider just printing it as shown with "support" enabled. then sand and file it and then use bondo to fill in any cracks/tiny holes, then prime it with automotive primer then paint with any kind of paint you want (maybe acrylic).

Also if you are painting it then it isn't so bad to print it in two halves. It's a lot of work getting those 2 halves to fit together nicely (both halves will warp) but lots of people have had success.

 

[bauermaker 0]

I absolutely agree to everything gr5 said, but for less warping and easier sanding you could try laybrick or Orbitech Pla90 those two materials have worked wonderfully for me.

 

[calinb 11]

This approach has its upsides and downsides. While it enables you to detect some problems, it does not adequately predict most problems associated with plastic shrinkage, including bed adhesion, and even bridging problems sometimes. I no longer bother to print under-size test prints, because they too often turn out to be a waste of plastic and printer time after the full-size version still develops problems, despite a successful under-size test print.

Under-size test prints are great for learning the art and wizardry of 3D printing, however, and I also recommend that you use them while climbing your learning curve.

I usually find it best to keep an eye on my first full size print to watch for developing problems. Usually I can abort the print, if I see an unacceptable problem developing.

 

Certainly print a test one at half size first.