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2012

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(Lower) Printed receiver with 75% scale model (Upper) Original AR-15 lower receiver (via HaveBlue)

 

Every time there comes an innovative technology, something like this happens.

 

It was only a matter of time before someone got the idea to use a 3D printer to manufacture fire-arms, and while he may or may not be the first, AR15.com forum member HaveBlue has succeeded in printing out polymer AR-15 lower receiver. Polymers have been used for some time now for firearms lower receivers (Bushmaster Carbon-15, Glock 19 and Smith & Wesson Sigma series to name a few) and are just as durable as receivers milled from aluminum. A polymer receiver is usually made through a molding process rather than being printed which could have hazardous consequences if it is not manufactured correctly.

 

HaveBlue took this into consideration when printing out his lower receiver and designed it using a modified IGES CAD file from cncguns.com which he used to tweak take-down pin hole diameters, buffer-tube threads and provide reinforcement in critical areas. He then used a Stratasys 3D printer with PP3DP UP! filament to make a 75% scale version as a ‘proof-of-concept’ and to get a rough idea of what needed to be tweaked or reinforced before moving on to a full scale version. The final version HaveBlue designed was made using the more robust black filament Bolson ABS and then ‘mated’ it with a CMMG upper receiver with a pistol length barrel which was converted to fire .22 rather than 5.56/.223 (for testing purposes and legal issues).

 

HaveBlue states that he successfully fired around a hundred rounds of .22 caliber rim-fire rounds through his pistol converted AR-15 with no problems what so ever which makes his design a success.

 

 

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CMMG pistol conversion (via HaveBlue)

 

Not satisfied with firing .22 bullets, he then switched the conversion back into a .223 caliber rifle where he encountered some problems regarding feed/extraction (bullet cycling) issues, which were also encountered using a manufactured aluminum lower assembly. HaveBlue’s (as well as others who have printed guns) accomplishment opens up a host of doors for firearms enthusiasts who want to design and print-out their own guns. It also opens a few doors that could lead to thin ice concerning how legal it might be to print out these guns. The Bureau of Alcohol, Tobacco and Firearms (ATF) considers the lower receiver the weapon itself; meaning you need a permit, license or background check in order to purchase the gun from an FFL (Fully Federal Licensed) dealer which come with a serial number stamped on them for regulation. It seems the laws concerning the manufacture of lower receivers for firearms is a ‘grey issue’ at best, it could very well be a way for criminals to build their own weapons through legal ‘loop holes’ as the ATF does not regulate the purchasing of upper receivers (barrel, bolt, etc).

 

So that is the question, do you think printing firearms should be regulated? If so, how might that be accomplished (regulating the printers themselves)?

 

Cabe

http://twitter.com/Cabe_e14

 

Bioengineering has traversed the all importaaant step of building artificial organs that could soon be used in place of traditional transplants. A working set of artificial arteries that deliver the nutrients and oxygen necessary to keep living cells alive and functioning properly has been made by current manufacturing technologies. Bioengineers from MIT and UPenn are developing a method for constructing networks of vessels by using a common, open source 3D printer modified to print using sugars.

 

Christopher Chen and Jordan Miller are leading the team that is using a RepRap 3D printer to lay the foundation for a lattice artery network using custom extruder made to print using a mixture of sucrose, glucose and dextran to trace where the vessels will be. After the network has been printed, it is covered by some type of Bio-Gel like Fibrin or Collagen, which also contains living cells. The researchers then dissolve the sugar network which leaves hollow capillaries, which can act as arteries within the artificial tissue matrix.

 

These artificial arteries can then be used to deliver Oxygen and nutrients to the living cells left in the bio-gel matrix. The team has been able to show experimentally that they can increase the survival rate of living cells and improve their function within this artificial tissue.

 

MIT Professor Sangeeta Bhatia, was part of the research team and explained, "More work will be needed to learn how to directly connect these types of vascular networks to natural blood vessels while at the same time investigating fundamental interactions between the liver cells and the patterned vasculature.”

 

The researchers are optimistic about the future of this method. These feelings are reinforced by the fact that soon, other researchers could start to contribute to the development of these artificial arteries. The printed templates are stable enough to be shipped to labs around the world where other bioengineers and cellular biologists can study and experiment with them. Although they could also use 3D printers along with necessary tools to print them.

 

Cabe

http://twitter.com/Cabe_e14

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