Thursday, February 5, 2015

3D Printing : Cold Vapor Smoothing

you can click on all the pics for larger views!
So I've been working on this Nexus 7 w/Battery Charger Holder/Stand (Prototype) which originated with this model on thingiverse http://www.thingiverse.com/thing:355918 .

Its an ok design, but the cable goes out the side instead of straight back, the stand itself slides around unless affixed to a surface even with the battery in the mount providing a bit a weight, and the magnet is so strong between the charger and the nexus7 that more than often the charger puck gets pulled out of the stand.  Not to mention that as presented its almost impossible to print on some printers.

So I took the design and tweaked it, I separated it into two sections so any printer can print it, I also placed in a small divot in the back of the charger area for some velcro or adhesive strips, as well as divots on the bottom to hold the stand in place on a surface, and included a "spinner" device so you can orient the viewing angle. 

However this post is really about the "finish" of the stand.  Being that I'm using ABS plastic which "melts/dissolves" in acetone you can use a process called vapor polishing to give your products a injected molded look. (You can't use acetone with PLA or other similar plastics, each plastic usually has its own chemical that similar effects can be achieved however some of those are really nasty compounds and I'd avoid using them in a process like this.)

There are typically two methods to do this and both are similar, one method uses added heat to hurry the vapor process and "melting" of the plastic along with a breif stint in the freeze of the object you want to smooth before you put it in to the hot vapor path.

The other method is using the same process minus the added heat and stint in the freezer.  This is the cold process

Tuesday, January 6, 2015

3D Printing : IKEA Hack - Lustifik Shelf Extension - Filament Holder

Filament! I've got plenty, but I'm always looking for more, especially if there are new blends, new materials, etc! I really like testing out new filament and thinking on the possibilities that these materials could end up becoming or how to use them.  Its one of the reasons I got the replicator 2x "experimental", which I regret, since that is so far from the truth.  But that's for another show ;)  Thankfully I have a delta printer as well! :D

With so much filament, 64 or so spools at last count, I was just stacking it on my shelves as wide as the shelf, two spools deep and two  or three spools high.  But this was a bit unwieldy and the spools had a tendency to slide, especially if I stacked them three high.

initial prototype no channel, testing
out the strength with filament
support added in (the white) 
I started using peg board to hang my spools of filament from and had everything arranged via ROYGBIV designation, but I noticed that even a few of my ABS spools were taking on moisture, so I'm was sure my PLA that was sitting out in the open too would be troublesome in the future.  You can read about a solution I constructed to help "dry" out spools.  While its a good solution  when needed, I didn't want to have to do this every time so I needed to make sure they remained bagged with desiccant. When I rearranged the peg board I could only fit 2 spools on top of two peg board pegs.  I needed a better solution.

I had an extra IKEA Lustifik shelf and when put side by side i could fit about 6-8 spools per shelf (depending on the thickness of the spools)  which was a much better solution.  You can also flip another Lustifik shelf on top of the initial shelf and attach via bolts however you're left with a "middle shelf" that's about an one inch high. Here is a pic of the starting of the "shelf tower".  As you might guess the"plugs" that attach two units will create a small shelf, which I plan to use for sample filaments I receive from manufacturers or unspooled filament, like laywood, or laybrick.

you can click on any of these pics to make them full size!

I designed the following files to fit between the two units and free up that space.

The rods extend between the two units when you flip the shelving units, the plugs are for the upside unit, where you remove the no scuff feet and insert those plugs so that you can join another unit together.


As you can see I print out 8 "halves" and then use the adhesive below, but you can straight acetone to "weld" the two halves together as well.  The larger holes are there to save on material, the smaller holes are there, if you want, to use as an additional method to strengthen the object by using 1.75mm filament which you put adhesive on and then slide into the holes which then are welded/bonded to the plug (as can be seen in the pic on the right) or strut.  After gluing I decided the extra filament welds weren't needed, those struts and plugs are plenty strong!  

The final feature is a channel going down the center to allow you to insert a 2in bolt/machine screw along with a nylon hex nut that fits in the 2nd hole from each side that goes through the tubing on the shelf unit.  With a bit of screwing the hexnut should retract and come to rest between the two circular holes with in the strut and provide extra added strength.  Oh and I got my adhesive at Tap Plastics here in San Jose, CA.  

As you can see in the last photo the print on the delta, this is with ABS, even though it has a heated bed with no "enclosure" the plastic really wants to "warp" and it pulling up the blue tape!

Hope you enjoyed this post and thanks for stopping by!

Friday, November 21, 2014

3D Printing Video : Printing With Ninjaflex and Rubber TPE

So with the holidays arriving soon, I again wanted to make some gifts this year for various relatives and friends who I'll be spending the holidays with.  While searching thingiverse i found this pretty cool Bear model in the Voronoi style.

So after printing it in a transparently blue PLA filament from polymakr, I decided to try out some of the flexible filaments I've had on hand for awhile but have done nothing more than print a sample chip out .

(if you're a filament manufacturer and want me to test a sample of a filament you're developing feel free to contact me)
I tried printing out with this type of filament before, and failed, mostly because either the extruder that I was using caused the filament to buckle and just wrap itself around the stepper motor, or after extruding a bit for the first few layers would just stop extruding as the gripper gear would just lose its grip and not push the filament along ending up in "air prints".  

Being that I have about 15 rolls of various flex materials I figured I better start using these filament and decided to try various methods of getting these filament to print correctly. (read and see more after the jump!)