Evolution of a Blog

This blog has evolved as I have as a maker. It starts at the beginning of my journey where I began to re-tread my tires in the useful lore of micro electronics and the open-source software that can drive them. While building solutions around micro-electronics are still an occasional topic my more recent focus has been on the 3D Printing side of making.

Saturday, July 16, 2016

Nozzle Cleaning - Extreme Edition

One of the advantages of having a removable nozzle is that you have additional options for clearing a nozzle jam.  In the old days the only solution was to do an atomic, or cold pull, clean.  Sometimes it may have even been necessary to use a 400 micron drill bit or syringe tip.  

With a removable nozzle you can still use these methods but obviously the fastest fix is to simply pop on a new nozzle!  With the feeder upgrade from the plus upgrade, coupled with my cleaning and lubricating the filament prior to the feeder, I have not had many jams to work with but my strategy is threefold.  

If I am in a hurry, just change the nozzle and come back to cleaning it later.  If I have time, or if I have come back to a nozzle from a prior jam, I will do a cold pull.  If this does not work, or if I want to be lazy, I toss the nozzle aside and come back to it later with my torch:

There is something about heating a nozzle to the point where it glows, and then holding it there for ten or fifteen seconds, that does a fine job of cleaning up a nozzle jam.  

Thursday, July 14, 2016

Launching of an Arduino / Raspberry Pi Project!

Going back to the roots of this blog on this one!   When I am doing an electronics project my multi meter is constantly on my desk somewhere taking up part of my limited real estate.  So I put it away only to need it a few minutes later!  So the thought occurred to me...why not build a multimeter that is small enough to stay on my desk (or even behind it with only the test leads on the desk)?  And since it is now hidden behind my desk it will need to have a remote display...so how about having that display on the computer in front of me?

So is born this project:  Create a multimeter that can measure voltage (DC only, zero to 30), resistance (zero to 100k), and amperage (0 to 500ma, .5ma resolution).  My platform is going to be, you guessed it, an Arduino married to a Raspberry Pi:

The Raspberry Pi that I am going to use is the new Zero shown on the upper right.  I had planned on using the Onion Omega on the left but I want to do my User Interface app in Node.js and getting it setup on the Onion was a hassle.  The Arduino that I will use is the smallest in the family (of the versions on a PCB) and is the Micro Pro shown lower right.

My original plan was to use the below schematic as the electronics for my multimeter.  It is from this instructable, and as you can see, it is pretty complicated:

That complexity does buy a number of features that I don't need and some accuracy beyond my needs as well.  The majority of the time when I will need my new multimeter is for a simple continuity test, or to see if I have power and whether it is 3, 5, or 12v.   My needs are simple enough that I could probably do a tester just using an Arduino but that would not be as much fun as what I am planning.

Anyway...the electronics that I plan on implementing are less complicated than the above and will be based on this discontinued Sparkfun kit:

I am going to add a couple of switching transistors to get the number of probe connections down to three as max.  I guess the project will be wrapped up in a little 3D Printed case!

Monday, July 11, 2016

N-Scale (1:160) Bascule Drawbridge - Animated by an Arduino

Have finally gotten to the point where I am shipping a copy of my latest model to someone in the States that will be incorporating it into their layout:

I got the idea for this model after doing a couple static bridges and originally was thinking about doing a lift bridge:

Once I started working on it I decided that it was both too big and too complicated (from a perspective of doing the animation).  I had already seen the Bascule type of bridge that I ended up modeling and had an idea of how to animate it ... so this project was born ... to model this bridge:

Here is a video of the final result.  It is not 100% finished as I have not got working tracks on it but that is why I was looking for a tester!  It should be noted that I was not after accuracy in rendering this model as my priorities were printability, ease of assembly, and ability to animate.  These requirements made some compromises necessary.

Here are the source files for the bridge and the lift mechanism as well as instructables covering assembly of the bridge, of the lift mechanism, and of the electronics.

This was a great project in that it combined some 3D Design and Printing that pushed my experience and the capabilities of my printers as well as combining the Arduino for animation.

Virtually everything that I design is "open source" under the "Creative Commons, Attribution, No Commercial Use" license and can be found here on Thingiverse!  I am also interested in project ideas so please reach out if you have one!

Saturday, July 9, 2016

Lubricating the Bowden Tube of an Ultimaker 2+ Printer

I have two Ultimaker 2+ (upgraded from 2's) that I have been running for 18 months.  Prior to these printers I had built a Prusa I3 and had a Makerbot Clone.

My number 1 recurring issue on my Ultimakers always seems to come back to extrusion.  I do a lot of atomic cleans, I regularly replace the teflon coupler, I keep the extruder gear clean, with the advent of removable nozzles, I change nozzles a lot.

What I have not done until recently is lubricate the bowden tube.  I did replace them with more slippery versions prior to the "+" upgrade which of course did come with new tubes.

The "+" upgrade certainly improved extrusion.  Startups are much more reliable without my attention (prior to the upgrade I often manually primed the nozzle just to be sure of a good startup).

Recently, however, my "+"'s have started to sputter a little on the extrusion front.  Having done all of the normal things that I have been doing I looked for something new that I have not tried and came across a suggestion to lubricate the bowden tube.  This suggestion was made on the 3D Hubs forum and since I had not seen it on the Ultimaker Forum I did a couple of searches and did find some references suggesting the use of dust filters that also lubricate.  The feedback was very mixed with recommendations that you not lubricate stuff going into the feeder.

I had used a filament cleaner on my Makertbot Clone and it did not seem to hurt so I decided to go ahead and try it on my Ultimakers.  The results have been profound (in a good way).  The only difference between the failed print, due to under extrusion, on the right and the near perfect print on the left was the addition of a filament filter that also lubricates:

The questions this leaves me with are:
  • First, is there a reason that I should NOT be doing this (as in will I see some long term harm)?
  • Second, what lubricant should I be using (right now I am using a high temperature nut oil)?
As I mentioned, I am now doing this on both of my printers and am really happy with the result though I have had to adjust my profiles to lower my extrusion adjustments to compensation for stuff getting to the nozzle more easily!

I do question myself as to why I have not done this before and wonder if my extrusion issues have been threshold related.   Meaning that I start to see issues at a certain threshold of resistance.   Say that "R" is resistance and R=100 is the point where problems start to occur.   Changing a nozzle gives you a benefit of -10, an atomic clean might add a little to that as it may also clean the boundary between the nozzle and the teflon coupler so maybe a -15 with a nozzle change.   Changing the teflon coupler gives you another boost, maybe a -30, depending on how bad it was.  In the meantime, however, the bowden tube has been adding resistance.   Say a +5 every month.   Once you hit the 100 you can improve things with nozzle changes, atomic cleans, and new teflon couplers, but the inexorable creep of resistance building inside the bowden tube will ultimately take you to the threshold and beyond.  Enter lubrication.

So...am I making any sense?   Why is lubricating the bowden tube not a more popular suggestion?

[Update of 14 July 2016]

Feedback on the Ultimaker forum has been sparse but with a concern raised in regards to strength of the ending component.  So I did a strength test with the before baseline being the results of a cooling based strength test that I did some months ago.  The result was a surprise in that the lubricated part was stronger than the non lubricated part.  I attribute this to the part being fully extruded.  The parts from the original test were not badly under extruded but may have been a little.......

The second concern that I have seen on other sites was in regards to vegetable oils ultimately clogging.  A suggestion was made to use silicon based oil so that is what I am planning on going forward.

Finally, below is a picture of the dust filter/lubricator in action: