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.

Friday, September 30, 2016

3D Printing Challenge

Every once in awhile something stumps me with my printers.  This is a test print of some tiny little reinforcing panels for one of my bridge designs.  The little dots are meant to be bolts or rivets.  The print is done using a 250 micron nozzle and 125 micron layers in PLA.

The panels printed at top, in normal orientation are fine, but the ones that are rotated by 45 degrees are not.  I suspect this is a belt tension issue but am not sure!




Thursday, September 29, 2016

Bowden Tube Friction

The bowden tube I mention is the teflon tube that moves filament from the extruder to the nozzle.  The use of a bowden tube, with the stepper motor on the back of the printer, helps make the Ultimaker 2 more accurate and speedy as it takes weight out of the moving print assembly.

I have two Ultimaker 2's upgraded this summer to 2+'s.   The + upgrade, and its new feeder, has really helped with my extrusion reliability but I am struggling at the moment with one of the printers and during debugging I observed a distinct difference in material flow between the front right and left rear of the build platform.

The below chart shows weights for a small test object printed on two locations of the build platform with #1 being the right side closest to the door and #2 being the back left.


With two out of two printers behaving this way, and some other posts on the same topic seemingly reporting similar things, it would seem this is not an unusual behaviour?   What percentage difference is tolerable?   I have not noticed an issue with a print but may need to watch more carefully!

Monday, September 5, 2016

Need a Custom Designed, 3D Printed, Model for your N-Scale Layout?

If you live in the UK and are actively building or upgrading an N-Scale model railroad layout, AND, you are interested in having some custom designed, 3D Printed, structures for that layout, please reach out to me either here or on Facebook.

My rates are very reasonable...just your time integrating my work into your layout and providing me feedback on the designs along with some photos of the finished product (and ideally the work in progress).  I am retired and do 3D design and printing for kicks but since I do not have the space for a layout of my own I am hoping to see my work on your layout...and I like getting ideas and seeing if I can turn the idea into a model.  My idea project idea would be for an animated structure but any other creative thoughts for things not readily available will be considered!

Below are images of some of the work that I have done.   All of these designs are in the public domain on Thingiverse for folks that have their own 3D Printer:

Parts of a Bascule Style Drawbridge

Design Rendering
Instructables for the Bascule Style Drawbridge: One, Two, Three, and Four

A Truss Railroad Bridge

Plate and Girder Railroad Bridge

Windmill


Bailey Bridge (1:100 Scale)

Field Wagon (1:100 Scale)

Best Approach for an Entry Level Printer

This is a follow-on to the article that I wrote a while ago in regards to what 3D Printer I would recommend.   I had a question about an entry level printer, in particular regarding kits, and thought I would add to my previous article.

My first recommendation would be that if you are going to build a kit...build a Prusa I3.   This is by far the most popular type of kit and there will be a lot of support from other users.

The kit that I originally assembled is still available from 3D Printer Czar in China but the price ($499) is certainly not the lowest that can be found for a kit.  In fact, and more on this in a bit, there are ready assembled I3's for that price.   I am not sure what the "best" kit is at this point but if I were looking for the lowest cost Prusa I3 printer I would go to eBay and do a search for "Prusa I3 3D Printer Kit".  I filtered the list by value to 100-500 quid to get rid of kit parts and checked the box for UK only stock.   This yielded a list of printers from just over 100 GBP to the top end of 279 GBP.

I am not familiar with any of these kits but would advise spending some time reading the listing carefully and looking at customer reviews.  I would recommend an aluminum frame for the extra sturdiness though my printer and its plastic frame worked just fine.   I would probably not go with one of the very cheapest kits but if you are really strapped for cash it could be worth the risk.  The worst case is that you may have to source an additional part or two from a range of readily available stock.  I suspect, though I am not completely sure of this, but you are going to be on your own when it comes to doing the build in any case of these kits!

Building one of these inexpensive kits is going to be somewhat of a challenge and it is going to be a while before you print your first object.   When you are finally printing it is going to take another chunk of time to get the printer tuned and calibrated so that prints are of good quality and can be done reliably.  On the plus side...you will have learned a lot.

I am not sure that I would do it differently but there are some entry level printers out there now that I think would be worth considering.   My particular favorite is the Wanhao Duplicator I3.  This is a ready built Prusa I3 and while I do not have experience with it directly I did have a Wanhao Duplicator D4S and thought it was pretty well done.  A ready to go printer, with the glass bed and a can of print bonding spray, will cost you 309 GBP.   This is 100-150 quid more than a kit (with a metal frame) but you will be printing from day one.

There are some other entry level printers in a similar price range to the Wanhao that I describe above but I like the idea of the Prusa I3 as it is open source...if you want to upgrade it you will be able to do so.  Some of the other entry level printers will not allow this as an option.

That is my two cents.

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!