This Blog is now closed

I have now moved the blog to its own wordpress site, apapageek.com, so all future blogging will be there.

Thanks you all those that have been reading this blog.

Geoff

When I win the lotto I want one of these machines.

http://bit.ly/18jMO9x

Interesting camera

I think this could be trained to recognize SMD parts for an automated pick and place machine.

http://www.kickstarter.com/projects/254449872/pixy-cmucam5-a-fast-easy-to-use-vision-sensor

3D Printer filament

I came across this on hackerday.com, it will be interesting to see the results.

http://bit.ly/19kwGbn

Delays

I've had a temporary set back in my cancer treatment am not strong enough to do any reprap stuff ATM. Back at it in a couple of weeks.

Printing a Robot Arm

For quite a while now the objects I have been printing have all had to do with extending, or improving, my Prusa.  So I decided that it was about time that I had  go at printing something else less machine  oriented.

So I found this on Thingiverse (Micro Robot Arm) and thought it would be fun to print it and to write the Arduino code to control it.

So the servos are ordered and I am starting to print the parts.  Photos and details to follow as the construction proceeds.

Update: 10 June

The main parts for the arm are printed, I am having problems printing the rack and gear.

Still waiting for the servos to arrive.

The future of 3D printing

It is nice to come across a post that helps to inspire you and make you feel that we are on the right track for the next generation.  Last year I took my Prusa to our local christmas faire and it was the kids who were most fascinated, a 6 year old who wanted one for making robots and a 10 year old girl who followed what was happening and pointed out at one point when I had forgotten to switch on the heated bed.  They get it.

So does this young inventor: An 11 year old and his 3d printer.

Making money on the side

My other half often asks if my 3D printer is ever going to make money (earn rather than print).  Up until today it seemed that the only way was to find local people who want to have something printed and to charge them  Finding these people has just got easier.  Enter MakerXYZ.

Raspberry PI Camera is now shipping.

I have been interested in the Raspberry PI with a view to using it as a driver for my Prusa, or as a general 3D processing workstation. e.g. Automating the production of GCode etc.  Well yesterday I found out that RS are now shipping the long awaited PI Camera module.  Well I just had to buy one and it should arrive soon.  I will post us my impressions of it once I get my hands on it.

Pi Camera module now shipping

People may have noticed that I have not been posting much lately.  This is because I have been diagnosed with cancer of the colon.  However, we are trying some alternative cures and the chemo, whilst tough, does seem to be having a positive effect.

I will be using some of my spare time to complete the hadron plus some accessories such as a simple laser  cutting head. So watch this space.

Building a Hadron

I've been fairly busy with work and Quick2Wire.com the past few months and my 3D printer has pretty much taken the back seat.  But one of the things I have been doing is gathering the parts to build an OrdBot Hadron.  This was given a big boost by the successful funding of a European MakerSlide project on ulule.com.

This weekend most of the parts have finally arrived and so I started the build.

The Y Assembly

Some of it went smoothly, but I found that one of the laser cut parts, the Gantry Plate, was totally the wrong size.

Upon investigation I found that the DXF file I originally used was wrong.  Fortunately the others were OK, so I only have to get that plate re-cut.








Serves me right for forgetting the old adage 'Measure twice, cut once'.  In this case, check that the dimensions make sense before sending the DXF off to be cut.

So project is back on hold until the reworked plates arrive.

I had the laser cutting done by 4D Modelshop in London.  An excellent service and really helpful to a novice in Laser cutting. I highly recommend them.

More once the new Gantry Plates arrive!

Motor Bracket

Y Carriage Leg

3D Printing is safe.

I came across this interesting post on Instructables.  It basically says that 3D Printers do not release dangerous levels of gasses when printing ABS and so long as you do not poke your fingers in the machine while it is printing it is safe :)

http://www.instructables.com/id/Is-3D-Printing-Safe-or-DIY-Testing-for-HCN-from-/

Kinect-Like 3D camera

I have recently been looking around the net for 3D camera/scanning projects, yesterday I came across this. It looks quite interesting and if you scanned both sides of the object and joined them it would make a cheap 3D scanner.



Once the Quick2wire.com project is underway I might get a BeagleBoard and give it a try.

Kinect-Like 3D camera 

Quick2Wire.com

One of the reasons I have been distracted from my Prusa over the past couple of weeks is Quick2Wire.com.

A group of us have got together and started to build a series of add-on boards for the Raspberry PI.  The first board will allow you to connect the PI to the outside world and will provide an API that can drive the connected devices.  It is early days yet, but I can see several projects evolving out of this.

Why not checkout Quick2wire.com. Sign up for the mailing list and we will keep you posted on our progress.

Slic3r 0.7.0

The next iteration of Slic3r has been released and has some nice additions.  For a start the slicing algorithm has been written and seems to be faster. It also is far far more tolerant of badly constructed STL file.  I tried two that I always had to fix before using V6 and they sailed though V7 with no errors and the generated gcode files look good too.

It has a new option to select the gcode variant you want to generate, e.g. Marlin/Sprinter.

It has a new option to control cooling. I do not have a machine controlled fan on my machine, so at the moment I can't try this out.

And what we have all been waiting for :---- an option to generate Support Material.

The few prints I managed to do this weekend looked as good as ever.  Next session I am going to try the support features.  I will post up some results when I do.

If you haven't tried Slic3r you should http://slic3r.org

Community

It never ceases to amaze me on the quality, generosity and level of sharing in the RepRap community.

I recently started using Slic3r and was getting fairly good prints, then I discovered RichRap's blog Slic3r is nicer with some excellent posts on how to setup and get the best out of Slic3r.  Excellent, and what's more my prints are now ever better.

That someone took the time to experiment with the various setting, and then made the time to share that information with the rest of the community is what makes Open Source and RepRap in particular a great place to hang out.

Automated stl creation and slicing.

Kaizen is the Japanese technique of continuous improvement. I.E. Spotting an area in your current process where a small change would make an improvement.

Recently I posted an OpenSCAD / STL file to Thingiverse but did not realise that when being sliced it came up with the dreaded 'your mesh is not manifold' error. To fix this I went back though the OpenSCAD file commenting out an operation and running a Render/Export from OpenSCAD, then running a slice with Slic3r until I found the operation that caused the error.  Each time this involved several clicks of the mouse, selecting in dialog boxes etc.  Eventually I thought there must be a different way.

Looking at the OpenSCAD and Slic3r documentation I realised there was.  Both have a command line option, so I could write a quick script to automate the operation.

The first stumbling block, this is computers there are always stumbling blocks, was that I work on a Mac and to execute either program from a script / command line is a bit cumbersome, so I created a symbolic link for each that made them easily accessible from the command line.
   sudo ln -s /Applications/OpenSCAD.app/Contents/MacOS/OpenSCAD /usr/local/bin/openscad   
and
   sudo ln -s /Applications/Slic3r.app/Contents/MacOS/slic3r /usr/local/bin/slic3r   
Now from a Terminal session I can type openscad or slic3r and the application opens up.

The next thing was to create a shell script that uses those.

In my local work directory I created a file, oss, that contains the following:

   #!/bin/bash   
   openscad -s $1.stl  $1.scad   
   slic3r --load ~/projects/mechanical/Slic3rConfigs/yellow_abs.INI --gcode-arcs $1.stl   

The #!/bin/bash line indicates which shell processor is required.

The $1 represents the first parameter after the script name

The openscad line processes the scad file and outputs an stl file with the same filename, but stl prefix.

The slic3r line loads my standard config file for the ABS filament currently in my Prusa. This will need to be edited when I load a different filament into the machine.

The --gcode-arcs option enables an experimental option in Slic3r that uses G2/G3 codes to draw arcs.  Not all firmwares support this, I use Marlin which does.

Having saved the file I setup another symbolic link to allow oss to be executed from anywhere. So:

   ln -s full_path_to_oss /usr/local/bin/oss   

On my machine the full path is /Users/geoffd/projects/mechanical/oss, you need to use the one for your configuration.

And that's it, now I can switch to the directory containing my scad files, type oss filename, press return and within a few seconds my file has been rendered, exported as stl and sliced for my current setup.  Kaizen in action.

For more details of the available command line options see OpenSCAD and Slic3r under command line usage.

As I said I use a Mac, so these instructions will also work on a Linux machine, but with slightly different source paths for the symbolic links.  On Windows you will need to use a batch file and full paths names.  I haven't used Windows for quite some time and don't have access to a machine that I can try them on.

Happy slicing.



 

Prusa Adjustable Z opto Endstop

I have been finding it difficult to adjust the Z axis end stop on my Prusa. I am normally able to get it to the correct ball park, but getting the adjustment of the bed to extruder spacing correct was taking some time. Each time I moved the end stop up or down I would move it too far.

So I came up with this solution.

It consists of two parts, the top plate holds the opto sensor and has a cable tie to hold the wires securely. The bottom plate mounts to the machine and fastens two bolts with spring and nuts to provide tension for the top plate. A bolt with a locking nut is used to move the opto sensor up and down by small amounts.

Full assembly instructions and the OpenScad and STL file can be found here on Thingiverse.

Second attempt at the PCB

This one came out much better.

I moved two connectors so that they lined up better, then made the signal lines slightly thinner.  This time the board auto-routed without me needing to manually route any lines. I then moved some of the tracks to be horizontal/vertical instead of diagonal, and I moved some of the marginal lines further apart.

When I plotted it only one pad was too close to another, but the SO08 pads still, as expected, merged and will need manual rework with a knife.

Here is the original.

And here is the annotated version.

1. Same as before these two pads should be separate.

2. These two should not be so close.

So the next step is to do that and then etch the board.

First PCB Plot.

So today I tried my first plot of a PCB.

Pretty pleased with it. There are some problems, but nothing too show stopping that a rework of the board layout won't cure, except one, and that can be solved by manually retouching the board before etching.

Here is the board as printed.

And here it is with marked with some of the problems.

1. Tracks touching each other.  Most of these can be solved by making sure the tracks are not so close on the board.
2. I reran the print to deposit a second layer of ink, but the pen went dry, so scraped the first layer off.  I will try to retouch these with the new pen I need to go and buy.
3. The diagonal tracks seem the be drawn too thick. It needs further investigation
4. The pads for the SO08 chips were drawn so that they touched, either I need a finer pen, or I need to retouch these manually.

So overall I am please with the way the first board came out.

Looking at the board as it printed I think I might be able to make the track widths slightly smaller, this would reduce the possibility of two tracks merging.