Sunday, December 16, 2012

Kossel Build Continues

The Kossel build continues. This is an easy build for sure if you already have a 3d printer. The parts for the top part of the frame were printed and assembled over Thanksgiving holiday. The leveling and calibration maybe where the real challenges are.

I have been using AutoDesk 123D Design to create parts with. The effector and the rolling carriage were redesigned just because I wanted some CAD practice with the software and wanted some customized touches such as beveled hole entries  and more mounting features. From OpenSCAD I exported the Kossel master files to an STL and then imported into SketchUp. From there I made measurements and dimensions that helped me get it into 123D Design.

I had one redesign spin (so far) on the roller because I forgot the hole for the top endstop. In all the roller turned out great. The bearings are sitting very nicely centered on the flats.  The roller uses 6 - 623 bearings. Three on each side.  M3 screws are used all around with the exception of the string attachment which is is and M4. The four nuts that are used to pull the two halves together are nylocks.

Once I had all three rollers assembled and installed I worked on the top part of the frame.  I inserted the bearing into the line tensioners. At first it appeared to be too small to hold the bearing but I worked at it more and got it centered on the axial holes and it was fine. I inserted the plastic axel and the bearing spun freely. The tensioners and the axial were original Kossel designs.

The rest of the top frame pieces went together without much trouble. Assembly method was similar to the bottom frame but easier since there was only a single frame to contend with. Keeping all screws about a turn from fastened so the frame pieces can move allowed for theme to come together.

Installing the fishing line was a bit fiddley but the time I did the last one i kind of got the hang of it. I printed the clamp and followed the method described in this video.
Fishing Line Install on Rostock Kossel using Clamp

For the most part the string does well winding and unwinding neatly. I'm not quiet sure of the tension needed. For now I will not worry about it as I will turn my attention on making the rods and attaching them to the effector

Santa will be bringing a Panucatt Azteeg_X3controller. I will be using an old ATX power supply from the old McWire to power it.

Wednesday, November 28, 2012

New Project: Kossel

After seeing the Rostock DeltaBot in action I knew i had to have one. I orderded bearings, screws and nuts last week. So, i took advantage of Thanksgiving holiday/weekend and started printing parts.

At first I only printed one of the lower corner sets to see how it would fit together. The latest GitHub master had fixed alignment problems and everything fit well together.

My main tools for assembly were a 2.5mm ball end driver and some spring loaded tweezers. Forceps would work as well.
Here Re some instructions that go with included pictures. I am writing this with my phone and will have to make them inline later.


Populate these four hole locations of each frame_motor piece with 3 x 8 mm screws and jam nuts.
Attach each corner with two and M3 x 20 screws. All screws should be loose at this point.

Slide the extrusion onto the loosen screws as shown.

Load the other two corners with screws and nuts.Work these in to the extrusions at the same time with the screws loose.

Slide in vertical extrusions.
Once together go around and firm up the screws.

You can test mount the motors with M3x8 screws. Using tweezers can really help with this step.

Sunday, January 22, 2012

Drag and Drop Slic3ring

I am excited to see that Slic3r 0.6.0 is out!

Some new features of this new revision are:
  • Thin walls
  • New output file name format
  • Option to create output file names using configuration option values
  • Automatic retraction at the end of the print

The new naming option inspired me to write a batch file for drag & drop Slic3ring. It ended up to be pretty simple. Here's the setup I have at the moment.

On my desktop I have 3 batch files for 3 different print qualities:

Each batch file uses its own configuration file and has a customized output file format See the Slic3r readme for details.

Heres the contents of  draftSlic3r.bat:

echo on
cd %~p0
C:\slic3r\slic3r.exe --load "C:\Documents and Settings\bjbsquared\My Documents\My Dropbox\slic3r_mosaic_draft.ini" %1

When an STL file is drug and dropped on one of these, the batch file will launch Slic3r, load the configuration file and slice the STL. Theres not much feedback with Slic3r working in this mode. There is no GUI and you only know Slic3r is done when the command window says "Press any key to continue..."  . I don't know if there is any warning if Slic3r had problems because I haven't had any yet.