Kossel Progress

The kossel project has been a little delayed but is finally starting to get somewhere. The main delay was due my failed first attempt at getting the whole thing together and up and running, which was admittedly a little rushed and during the construction a few of the printed parts cracked. But the main issue was the rods for holding to the extruder to the towers were not glued well enough and came loose which meant calibration failed also they were not all the exact the same length.

To resolve this I:

  • Reprinted all of the parts in PETG (polyethylene terephthalate glycol-modified msds) which is less rigid, slightly flexible filament which is as strong as ABS but prints like PLA. However the filament did take some dialling in on the Hictop Prusa i3 mainly due to stringing which is common with PETG.
  • Unscrewed and drilled out the existing glue on all the rods, Then glued the rods back together use Gorilla Glue Epoxy, this time using a jig from thingiverse (here) to ensure the rods were at equal lengths. I let each rod set for an hour to ensure they were probably set before removing them.

Once all the parts were printed, I figured this time it would be better to get the machine together nicely instead of fast, towards that end:

  • I modified and attached the power supply unit to the back of the machine using some mounted I designed (here), I decided it would be easier to glue these on the PSU then printing something large to go around the unit which would of almost certainly restricted airflow from the fan.
  • Mounted the RepRap board using a mount that I found and on thingiverse (here) I had to modify it slightly to make it easier to print as I was having issues with the comb effect.
  • Designed and printed a mount for a relay to control the PS_ON from the PSU as for some reason I was unable to get ramps to directly close the circuit thus powering on the PSU. available here.
  • Printed a spool holder to go on top of the printer I found on thingiverse (here)

The current state of the machine is looking good, the next steps is to get everything calibrated and get a first print out of it, Providing of cause everything goes to plan!

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