The still progressing at a good pace but a lot of smaller and bigger problems have also been cropping up : on some days it really seems like ” solve one problem and 10 more will appear”:
Here is a rundown :


  • done an almost complete wiring test (albeit temporary),
  • the controller arduino is now running the Reprap gcode interpreter software
  • did the first curvy/ more complex drawing tests and precision seems quite ok
  • for the “2d” tests I used the Inkscape to Gcode extension that you can get here + a cleanup program i did in python
  • since replicatorG would not work correctly I whipped up a very basic python program to send the Gcode commands to the arduino ( using a slightly modified version of the code I use for my HydroDuino project) I might add a (very) minimal interface and make it available , as its very simple to use for basic tests
  • completely trivial , but the sound of the steppers , in particular when drawing spirals, is really hypnotizing : i knew steppers had a certain “musical” quality to them (hence the many people using them to play a varierty of tunes, but still, quite nice)
  • it seems i have almost everything i need to start working on a pinch wheel extruder , except for the nichrome wire and a few bits and bob, so i will begin work on that pretty soon

Problems :

  • wiring is a mess so I will have to build a specific screw shield for the arduino, also the current “front-top” placement of the electronics is not practical at all so i might go back to this type of setup:
  • the vertical axis is acting up again and is driving me nuts ( and bolts…) there is a massive 4 fold speed difference between the up and down movement , some heavy squeaking from time to time and in the worse case of of the threaded rods detached from the motor!! No good!
    • I am actually starting to wonder if the system i came up with to transmit the rotary movement to the axis platforms is at fault:
    • Or perhaps its is due to the axis bearing/rail system ? It is a generic piece that i can easily adjust ensuring a tight fit on both local axis, and very easy to build as-well
  • on some axis the transparent aquarium tubing I use to attach the motor axis to the threaded rods detach from time to time…so I will have to change that aswell
  • on those axis where the bearings have even just 0.5 mm play with the rails, the wobble is noticeable
  • the last of the steppers i was still using, for the X axis stopped working reliably, but i anticipated that , and installed one of the newer but heaver steppers
  • there is something weird and worry some going on with the new steppers: whenever they are working, if i touch the stepper, or any part of the box, i just STOPS , as if it was suddenly grounded or whatever: i really do not know where this is coming from, i double checked all the wiring, and the circuits are already correctly grounded : perhaps the new steppers cables are not insulated properly ?

And for the usual “video bonus”:

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One thought on “Building a repstrap (4) progress and problems

  • July 9, 2010 at 09:42

    So I guess, in the video, we can hear the hypnotizing sound, right?
    It looks like outer space music.
    But it’s nice.


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