Putting a TPU Shell on a PLA part

[vangalvin]

I have a part i would like to put a TPU shell on. The shape is a dome and I was wondering if it would be possible to first print the part in PLA then once printed put the TPU in and have that printed on top of the PLA. My printer only has a single head at the moment so doing it this way seem to be the only option at the moment unless i print the two parts separate and glue them together however I would like them to fit perfectly and printing one on top of the other would do this.

I realize that there will be restrictions as to how deep I can go without the head hitting the pre-printed PLA base but the angles of the dome are not overly steep so should have plenty of clearance.

Any ideas as to how this could be done?

[dorsai3d]

If you design it so that it will clear your nozzle (and make sure that your start sequence won't run into the finished part), you could run them as sequential prints right on top of one another. You'd be pretty limited in geometry, though. Is there a reason why something like plastidip wouldn't work instead of trying to print the coating on?

[vangalvin]

I am trying to find a TPU that is conductive, If i have no puck with this I may end up just using conductive PLA or ABS.
the main form needs to have 2 conductive strips on it and this seemed to be the easiest way to do it. However I may end up having to bite the bulolet and put a dual feeder on the machine so I can do this properly.

[ear0wax]

How would you set this up with dual extrusion?
What would the process settings be??
I figure for Tpu 1 shell 1 top 1 bottom 0% infill but what about the pla process?
How do you have it remove one outer shell so there is no overlap?


I like this idea of a tpu coating, or any material for the coating really.