Thermoplastic Elastomer Printing
Posted by ttsalo
|
Thermoplastic Elastomer Printing April 03, 2012 05:13AM |
I finally got my new geared extruder up and running so I decided to try printing with the thermoplastic elastomer (TPE) which I bought from orbi-tech.de.
Here's my very first print, a 15mm cube which ended up being 9mm tall:
Here's a couple of other views: TPE printing
It's not very pretty, but it's solid, rubbery and close enough to the model that overall I'm pretty happy to get something like that as the first print.
Some notes about printing with it:
- As someone said in another thread, rubbery stuff like this has a pretty big delay from extruder input to extruder output. If you prime the extruding by hand and start the print, by the time the printer has homed and started the print, one skirt loop isn't enough to get the extrusion going. Using retraction is obviously completely out of the question.
- On the other hand, if you print at low, constant speed (I tried 10 and 15 mm/s) and use fast acceleration rate and move speed, the delay doesn't have that much effect on the printed shape. The extruder doesn't have time to ooze much while it's moving to another location.
- It's so flexible that the extruder has to have complete guiding for the filament. I'm using the Greg's Wade reloaded extruder and it has pretty good guiding, but there's just a bit too much space between the idler bearing and the filament channel and sooner or later the filament produces a kink there and starts slipping. I made a modified model which should eliminate the extra space, I'll just have to print that.
- My filament driver is a bolt with 12 slots cut into it (about 1mm wide slots with 1mm spacing). The slots have sharp edges and seem to grip the filament pretty well. Actually it works much better for TPE than ABS, it's worthless for printing ABS.
- Looks like you can simply interchange ABS and TPE in the extruder, but the extruded filament is pretty funny for a while after going from ABS to TPE. It has a core of TPE and a sheath of ABS, and if you stretch it, the ABS flakes off. I used the same 260C for both.
- It seems to stick onto the PET tape at 110C reasonably well. It seems to contract more than ABS when cooling, but since it's so flexible, the object itself ends up contracting from the sides instead of corners being pulled up.
- It also sort of looks like the extruded filament doesn't want to be squashed flat. I was using a 0.5mm nozzle, 0.25 layers and 2.0 W/T setting with Slic3r, and especially the perimeters showed signs of the filament being stretched too much (some of the perimeters were a total mess for the first few mm but became neater at upper layers). What I mean is that when the 0.25*0.5mm track tries to contract into a more circular shape after exiting the nozzle, it starts breaking up. At least this is what it looked like. This needs a bit of experimenting...
Edited 1 time(s). Last edit at 04/03/2012 05:16AM by ttsalo.
Here's my very first print, a 15mm cube which ended up being 9mm tall:
Here's a couple of other views: TPE printing
It's not very pretty, but it's solid, rubbery and close enough to the model that overall I'm pretty happy to get something like that as the first print.
Some notes about printing with it:
- As someone said in another thread, rubbery stuff like this has a pretty big delay from extruder input to extruder output. If you prime the extruding by hand and start the print, by the time the printer has homed and started the print, one skirt loop isn't enough to get the extrusion going. Using retraction is obviously completely out of the question.
- On the other hand, if you print at low, constant speed (I tried 10 and 15 mm/s) and use fast acceleration rate and move speed, the delay doesn't have that much effect on the printed shape. The extruder doesn't have time to ooze much while it's moving to another location.
- It's so flexible that the extruder has to have complete guiding for the filament. I'm using the Greg's Wade reloaded extruder and it has pretty good guiding, but there's just a bit too much space between the idler bearing and the filament channel and sooner or later the filament produces a kink there and starts slipping. I made a modified model which should eliminate the extra space, I'll just have to print that.
- My filament driver is a bolt with 12 slots cut into it (about 1mm wide slots with 1mm spacing). The slots have sharp edges and seem to grip the filament pretty well. Actually it works much better for TPE than ABS, it's worthless for printing ABS.
- Looks like you can simply interchange ABS and TPE in the extruder, but the extruded filament is pretty funny for a while after going from ABS to TPE. It has a core of TPE and a sheath of ABS, and if you stretch it, the ABS flakes off. I used the same 260C for both.
- It seems to stick onto the PET tape at 110C reasonably well. It seems to contract more than ABS when cooling, but since it's so flexible, the object itself ends up contracting from the sides instead of corners being pulled up.
- It also sort of looks like the extruded filament doesn't want to be squashed flat. I was using a 0.5mm nozzle, 0.25 layers and 2.0 W/T setting with Slic3r, and especially the perimeters showed signs of the filament being stretched too much (some of the perimeters were a total mess for the first few mm but became neater at upper layers). What I mean is that when the 0.25*0.5mm track tries to contract into a more circular shape after exiting the nozzle, it starts breaking up. At least this is what it looked like. This needs a bit of experimenting...
Edited 1 time(s). Last edit at 04/03/2012 05:16AM by ttsalo.
Sorry, only registered users may post in this forum.