I have spent most of the evening trying to print PrimaSelect PETG and finally we have succeeded!
My initial problem was that I did not get it to stick hard enough on the BuildTak. Tried all possible settings to make it more firm on the surface, but nothing worked.
The first thing I did today was to sand the BuildTak with a fine sandpaper (steel wool type) then I cleaned up thoroughly with Kemetyl and did the same process again. It´s now sticking good, but not good enough and still messy print).
Kemetyl’s T-Red consists of 50-75% ethanol, 10- <15% propan-2-ol, 5 – <7.5% butanone and 1 – <2.5% acetone
The second thing was to study the first layer. Here I clearly saw that the layers did not go well enough together. So The next thing was to adjust the Z-offset (in my case P-offset, Probe offset)
I adjusted back and forth from what has worked relatively well on my previous tests. P-offset was adjusted in the range from 0.00 to -0.150. With the different settings the stick had was quite different. My main goal here was to get the stick perfect before mowing on to other beauty adjustments and the durability of infill. In my case I found the P-offset -0.125 to be absolutely perfect, a very stick and still relatively easy to remove. So I was a happy camper.
Now the next thing. Getting the perfect first layer. So, I started trying to see how the first layer lay down on the bed. I immediately saw that small details still had difficulty attaching to the build plate. So I adjusted the first layer speed down to 10mm/s and it was a winner. All strings where sticking (even minimal details).
In addition, I now examined how the layers look and how the model was looking as a whole. It was not very nice. Zits and blobs are all over the place. I also saw that filament was sticking on the nozzle and this contribution to the mess. So I set first layer flow rate down to 95% and Immediately saw less filaments stuck on the nozzle and also less mess overall.
I made temperature tower to verify the perfect temperature for the PrimaSelect PETG (rated at 195-235C on the box. I split the different sections of the temperatures zones and pulled the layers to see where is was the strongest and the weakest. In my opinion, it was strongest at 245C but the bridging was a mess. The best bridging was seen at 220C but it was a bit weak. I decided to go for 235C in the end.
So now things are starting to looking better. I did a few test runs and decided to turn back the flow rate for bottom and top to 95% And was quite happy with the result.
I now checked the infill checking the strength and the looks. It it seemed a bit weak and looked a bit messy. I googled around a bit and found that the max speed should not be more then 70mm/s for PETG. I set the recommended speed of 50mm/s giving the layers time to lay down. It was now looking better and a lot felt better. the model seems solid and sustainable.
Here is the final result (some small things still left to adjust) I think I will need to check the react amount material. At least I can print now! 😉
Do you have any suggestions on settings to tweak for a better result?