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Print does not stick


#1

Hello,

we got a new Titan 2 in the lab.
After unwrapping I followed the installation manual. Z-Axis was unresponsive, until I found unplugged arduino wiring. Since then it was moving properly. I did set the Z-Zero manually, lowering the platform, losing the ball knob and moving short steps until full contact achieved.

Then proceeded to the first calibration print. Calibration grid from the projector had the right dimensions. So I poured HT resin and started printing, from 1.0 mm z-height. The print does not stick on the platform. I have tried three times with different initial z-level heights from 0 to 3 mm with similar output (picture attached). I have always printed between 100-150 layers.
I guess, the print is not lifted from the platform at all. As I find it always on the bottom, but can’t say for sure, due to its opaqueness.

I tried prolonging exposure for the first 10 layers to 25 seconds with no effect.

Would be happy for any advice. I have done a lot FDM printing, but this is quite new to me… :slight_smile:
Tom


#2

Is there a particular reason you tried starting the print at higher Z? Generally speaking, build plate adhesion issues have to do with an insufficient light dose at the surface of the plate for the initial layer, so moving the build plate higher will make the problem worse, since you’re moving the plate further away from the light source. Usually, if I have build plate adhesion issues, I will adjust my calibration to move the Z=0 level of the plate lower, or increase the initial layer time.

However, before make any changes, it would be good to validate a few basic things.

  1. What XY resolution are you printing at?
  2. Which Spot-HT are you using? Grey or bronze?

The recommend initial layer time is 10 times the normal layer dose based on the chart at:

So based on the type and resolution you are printing at, you would do something different. Make sure to dial in the layer settings for the first layer and base layer zones as recommended. If, at the recommended times, you are still having adhesion problems, then try changing the Z=0 level to be slightly lower, moving in 0.1mm increments. The amount of distance you need to move if the build plate is already fully flush against the vat is very small in order to get a very big difference in adhesion.

Also, if you do find that you need to tweak exposure times for build plate adhesion issues, you should only adjust the first layer, and not the higher layers. Increased exposure times will increase the amount of adhesion on both sides of a printing part, meaning both the build plate side and the vat side. Increasing the first layer will increase the amount of adhesion to the build plate, but increasing later layers will make it more likely that the part will pull off the build plate due to vat adhesion.


#3

Thanks for the reply.
First, to the questions. I use HT grey. And the printing resolution now is projector default - 1080x1920, 50um thickness.
My intention is to do later as high resolution as possible (I have designed features down to couple micron dimensions), so I will do re-calibration on 37um resolution at some latter point. Now, I need to get things running smoothly, before I try anything more complicated. :slight_smile:
As I was printing the default Kudo3DCalibration_5050, I dare not to change the .csv for curing at first. When I failed twice, I tried to increase time for the first layer to 25s, 2-10th layer to 10s, everything else kept as original.

Why I tried different z starting points? I probably misunderstood the first manual, where I was supposed to lift the vat. But I thought it is weird to get further away from the light source…

I will try tomorrow to lower the vat even a bit more, yet I already feel it is touching the bottom. However, not bending the container yet.