Build Your Own SLA/SLS

Hi All!

Currently trying to develop a low-level light bottom-up printer.

The images from the rudimentary prototype are distorted in very repeatable ways: -

- Initially layers are small and increase in area to a constant X-Y geometry.

- Cube templates taper to a point (not consistent directionality) in the X-Y plane, which also confers with an overhang in the Z-plane at this point.

Overhang in Z Axis

I have read a lot of information on this website, which has helped me immensely and am very aware of the skill base that exists. I would be immensely grateful if you very knowledgeable and sharing folk would offer your expert advice and opinion on this issue.

Thank you so much for your time.

I should perhaps explain it is a UV LCD arrangement with Sylgard 184 screen cover at 1mm thk.

Initial thoughts are a combination of light behaviour through the various screen layers, progressive residual temperature increase generated by screen electrical components and bias toward light source (edge-lit currently).

Please explain how you are using UV with an LCD? LCD's block UV.

If you are indeed using an LCD, what LCD panel? Light source?

LCD printers do not suffer from X-Y scaling issues, your X-Y dimension is determined by the actual image size on the LCD. The X-Y should not change as its fixed by the LCD.

Post up some pictures of your setup.

Thank you for your reply....much appreciated!

I have butchered the LCD display to remove UV damaged part. I have used UV strip lighting along top edge close to screen components.

I managed to figure it out with a lot of surfing the various 3D boards.

It is a combination of favourable growth in the direction of the light (top of LCD screen) combined with stress-induced alteration of the 'green' resin due to the peel mechanism and slight misalignment of the print platform in the y-axis, causing peel to start in one corner, rather than at one edge, resulting in 'bulging' at the lowest point due to compression.

I will be doing further trials to confirm this, nevertheless your input is greatly appreciated....thank you