LanternFish - DIY Flap Flat Panel

[kbrown]

Been working on this motorised flap flat panel for quite some time already. Thought I'd finally post something about it as I just got the flap opening and closing properly for the first time. I initially designed this around the 28BYJ-48 stepper but that just turned out to be too weak. I did manage it to make it move by converting a 5V version to bipolar mode and driving it with 12V. But as soon as you removed power the gravity would take over and the flap would be a bit too flappy...  Keeping the motor energised continuously would have made it too hot over time and it probably would have not lasted very long so I decided to go with a high torque servo instead. This one is using a Hiwonder LDX-227 servo. Seems plenty strong for this application.

The flat panel itself is still work in progress. My original idea was to shine the light straight to the edges of the diffusing perspex but that didn't work out very well so I started experimenting with other ideas. At the moment the LED strip ring is hidden behind the diffusing perspex and reflecting off a reflector (aluminum foil on a concave surface). To the eye it looks pretty flat but if I take a photo of it and stretch the levels, you'll start to see a bit of a gradient. Whether this is a problem, I'm not sure... More about this later...

 

 

[PlankWithANailIn]

If your imaging setup has vignetting and most do then you would expect see a gradient, the only way to be sure is to use it against real data and see what happens. 

[rsarwar]

Hi. I am in the process of making one as well. 

For led strip I am using these 13cm Diameter Backlight Panel 
https://a.aliexpress.com/_mMybhPc

It means there is an inverter I have to include along with a rpi pico to control it, but the light from it is well balanced I think.... Have to confirm, item still on its way. 

 

Still going to use a defuse to mitigate hots tops or lines

Edited July 30, 2022 by rsarwar

[kbrown]

15 hours ago, rsarwar said:

Hi. I am in the process of making one as well. 

For led strip I am using these 13cm Diameter Backlight Panel 
https://a.aliexpress.com/_mMybhPc

It means there is an inverter I have to include along with a rpi pico to control it, but the light from it is well balanced I think.... Have to confirm, item still on its way. 

 

Still going to use a defuse to mitigate hots tops or lines

Yes, EL panel is probably the better choice for better flatness. But it does require more electronics and isn't so easy to control brightness with.

I'm still tweaking my setup and haven't been able to verify whether my design is good enough yet or not.

Edited July 31, 2022 by kbrown

[Synchronicity]

21 hours ago, rsarwar said:

For led strip I am using these 13cm Diameter Backlight Panel 
https://a.aliexpress.com/_mMybhPc

I spent some time designing a cap that I could put over the end of the scope with a switchable light that would allow the setup to do darks and flats automatically.  The lighting was becoming far too complex to achieve something flat so I parked it.  I might just order one of those panels and resurrect the idea!

Michael

[rsarwar]

Got the EL panels. Very flat. The lines appear only with shutter speed less than 1/250. The examples is with 1/4000.

Will need to be dimmed, I am adding a opal acrylic which should reduce brightness. Will see what happens with lower voltage 

 

Edit-- lowered voltage from 12 v to 5v, and the brightness scales accordingly. Power draw drops from 1.5 w to 0.2 w. 

Edited August 9, 2022 by rsarwar

[Dr_Ju_ju]

To get around the problem of the lines, you can use electroluminescent panels e.g.   https://www.ebay.co.uk/itm/233203448748?hash=item364c023bac:g:tboAAOSwt5hYdNSl&var=532702488185