nanoDLP

mandreas

Member

Registered: 2016-03-13

Posts: 136

Dimming honeycomb structure

Hi Shahin,

it would be useful to have a dimming function that creates inside a honeycomb structure,
in large size models they would be light but also robust,

Andrea

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,541

Re: Dimming honeycomb structure

Hi Andrea,

I think it is automatic hollowing and not dimming. I will work on it to see if it could be easily integrated in nanodlp or not.
But generally these kind of structure require complete knowledge of all layers to know where could be hollowed. It will increase workload on nanodlp substantially.

mandreas

Member

Registered: 2016-03-13

Posts: 136

Re: Dimming honeycomb structure

Hi Andrea,

I think it is automatic hollowing and not dimming. I will work on it to see if it could be easily integrated in nanodlp or not.
But generally these kind of structure require complete knowledge of all layers to know where could be hollowed. It will increase workload on nanodlp substantially.

Thank you for wanting to to evaluate this function,
you're right it would be more technically speaking an hollowed, unless there is a way, with the dimming algorithm, which instructs it to start, for example, (xx) mm from the tangent of the outer edge,
(Just an 'idea, from a totally ignorant person like me about  programming)

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,541

Re: Dimming honeycomb structure

We are doing such check in 2d plane. But having that in 3d space will require much more processing.
Still I think it is quite useful feature so I will investigate possible solutions.

Xmike

Member

Registered: 2016-03-25

Posts: 97

Re: Dimming honeycomb structure

How will you remove the resin out of this structure after print ?

mandreas

Member

Registered: 2016-03-13

Posts: 136

Re: Dimming honeycomb structure

How will you remove the resin out of this structure after print ?

another big problem indeed !

mandreas

Member

Registered: 2016-03-13

Posts: 136

Re: Dimming honeycomb structure

the solution to this problem could be the following:
instruct the program that executes the dimming / hollowed, but from point A to B runs the Honeycomb...

Kvirre

Member

Registered: 2016-08-07

Posts: 47

Re: Dimming honeycomb structure

You guys should have a look at this
http://lattice-infill.spark.autodesk.com/

heavypoly

Member

Registered: 2017-01-12

Posts: 14

Re: Dimming honeycomb structure

Agreed, even a 2D honeycomb or hatching pattern as used in the FDM slicers would be greatly helpful.  In those slicers they give you an option for how many solid bottom and solid top layers to have, the middle layers are hollowed with a patterned infill

adam

Member

Registered: 2016-02-18

Posts: 100

Re: Dimming honeycomb structure

exactly, for a simple version you would not need to have knowledge about volumetric structure. You could solve this by using the existing dimming, but instead of dimmed pixels just overlay a static hexagonal pattern. It won't be pretty but it would do it's job. getting the resin out is a pain though. A every hollow pillar is closed, you would need one hole per cell which is not practical when using a simple infill.

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,541

Re: Dimming honeycomb structure

As you mentioned if the structure get closed, only for tall objects you could save some resins as lots of resins will get blocked inside.

But the main issue is the performance and memory issue. Lets say you need wall thick as 5 layers. So for each layer we need data belong for next 5 layers and 5 previous layers.
Each layer we have 1920x1080 pixels each pixel is equal to 4 bytes so we will require 88MB memory. For 4K display it will be 352MB.

There is a workaround but it will need lots of time to develop. Will try to put some time into it after finishing new support generator.

heavypoly

Member

Registered: 2017-01-12

Posts: 14

Re: Dimming honeycomb structure

Getting the resin out is a problem, but aside from that, hollowing helps minimize thick cross sections warping.  In some geometries it could work even without any honeycomb structure, just pure hollow.

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,541

Re: Dimming honeycomb structure

Hexagonal infill is available on the beta version.

heavypoly

Member

Registered: 2017-01-12

Posts: 14

Re: Dimming honeycomb structure

Amazing....thanks Shahin!

macdarren

Member

Registered: 2017-03-20

Posts: 411

Re: Dimming honeycomb structure

every time I have tried to check out the infill feature my Pi crashes...:(..

web interface stops responding...some time ssh too and I have to power cycle...
when it comes back up slicing resumes followed by a crash, so I have to power cycle and quickly delete the plate.

looks like a another great feature....would love to try it out...for now given the above I think I will wait for the next release.

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,541

Re: Dimming honeycomb structure

Darren,

Try it on smaller plates. Maybe it is a performance issue. Also do you see any abnormality on dashboard (high memory or cpu usage)?

macdarren

Member

Registered: 2017-03-20

Posts: 411

Re: Dimming honeycomb structure

here is a link to see the dashboard right before the Pi crash...as you can see it does do some layers, it should have been into the 'Infil' section at this point I think.
This was a small model (same one shown in my posting about the missing support types)
I let it run all night just to be sure it was actually crashed and not just super super busy...but this morning I can't connect so I think it is a crash.

I also previously tried a super simple model (just a small cylinder 20mm diameter 10mm high but it crashed too.

https://www.dropbox.com/s/plx78l8asqwff … M.jpg?dl=0

you can see CPU climbing am memory usage too but they are flattening out I think...this is hard to capture because at some point it just dies....
I guess I could wait until I get the disconnection message or stop getting log entries but it looks pretty much like this.

By the way  this was after a fresh reboot to update to the latest build.

I just tried to ssh to the pi and while this is not always the case I got in....so even though nanoDLP seems to have died the system
is still up.... CPU is basically idle, memory is not locked up and shows a typical usage...drive space is only 15% used with 12G available.
I will try to copy out the logs.....

Last edited by macdarren (2017-05-18 16:52:56)

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,541

Re: Dimming honeycomb structure

Darren,

It will be great if I could reproduce the issue locally. could you share sample file + debug file?

macdarren

Member

Registered: 2017-03-20

Posts: 411

Re: Dimming honeycomb structure

I just sent you an email with the log I was able to "scp" from the Pi, not sure how to get the debug file once nanodlp has failed (I can't get into the web interface)
Also just to be sure I send matching items is there a way to get the STL file from the Pi...the plate file must be on the pi somewhere?

macdarren

Member

Registered: 2017-03-20

Posts: 411

Re: Dimming honeycomb structure

I just restarted the pi and it resumed slicing at layer 66....It is having intermittent "can't connect errors" but it reconnects a second later .. up to layer 130 now...

And it seems to have died no more log updates...I can't get the browser to reconnect however the ssh connection is still up....system is idle...so just nanoDLP seems dead
Experience shows I can keep restarting the Pi (maybe I could just restart nanoDLP if I knew how) and it will slice a bit and die...only way to get it useable again is to
restart and quickly delete the plate before it dies again.

Last edited by macdarren (2017-05-18 17:46:07)

oliveenchine

Member

Registered: 2016-03-11

Posts: 26

Re: Dimming honeycomb structure

If you still have the SSH connection alive , you can navigate to "/printer/public/plates/"(no really sure about the exact path) and delete the problematic plate.  restart your Pi and should be fine .

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,541

Re: Dimming honeycomb structure

Copy plate causing the issue by ssh into device. Files are available on below address.
/home/pi/printer/public/plates/

As Olivier mentioned you need to delete plate manually. Next go to setup page / tools tab and press debug button. Debug and STL files will be enough to reproduce the issue.

mandreas

Member

Registered: 2016-03-13

Posts: 136

Re: Dimming honeycomb structure

An update about better reinforcement structure for use in 3d printing, the spaceclaim program produces beautiful structures and shell, my favorite is this image, solves the problem of resin drain and creates an extraordinary structural strength

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,541

Re: Dimming honeycomb structure

Andrea,

It is too much processing on rpi. We need generate structure for each layer.
For resin issue maybe we should put gap in two walls of each hexagon.