nanoDLP

sgraber

Member

From: Indiana

Registered: 2016-03-11

Posts: 54

Website

Verify Slicing Images

Here's something I had happen to me last night:  I sliced a ring @ 25um with Slic3r to svg.  I then uploaded it to NanoDLP and it went through it's routine of creating png's out of the svg.  During the process, four bad images were created:  one was a garbled image that was maybe 1/5 the total height the image should have been and the other three were non-existent (meaning no image showed up for those three layers in a row during a layer preview).  I did not catch this prior to printing so when NanoDLP hit those problem layers, it errored out and ended the print (it did not crash or reboot - it just indicated the print was done and ran my end gcode). This was about about 80% through a 5 hour print. 

IDEA:  Is there any way to add image error checking on individual layer images once it's been converted from svg to png?  This would help reduce failed prints.

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,541

Re: Verify Slicing Images

Could you share the SVG file?

The issue is that, until the PNG files get rendered we could not be sure if everything with source file is OK. To do so automatic validation would requires slicing or rendering process to be completed which block entire printing process.

Manual validation (Button) will be much easier to implement. Checking missing frames is pretty easy, checking overhanging and other issues will be harder to do and probably require some inputs from users.

It is something extremely useful if we could come up with good ideas about what should be checked.

Will it be fine with you if the printer quite printing lets say after layer 100? By layer 100 or so usually whole conversation process would get completed so we could do automatic validation.

sgraber

Member

From: Indiana

Registered: 2016-03-11

Posts: 54

Website

Re: Verify Slicing Images

The SVG wasn't the problem. I deleted the problem plate and re-uploaded the SVG and it created the PNG files just fine the second time (I manually verified it by going through each layer image).  Something apparently happened on the Pi during those four layers when they were generated.  I can share it if you need it though. Please let me know.

A manual validation button would be nice!  A lot of what I am doing is jewelry printing @ 25um layer heights and most rings end up generating about 1200 PNGs for the entire print.  That is a lot of layers to manually check. 

The two problem scenarios I found were 1) missing images and 2) corrupt images.  I would imagine just checking the file size and the image dimensions would be adequate?  If filesize = 0, then image is not present.  If XY dimensions of the image are off, then the image somehow got corrupted.

Usually I let the SVG conversion complete before I do any printing.

Incidentally, I am running this on an old Raspberry Pi B (not even a Pi 2!) and it's running just fine! 

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,541

Re: Verify Slicing Images

Actually by manual validation, I means automated check which triggered by user action and not run on every plate automatically.

That is a strange problem which I have not seen before. If we could know real cause maybe we could put safe guard. My guess is SD card issue.

You should have pretty slow performance on Pi B. Anyways I will put those checks into code, and make it runs just after conversation completion.

jamesarm97

Member

Registered: 2017-02-02

Posts: 69

Re: Verify Slicing Images

Would be nice to somehow generate (should be easy now that I think of it) an rapid (GIF type) animation of all the layers flipping through them so you an at least visually check them quickly. Right now I just click on the layer button and click through each layer looking at them.

adam

Member

Registered: 2016-02-18

Posts: 100

Re: Verify Slicing Images

@sgraber:
a little off topic: even if it was all fine til now, since it looks like you use the printer commercially, wouldn't it be a good ide to invest the 40 bucks and buy a better Pi? I guess it's gonna save you tons of cash in the long run (maybe over 2 oder 3 prints)

Shahin

Administrator

Registered: 2016-02-17

Posts: 3,541

Re: Verify Slicing Images

James,

You can use keyboard arrow button to navigate. Select slider and press right button. It could be also animated but I am not sure if it will be useful.