Optimising the 80 micron head - Development Project

[Jack @jack-strong]

Hi,

Ive been getting really good results from a U shape piece I am currently designing. Build time is 14 minutes, using custom settings. Layer height is 30 microns. All is well and am very pleased, apart from shrinkage, but I am getting a recurring blob on the z axis. Anyone care to help ? Additionally I have performed all the calibrations but the first few layers there is always a region where nothing is deposited. Hopefully the picture shows it. At a guess i would say the bed isnt flat, but i find it weird that it doesn’t put down anything.

Will upload some pictures of the part, but he’s some of the defects.

 

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[Jack @jack-strong]

Here they are

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[biscuitlad @biscuitlad]

I suspect your recurrent blob is unfortunately where you start each layer or alternate layer. Think there is an option to start each layer in a random position in Slic3r, which might make it a bit less conspicuous (you’ll still get blobs, but possibly fewer and not in a vertical line).

Where nothing is deposited sounds like your bed as a low spot. Try moving your piece around on the plate.

[Jack @jack-strong]

I see it on all my models, always well ordered blobs. there so annoying!

[BHudson @bhudson]

I see this on my head also. As @biscuitlad said, it is the start of the layer. I suspect there is a little pause or a little extra material that lingers on the nozzle. It is annoying but I haven’t found a way around it yet except to use the .3mm head for the perimeters.

[Rob @bespokeproductdesign]

You can randomize the layer start position in the print profile config file, just change the 0 to 1 on line “randomize_start = 0″. Seems to be quite common for home printers to blob on the start of a new path, looking round Google, read an interesting blog a while ago where they’d coded a stitch between the start and end of the paths to try to even it out and make it watertight. Guess it makes it easier to clean off though if they’re all in the same position.

[Jack @jack-strong]

So you only see it with the .8 nozzle ? Not .3. I wish the layer steps were done on an internal section.

• This reply was modified 1 week, 5 days ago by  Jack.

[Jack @jack-strong]

Did a bit more over the weekend.

From my initial post where I was getting areas where the bed may have been to blame, I decided to do a simple test to figure out how flat the bed was. To reduce problems I reduced the speed of the head, just using the .8 nozzle. The results were pretty good. Think for any future small prints I will locate them to the near front right of the bed.

I also recorded a time lapse video after showing the sheet popping off. Will upload.

Then, after doing soo many pyramids I decided to do something a bit more tricky. A sphere, 30mm diameter on the .8 with no brim, just a little facet on the bottom so that it didn’t roll away. Results started off bad but got really good in the main section.

 

• This reply was modified 1 week, 3 days ago by  Jack.

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