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chiloschista

Which 3d printer?

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mtreble

Yes - the Cura previews look a bit strange, but I can't see anything wrong with the Slic3r ones.

I would try printing something - you can't rely on the previews to be accurate.

It's also worth reorienting the object to minimise the amount of support material required and put the grain in the optimum direction.

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Ribs

Agree with Mark - you learn loads from printing things.

I've found that the same print settings for the support structure work differently depending on the material too, Ric. ABS support seems to come away really nicely, while PLA was much more 'chewy' and I scrapped a part trying to remove it.

Hole sizes, warping, grain strength, fill density - all benefit from a bit of trial and error.

I've only used Cura and so far it's been great - but I'll often redesign or at least split a part up to avoid overhangs and support material.

The rogue bit of support structure, detached from the main print in your picture, looks like a bit of a brim anomaly - do you use brim to help the part stay down?

 

cheers,

Chris

 

 

 

 

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Ribs

Hi Ric,

You probably sorted this by now, but I just got your detached printing path thing in Cura.

In this case I selected no brim, which works fine for PLA, as it doesn't have the same warping problem of ABS. With no brim selected, I think that Cura is laying down a path for a few moments outside the print, to get the flow rate and heat rate nice and steady at the nozzle, before proceeding with the main print job. In this case, the detached path really has a purpose, though it looks a bit odd in the software.

all the best,

Chris

 

 

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chiloschista

Hi Chris, Mark,

sorry for late reply. The printer is quiet at the moment ... focusing on seasonal works.

Chris, your could be a good point, but it seems to me that the support will anyway be printed suspended, which sounds not likely.

Next steps are mount the heated bed, but more urgent is swapping a horn for the Vector III aileron. I have to build one, but have no idea how it is in the hidden part.

And then gear up with the RedAcro build for the coming season.

Thanks for your interest and answers!

Best regards,

Ric

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chiloschista

Hello,

I'm facing problems with under extrusion.

This seems more related to retraction, as this occurs at start point of a layer. There is a hole.

I tried several settings in Cura, like reducing printing speed, increasing a bit flow, increasing temperature, cleaning the extruder and several combination of retraction values.

The results are always not satisfying. The only thing which I really miss and would like to try right now is Slic3r detraction-extra length on restart. The problem is that Slic3r does not like the object I'm trying to print (3D printed plane) and does not recognize the inner structure or, better said, probably I'm not able to make it working right.

Suggestions about using Cura (which I like the most)?

Other suggestions?

Thanks!

Ric

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mtreble

Hi Ric,

I know the feeling well. Some objects just print better than others. I generally find that over-extrusion is better than under extrusion (A bulge is better than a hole), so I would normally just up the extrusion multiplier a small fraction if I start seeing holes.

If it is just the start of the layer, can you add some custom G-code between each layer just to push out maybe 1mm of filament before the start of the layer? I know you can do this with Slic3r.

The biggest problem, I find with 3d printers is the slicing software. Hopefully algorithms will improve in the future.

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chiloschista

Hi Mark,

how are you?

Thanks for your suggestions!

I thought about changing all the retractions lines of the code, to add some 0.3mm or something like that, but hey: 700-800 layers, with several retractions each! Could probably be done with a script, but unfortunately this is well behind my knowledge. Yes, Slic3r has this function.

In the mean time I discovered that the designer did files for other planes exactly for Slic3r. I'm pretty sure now that the files I have can't work with it.

Will try with MatterControl or Repetier.

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mtreble
2 minutes ago, chiloschista said:

how are you?

I am ok,  but still waiting for my 3d printed implant to be manufactured - maybe they are also having problems with the software...?

 

What is it that you are trying to print?

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mtreble

If you have 700-800 layers, then I would presume you are using a layer height of 0.1mm?

Sometimes I find more complex shapes are better printed at lower res (0.2mm layers) as inaccuracies in the algorithms are more prominent the thinner the layer.

I only print at 0.1mm layers with my own hand written G-code.

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chiloschista
12 minutes ago, mtreble said:

I am ok,  but still waiting for my 3d printed implant to be manufactured - maybe they are also having problems with the software...?

 

What is it that you are trying to print?

I imagine them: hey, there is a bulge ... and now a hole ... So you have the choice between a bulge or a hole = : D

I'm trying to print a Spitfire. It is 1m wingspan and I would like to do it PSS. Layers are at 0.25mm already. Results are not bad at all, but as you says, there are few pieces coming relatively bad. I mean ailerons and wing tips. The rest is more than acceptable (I have never seen a print to compare from someone other before).

I would like to print a wing for the Trisel, to see what comes out. CAD design is already on the route.

Summarizing I'm wasting my time in those things, instead of finishing the RedAcro for Monte Cucco meeting.

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chiloschista

Well, I just got better ailerons, setting retraction down from 0.7 to 0.3mm, but now there are a lot of extra filaments around, but easy to sand.

I guess the issue is related to multiple pieces print, when the head moves from a piece to another one. Will try to print one at a time as I do for the bigger pieces.

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mtreble

Printing one at a time can lead to another problem...

If the layer is small, it can complete the layer, then start the next layer before the previous layer has solidified - which generally winds up in a gooey mess.

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Ribs
37 minutes ago, mtreble said:

Printing one at a time can lead to another problem...

If the layer is small, it can complete the layer, then start the next layer before the previous layer has solidified - which generally winds up in a gooey mess.

Hi Mark and Ric

In Cura, you can defend against this with minimum layer time - the head moves away and lets the layer cool before coming back to continue the print. The setting is on the advanced tab under 'cool -> minimal layer time'

Fan speed also makes a big difference too, along with nozzle temp. I was printing some carbon impregnated pla and the standard PLA nozzle temp was too low, leading to bunging up and under-extrusion. Temporarily increasing the nozzle temperature made a big difference.

There's just so many things to tweak - it's crazy!

cheers,

Chris

 

 

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Rob Thomson

I would highly recommend using the software called simplify3d for your slicing. 

It is allot better than some of the opensouce solutions .

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mtreble

ooh - that's expensive. I haven't spent money on software in years.

Might give it a trial though, and see if I think it is worth it. Thanks Rob.

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chiloschista
On 19/6/2016 at 17:12, mtreble said:

Printing one at a time can lead to another problem...

If the layer is small, it can complete the layer, then start the next layer before the previous layer has solidified - which generally winds up in a gooey mess.

Thanks for that, I tried slowing the speed.

 

On 19/6/2016 at 17:57, Ribs said:

Hi Mark and Ric

In Cura, you can defend against this with minimum layer time - the head moves away and lets the layer cool before coming back to continue the print. The setting is on the advanced tab under 'cool -> minimal layer time'

Fan speed also makes a big difference too, along with nozzle temp. I was printing some carbon impregnated pla and the standard PLA nozzle temp was too low, leading to bunging up and under-extrusion. Temporarily increasing the nozzle temperature made a big difference.

There's just so many things to tweak - it's crazy!

cheers,

Chris

 

 

Thanks Chris, I have a minimum layer time of 5 seconds. Fan is off, for very thin walls. That's what the designer recommends.

What I really miss is retraction over extrusion at restart. Cura does not have it, while Slic3r has it but the object is not recognized correctly.

 

20 hours ago, Rob Thomson said:

I would highly recommend using the software called simplify3d for your slicing. 

It is allot better than some of the opensouce solutions .

Rob, I have already considered that software, but I have read comments which said it's not really great as they say (but comments are comments ...).

I just would avoid buying another software, which does not match my needs or does not really improve above Cura.

Anyway I lowered the print speed to 60-50% and raised the temperature for PLA to 210°C and 220°C for PET. Results are way better and starts to be acceptable or even good.

Yes, there are so many variables ...

Ric

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chiloschista

I'm having a look at MatterControl. Seems it has the features I need.

Will try to print something next week.

Anyone using it?

Ric

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