ugly surfaces

[SG91 0]

umo+ 25mm/s 195c

I want to print nice new Blocks. Tested one .

But there is some ugly spots and blobs. Has to do about retraction?

did a fine test too same settings.

Edited January 26, 2016 by Guest

[yellowshark 153]

A variety of things to try.

1. ensure your minimum layer time is at least 10 secs to give the printed layer time to cool before the next layer is deposited. It look small so if that is not possible to achieve you can either print 1 or 2 copies concurrently to increase the layer time. Alternatively you can give z-lift a go - both have their advantages and disadvantages.

2. Use the same print speed everywhere for the printing beyond layer 1. By that I mean the walls/perimeters external and internal, and infill. Changing speed changes changes extruder pressure which takes time to stabilise and can cause spots like you have on the vertical wall of the circular section.

3. Go slow, 25mm/s is good and go cool. Get those fans pumping out 100%; try and get that 195c down as low as possible. If that is normal pla I think you have headroom to go lower.

4. I am not sure what is causing that mess about halfway up the z-axis. maybe you got a stick and too much filament was extruded for that layer, not sure.

5. Actually as you have these problems I would drop to 20mm/s or even 15mm/s although I do not think I have ever gone to 15.

6. Try a different filament, sometimes that can all the difference.

7. Retraction; hmn I am no expert in that area. I got it working a couple of years ago and have never changed my settings since. No doubt someone else will have a view on that.

8. Fine test; yeah difficult aren't they. To me that says extruder too hot; maybe fans not 100%; minimum layer time less than 10 seconds; or just the impossible dream. Maybe worth trying a thinner layer to reduce the amount of filament being extruded

[SG91 0]

hm hard for me as a novice. I ment 25mm/s inside and out as you said.

100% fan speed .  lol tried 0.06, did not work at all this time. Almost nothing came out. re started a few times .. jam.

 

A variety of things to try.

1. ensure your minimum layer time is at least 10 secs to give the printed layer time to cool before the next layer is deposited. It look small so if that is not possible to achieve you can either print 1 or 2 copies concurrently to increase the layer time. Alternatively you can give z-lift a go - both have their advantages and disadvantages.

2. Use the same print speed everywhere for the printing beyond layer 1. By that I mean the walls/perimeters external and internal, and infill. Changing speed changes changes extruder pressure which takes time to stabilise and can cause spots like you have on the vertical wall of the circular section.

3. Go slow, 25mm/s is good and go cool. Get those fans pumping out 100%; try and get that 195c down as low as possible. If that is normal pla I think you have headroom to go lower.

4. I am not sure what is causing that mess about halfway up the z-axis. maybe you got a stick and too much filament was extruded for that layer, not sure.

5. Actually as you have these problems I would drop to 20mm/s or even 15mm/s although I do not think I have ever gone to 15.

6. Try a different filament, sometimes that can all the difference.

7. Retraction; hmn I am no expert in that area. I got it working a couple of years ago and have never changed my settings since. No doubt someone else will have a view on that.

8. Fine test; yeah difficult aren't they. To me that says extruder too hot; maybe fans not 100%; minimum layer time less than 10 seconds; or just the impossible dream. Maybe worth trying a thinner layer to reduce the amount of filament being extruded

 

Edited January 26, 2016 by Guest

[Labern 775]

seeing you are printing with such a low layer height and so slow you may need to go colder, 190 or even 185.

you could try printing it a bit faster or a 0.1mm layer height which could make it come out a bit better. in your blocks you can see the little blobs and a few little strings. this means its to hot. increasing the travel speed might also help.

[SG91 0]

okey but the Lars block was in 0.1  so I should do it again at 185c this time?

and the travel speed was 150 or 160 at that time.

 

seeing you are printing with such a low layer height and so slow you may need to go colder, 190 or even 185.

you could try printing it a bit faster or a 0.1mm layer height which could make it come out a bit better. in your blocks you can see the little blobs and a few little strings. this means its to hot. increasing the travel speed might also help.

 

Edited January 27, 2016 by Guest

[Labern 775]

Try colder or speed it up a little. I normally run travel speed at 250.

[SG91 0]

150 looks fast to me, the whole thing shakes . Wont faster make it miss steps ?

its the tiny short wall im afraid of the most.My opinion sometime it choose unnecessary ways

around things in travel mode. instead of short cuts.

 

Try colder or speed it up a little. I normally run travel speed at 250.

 

Edited January 27, 2016 by Guest

[Labern 775]

I dont have a UM0 but UM2 can handle 250 fine without missing steps. I run my UM2go at 300mm/s travel. yeah they move around but the item you are printing is small. I have dropped the acceleration from standard as I had to much ghosting so that may make a difference.

[SG91 0]

ah I see. but u have nice tight belts then? I wait for my gt2 belts to come before I try boost it

anyway for this small part sonic speed moves is not needed really ?

 

I dont have a UM0 but UM2 can handle 250 fine without missing steps. I run my UM2go at 300mm/s travel. yeah they move around but the item you are printing is small. I have dropped the acceleration from standard as I had to much ghosting so that may make a difference.

 

Edited January 27, 2016 by Guest

[Labern 775]

shouldn't be needed.

[SG91 0]

its up and running now cold as 184c. about 30minis in I lowered to 180. I suppose I should not go lower. The first positive sign is the blobs didnt occure inside the lower holes. Will see what happens at higher layers. i hope it wont screw up again.

 

shouldn't be needed.

 

Edited January 27, 2016 by Guest

[Labern 775]

That is quite cold for that speed but machines do differ and also materials. As long as you don't get under extrusion is should be fine.

Hope it turns out good.

[SG91 0]

Yes I cant see that its under, operates fine. its the small wall I hope for will be right.

Another thought, increasing time spent on each layer. Will it just go slower or take an extra turn around the block?

 

That is quite cold for that speed but machines do differ and also materials. As long as you don't get under extrusion is should be fine.

Hope it turns out good.

 

Edited January 27, 2016 by Guest

[Labern 775]

it goes slower. this can be good and bad. if slower then the hot head can overheat the layers. but it can allow the rest of the part to cool.

if you need more cooling its best to print 2 parts at a time or a small tower next to the model.

[SG91 0]

Right! btw the second one looks better.

But there are small errors still I Think. and from the top side both seems

leaning abit if you can see. (the thick walls to the right.

and half way up there is still some minor errors and to the left a tiny "bridge" look .

 

it goes slower. this can be good and bad. if slower then the hot head can overheat the layers. but it can allow the rest of the part to cool.

if you need more cooling its best to print 2 parts at a time or a small tower next to the model.

 

Edited January 27, 2016 by Guest

[Labern 775]

It looks vastly better but yes there still is some issues.

Have you looked at the model in x-ray mode to make sure there are no issues ( shown in red )

[SG91 0]

Nope there was no red . either in overhang view .weird

 

It looks vastly better but yes there still is some issues.

Have you looked at the model in x-ray mode to make sure there are no issues ( shown in red )

 

[Labern 775]

have you noticed if the printer slows down or speeds up during any part of the print?

these areas with problems maybe slowed down by the minimum layer time so you will need to adjust this so it doesn't slow down. otherwise it could be slowed down and overheated.

[SG91 0]

think I heard it slow down some time . shall I remove the 5sec spent on ea layer then?

 

have you noticed if the printer slows down or speeds up during any part of the print?

these areas with problems maybe slowed down by the minimum layer time so you will need to adjust this so it doesn't slow down. otherwise it could be slowed down and overheated.

 

[Labern 775]

yeah, put it on 1 or something

[SG91 0]

In what case is that good for then,  a big object I think wont need slowing down .

And a small bit would get over heated. ?

 

yeah, put it on 1 or something

 

Edited January 27, 2016 by Guest

[Labern 775]

Its an ok feature but only helps on a small amount situations. The problem is, When it slows down the material feeding is slower. this means the material absorbs more heat and has more thermal expansion. this tends to give fatter lines and can give blobs. Also you have a hot nozzle moving slowly, this can also overheat the part.

If you have a small part and it start printing a already soft layer then this is also an issue.

So the best way to solve the issue is to print 2 items. the print speed stays the same and the part has plenty of time to cool.

[SG91 0]

yes you are right. But driving faster on one small cant be good either?

this one 180c just without the minimum time spent ea layer.

the left part looks good now, (maybe of that Or me changed temps before)

BUT still the issue at those two small walls.

Can make 2 for cooler but it might be something else?

Even did one in 0.2 today, turned out the same.

Now printing 6 pieces at same time was suppose to be the parts to use.  

But as I thought there are some blobs caused by travel/retractions between the parts.

And It irritates me

 

Its an ok feature but only helps on a small amount situations. The problem is, When it slows down the material feeding is slower. this means the material absorbs more heat and has more thermal expansion. this tends to give fatter lines and can give blobs. Also you have a hot nozzle moving slowly, this can also overheat the part.

If you have a small part and it start printing a already soft layer then this is also an issue.

So the best way to solve the issue is to print 2 items. the print speed stays the same and the part has plenty of time to cool.

 

Edited January 27, 2016 by Guest

[Labern 775]

Now I understand the thin part that you have been explaining.

Do you know the width of this area?

Have you looked in layer view to make sure it prints every layer for that one section?

If you print multiple items you need to put them as close together as possible to help stop getting the blobs.

[SG91 0]

Ok , I dont know details about it .

I placed them very close.

I just know it has to be the retraction. Its feels wrong to avoid the multiple parts feature cos of blobs.

 

Now I understand the thin part that you have been explaining.

Do you know the width of this area?

Have you looked in layer view to make sure it prints every layer for that one section?

If you print multiple items you need to put them as close together as possible to help stop getting the blobs.

 

Edited January 28, 2016 by Guest