Cura not printing raft correctly?

[borgqueenx 0]

In alot of prints i tried with multiple objects, cura prints the raft too small. Actually only wants to build the raft under under the empty space in the prints and then after making the raft suddenly starts printing the whole object on top and besides the raft, resulting in some parts being printed in mid-air.

Cura and rafts do not go well together it seems. A bug perhaps?

Screenshots to show the problem here:

As you can see the object to print is quite round, but cura wants to print different smaller circles.

I cant find anything in the settings either that would result in this weird raft creation.

Edited November 21, 2016 by Guest

[bagel-orb 61]

Definitely sounds like a bug, not some esoteric feature.

I can see you re using cura 2.3.1. could you post a picture of the first layer as it is in the layer view?

Can you share your model so that we can reproduce the problem?

[borgqueenx 0]

Definitely sounds like a bug, not some esoteric feature.

I can see you re using cura 2.3.1. could you post a picture of the first layer as it is in the layer view?

Can you share your model so that we can reproduce the problem?

 

Thanks! i was losing hope to get a reply.

Here it is in layer view:

https://puu.sh/ssqWA/7f8139af4d.png

Here is the model:

https://www.amazon.com/clouddrive/share/YipAfCcxXYScnvfzOtaR4Iv4SruPo1jIWNcSOiRswt?ref_=cd_ph_share_link_copy

Note that the raft is different from the one in my post above. For some reason it messes up alot of times, but sometimes it works correctly. In any case i can't really trust Cura at the moment.

I have the same model without the claws on the right, wich does seem to make a correct raft:

https://www.amazon.com/clouddrive/share/meMgjiDqdvucbUpsm7W2PoSS1yPNsvfZEqqhpaQ3VLH?ref_=cd_ph_share_link_copy

Note

[DaHai8 74]

Your model's base is not flat:

Move the model's Z position down -.1mm and it will cut that bump off and slice properly.

[borgqueenx 0]

Your model's base is not flat:

Move the model's Z position down -.1mm and it will cut that bump off and slice properly.

 

Thanks for that tip. i hope it fixes this raft problem. However cura shouldn't be excused for this? Flat or not flat it should still make a flat and even raft?

[DaHai8 74]

Yes, and no.

The resolution of the raft is limited by your Layer Height setting.

If you set your Layer Height to .1 (from the default .2), then it can compensate for that one area that sits slightly below (~.1mm) the rest of the base and supports everywhere else.

Edited November 24, 2016 by Guest

[borgqueenx 0]

Yes, and no.

The resolution of the raft is limited by your Layer Height setting.

If you set your Layer Height to .1 (from the default .2), then it can compensate for that one area that sits slightly below (~.1mm) the rest of the base and supports everywhere else.

 

I have removed the .1mm rounded thing sticking out of my model, yet cura still wants to make a weird raft as the image i have in post 1 of this topic.

I should note that Simplify3d prints/slices the raft correctly.

Here is the model again- updated to have a flat base.

https://www.amazon.com/clouddrive/share/gqcx4AlbAhFgH6yUW584vzvTMOlL0CzjipoMYPkIExq?ref_=cd_ph_share_link_copy

[DaHai8 74]

I'm using Cura 2.3.0 (Release) and not having that Raft issue with your latest model.

.2mm Layer Height...

Not sure what's going on. Maybe is a bug in 2.3.1 (but not in 2.3.0)???

[borgqueenx 0]

I'm using Cura 2.3.0 (Release) and not having that Raft issue with your latest model.

.2mm Layer Height...

Not sure what's going on. Maybe is a bug in 2.3.1 (but not in 2.3.0)???

 

Did you look from the part from below? Mine looks the same from that angle/perspective.

My settings and again a picture: https://puu.sh/ssT9O/6455d07ae7.png

[DaHai8 74]

My raft settings are slightly different than yours, but I'm not getting that bleed-through like you are. Mine look OK

[borgqueenx 0]

then its probaly a bug. is there a way to report this and hopefully have it fixed?

[jerooney 6]

Hi,

Thank you for contacting us through the forums. I've tried to recreate your issue, and it seems nearly impossible.

The combination of settings necessary are:

- Layer height = 0.25mm

- Printer = Prusa i3 Mk2

- Raft extra margin = 5

I could not recreate this issue with an Ultimaker machine selected.

Loading different models did not reproduce this issue.

Please always use the layer view to review your created slice.

If this issue occurs again, please post it! If we can find a way to reproduce this we can fix it!

Regards,

Jeroen

[borgqueenx 0]

Hi,

Thank you for contacting us through the forums. I've  tried to recreate your issue, and it seems nearly impossible.

The combination of settings necessary are:

- Layer height = 0.25mm

- Printer = Prusa i3 Mk2

- Raft extra margin = 5

I could not recreate this issue with an Ultimaker machine selected.

Loading different models did not reproduce this issue.

Please always use the layer view to review your created slice.

If this issue occurs again, please post it! If we can find a way to reproduce this we can fix it!

Regards,

Jeroen

 

Hey Jeroen, thanks for trying to find this bug.

Some models work and some don't for me.

Here is even a more extreme example. Note that with -every- model i throw into simplify3d works, cura sometimes makes weird stuff like this.... This is the raft for the following model:

https://puu.sh/sxIO5/e670cbc8ee.png

Wich then prints the entire model over that raft resulting in the whole model getting out of shape.

Here is the model for download:

https://www.amazon.com/clouddrive/share/LWq5ohIxMbiyMOXh6E3s6fqR4yHCy2Xvxj9FP2uFNmM?ref_=cd_ph_share_link_copy

[borgqueenx 0]

i have re-installed and purged the saved data from the appdata folder, and now cura does the raft well again.

I hope it stays that way this time.

[borgqueenx 0]

the issue is back, that didn't take long. all i really did is put in the same settings as i had, worked finr for 2 times, not anymore.

[jerooney 6]

This issue is solved:

The raft not printing was caused by the initial layer height set faulty:

Initial layer height = 0.15mm

Layer height = 0.3mm

The initial layer height was set way too low.

The user error that occured here is not @borgqueenx his fault, since we do not warn for this in this version of Cura.

In future development we will:

1. Warn the user for this error. (By a yellow input field)

2. Calculate the initial layer height for the user.

Regards,

Jeroen

[borgqueenx 0]

thanks for the help!