Cura settings to force combing on first layer

[V3DPrinting 11]

Hi to all

 

I have an issue with a part printed in TPU 95A on an UM S5  where I need to print letters carved in the part. Due to the shape of the part, the face with letters must be on the build plate.

 

 

I have no issue printing the part with the letters at the right dimension (tuned retraction, no supports, some CAD tweaks, negative horizontal first layer expansion, combing on "not in skin", no z hop when retracted)

But I still have a line on the build plate when the nozzle moves over the letters when printing the first layer.

 

Z hop when retracted is worse because of the oozing of the TPU.

 

Thanks for your advices on how to tune Cura for that particular need.

 

David

[Cuq 172]

It's always much more easy to help someone when he share his project for analyse.  Attach a curaproject.3mf to your post.

[V3DPrinting 11]

2 hours ago, Cuq said:

It's always much more easy to help someone when he share his project for analyse.  Attach a curaproject.3mf to your post.

Thanks for your reply.

 

Unfortunately I am not able to share the project due to the confidentiality agreement I have with my customer.

 

It is pretty much the Cura default 200 microns profile with Ultimaker TPU except the parameters I gave on my first post.

 

To clarify the point, I would like to force Cura to comb on the first layer instead of making retractions and straight move, except for islands of course.

Edited May 28, 2021 by V3DPrinting

[V3DPrinting 11]

I made a mock-up project. So everybody can have a look at it.

 

Thanks for your feedback

 

UMS5_Body1.3mf

[Smithy 1,141]

Try to set under Travel / Layer Start X and Layer Start Y to 0

and be sure to have a Skirt enabled.

 

Don't ask why, just an idea I got from somewhere else. Maybe it doesn't solve your problem, but you can give it a try.

[V3DPrinting 11]

5 minutes ago, Smithy said:

Try to set under Travel / Layer Start X and Layer Start Y to 0

and be sure to have a Skirt enabled.

Thanks Smithy

I had a try, but no impact on the preview. still the same tool path.

[Smithy 1,141]

too bad, but it was worth a try. 

Sorry, but I have no more ideas at the moment.

[V3DPrinting 11]

No probs.

i have made a test with a bit more retraction and reduced temp for the first layer.

If it improves the oosing, I will try with a Z hop when retracted.

 

The latter should be the best option, but due to the oozing of the TPU, it is currently worse than no Z hop.