UMS5 Dual Extrusion Problem

[GoncaloLaranjeira 1]

Hi everyone!

 

Lately I'm getting a lot of 2 colored prints orders.

 

I'm going to assume the 1st color as the main object color and 2nd color as the detail/text/etc color.

I was having some quality problems when printing thin text with the 2nd color but got them resolved by reducing the Layer Width in Cura to 0.26mm and maintaining the default values of "Initial Layer Line Width" to 120% and "Initial Layer Horizontal Expansion" to 0mm (in all my prints I use 100% and -0.2mm respectively to annul the "elephant's foot").

 

The problem is that I enabled the "Prime Blob" for both extruders but only the 1st printing extruder (in this case the 2nd color) will prime blob and will start printing fine, but as soon as the extruder changes to the 1st the filament is not "Prime Blobbed" and the filament is far from the nozzle causing it to not print anything until some time (until the filament reaches the nozzle), so I have to do some baby sitting and after the nozzle changed I got to the 1st extruder opened the feeder lever and pushed the filament into the feeder until I feel it can't go further (reached the nozzle), and it worked fine, but because the 2nd extruder was also printing on top of the object it would fail if not "baby sited" 😞 I resolved this by using a prime tower 🙂 .

 

Here's the result:

 

I'm currently printing a custom handbrake for racing sim games (e-brake) and one of my orders requested a red 1st color with the text in 2nd color.

The issue is that the prime tower is only printing the 2nd extruder when there's a layer with that color (really don't understand why), so when it arrives the actual 2nd color printing layer it's not printing anything because the filament is far from the nozzle:

 

 

The other issue is that if I push the filament to the nozzle it will print the layers correctly but there's the chance of getting this blobs in the print:

 

 

This blobs cause the nozzle to hit them in the next printed layer and end in a massive layer shift 😕 

 

 

I resolved the under-extrusion on the letters by instead of printing only the letters with the 2nd color by printing an entire 1mm layer of it and the result was perfect!

But got the shifted layers (probably a blob) 😕

 

 

 

Gonna re-print right now with a custom Prime Tower to see if it resolves the issue. Fingers crossed!

 

If someone knows how to resolve this problem with the second filament not being prime blobed and being so far from the extruder please help!

Thank you all!

 

Edited June 10, 2021 by GoncaloLaranjeira

[Enigma_M4 125]

Hi,

I bet you're using Cura 4.9.

The missing prime blob #2 was a known -and actually solved- bug.

Switch to the actual version of Cura (4.9.1) 😉.

Regards

[GoncaloLaranjeira 1]

Yep I was using Cura 4.9.

Looks like a easy fix 😄

Thanks @Enigma_M4 !