How to change filament part way through

[clinton 7]

I'm trying to print a calibration stick - a bit like a ruler. I would like to print the ruler in white and the raised numbers and gradations in black.

How can I pause the print at a certain point so that I can swap the filament from white to black just before the numbers and gradations start? I admit 3D printing is fascinating but I don't really want to sit watching it waiting to press the pause button ;-)

Edited April 14, 2016 by Guest

[Labern 775]

Under plugins tab there is pause at Z

This will allow you to set a height for it to pause at. You can add the pause at Z plugin more then once in the same print.

[clinton 7]

Thanks!

So if I want to change the filament do I need to give "Head move Z (mm)" a value other than 0?

Edited April 14, 2016 by Guest

[tommyph1208 55]

Thanks!

So if I want to change the filament do I need to give "Head move Z (mm)" a value other than 0?

 

You don't need the "Head move z" (actually messing with it will make it harder to resume the print), you do want to enter a "x y parking coordinate" so the hot nozzle moves away from your printed part and doesn't burn a hole in it... 0,0 should be fine.

To figure out at what height to do the pause, you can use Curas layer view to find the first layer of the numbers, multiply this layer number with your layer height to get the height in mm.

To avoid a bit of stringing when it does the parking move, you might also want to enter in your normal retraction amount (you'll find it under the advanced tab)...

Just make sure to actually manually prime the hotend with your new black filament (press it all the way into the block until pure black filament comes out the nozzle), otherwise you can get problems with under extrusion as it starts the black layers, and they will initially be grey rather than black.

Edited April 14, 2016 by Guest

[avogra 68]

To figure out at what height to do the pause, you can use Curas layer view to find the first layer of the numbers, multiply this layer number with your layer height to get the height in mm.

 

Don't forget first layer height in advanced tab! In most cases it's different from layer height setting but still counts as only one layer in the layer view.

[clinton 7]

I've given that a try and it's just the job. However, is there a way of changing the layer height after the change of filament? I'd like to print the ruler at 0.15mm and the gradations and lettering at 0.06mm

[Labern 775]

You can use swap at z plugin but it will end up so complicated.

For all those things simplify 3d might be your best option if you want to falk out the cash.

[tommyph1208 55]

 

To figure out at what height to do the pause, you can use Curas layer view to find the first layer of the numbers, multiply this layer number with your layer height to get the height in mm.

 

Don't forget first layer height in advanced tab! In most cases it's different from layer height setting but still counts as only one layer in the layer view.

 

Oh your right, totally forgot about that ... But yes, of course that applies - Good catch

Actually, does anyone know if the pause will happen before or after printing in the specified height?

[avogra 68]

I had that question too everytime I used it, found it out by trial and then forgot it the next day Would be great if the text in the plugin was clear in that respect.

[tommyph1208 55]

ping @Daid

[gr5 2,234]

I would do it this way - flip the ruler over.  it looks MUCH nicer.  Print the black first.  Make the bottom layer height .2mm.  Then as a seperate print print the ruler on top of the black.  Make the bottom layer .3mm and just make the model with a flat bottom - no need to create all the insets where the black was.  In fact it looks much better if you make the ruler flat.

Edited April 14, 2016 by Guest

[gr5 2,234]

This is also a great use of the .25mm nozzle to get fine lettering.

[clinton 7]

I would do it this way - flip the ruler over.  it looks MUCH nicer.  Print the black first.  Make the bottom layer height .2mm.  Then as a seperate print print the ruler on top of the black.  Make the bottom layer .3mm and just make the model with a flat bottom - no need to create all the insets where the black was.  In fact it looks much better if you make the ruler flat.

 

I've just come back to this and thought I'd give it another try now that I'm a bit more experienced with the Ultimaker. However, I still can't get to grips with this one.

So I create my lettering in Fusion360 and extrude the letters to 0.2mm.

I then create the base for them and set Cura with a bottom layer of 0.3mm and print it as separate job. If that's correct so far, what I can't work out is how to get Cura 2.1.3 to print the second job in exactly the right place. I must be missing something I think.

Edited October 13, 2016 by Guest

[gr5 2,234]

Tell Cura to make the bottom layer 0.2mm for the letters.

Well if you make clips like I did you want the letters centered exactly in the part. Unfortunately this is probably rare. But cura places the parts exactly at the center of the bed so if both the letter(s) and the part should be centered then there is nothing special to do.

If however you want the letters placed other than exact center you have a few options. One is to use the grid guide in cura. Each square is 1cm. However a more exacting solution would be to add a fiducial in both your prints. A plus shaped or L shaped thing to print on the bottom layer of both prints and in cura move your part until both L shaped fiducials are over the same spot (same 1cm checkered marking on the print bed). Remember to peel off the first fiducial before printing the second print.

[clinton 7]

I'm having a few problems getting the two prints to line up. I'm making a speedometer for a child's toy car and I've managed to print the numbers and gradations in white and then print the background in black and it looks good. However, they don't line up even though I told Cura to centre the print each time.

I print the numbers in white with a 0.25 nozzle then change to a 0.4mm nozzle while swapping the filament to black. That shouldn't confuse it should it?

[tinkergnome 927]

I'm having a few problems getting the two prints to line up. I'm making a speedometer for a child's toy car and I've managed to print the numbers and gradations in white and then print the background in black and it looks good. However, they don't line up even though I told Cura to centre the print each time.

I print the numbers in white with a 0.25 nozzle then change to a 0.4mm nozzle while swapping the filament to black. That shouldn't confuse it should it?

 

My "poor solution for beginners" was to add a circle (or square) around all parts of the model at the same place. With a very small wall width (smaller than the nozzle size) and the same small height as the letters, it will not be printed, but helps a lot to find the right position on the buildplate. On this example it's the purple square: