printing in a different color on top of an existing model

[-richard- 0]

Hi all!

I'm looking to buy a 3d printer and after some research i'm leaning towards the Ultimaker. I have some remaining questions; I would like to print abstract information, for example; a graph. I would like to add text to it, so for example I would like to print a cube, and on top of this cube I want to print "Cube 1". It would improve readability if I could do this in another color than the cube itself. Is it possible to print for example a green cube, change material and then print a text on top of it in a different color? I imagine the second print job that prints the text would then have to know at what z height to start...

I saw the makerbot replicator has dual extrusion functionality, so I imagine this would be possible with it. However i'm really impressed by the quality of the Ultimaker and it's output and i like the DIY mentality of it. Given my goals of printing text in a different color on top of something, would the Ultimaker still be a good choice?

Somebody told me that it is possible to add an extra head to the Utimaker, has anyone ever done that? Does it make sense? I haven't seen any kits for a separate head and I imagine constructing one myself is perhaps too ambitious.

Any thoughts?

thanks!

Richard

[Daid 278]

 

http://www.facebook.com/europerminutedesign

Joris is well known for changing colors during the print. It will require some measuring and experimenting, but it is possible to do this in 1 go.

This is a good example:

http://www.facebook.com/photo.php?fbid= ... =3&theater

 

[mm_build 0]

If you're talking about something that's already been printed, then yes you could still print on top of it in a different colour. I believe the people who print in multiple colours like to feed a new stock in while the machine is running, there is some method or another to calculate how many mm of filament you will use to a certain height in the model. But if that seems too hard you could also finish printing your cube, then print a different model on top of it as long as you start at the height the last model left off. There is a setting (bottom) in skeinforge for that. You would likely want to manually purge the nozzle, should be fairly easy as long as you don't bump your first print and knock it out of alignment.

If it's an old print that you one day decided you want to print on top of, you could still do it by tracing the outline of the print in PLA (just re-start the print and stop it after the first perimeter), and use some double sided tape to stick your model back down into position. [edit] if there is not enough surface area on the bottom or the tape is too weak you could also dab a bit of glue to make it work, Just sayin, where there is a will there is a way

[Daid 278]

It can be done. The red was printed on top of the black in 2 goes. I just changed the starting code to have the startZ 7mm higher then normal.

[mr_seeker 0]

I saw the makerbot replicator has dual extrusion functionality, so I imagine this would be possible with it. However i'm really impressed by the quality of the Ultimaker and it's output and i like the DIY mentality of it. Given my goals of printing text in a different color on top of something, would the Ultimaker still be a good choice?

Somebody told me that it is possible to add an extra head to the Utimaker, has anyone ever done that? Does it make sense? I haven't seen any kits for a separate head and I imagine constructing one myself is perhaps too ambitious

hello, I see a lot of questions about "multiple extruders" on the makerbot and BfB machines, but there are some drawbacks on having multiple extruders (this is currently true for all machines with dual extrusion):

 

1. [*:3dub05x2]Unwanted extrusion. The bowden tube (that feeds the filament in the printhead) is a bit flexible. When you stop the printhead in the middle of a print, it will continue to extrude a couple of mm, even when you are not printing. For dual printheads, this means that you get a little blob on your print when you are changing printheads. Onliest thing to prevent this is to cool down the printhead so that the plastic will not become liquid.

   [*:3dub05x2]Switching of printhead. The printhead will need to reheat itself if you are printing in multiple colors, to prevent the problem of dripping. This takes time & will reduce speed. The printhead will also change for every dual color layer.

   [*:3dub05x2]Software is not adjusted to print in multiple colors. Even with makerbot, you need to have 2 STL files (one for every color), create 2 files, and then merge them together. It is not possible to print "1 file".

   [*:3dub05x2]Print in 1 color at a time. The printhead cant print multiple colors, at least not at the same time. Its either color 1 or color 2, not a mix of both.

 

So best is just to print 1 color, then change filament, and print the second color. Ultimaker has support for dual extrusion, they had it even before the makerbot came with "dualstrusion", but Ultimaker never made dual extruders due to the problems that I mentioned.

What I would recommend for you (and I think this is the best solution) is to make the print in color 1 (and leave a little bit of space for the text), change filament, print the letters in color 2, and glue them on the print with a drop of superglue. The machine is accurate enough to do that (and you wouldnt lose too much time)

[3dtopo 0]

It can be done. The red was printed on top of the black in 2 goes. I just changed the starting code to have the startZ 7mm higher then normal.

Sorry to revive an old thread, but is there something like "startZ" in Cura?

I want to print a different color on top of a color just printed. Thanks!

[Daid 278]

There is no setting for it. But you can adjust the start code a bit to trick the machine.

The current start code says:

 

G92 X0 Y0 Z0 E0         ;reset software position to front/left/z=0.0

 

If you adjust this to:

 

G92 X0 Y0 Z-7 E0         ;reset software position to front/left/z=0.0

 

Then it will think the bed at the highest position is Z-7, so the print will be 7mm in the air.

[3dtopo 0]

Thanks Daid!

It would be nice to add little things like this to Cura. Need any help with the dev? Is there a dev list or something?

[Daid 278]

I am a bit scared of feature-creep. But I have some ideas how to add this, and for example, a pause on reaching a certain layer. (So you can switch colors, or insert objects into your print)

But I really need to be careful not to create an interface with 10.000 options on it.

There is the github issue tracker:

https://github.com/daid/Cura/issues

Which can be used for both bugs and feature requests.

Once I start working at Ultimaker I will have more time to add new features.

[3dtopo 0]

I understand completely. I didn't develop the iPad Photo App of the Year (named by Apple) by creating an interface with 10,000 options.

Its power is in its' simplicity.

That said, there are some very useful things that could be added carefully without taking over the primary focus: to print!