4 Extruders?

Hello!

So the current Ramps electronics I have on my RepRap allow for 2 extruders (which I am assuming would allow me to print in two different colors, correct? Or is it that two extruders allows you two print two of the same object at once?)

Anyway, Now that they have several different models of "Duel Extruders" that are essentially two extruders that take up the same space as one, what are the possibilites of printing with 4 extruders at once?

I would like to make prints with 3 or 4 different colors rather then just two!

Thanks so much guys!!!!

-Jeff

Keep in mind that you will need a tool chain that will let you design a multi color object and slice it. That's not as easy to come by as it might seem it would be.

With a multi head (as opposed multi carriage ) setup, you will have ooze issues. Being able to park the un-used extruder is the feature you gain with the multi carriage approach.

Hmmm so the multiple extruder approach in general is not used for multicolor objects OR printing the same object twice at the same time?

The ooze issues seem to be mitigated, if not solved entirely, by many of the newer hotends that are either all metal or take advantage of combining many of the extruder parts.

Ignoring oozing issues then, is printing in at least two colors still not practical/possible?

Well if ooze is not an issue on all metal hot ends, the new / modern / state of the art ones I have didn't get that memo. Ooze is no more / no less an issue with an all metal hot end than it is with any other approach. It's a function of the filament material as much as anything else. Filament heats up, melts, gets liquid, and it drips .. you have ooze. It also piles up on the print head and drops off from time to time. That's not ooze, but it will mess up your colors.

Multi extruder with the tight packed extruders you mention in your original post aren't going to do very well for multiple copies of the same part. The parts are likely to overlap. How may 5mm diameter objects to you really want to duplicate?

Multiple extruders are used for multi color, they are more commonly used for printing support material. With simple support, you print that first and then shut down the hot end. No heat, no ooze. Then you fire up and print the rest of the gizmo. With multi color most designs want to alternate a lot. That makes parking the head and waiting for cool down a bit of a hassle.

Weight can also be an issue. With 4 direct drive extruder motors on a carriage designed for the weight of one, odd things can happen. It takes a pretty good motor to push filament reliably. The weight will be there regardless of the size.

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uncle_bob
Multiple extruders are used for multi color, they are more commonly used for printing support material. With simple support, you print that first and then shut down the hot end. No heat, no ooze. Then you fire up and print the rest of the gizmo.

This is just NOT TRUE!

Support and plastic must be printed alternatively for perhaps the whole object as in the Hilbert Cube below:

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

I *knew* as soon as I typed that there would be a cube picture popping up.

Getting the neutral extruders out of the way seems to be the way to go, but multiple carriages do not allow much space for build volume, nor would I think for proper registration between colors. Retraction is, for most multicolor systems the place to start...

With good hot ends and proper settings, oozing isn't a huge deal on multi-extruder parts. See this two-color octopus I printed a while back: [www.thingiverse.com] . Support for more than two extruders is highly experimental at this point, although it is being worked on. See the 4 nozzle Kraken hot end for example.

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Quote
NewPerfection
With good hot ends and proper settings, oozing isn't a huge deal on multi-extruder parts. See this two-color octopus I printed a while back: [www.thingiverse.com] . Support for more than two extruders is highly experimental at this point, although it is being worked on. See the 4 nozzle Kraken hot end for example.

Wow thats incredible! I would love to know more about your duel extruder set up!

You have at least 4 places to park a "idle" carriage on a cartesian printer like an i3. If they are small enough, the loss of X travel would not be very great. You could extend the Y rods by an inch or so to get back what ever you lost in that direction.

Software support, firmware support, mechanicals, that's where the issues are.