Hi,

New in the 3D printing arena, I'm looking to build a RepRap based printer, possibly buying a kit from some local vendor.

Print size is one thing of course, but I also would like to be able to extend the printer with other extruders if possible: ceramic clay and color mixing extruders.

What extruders would be good for ceramic clay? I assume the clay would have to have some extra water added to make it semi-fluid - I can experiment with that, as well as "paper clay" for added stability and less shrinking when drying, which might be a problem I guess. I would like the layering to be as thin as possible so it doesn't appear too "striped". Print speed not important.

What extruders exist that can mix multiple colors of plastic? I know there are dual extruders, but can they mix the colors? To what print resultion? And are there any that can mix 3-4 color for CMY/CMYK like capabilities?

This is for hobby use, so I can't spend thousands of dollars... :-)

I think as a beginner, you should dial it in a bit. Not to squash ambition, but once you make a printer and realise its limitations you will understand why. For example, mixing colours is a possiblity but it is not like mixing ink. it makes a sort of 'toothpaste' stripe instead. If you need multicolour models, have you considered painting and finishing techniques? You can get an amazing finish from just a few hours work.

Personally, I would suggest making a build out of V-slot extrusion. It is expensive initially, but it gives a quality on par with linear rails and it is extremely modular, easy to construct and easy to change the design as and when you please. This will give you the best flexibility if you want to really try out mixing extruders, clay, paste etc.

There is no CMYK kit printer, but the official Prusa I3 V2 can print 4 colours with an addon kit.

Edited 1 time(s). Last edit at 12/13/2016 11:55AM by GRAYWOLF.

One printer that does all not a good idea

Build up a printer to FDM print -- keep it to print parts for
a clay shooter, chocolate shooter whatever?

Hi Krilbe,

Welcome. 3D printing as it stands now is a bit of a steep learning curve. Chose a good kit (not necessarily the cheapest - that's a false economy often) and build it, then move gradually forwards towards the goal you have in mind. There is a lot to learn to just print a 20x20x10mm cube in PLA, and for it to be cube shaped and the right size. But if you proceed with sensible expectations you can enjoy the process and the outcome. It's a journey.

The mistake a lot of people make is going from A-E without passing through B-D, and wondering why it doesn't work.

Edited 1 time(s). Last edit at 12/16/2016 04:11AM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Most people start with a Prusa I3 or variant and work up from there...

... it's kind of the "Model T Ford" of the reprap world. Currently, anyway. PrintRBot is one alternative - probably more beginner friendly, albeit a little bit more restricted on modification.

Check out the sections on this board for ceramic extruders... typically, you need a plastic printer to be able to make parts for a ceramic printer.

There are some hacks around for "diamond head" style of hotend for full colour printing, using the Repetier firmware (you can use different firmwares on the same printer, but only one at a time). The latest Marlin might have it too (haven't tried latest Marlin).

You have to have a variety of skills to build a reprap - combination of metalworking, hand tools, electronics, and programming, So it's a steep learning curve.

The book "3D Printing for Dummies" is quite helpful, as the core of it is getting an i3 built and running Marlin,.

Edited 5 time(s). Last edit at 12/16/2016 06:27PM by DragonFire.

Thanks for the feedback everyone!

I was wondering about "V-slot extrusion". Googling it I found that it appears to be referring to a kind of beam/rail and wheels to position "something" along it, presumably with high precision. I assume this is one way of building the positioning system for the extruder. Any useful links about it?

Will probably start looking at Prusa I3 V2 which seems to be a good starting point, judging from the replies I got. And... with "V-slot extrusion"?

So V slot extrusion is a type of extruded aluminium bar/rod which can be joined together to make a frame. You can make carriages using v-profiled wheels which can run in the v-slots in the extrusion. This enables you to get reasonably precise linear motion relatively easily and simply.


Here is an example of carriages moving on roller wheels.

The alternatives are using smooth rods and linear bearings, or probably the best at the moment is using linear guide rails such as the ever popular Hiwin MGN-12 series. These bolt to your frame and provide you with almost zero-play carriages. More expensive than using roller-wheels & v-slot or smooth rods and bearings, but the difference in price has come down a lot lately they are widely available from china, and IMO these should be the default for linear motion in small/medium sized 3d prnters.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions