A few general questions for a beginner

Hi,

I am new to the RepRap project (and 3D printers in general) and want to build myself a Mendel. The problem is that I am not an engineer and find that the RepRap website presumes a lot of understanding of 3D printers from the visitor. I think there needs to be an overview page that explains in more layman terms the overview, the concept, the terminology, about 3D printers, maybe a little history and their components and where to buy them and where to obtain the manual specific to assembling those components. The only reason I am able to articulate some of the questions below is because I have had to spend several hours in research (mostly from videos and external sites and searches) even to get enough understanding to know what to ask.

Firstly when visiting the site the only knowledge I had was a realisation that now I can get my hands on a 3D printer for a more realistic amount of money and that having a 3D printer could be really useful to me. I had no idea what an extruder is, what PLA is, the difference between a Darwin, Mendel or a Huxley etc. Please don't take this as a criticism, I commend everyone for this great work, I just don't want to see people scared off because it all seems too much for them or too complicated or they fail to grasp essential concepts. Maybe once I am knowledgeable I can assist with making the site and information more newbie friendly.

So my questions are:

1) I have decided to build a Mendel because it seems to be the most appropriate version from what I can gather. Is the Mendel the default/best option for anyone visiting the site unless they have any specific requirements?

2) I notice that the extruder tips or nozzle (I think that is what they are called) come in ranges from 0.5mm to 2.9mm. What difference does this make? Which is the best size for the best printing resolution?

4) Is the extruder the general "print head" or does it refer only to the nozzle?

5) There is so much choice to confuse me, where can I get ALL of the parts to build the Mendel and if there are different options for different applications then which one is the default/best option for someone wanting the best quality out of their open source 3D printer?

6) Does setting the printer to print more slowly increase the precision and quality of the end product? What factors determine the best output quality?

7) If I use PLA filament, can I recycle my printed objects? If so, how do I get them back into the long filament coil form (as when new) in order to feed them back into the printer or is there another method or am I missing some fundamental understanding?

8) In one of the Videos, Dr Adrian Bowyer mentioned recycling milk bottles, how can I obtain household plastics in order to use in my RepRap? How do I know which plastics can be used and which can't? How do I get them into a useable form?

Thanks in advance for your patience with me.


John

Hi John,

I agree that it can be a bit overwhelming/confusing for those new to the reprap world (I only built my Mendel a few weeks ago, so it's still a bit fresh in my mind), and it would be useful to have a few more resources geared towards those with little prior experience. (That's one of the reasons I put together the Prusa Mendel Visual Instructions).

I also think there is a need for a resource (wiki page perhaps) to collate the current state of the reprap world. Because there are so many aspects (electronics, firmwares, tool chains, hardware, etc) it can be difficult to know what is relevant and what can be disregarded. This would probably also be useful for seasoned reprappers too I think.

I've been thinking about how to contribute in this regard - and hopefully I will be able to do so soon. In the meantime I'll take a stab at some of your questions...

1) As someone who has just finished building a Prusa Mendel I would personally recommend it. The build is pretty straightforward and the fewer parts appeals to my sense of efficiency

2) I started off with a 0.5mm, and just received a 0.35mm hot end, so my experience is pretty limited, however the 0.35 should produce objects at a finer resolution, but will take longer to complete. You can get pretty good results with a 0.5mm but you have to fiddle with the settings of the program that converts the 3D model (in STL format) to instructons for the printer (called gcode).

4) The extruder is the part that pushes the plastic through the nozzle. This usually refers to the gear and motor mechanism, of which there are several variations (I use Wade's Geared Extruder, and have just printed out Greg Frosts variation of it). The nozzle (plus heater, thermistor and insulator) is usually referred to as the hot end. And I have seen references to the rest of the extruder being called the cold end.

5) I worried about sourcing the parts when I began, but as it happens I got them all through in a matter of a couple of weeks - from various sources in the UK and Germany (i'm based in Germany at the moment). You could probably find a full kit somewhere, but it'll cost more. I would say use the wiki page to find a few sources and look on the "for-sale" forum pages too perhaps. If I get a chance maybe I will write a blog post listing the suppliers I had success with (I think it's frowned upon to list suppliers in the forum) - if you're really interested let me know and I can PM you.

In terms of calibrating the software (Skeinforge, firmware, etc) that can also be pretty daunting, and the information is scattered and difficult to pull together. I hope to write up my experiences soon - as soon as I finish my battle with the latest version of Skeinforge. [edit- battle over]

6) Speed plays a part, but also the skeinforge settings (layer height), and nozzle size too.

7) Sadly direct recycling of used PLA is not currently possible (unless I have missed something).

8) I think Adrian was ruminating on what may be possible with the technology, and at the moment there isn't a way to use household plastics and such in a reprap (please someone correct me if i'm way off here)

Hope that helps.

Gary

Edited 1 time(s). Last edit at 04/12/2011 06:18PM by garyhodgson.

Thanks for the reply!

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1) As someone who has just finished building a Prusa Mendel I would personally recommend it. The build is pretty straightforward and the fewer parts appeals to my sense of efficiency

My first impulse was to go for a Prusa Mendel but then I did a Google search for Mendel vs Prusa Mendel and found that people had commented that the quality of the Mendel was slightly higher. I figure that if I am spending money anyway, I may as well put a few extra pounds in to get that little extra quality out of my build. I’d like to know if this is unfounded though. What’s the consensus? Does anyone have both to be in a position to comment?

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2) I started off with a 0.5mm, and just received a 0.35mm hot end, so my experience is pretty limited, however the 0.35 should produce objects at a finer resolution, but will take longer to complete. You can get pretty good results with a 0.5mm but you have to fiddle with the settings of the program that converts the 3D model (in STL format) to instructions for the printer (called gcode).

Didn't know you could get a 0.35mm. Is that the finest? If not what is the smallest as speed really isn't a much of consideration for me over detail and quality?

Thanks for 4 and 5! I'll contact you when I am I have fully made up my mind as to what I am going to build.

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6) Speed plays a part, but also the skeinforge settings (layer height), and nozzle size too.

So what are ALL the things I can do to enhance the resolution to its maximum and can I do these things with both the Mendel and the Prusa Mendel? What is the lowest practical layer height setting?

Thanks again!

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Didn't know you could get a 0.35mm. Is that the finest? If not what is the smallest as speed really isn't a much of consideration for me over detail and quality?

I would think that a difference from 4 hours to say 32 hours would make a difference.
I know of people using 0.25 mm nozzles with ABS and have heard of at least one person using a 0.20 mm nozzle.

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So what are ALL the things I can do to enhance the resolution to its maximum and can I do these things with both the Mendel and the Prusa Mendel? What is the lowest practical layer height setting?

With a 0.25 mm nozzle you should be able to get down to at least 0.20 mm layer height.
With a 0.20 mm nozzle 0.15 mm should be possible.

You use a finer nozzle and extrude slower (less plastic).

The smaller the nozzle the higher the pressures and the more difficult it is to extrude which is why a lot of people are using 0.35 mm nozzles with which you can obtain a layer height of 0.25 mm).

nophead can give you better figures I am sure since he has/does use smaller nozzle sizes (and sometimes a 0.6 mm nozzle).

If you need that fine of a resolution then you might consider building a High Resolution DIY 3D Printer.

Edited 1 time(s). Last edit at 04/12/2011 11:30AM by rhmorrison.

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

I have built multiple of both the sells and prusa mendel. Prusa Mendel prints at a higher quality just because it's many times easier to calibrate. True quality is mostly a fuction of software, and Sells/Prusa use the same software.

Go with the Prusa, you will not regret it.

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repraplogphase.blogspot.com

Thanks. 32 hours is not a problem. Several days would even be OK, I am not going to be in a hurry. I presume I can just leave it running in my workshop? A 0.35 nozzle with a 0.25mm layer height would probably meet my requirements. I want to stick to the Mendel or Prusa Mendel as there are a lot of people with them who can share info and support. I presume I can swap out my entire extruder unit including the hot end when I want to print something quickly at a lower resolution?

Also, does anyone have any photographs of something fairly detailed printed with a 0.35 nozzle? I’d like to be able to compare the difference.

Take a look at nopheads blog, AFAIK he has a 0.35 nozzle on his Hydraraptor.

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

Its 0.4mm at the moment but I did have 0.3mm for a while when I had a DC motor based extruder: [hydraraptor.blogspot.com]

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[www.hydraraptor.blogspot.com]

In reference to my first post, I finally found the glossary. Surely there should be a link to the glossary from the main page? Thanks.

I agree, and I also think the General FAQ should be there too (and it should be renamed to "General Introduction" as it doesn't contain any questions!).

Perhaps it would help if there was a real FAQ, in the style of "What is a toolchain?", "Where can I learn skeinforge?" and such, divided up under sections such as firmware, electronics, hardware etc. Probably each answer would lead to a wiki page, the glossary or perhaps a more detailed FAQ.

I guess there are a couple of interested parties in the wiki: The beginners who want to find definitive, reliable information for building and learning; And developers who want to share their research and activities, and find out the latest ideas and designs. (There could be more but none come immediately to mind.) My take on the wiki at the moment is that the information is a bit scattered and some is out of date (or it's not clear if it is or not), but that a few key overview and directional pages could help alot. When I next get a chance i'll have a go at cobbling something together.

Sebastien Bailard seems to be the go-to guy for wiki stuff (although I may be wrong). If he doesn't catch sight of this thread i'll PM him to forward the suggestions on.

Cheers,
Gary

@johnnfullerroot these are a few months old but they were all printed with a 0.35mm nozzle.