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quality of items

Posted by rapper 
quality of items
May 01, 2010 07:19AM
I'm a complete newbie to this area, but very excited about the possibilities. I have computer programming skills and also some experience in metal working, and I think it would be fun to build and use a reprap. I'm also considering starting with a makerbot version.
my question is about the quality of items that can be made with either system. I've seen in the pictures and youtube videos examples of objects. Many of them appear to be kind of cheesy looking, with rough edges. People have made useful items, like coat hooks and all. But if they look like old broken down plastic, would anyone really hang them on their walls? Are there ways to improve the final finish of made items? Sanding or painting or something? Thanks very much
Re: quality of items
May 01, 2010 09:03AM
[blog.erikdebruijn.nl]


Does anybody plan to build an open source Vapour degreasing machine? It could be a great addition to RepRap.
Re: quality of items
May 02, 2010 08:36AM
So, no one will vouch for a way to use this technology to create nice smooth looking objects then? Maybe it is premature with the current state
Re: quality of items
May 02, 2010 09:12AM
Quote
rapper
Maybe it is premature with the current state

And that after only your 2nd post. eye rolling smiley


Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse
Re: quality of items
May 02, 2010 10:59AM
Rapper: You might want to spend a little more time looking through Thingiverse before getting in everybody's faces about print quality. Your ignorance is showing.

Edited 1 time(s). Last edit at 05/02/2010 11:33AM by Forrest Higgs.


-------------------------------------------------------

Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison
Re: quality of items
May 02, 2010 12:39PM
Even with commercial FDM machines, the surface finish maintains those rough edges and bumpy surfaces (although the bumps are ~2-3 times finer than most repraps). Sand paper is always your friend =)
Re: quality of items
May 02, 2010 02:32PM
I'm using a 0.3 mm extruder head instead of the usual 0.5 mm. It makes a world of difference to print quality.


-------------------------------------------------------

Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison
Re: quality of items
May 02, 2010 05:22PM
Easy there, no need to get offended and start with the personal attacks. I asked several honest questions in good faith, and was not trying to impugn your system. I would like to help, if I can, but it is important to know what are the limitations, and areas that need people to pitch in. I did actually look through Thingverse and that's why my question came up, because many items are rough. The tip on sand paper is a good one, and so is the smaller extruder head comment. In any case, if there is a need for nicer materials/smoother surfaces, I would rather spend my time and money on seeing what I can do in that area. I suspect I can just buy or make an extruder, and see what happens when the parameters are messed with. I doubt I can improve on what the groups have done, but the more people that explore the possibilities, the more everyone can benefit.
Re: quality of items
May 02, 2010 06:12PM
The Rapman and RepRap printers use a stepper extruder, they have a higher quality then a Makerbot, just because they have more control over their extrusion rate (Makerbot really only has 1 extruder speed setting 255).

The print quality is the function of many different factors:

-Colored ABS does not generally print as well as natural
-Stepper extruders do better than gear motors
-Skeinforge settings play a HUGE role
-Heated build plates prevent warpage, and failed prints
-High temp extrusion with a fan helps

Think of it this way, CNC cuts can look WONDERFUL, or HORRIBLE, completely depending on who is running the machine, same with CNC extrusion.


repraplogphase.blogspot.com
Re: quality of items
May 02, 2010 10:40PM
In terms of the upper limits of part quality (without post processing), I think Nophead's parts are the best so far. Some of his parts are made on a RepStrap, and some on a Mendel, but they all look very nice.

Check out his blog here:
[hydraraptor.blogspot.com]

Or some of the parts he has for sale -
[forums.reprap.org]

and

[cgi.ebay.co.uk]

All of the reprapped parts do have a fair amount of surface roughness, and I don't think we'll see anything like the sort of surface finish one gets with professional moulded plastics in the near future. On the other hand, reprapped parts are perfectly adequate for what we're using them for. I'm pretty stoked that we can print functional gear trains now - that opens up a lot of opportunities.

Wade
Re: quality of items
May 03, 2010 10:59AM
I agree with Wade. Nophead has gotten great results. A huge percentage of print quality also comes from the resolution and accuracy of each axis.
Re: quality of items
May 03, 2010 03:40PM
Whilst quality of items is important for some things, it is not that important for others. It all depends what you are making.

I make many of my parts at 0.5mm layer spacing, I would go bigger if I could. I can produce a usable part quickly and the quality is good enough for any little project I have. If anything is a little rough a few minutes with a drill or knife usually sorts things out.

I also like the way reprap items look anyhow "Reprap Chic!"
Re: quality of items
May 04, 2010 05:22PM
Another way to improve the surface roughness is to add another 'head' to the reprap that does not extrude but passes a hot spoon or spatula over the surfaces with enough heat and pressure to smooth out the bumps and lines. This surface following will require one or two extra degrees of freedom in moving the spatula around, and lots more software to generate the surface following tool paths. But that would provide smoothness in the convex parts of the exterior.

Mike


Team Open Air
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