reprap opinions?

[blackbeard]

so i managed to nab most of the electronics to build a reprap (no mechanical systems or servos) and i'm wondering whether or not this is a good thing to go ahead with. i'd probably have to spend another 300 to get all the parts i need over the 80 i've spent (or do some creative scrounging) and i suspect this might turn out to be a money pit if it doesn't live up to my expectations. it would be nice to design parts for my projects and then print them out and i'd be the only kid on the block with a 3d printer

[futmacl]

so i managed to nab most of the electronics to build a reprap (no mechanical systems or servos) and i'm wondering whether or not this is a good thing to go ahead with.

As far as I know, Reprap and Makerbot have absolutely horrible accuracy / finish quality:

http://thingiverse_beta.s3.amazonaws.com/renders/17/2d/34/21/16/3534702213_144f9ed9fe_o_display_medium.jpg
http://bbot.org/blog-images/metrix-reprap-output.JPG

I seriously doubt they can be used for anything that could not be achieved in a comparable time with hand tools, though YMMV. 3D printers with acceptable output quality begin around $10k-$20k today. CNC systems begin around $1k.

[blackbeard]

i've seen some pretty gnarly reprap products but i've also seen some very workable parts. that's a pretty sad Utah teapot but it's not necessarily a representation of what a reprap can do. here are some examples of parts i'd consider reasonably workable

http://www.thingiverse.com/thing:2030

3D Printing a chess pawn with my RepRap

RepRap Mendel making Mendels

My RepRap 3D printer printing itself an upgrade (Bowden extruder clip)

[Admin]

It depends on what you want to make parts for . . . I've seen RipRap parts and the accuracy is horrible. If you want to do it for fun or as a learning experience, go ahead - it's a huge project on it's own. But don't do it with the expectation of good functional parts for robots.

The MakerBot is much better. You can't do high precision stuff, and materials are limited, but for making neat little thingamabobs it can do the job.

That said, keep in mind you can also pay to get 3D parts from *quality* 3D printers, too. An interesting part will cost you about $50 including shipping, with big discounts if you order many at once. If you want functional parts for robots, I recommend this route.

[blackbeard]

i appreciate hearing from admin because lets face it, he's robot god. anyway...

what about the reprap self replication? if it's accurate enough to print 3d it's own parts wouldn't it stand to reason that it can print other robot parts effectively? if not is it because the reprap doesn't really move or are the parts just too brittle for moving projects?

[Admin]

i appreciate hearing from admin because lets face it, he's robot god. anyway...

what about the reprap self replication? if it's accurate enough to print 3d it's own parts wouldn't it stand to reason that it can print other robot parts effectively? if not is it because the reprap doesn't really move or are the parts just too brittle for moving projects?

It's because you'd spend less time, and end up with stronger parts, by making robot parts the traditional way - getting sheets of plastic/metal and drilling holes/cutting it.

With the RipRap machine, only a few parts of it are actually printed - like the corner brackets for example. And there is a reason for that

Now if you just wanted to make artistic 3D structures, that aren't functional in any way, you can probably use acetone and sandpaper to smoothen it out to make it look nice.

fyi - I haven't used either machine, but I've seen other people using them (in person), and got to play with the parts that came out of them. The MakerBot printer was impressive for it's cost, but it's not a professional 3D printer but any standard.

[nickc]

You can get a used minimill for that money and make much better quality parts from soft materials ....
or spend a little more and get a used bridgeport that weighs more than your car.   
Twenty years ago we built one of a rapid prototyping machine as a government research project.  We used a wirefeed welder and a 4-axis robot arm to lay down layers of steel and build part just like the current 3d printers.  It was going well until the welding current found its way through the robot case and fried some circuits
I worked with another really cool one a couple of years ago that that was made from a 6-axis robot arm that carried a powered metal feeder and a CO2 laser.  The robot laid down a thin layer of powered metal as the laser fused it to the base material.  It was developed for Rolls Royce aircraft engines to build up components on engine casings.

[Asellith]

I'm crying inside right now because a guy in pensacola is selling a cnc machine from a harbor freight mill. He wants $950 for the machine converted and working as a CNC machine with Mach3 and a PC. I set a search RSS feed on craigslist for just this moment and I saw the post right after I passed on renewing my contract. So with unemployment looming in August and my so far failed attempt to start my own company rolling I just can't come up with the cash.

[madsci1016]

I'm crying inside right now because a guy in pensacola is selling a cnc machine from a harbor freight mill. He wants $950 for the machine converted and working as a CNC machine

Blast! only and hour drive from me, and unfortunately that's the exact amount I owe in taxes this year. Man, I wish money grew on trees.

[Asellith]

If I knew I could make cash with it I would do it in a heart beat. I also don't have room for it nor know how to use it. I may have to move in august as well... We need a hackerspace down here to buy stuff like that

[madsci1016]

We need a hackerspace down here to buy stuff like that

Agreed, though it would only be us two going to it! Any more Florida panhandlers here?

[Asellith]

There was one guy on the hackerspace wiki trying to start something but I think it just him and me in pensacola. He is a teacher at UWF I think.