software stuffs.

I actually got into this project through the arduino microprocessor that the newer versions of the reprap electronics use.

I was struck by all of the art/hobby uses of the arduino and its clones across all sorts of different areas. from plants that can tweet when they need water, to a simple robotics platform. It's inexpensive, a breeze to program, and there are so many different physical packages, that you can certainly find one that fit's well with your project.

The newer versions of reprap electronics use the arduino platform, and the associated programming environment. It has done wonders to make the project more accessible to people who may have difficulty with such thigs.

Anyway, I wanted to mention a bit about the software side of the reprap project. Personally, I'm a very mechanically minded person, it's what I studied in college, and I can even hold my own electrically too. Basically, they are physical systems and I understand those easily, I can visualize voltages and torques and balance and currents, I can see when something I put together probably won't work. I'm also pretty good at seeing how things might/will fail, and that's what I do in my day job, actually.

When it comes to programming, however, I have a hell of a time keeping variables and functions straight. I've spent plenty of time dealing with more simple languages, BASIC back on my commodore64 as a kid, HTML/general web stuff in high school, C and C++ in college. I've been wowed as to what some reprappers have been able to do, specifically some of the JAVA and PYTHON work.

At some point, once you've decided that you actually want to build and run one of these things, you need to sit back and take stock of what you need to download/purchase/learn. Like i mentioned in a previous post, there are many options mechanically, and there are actually a few on the software side as well. Personally, I use a mac, which happens to be one of the less common platforms used. Linux and windows seem to be the defacto standards, and there is some tough going for mac users. There are options, but one in particular, the JAVA host software I linked to above, doesn't seem to work yet on OS X.

The tool path is this: 3d model in STL (and it seems like it is now possible with STEP files too!) is sent to the Skeinforge "slice and dice" program to be converted to gcode instructions for fabrication. These instructions are what the printer will follow to rebuild the solid layer by layer.

This gcode file then has to be fed into the printer's microprocessor. These are instructions like, "print a perimeter from (2.3, 4.4),(4.3,4.4),(4.3,7.8), (2.3, 7.8), and back to (2.3,4.4). then fill it with zig zaggy lines" This is slightly varying for every machine, line thicknesses for example, so there are pretty deep parameter fields in skeinforge to be adjusted. Normally, someone may use the standard host software. I don't have that option, but luckily there is another package available. This one is called ReplicatorG. It also seems to have some issues (i've heard accounts that it may hoard resources on the computer if you are doing very long prints) but it does what i need it to do. i can jog each axis, and run the heater and extruder motor manually. I can then load a gcode file after conversion in skeinforge, and it then feeds those instructions to my system. i'm not quite there yet, but right now it looks like everything is coming together.

My apologies for all this, if anyone has read this and my previous posts i hope you got some thing out of it. i do plan on doing some shorter, more frequent posts with my own specific build details, but it feels like i should do some kind of service to people just getting involved in the project. paint some big broad strokes in one place, to at least get you started. everyone has probably tried finding some specific information in a message board site, and the search output is usually terrible.

best of luck if you're inclined to try some of this stuff.

blog jammed

I've gotten my XYZ system running and now starting work on the extruder. I have a bunch of draft posts written, but haven't had the chance to finish them with appropriate pictures and links. I'll try to get a bunch of those out this week.

My deal.

((note, this post has been sitting in draft status for a little while now. i'm going to try to catch myself up and hopefully soon, start posting about what i'm dealing with in more or less real time.))


This is where we quickly go through the mechanicals and some of the hurdles I've seen and some that I expect.

There's a few ways of getting into the project. The best, and hopefully eventually the easiest way, is to get in with someone or some group who have one up and running. They can print you the parts and you can be on the merry way (though the non-printed portions are still a bit expensive, you'll still save a bunch).

We've haven't hit saturation yet, so it might be a bit hard to get a hold of some reprapped pieces. That's where the concept of repstrap comes in. A reprap is a self-REPlicating RAPid prototyper. a repstrap is a bootstrapped method of making a repstrap, it can't make itself, but it can make parts for a reprap.

There are quite a few ways of doing this. Two common paths include a Mcwire, or a Darwin clone (Darwin is the name for the "standard" community designed reprap, but you knew that if you checked the link I gave in the last post.). Mcwires are a good quick and cheap way of getting a cartesian bot setup up and running. Darwin clones look and feel like a standard reprap, but are generally made of differnet materials. Laser cut acrylic is very common (ponoko or bits from bytes), the original darwin unit was made with cast plastice parts, and some have even successfully cut and carved darwin pieces out of wood.

the benefits of the clones is that you can replace parts as you go, a corner bracket here, a motor mount there. with the mcwire, you can fabricate all of the darwin parts, and then build it up and swap your motors and electronics. right now all use the FDM head, and that would simply be transfered (oh don't worry, people are working on all sorts of fabrication heads and methods, dunno how close they are though.)

oh, and there is also the little and cute Cupcake from Makerbot. basically a small modified mcwire (by what i can tell, moveable stage, though i can't see how the z-axis is implimented.) It's made to use the generation 3 electronics which look real good, but since it is so small and cute it is limited to a 10x10x10cm build volume.

I knew I only wanted to buy one set of the electonics, and only one set of motors so I didn't want an eviscerated mcwire sitting about. Not many reprappers in these parts so no reprapped parts available, and I'm sure that normal demand for parts is through the roof anyway, or at least great enough that the laser cut solutions can charge me $300+ for the privilege. So that's what I went with. Vik on the forums was able to provide a slight discount through Ponoko, which is definitely nice.

Now, when I start building parts I can replace them as I go (or as they break; unfortunately acrylic is fragile and so I have to avoid over tightening, and so it can loosen, and as I re tighten, there's another chance of breaking, etc.) The build instructions aren't identical, but they are similar enough to make it work (as far as I can tell)

As an mechanical engineer, the physical build is where I think I can help the most. Of course one member of the forum, Forrest, is quick to dismiss if he doesn't feel you've put in the time and I'd have to agree, so I quietly decided to hold my cards until I've followed the group and built a working unit. Then I can start pushing out modifications and updates that can maybe simplify or refine issues I feel the design still has. Of course the community doesn't have to follow, but I'll state my case here on this blog and we'll see if the refinements are determined to have merit and are adopted or at least considered in the general design direction. When I first got involved in the project I made some comments on some gaping holes I saw in the heat transfer design of the extruder, and hopefully that helped one of the key engineers, nophead, decide to look into it a bit more with some fantastic experiments and prototypes. Even if my comments just happened to coincide with his efforts, I'm glad I made them. When I have my hapsrap running I'll be right up there with them, testing the state of the art.

yes?

So I've been going back and forth on actually starting this blog. Mostly because I'm not too great with keeping up with this sort of thing, and I do enough documentation and reports while at work. But, here we are. I hope it's informative.

For a while now I've been following along with the concentrated efforts of a great variety of people through the web. The goal for this group is "democratizing manufacturing" or "China on your desktop" or a bunch of other PR slogans people have put together on a bunch of articles and interviews and blah blah blah. I've come to just refer to it as "my nerd project". Others know it as RepRap, or more descriptively it's an open source Fused Deposition Modeling (FDM) 3D rapid prototyper.

The basic premise is this; Wouldn't it be awesome if you could hit print on a 3d model you just downloaded on the web and then have it in your hands later the same day? If you need a custom bracket or brace, why not sketch it up in a free program and then have it built one layer at a time? For pennies.

I'll tell you why I was attracted to it, it is probably similar to why many of the participants spend so much weekend and evening time on it. It's a playground. These machines already exist commercially. They cost thousands of dollars and that puts it out of reach for many many people. Plus making something out of plastic can only be so much fun. It's the building and tweaking and hacking that's the real appeal. The project is open source, and there is a fantastic array of people of all different spheres to help you through with just about any problem (I'll start a list of links sometime soon, I promise). There's been great strides on all aspects of the project; electronics, mechanics, and software, and a lot of different ways to put all of those parts together as a functioning system. Imagine an erector set that is self-expanding.

Now for why I'm starting this blog. I've been doing "hella" research on this project. What's the way I want to get started? What do I need? What do I need to learn? What are going to be my biggest hurdles? After months and months and months of following the forums and trying things out myself, I've got a good idea of what I need to do, so maybe I can share that with other people interested in the project. Eventually, when I do have my hapsrap built and functioning, I'd like to push new "technologies" and methods, bring a little bit of my engineering experience and design some experiments to hopefully help the certainly capable people who already helped me get to that point.

Also I can point my friends and coworkers to this page and they hopefully get a better idea about what this nerd project I keep referring to is about.