I've been a bit busy lately and mainly working on other people's projects, so I haven't had a lot to post lately, but I have been working on the R3 (RepRap Router) again.  My laser-strap prototype has taken up residence in the new CNC room at Hamerspace and is now sporting new endstops and tool mounts including a boom for its powerful little flex shaft spindle.  I got in a quick test of the tool mount and spindle last meeting and grabbed some video:

Here's some additional pics:

Next on my list of stuff I need to do for this prototype is to get the hold down system in place and mill the sacrificial top flat.  I plan on embedding some extruded aluminum T-slot that works with 1/4" hex bots into the MDF work surface like the bigger CNC setup at the space and using standard woodworking hold down clamps for now and maybe design some milled or 3D printed ones as the project progresses.

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Here's a sneak peek at the prototype of the laser cut version of the R3 platform with just about everything but the lead screws installed.  It's based off of the OpenSCAD models for the milled R3 parts with a few modifications, primarily to use T-slot construction rather than 1/4" threaded rod.  I experimented with match drilling as mentioned in the Mantis 9 build page and it yielded some very smooth motion on every axis of travel.  If all goes well, I should have my R3 prototype up and running for demos at the Kansas City Maker Faire June 25th and 26th along with my Makerbot, PE00001, in the 3D printer village section!

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I haven't gotten much done on the hardware side of things lately, but I've been busy with the electronics of the R3 platform I'm working on.  Above is the first draft of the parallel port adapter that will be used for the first round of machines.  This board allows a PC running Mach3, EMC2, or any other G-Code interpreter with a parallel port driver to control up to 4 RepRap/Makerbot stepper motor drivers and has separate inputs for X, Y, and Z axis home, emergency stop, and limit switches, as well as a few additional outputs and it exposes the enable functionality of the stepper motor drivers, allowing you to disable all stepper drivers if needed.  I'm planning on using Mach3 for the initial prototypes and then moving to a microcontroller based G-Code interpreter (possibly based on GRBL) once development is further along.

Other than the main PC breakout board, I've also designed boards for mechanical end stops (seen above) and a stepper signal splitter board (seen below) that will allow two stepper drivers to be controlled by the same signals, allowing for some interesting mechanical drive options.

While designing these boards, I tried to keep them single sided if possible, keep the required part counts low, and use big parts where applicable to make them easy to construct.  The idea is to make them easy to "bootstrap" via traditional DIY PCB etching methods and easy to mill once I've got a machine up and running.

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So my CNC design is coming along nicely now, and I'm really liking developing it in OpenSCAD.  I'm trying to organize everything well to make the design easy to modify and come up with a good work flow for going from designing individual components, to fitting them together into assemblies, to actually generating the toolpaths to cut out the parts on a CNC router.

One of the cool things you can do if you build full assemblies from your individual parts in OpenSCAD (or any CAD program, really) is do a quick first pass of your design and make sure everything fits together nicely.  Here's an example issue I caught when looking at my X-axis assembly:

One of the pipes that span the X-axis frame intersects the spans of the gantry.  To fix this I can open the include file for the X-axis and change a single line that defines how wide the  spans are or the  spacing of the guide rods, recompile, and end up with this:

Problem fixed!  If I extend this approach and make an assembly for each full functional unit, each axis, each tool head, etc., I can throw them all together and see how my whole final machine will look and identify problems with the design before I start cutting parts.  Moreover, others can also easily see how the hole thing fits together, make changes, and check their mods easily as well.  That's the plan at least.

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I also made some spools for jumper wire that fit in my trusty electronics tackle boxes:

I've also been working on a set of parts that'll attach to a standard Cupcake CNC to add fume hood functionality for a fellow Makerbot operator.  It's not done yet, but the parts I have done make it look like a little oven, which I think is pretty awesome:

I've also been working on the CNC router at CCCKC, which has had a few successful test cuts and should help me finish a few long-running projects I've had on the back burner.  Check out this CCCKC blog post for video and some more info.

Lastly, I've been working on my self replicating CNC project again.  I've decided to make this project even more ambitious and I've acquired most of the hardware that I think I'll need to finish it up, or at least get it off it's feet.  I'm also learning OpenSCAD and doing all my initial design and prototyping in OpenSCAD.  I'm going to try and use OpenSCAD to model all the milled components in 3D and then use OpenSCAD's 2D rendering capabilities to generate the DXF files that will eventually be used to generate tool paths to actually mill the parts.  I'm trying to make the design very parametric and well organized so it'll be easy for me to tweak and easy for others to modify use the parts they have on hand or make new  derivatives.  The CCCKCCNC being up should help prototyping as well.

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