…code, cg, electronics, 3d printing…

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This is really ‘Part 0’, since Mason printed all these parts for me (on my Rep1 he was borrowing) while I was on vacation, before I even started blogging about it.  But it’s worth bringing up the specifics.

Carl Feniak has a full list of the stl’s to download & print over on the C-Bot’s OpenBuilds page.  Mason ended up 3d modeling the entire printer in Maya as a sanity-check for himself, and based on that, made some adjustment to Carl’s files (which my prints are based on).  If Mason posts those updates I’ll be sure to link to them.

I still need to print out a few more things, like the attachment for the E3D Volcano, but otherwise most of the printing is done.

Print settings were:

• Printed on Makerbot Replicator 1
• MakerGeeks ‘Maker Filament’ PLA 1.75mm, “Soulful Blue“
• 300 micron layer height, 2 shells (probably should have been 3), 40% infill, 4 ceiling/floors, .4mm nozzle
• HPB @ 60 (to help them stick\lay flat)
• Sliced in Simplify 3D

The filament is slightly translucent, and a really nice color blue.

Jump to C-Bot blog index to see all the posts.

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For this build, based on the recommendation of Mason, I picked up a Corsair CX 500 PC power supply from newegg.  500 watts of power, can do 38A at 12v (with a single dedicated 12v rail), so should be more than enough power for now, but room to grow.

Simple current calculations based on the biggest offenders:

• 6x nema 17 steppers @ 1.68A (max) = 10.08A :
  • Core-XY mechanics, x2.  Z-stage. x2, Extruder, x1 (+ 1 extra for dual-strusion later…)
• 12×12″ heated build plate : 20A
• + other smaller draws.

After I got it he mentioned: “Oh yah, you’ll need to modify that too”.  Uh, what?

He pointed me to this great vid by MakerGeeks (I also like their (US made) filament), which shows you how to do the whole operation.

Highlights are:

• Ground the green wire to trick the system into thinking there’s always a load.  Otherwise it won’t want to turn on…
• Strip and plug the 12v wires/ground into your mainboard.

But this power supply has many bundles wires pouring out the side, far more than I’ll need.  I also knew this supply supported three different voltages, so after I hack-grounded the green wire using a paper-clip, I used my multimeter to check different colored wires:

• Yellow : 12.46v
• Red : 5.01v
• Orange: 3.36v

Telling me, cut everything but yellow (and black).

So I got to work:  Opening the case, I isolated the green wire, and soldered it to one of  the grounds.  Heat-shrinked the result, tucked out of the way.

I need two separate lines of power out of the box:  One for the Rumba, and one for the HBP.  There were three bundles running out of the machine with yellow & black wires only:  Removing them from their protective mesh sleeving, I collected/connected (via twist & solder) three yellow/black for my HBP power, and another two yellow/black for the Rumba board power (could probably get away with one, I’m just playing it safe):  While the Rumba can power a HBP, it’s rated at 11A.  Since my monster 12×12″ HBP can draw up to 20A when heating, I need to connect it directly to the power supply (it’s temp will be controlled via a relay).  I choose to use three wires to visually match the gauge of the wires pre-soldered to the HBP.

Finally, everything else got chopped to about 3″ off the mainboard (in case for some reason I need to use them in the future).  I wrapped each end in electrical tape, wrapped the whole bundle in electrical tape, then clamped it down with zip-ties so nothing will come undone if things get hot.

I was very happy than upon reassemble it worked 😉  Next steps would be hooking it to the Rumba (which hasn’t arrived yet) and the heated bed.

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Sneak peek of the final result:

Finished C-Bot!

This series of blog posts tracks my progress of building a “C-Bot” 3d printer.  All the pages should be considered living documents, and will get updated throughout the build as I learn/understand more of the process.

This is not a ‘printer build howto’, but rather my experience during the build.

Also, this is by far the most complex thing I’ve ever built:  While I’ve been actively 3D printing for three+ years now, have built quite a few electronic/robotics projects (as covered by this blog), and have no fear of programming, I definitely feel like an explorer who just crested a rise to see a fascinating valley full of unknown wonders I must traverse.  I hope the locals are friendly…

I’ve owned a Makerbot Replicator (1) 3d printer since early 2012 (when they were first released).  Like all 3d printers it took some time to get ‘tuned in’, but overall it’s been an extremely reliable machine, and I haven’t had any problems with it for over a year.  However, I’m yearning for something more.  Specifically, something bigger.

The idea of a cubic foot is enticing, but limiting:  At that size, my first (and really only, based on my specs) choice was the Type A Machines Series 1 ($2749, or $3199 for the new Pro):  I love everything about it, and they make it close to where I live.  I was almost ready to pull the trigger on it, when my friend and co-worker Mason Sheffield did some research, and decided to build the “C-Bot“, over on OpenBuilds.  He’s been blogging about his experience here.  The C-Bot was designed by Carl Feniak, and seems to check all my boxes:

• Core-XY mechanics.
• Modular size: make it any size\shape you want (within reason).
• High-resolution, fast.
• OpenBuilds V-Slot linear-rail system for all moving parts.
• You choose the electronics.

Carl did a great job with providing build documentation and a BOM, considering he’s releasing it all for free.  Mason took that improved upon it with more info, and even redesigned some of the printable parts.  All told he probably spent around +-$1200 (+ his time) for a great printer with a square foot build volume.

The rear of Carl’s C-Bot

Mason’s C-Bot

The closest competitor doesn’t even come close to that cost:  The F306 (which looks amazing) is around $4k, and the Makerbot Z-18 is $6500.   I liked the size and specs of the gMax 1.5 XT ($1895), but I’m not a fan of moving build platforms.  The Rostock Max kit is also a great value ($1k), but talking with their support and users, it just didn’t have the speed I was after.  I should note I’m not trying to speak ill about any of them, they all seem like solid offerings.

While I was on vacation I loaned my Replicator to Mason, and he printed out all the parts for his printer (and mine, before I was even sure I wanted to build one).  When he got his printer assembled & running, and started bringing the results into work, I knew it was the time:  Armed with Mason’s updated BOM, over the course of two days I ordered all the parts, and am currently eagerly awaiting their arrival.  The only difference between mine and his:  Mine will have a build volume two foot tall, with a negligible impact on price:  just some longer aluminum extrusions & wires.

That means I’ll have a core-xy printer with a two cubic foot build volume, for around $1300.  Presuming I can actually build it

Current Hardware\Firmware highlights:

• Print volume: x/y 12×12″ (305x305mm), z 24″ (610mm) = 3,456 cubic inches (56.75 liters). My Rep1 has around 300 cubic inches (5 liters)…
• XY Mechanics: Core-XY
• Z Mechanics: Cantilevered bed, dual lead screws.
• Mainboard:  Rumba (based on RAMPS 1.4), 12v
  • + LCD Screen & ctrl pad, SD card, USB, allowing for untethered printing.
• Firmware: Marlin
• Power: Corsair CX500 : 500w, 38A, 12v, PC Power supply
• Steppers: Nema 17, 76oz torque
• Extruder: E3D Volcano, Bowden , 1.75mm filament, 12v (see Step 2)
• Heated bed: MakerFarm 12×12″, + custom cut removable glass bed.
• Linear Rail : OpenBuilds V-Slot
• Wheels : OpenBuilds Delrin Mini V Wheels
• Slicer : Simplify 3D
• + many other bits from multiple distributors…

Future posts will cover the build process as the parts arrive!

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