Wow 8mm, I am currently using 1.2mm with a normal sized nozzle and MBI stlye hotend. Such a difference direct drive makes. What are your thoughts on the volcano? I got an eruptor pack in the mail this week, and a .8mm nozzle for my current setup. I am hoping to get it installed this week. I did manage to get my printer straightened out. It was the 6th attempt at rewiring steppers/endstops/inverting axis that finally did the trick. I did manage to get my printer to match a replicator. X=width,Y=depth and homing to min @ back right corner. My first try, and I'm not sure quite how I did this one, switched endstops and inverted XY axis settings, caused the Z to travel the wrong direction.

If I remember that brisket was a 28# packer when it started, smoked for 30something hours, that cutting board is a jumbo from work and does no justice to the scale of that brisket. I had the heatermeter setup on a cheap akorn kamado, giving it oven like accuracy. It would hold whatever temp I set it to, indefinitely, I cooked bread, cookies, biscuits, cake and even lasagna on my grill. We are buying a new house here in NorCal, its coming with a Kamado Joe, I am super excited for that. Big ceramic grill like that should have a thermocouple.

 

@CapnBry I just found this http://www.akeric.com/blog/?p=3360

 

You're right, that cutting board does mess with my perception of how big that hunk of meat is. That's huge!

As for the Volcano, I haven't used it for its designed purpose yet really. I've been printing 0.6mm nozzle 0.24mm layers at 60mm/s until I get the print quality where I want it. I've been trying to figure out if the blobs are at the beginning of the line or the end, but that wipe/retract might answer that question.

I bought Simplify3D as well because everyone raves about how great it is. It's got a pretty good UI, visualization, and some good options. For the price, it way underdelivers though. It has no perimeter gap fill that isn't zigzag lines, it doesn't solid fill areas that the infill pattern doesn't fit into, no firmware retraction option, no command line slicing ability, no hotkey for saving the G-code files, and no cloud sync for profiles so you have to manually import export them all the time. The slicing isn't significantly better than any other package, and its world-renowned support structures won't even work on the one thing I bought it for. If it were free or $20 I wouldn't ding it so hard for these things, but when you price your product at $150, you really raise the bar on my expectations and I find some of these omissions inexcusable.

 

I'm in the process of printing the stl files to attempt this build, however I am finding that the carriages/both single and dual's have parts that are not on the build plate and can't seem to find a way to print them(without support). Any suggestions?

 

Some slicers will allow you to separate parts like this, I think Carl mentioned using slic3r, then drop each model to the table. Alternatively, import into cad program of your choice and separate them that way. Using tinkercad is easiest, just drag a big box over one of the parts, turn it into a hole, then save as the single part. from there just drag you box "hole"to the other part and save as the other single part. Good luck with your build.

 

I'll give that a shot! Thank you for commenting and sharing! Much appreciated!

 

Well, I finally made it to the end of the thread. Took me a few days. Not to mention, three weeks ago I had no idea such a thing was feasible to build. And now I can't seem to stop learning about all the options.

At first I was just looking at the Prusa i3, since that seems to be the defacto kit to buy. Although, I'm not one to buy something throwaway, which is what most of the kits seem to be. I also don't like the idea of getting too many proprietary parts because the whole 'print your printer' is an intriguing concept.

I'm not certain how I stumbled upon this thread in my research, but the design of the C-Bot stands out to me as a rugged flexible design. I really like the 12x12 size option as well as dual heads. The last thing I want is to build a nice printer and find it's not big enough. I just got done building the welding table you see in my profile pic and it's a perfect work surface to begin building a 3d printer. You can probably tell from that pic that I'm all about doing it right the first time. It probably weights 1100 lbs, has a 4'x8'x0.5" top, a tool chest on each end. It's ready to rock.

The big problem with this thread for me is that there's so many good ideas, and I don't fully appreciate all of them to know which ones would work best for my plans. I'm thinking at this point, I continue down the path of purchasing a Prusa i3 kit first. Get familiar with the printing process and all the electronics/parts involved. Then once I get to the point of some understanding, I'll be prepared to make the proper decisions regarding which electronics to select as well as other design choices. Not to mention, I need a printer to print the parts for the printer, right?!!? Hopefully once I build this C-Bot, I'll be able to find a buyer on craigslist for my Prusa and it won't have been a waste.

I really like CapnBry's variant with the belt used to sync two lead screws for the Z axis. I'd likely use the 2mm pitch screws. I'd add the extra 30mm or so depth as well as a sleight height addition so I could use the 20x60 Z support. Easier to cut it off later than glue it back on. Of course, I have lots of questions, but I'll just wait until I get to the point of building one before I get too carried away.

This is the Prusa I was thinking. It's a bit larger bed than most, and it uses extrusions so should be a bit more sturdy.

I'll certainly be keeping an eye on this thread though, there's some very creative builds going on. And CapnBry, if you could take a ton more pictures of various bits and post them somewhere, I'd download them for future use, in the off chance you decide to take a hiatus by the time I start my build. It probably won't be until next Spring.

 

Just because I own one, Wanhao makes a duplicator i3, same price point, steel frame, super reliable direct drive extruder, enclosed electronics that are not mounted on top of your Z azis( makes the frame much less pendulous).

Since I was again pleased with my printer, I decided to mess with it some more. it seems that a 1.2mm nozzle is just what the doctor ordered. I installed the volcano heaterblock and big nozzle onto my direct drive all metal stepped bore thermal barrier. printed my first cube and decided that i only needed to back down the extrusion multiplier a touch ( .05 ). WOW thats a fat nozzle.

75mm/sec *1.2mm nozzle*.6 layer height = 54mm^3/sec Thats a lot of plastic. Watching the spool turn is almost hypnotic. I will post some more vids in TripleC thread.

 

Hi Souprmage,

First of all sorry for my English (will try to keep it simple...)

I'm in the same boat.
Never used a 3d Printer, and the only thing that I did with them was helping my uncle to assemble his Prusa i3 Hephestos.

And you know what? I've decided to go straight to the C-Bot.
Asked my uncle to print the needed parts (still waiting for some) and ordered the rest from the net.

I've read this thread countless and I will use some solutions from users that made they're C-Bots, including the 1 motor -> 2 lead screws like CapnBry did but with some adaptations.
Because of that I'm still waiting for some parts. For example I bought two couplers for the Zs and I will now use two 8mm pulleys for that closed loop belt of one motor and two lead screws...

I saw the BOM list and ordered 3mt of GT2 Timming Belt (the BOM states 2mt) and two days ago when I went to assemble the motors to try the XY movement I noticed that I need two GT2 Belts with approx 2,1mts! Just because I simply forgot that my printer is a "bit" bigger that the original one! I know... DUMB!

I take all this back steps like learning and try to improve. And I'm pretty sure that when I finally finish my C-Bot I will be thinking that some other solutions/path would have been better. But by then I will be able to make my own parts and continue to improve it.

I do have a lot of doubts and don't know how it will end up, but I do know that people in this forum are really helpful and that makes me go on and on.

Here is a photo of my early build stage. I hope to receive more parts during next week so I can move forward. Yes I'm not going back!



I think that if you want is a C-Bot, go for it!
You will have help if you ask.

 

I thought about just foregoing getting something else and just starting with a C-Bot, but I look at the C-Bot as an ultimate machine for my needs. As such, I want to know what I'm building is all the right bits, not that I couldn't just upgrade it later, but still. I think there's a lot to learn about printing in general with a smaller machine. And before I dive into a 12x12 build, it's probably good to start with a slightly less complicated solution while I increase my knowledge.

I was going to wait until I got finished with a few more honey do tasks, but I couldn't resist. I placed an order for the Pegasus, so if it doesn't help me along this journey, I'm coming for you Kyo! Now I just have to figure out a decent power supply to use.

Back on topic and because I don't want to wait to answer my questions...

Since a 12x12 heat bed really takes it's own power supply and all, what about a solution like this that has it's own controller too (there's also a 35x35cm version, but I think that may just be too much of a good thing)?
http://www.ebay.com/itm/30x30cm-750...ontrol-Plug-/281716682121?hash=item41979f6d89

Can it still be hooked up to the printer's controller for temperature reading so it waits until it's warm before it starts even though it's not controlling the temperature itself?

Also, does the extrusion calculator take into account the extra width needed for a dual extractor setup?

 

You'll still want to use a thermistor hooked up to your control board. You'll also want to use a solid-state-relay and use the heat bed output from your controller board.

My suggestion for anyone wanting to build a C-Bot or any of its derivatives is to model it:

- Download all of Carl's STLs and any STLs you see posted here in the discussion that might remotely apply to your build.
- Download the STEP files for V-Slot extrusion (OpenBuilds has a wonderful STEP library full of awesomeness)
- Download Carl's BOM and use the second sheet to get your extrusion lengths
- Import everything into your favorite modeling program and see how it all fits together

I happen to be using Blender and FreeCAD (for STEP to STL conversion). I really wish I had followed this advice when I first started. My problem is that the steppers I chose are taller than 40mm, so my planned build height is actually a bit shorter than I wanted. If I had modeled it all, I would have seen the issue and planned on taller legs (before cutting )

Anyway, it's also helping me now with figuring out where to place all my endstops. I'll be posting up some parts when I get it all assembled.

 

I also went the A/C route for the heated bed from the same seller. Keenovo has a 30x30 750W w/thermistor version that is cheaper and includes the thermistor (220V also available if that's what your plugs are). I just wired that into a FOTEK 30A SSR and was good to go. Keenovo will email you the PDF with the thermistor curves but I compared to the standard EPCOS 100k and found that it was within a degree up to 100C so I just used that. It did take over a month to get it to the US though, so order early if you're going that route!

Heats my 1/4"x12"x12" aluminum bed 27C to 100C in 3m 15s, but takes about another 2-3 minutes for the heat to spread evenly through the build plate (you can see this from the M105 temperature output that the "@" number keeps dropping until it is evenly heated). Only problem I have with it is that a 1/4" slab of aluminum takes a really long time to cool down so I have to wait to get my prints off because I print right on kapton on the aluminum.

 

I've gotten my printer going and in the process of calibrating, I started running into a situation with my electronics. I'm using a Geeetech Rumba Board with the Discount Smart LCD with 8825 drivers. I noticed early on that the SD reader was not reading my SD card. I passed on this as I was tethering to my Win10 laptop with S3D. I noticed that during printing the job would just halt and wait until I ran out of patience and Force Continued the job. This would happen once per print at random times. Then the LCD display stopped displaying characters, although the encoder seemed to continue working.

Finally, the USB connection to the computer stopped being recognized, but strangely enough, only when the jumper was set to Stand Alone mode. When using USB power (with the main power turned off) I could connect with the Rumba and upload firmware with no problem. Once I set the jumper back to Stand Alone and power up the printer, the port tries to connect and is rejected by windows (USB device not recognized).

Has anyone seen this happen? It has been working right up to when I changed out my V6 for a Volcano. Any thoughts?

Update: I've tracked it down to a bad thermistor on the Volcano. How that can interrupt USB communication is beyond me. Waiting on a new LCD display.

 

With my lack of electrical knowledge, I was thinking of keeping it easy, but I found a link that seems to explain exactly how to wire everything up using the SSR, and it makes sense to me now. Thanks for giving me a prod in the right direction. LINK for anyone else interested. Would a 40A SSR work? The only place I'm seeing the 30A variety is on aliexpress in lots of 5. Ebay and Amazon have 25A and 40A, but no 30A.

 

Absolutely. The heater is actually less than 7A, but like you say they're pretty easy to find in very large amperage. Might as well get the 40A because they're cheap and don't always handle their rated current. Well what do you know, mine is 25A after all.

I also ran a wire from the ground on the power supply to the mounting holes on the SSR (with a spade terminal and a star washer). This grounds the whole C-Bot frame so that if something terrible happens and a mains voltage wire touches the frame, it will pop the breaker. If not, it will just energize the frame with 120VAC and happily transfer it to you when you touch it. The wire in the center just goes to the GND terminal on the power supply (NOT THE NEUTRAL).

 

I was just about to post that up there Yah, I'm finally getting the volcano to print 'better'.
Along those lines, I just upgraded my cooling fans on it to dual 24cfm monsters, wanted to pass that info along: http://www.akeric.com/blog/?p=3374

 

@adamcooks I have been meaning to ask you about the extruder you are using. Who makes it and what do you think of it? I found this one on Amazon and it looks similar. I found a version with dual hot ends, but not sure how all the extra weight will effect the printing. Figured I would at least have to slow things down.

 

Elmo's reversed LCD mount was a good idea but since I didn't have t-nuts to attach the front, I stole from him and Eric and made my own version that didn't have the big front part and has a nifty curved back support because why not.


Also installed my 900mm GT2 belt on the Z axis (up from 848mm), which allowed me to push the threaded rods back about an inch or so. Just that small amount made my bed 4mm more level. The front had always been higher due to most of the weight being aft of where the rods supported the Z stage, and I compensated with the bed springs. The back is still a little lower because I still am not at the center of mass, but I can't go any further due to the electronics back there. Good as it gets!

My 12V 30A power supply gave up the ghost sometime last night. I went to print something this morning and Octoprint was down. Went to check it out and the power supply green light wasn't even on. Disconnected it and took it apart to look for obvious problems but I don't see anything. Fuse is good, MOV is good, caps look fine, power is coming in. Funny because I can't use more than 5-7A out of the 30A due to my bed running on A/C.

 

My extruder is kind of a hodge-podge of parts. From bottom up, E3d V6 1.2mm nozzle, E3d Volcano heater block, Carl Raffle stepped bore all metal stainless thermal barrier, Qu-BD aluminum cooling bar, Robotdigg stepper, Reprap.me Drive gear, 3-in-1 filament pusher

Sorry I have not gotten back to you on the extruder you linked. I feel that the cooling bar is not adequate and you would most likely have difficulty printing PLA. I do like the idea of the aluminum filament pusher module but I don't think that incorporating it into the cooling system is a good idea. I think it would allow the area in the filament path to get too warm, sinking heat from both the hot end and the stepper motor.
I almost assure you that the thermal barrier would be a straight bore, or 3x2mm ptfe lined. The "magic" as we refer to it in the replicator world is the step in bore size at the hot end. The hot end of the barrier is 2.2mm ( the first 10mm just above the heatbreak) the cold end of the barrier is 2mm. This step allows the molten filament to sheer off before being retracted into the cold zone, preventing the pla jam. This magic was present for the replicator 1, but "mysteriously" was absent on the open source drawings. All the chinese ( and others ) copied the posted drawing and had jam after jam, The chinese engineers came up with PTFE liner all the way to the nozzle as the fix. Other then Carl Raffle, you can get a magic thermal barrier from AVN Swiss, or MBI themselves, if you can manage to a competent person on the phone. My replicator has the AVN tubes and I like them very much. Carl has moved on from parts and is about to introduce a banging new printer, and redesigned mightyboard to the OSHW world, and will not likely be producing any more replicator parts.

 

So without the T-Nuts, how does it attach? (I didn't put the curve in on mine because I was too lazy to work it out in OpenSCAD )

 

It has the t-nuts on the top part (the 20 part of the extrusion), just not the 4 on the 40 part. The only flex seems to be in the uprights so it doesn't seem to need the extra stability. Granted, that extrusion is one of the easier to remove and put more drop in t-nuts in, but this seemed easier (until I spent 20 minutes in OpenSCAD!).

I need to get some drop-in t-nuts though because I want to mount a 120mm blower on the back Z rail. My aluminum bed takes like 20 minutes to cool down from 110C to 70C where I can start to pull the pieces off, but with a 120mm fan which kicks in in the end g-code, it takes only 3-4 minutes before the pieces pop off. Right now I have it attached with some mini quick-grip clamps and I am ashamed of it. :-D

 

Okay. Sounded like you didn't use any T-Nuts and it somehow clamped on. I only used the top connectors too. I put the holes in the front just in case the upper ones weren't enough. They were so didn't add any more.

 

Question to the community about ringing: I was under the impression that a core-xy design such as this, with a Bowden extruder (thus removing a bunch of moving mass) would help to reduce xy ringing in a print. I've been doing a bunch of organic stuff up until now, and the printer has been working great. But yesterday I did a print that really shows off how much ringing is going on. Arguably worse than what my Replicator 1 does on the same print. It was printed with a .6mm E3d-Volcano nozzle @ 300 micron, 60mm/sec extrusion & travel. My firmware is Marlin, running on a Rumba, using DRV8825 stepper drivers.
(click for bigger to see the ringing better)
So my questions to those with their own c-bot is:

• Do you experience similar ringing?
• If not, what do you suspect is causing this?
• Any thoughts as how to fix?

My first guess would be my xy-stepper belts aren't tight enough. Which raises the question, 'how tight should they be', and 'how does one measure said tightness?'.
Finally, I've never messed with all the Marlin firmware acceleration settings, I think they're all default. I'm wondering if maybe these should be tweaked? And if so, to what?

Any thoughts appreciated!

 

FYI, I just posted this question over on the 3D Printing Google+ page too:
https://plus.google.com/117814995679657521943/posts/Td7oQR21Vqy

 

I think I agree with Ryan on this one. Frame wobble, I might also consider bed oscillation due to the cantilever.

 

I will put up some pics when I get home tonight, My bot has 4 cross members additional to the c-bot. Two on the bottom for the z belt idler and two under the moving gantry parts. It's quite stiffer then before. I do plan on enclosing mine with acrylic which will even further reinforce.