I recently hit 100 instagram followers and decided to make a piece using both the C-Bot and the X-Carve, and came up with this silly thing:


Not rocket-science when it came to 3d printing, but the large volume of the C-bot made it go fast in one print.
More info and pics on my blog:
Making The OneHundred

On a side note: I've been having a hard time keeping my 1.2mm Volcano nozzle to temp when the cooling fan runs and it's extruding at 45mm/sec @ 600 micron (which is an extruded volume of 32.4 mm3/sec, about 4.5x the amount of a 'normal' nozzle at a comparable speed/height). Realized that E3D shipped me a 25w heater cartridge: My 40w just showed up in the mail. If that works out I'll be sure to let everyone know...

 

I also had some binding problems at first with my leadscrews. Turning the brass nuts all the way down and then back up a few times seems to have fixed it. I'm not sure if the nut is being cut by the leadscrew to make it happen but my gantry will slide right down as well now if the stepper belt is disengaged. Well, slide right down until the cantilever causes it to get off balance and jam up.

That's a pretty giant volume of extrusion you've got there, @AK Eric! I'm not sure why they include the 25W heater by default with these E3D hotends + Volcano packs. The 40W is only a few cents more and we could definitely use them! My official 25W heater cartridge pulled 1.8A at 12V (21.6W), 15% under spec! I didn't want to pay E3D prices so I ordered a couple heater cartridges from eBay/China. 30W = 12V 2.6A (31.2W), 40W = 12V 2.9A (34.8W). As far as the difference in heating:
25W = 24C -> 230C in 2m 25s
40W = 24C -> 230C in 1m 41s

That is the only reason I upgraded, was the startup times. I max out my printing on the 0.6mm Volcano at a little over 15 mm3/sec which the 25W could keep up with.

 

what are your guys thoughts on more or less hot swappable hot ends for different things? ive been toying with the idea on my delta, of incorporating a plug for all the connections on the effector, so i can easily just disconnect the hotend. ive seen people hook the fans, thermistor, and hotend up to an ethernet jack on the effector Typpa 3D printed Delta Effector for E3DV6 & 2x 40mm fans by Robkar like that. and i was curious on two fronts

1- what sort of detail can you get with an E3d Volcano? since this will be my large and, more importantly, most consistent printer i want this build to be able to handle large fast prints, but also more detailed prints, and possibly even small detailed prints. so that leads me to think of two hotends, a volcano with something like a 1mm nozzle, and then an E3dV6 with like a .4mm nozzle. and making a carriage that has a mechanism to quickly change between them will greatly help efficiency and also reduce the calibration necessary between changes. is that something anyone besides myself are interested in?

2- even regardless of the quick changing of hot ends, is having a plug more practical? esspecially with all the things that end up going onto the hotend and carriage, (heater cartridge, thermistor, fans, Z-endstop). i know it feels easier for me to just disconnect the hotend so its much easier to clean or whatever. that being said, does anyone have any suggestions? the best idea ive found is ATX molex plugs, since they seem to be rated high enough to handle the high power loads from the PSU so it should be fine for handling a 40w heater cartridge...right?

has anyone done something like this before? what sort of issues did you find adding a plug to the hotend wiring?

 

Keep in mind that if you are changing out hot ends/thermistors for various prints you would have to redo your PID tuning each time as it is hardware specific. If your thermistors were different you would also have to define it each time in the firmware.

 

Congratulations on your minions, if only I used instagram. I do get updates to your blog in my google now feed, and dont tell my wife but your blog gets listed first.

With the 24v40W heaters i was in the 56mm^3 flowrates with the petg. But I am using a 40mm stepper as well for my extruder, my clone and i3 both use 34mm steppers.

 

Wow, that's crazy! Maybe once I get the new heater installed I can crank the speed up even more.
And I won't tell your wife about your blog order preferences

 

I bought both the regular E3Dv6 and Volcano ends, along with like 6 nozzle sizes, with the notion that I'd swap them around based on what I was printing. I slapped regular dupont connectors on for the thermistor and hotend fan (with them wired male on the removable side for the fan, and female for the thermistor removable side). For the heater I used a JST 20AWG connectors. All my connectors are right above the hotend because the "umbilical" that runs over to there is all tiewrapped so removing wires from it would be a problem. The fan stays so unplugging the two wires isn't a challenge. The 20AWG wire, even running 4 amps (48W) through a foot of it is only 0.16W of power being dissipated in the wire which isn't a lot and I don't even have a foot of wire. ATX power bridles are either 16AWG or 18AWG so they are more than capable of this kind of power.

What is a real pain in the butt is trying to swap the heater block or nozzle. The heater block (v6 or Volcano) you have to unscrew like 50 revolutions to get it off with all the wires sticking out and bumping into the 10 things you've got strapped to the carriage. The plugging / unplugging comprises like 1% of the time to change the heater block. Just changing the nozzle isn't very easy either, as they really seem to get gobbed up with plastic over time and really take some force to break free. That doesn't require any special wiring. They make volcano nozzles down to 0.4mm, which is good for pretty good detail unless you're making 30mm tall figurines. The final alternative is to pop out and swap the entire hotend, which comes out pretty easily with two screws. That's pretty **** expensive though. In any of these scenarios you're going to need to recalibrate your Z offset to some extent. PID constants I really don't mess with because they don't make that much difference unless you're way way off.

I've just compromised by just putting a 0.6mm volcano nozzle on and the rest sit in the toolbox. It's too much effort to change the hotend configuration and I can print pretty quickly with this, or slow it down and thin my widths/heights for some decent detail.

 

now that is really good info to have! i already have an E3dv6, so i was planning on having them both anyways, but i think i will just follow your path and get a Volcano with a .6mm nozzle. im sure thats plenty small enough to do 99% of the detail i have in mind, and if not, theres always my delta printer for the smaller parts and builds.

now that thats cleared up a bit, i do really like the idea of having an umbilical thats essentially plugged into the carriage and then having the hotend and accessories plug into that. to make for easy detachment and clean wiring. ive been using 'Deans Connectors' for my batteries for rc cars and airsoft guns for years, and i think ill do the same thing with the heater cartridge wiring. their designed so that they cannot be connected incorrectly, which is wasted on this particular application, but they certainly can handle the current flowing through em and i have plenty lying around. they would probably even make for good connection points into the electronics from the PSU. instead of straight soldered wires leaving you bound to that powersupply unless you break out the iron.

in case someone doesnt know what deans connectors are, heres a pic. they make REALLY clean and solid connections and are very robust, yet very cheap and easy to come by

 

I originally had the middle one on my Printrbot. Switched to the spider type and glad I did. Saved my bed from some bad head crashes. I put them on my C-Bot even though it shouldn't have the same issues as the Printrbot does.

 

I think the difference is that they have the cute little LED and are easily mounted. I use the Hall Effect sensors for my endstops which are much much smaller but even more challenging to mount because you have to basically crush the wiring into place and the head just dangles out. I'd love to make some PCBs with mounting holes in them but they'd be more hole and connector than components.

 

I think this size microswitch is most commonly found with M2.5 clearance holes for mounting. If you found one with M3, it might be difficult for others to source. nothing stopping you providing the choice between the two?

I personally chose the PCB mounted switch because they're pretty much a standard part; they use M3 screws, which I have in abundance; and have the LED indicator.

 

Going back to swapping hotends...

No one using dual extrusion? I'm planning to use two extruders and hotends, one with a normal e3d-v6 0.4mm, and another with a 1.2mm volcano. Planning to dual extrude and use the volcano for infill and (possibly) support.

Obviously this would allow you to choose between one of two nozzles if you wanted single extrusion. Could remove the bowden tube to the unused hotend to save on moving mass

 

ive really wanted this to be my dual extrusion printer, but i also really want this to be direct drive so i can use flexi filaments and also reduce backlash and up the speed etc... so im super torn between the two and im thinking of even just doing one of the extruders as direct, and have the second extruder on the bowden. im not sure the coreXY would allow for the high mass of two direct drive extruders on the carriage while maintaining any resemblance of speed

 

I think that's the most I've heard of someone attempting dual extrusion on a c-bot. I'd like to hear about how you find it if you do give it a go Carl.

Must say, i'm a bit worried about excessive oozing with the 1.2mm nozzle and volcano heatblock. I've heard dual extrusion is a pain with ooze regardless of hotend. #reprap on freenode suggested having the momentarily unused hotend mount lift on the gantry plate (possibly a mini-servo), and actuate a small ooze-catcher of some sort!

Will have to see if it comes to that. Hopefully an ooze shield will suffice.

 

I'd like to see a direct drive and bowden dual extrusion mount plate. Best of all worlds that way, with only the penalty of the direct drive stepper mass.

What you might lose in acceleration speeds, you could gain back with less moves by using the second (assuming wide nozzle volcano) hotend for infill? Obviously the time-saving is print dependant, but could be worth considering?

 

Has anyone ever experimented with running a flexible motor shaft cable similar to what is used on some dremel tools like this for a direct drive extruder with a static mounted motor?
Combine the low mass advantages of bowden with the extruding abilities of direct?

 

i always thought that bowden setups didnt work with flexible filaments because the filamanet can 'squish' itself inside the bowden tube and get stuck. if thats the case, the same issue would be present in something like the drive shaft wouldnt it?

 

thinking about dual directdrive extruders on the carriage, is there any reason why just upgrading the XY stepper motors wouldnt add enough to the torque and stopping/starting power necessary to keep the sharp corners when moving with all that mass?

something like this 5704M-03 Stepper Motor | NEMA 23 | 0.45° | Lin Engineering should provide the torque needed, and is also not a huge difference power-consumption-wise compared to a NEMA 17. it offers nearly double the torque (140 oz-in vs 65 oz-in), and even has twice the angle-per-step resolution. instead of 1.8 degrees per step its .45 degrees per step, which should enable things like 1/128 micro stepping, but with the torque and holding power of something like 1/64 ustepping.

what do you guys think about something like this? i am unsure how readily available these particular motors are, but the concept should be consistent right?

 

I just meant putting a long flexible rotating shaft on the extruder motor so it could push the filament at the same place that a direct drive setup would but the extruder motor itself would be mounted to the frame to keep mass low.

 

oh! thats actually a really interesting (good?) idea! i wonder what kind of torque those shafts can handle? and with what sort of precision they can be turned with. im definitely going to do a little more research on that front!

 

Search for 'flex3drive'.

 

Yep. Why have I never seen this on a printer? Is it too good to be true? It seems like a perfect fit for the Cbot, or maybe a diy flex3drive clone could be made.

 

I think the idea of having two heads of different sizes for the same print is conceptually cool. And while I've never done it itself, having used .4, .6, 1.0, 1.2 nozzles on different machines, I personally wouldn't do it. I have a feeling the reality is quite different than the theory.
Food for though:

• I've always used the rules of high\med\low res on a head based on % of the nozzle size: For a .4mm nozzle, 'high' res is 1/4 the nozzle size, or 100 micron. 'medium' is 1/2 or 200 micron, and 'low' is 3/4 or 300 micron. For a 1.2mm nozzle, that's 300 micon, 600 micron, 900 micron. If you have a .4mm nozzle and a 1.2mm nozzle, they have radically different preferred layer heights: the only place they really meet is at the 300 micon layer height: Super low res for the .4 nozzle, but super high-res for the 1.2 mm nozzle. You're going to have to have radically different print settings for both nozzles to get optimal performance of them in the same layer, since you can't have them printing at different resolutions or you'll crash nozzles into prints.
• Infill : I'd actually go the reverse than common thought: I'd rather have the small nozzle do my infill (presuming this is an art piece, rather than a structural one), or you'll end up eating up a ton of filament in your infill with the big nozzle.
• Big nozzles handle overhang worse than small ones, since the thicker your layer height the less overhang you can support. Presuming you're using your big nozzle on the outside. I made a visual comparison here: Visual comparison of 1mm 3d printer nozzle overhang tolerance
• Support material generated by big nozzles can be really, really hard to get off, and can burn through a lot of filament. Better off using the small nozzle for support.
• Nozzle hitting printed material: Using the big nozzles, it magnifys all the surface flaws. Small bumps on my .4 nozzle look like huge artifacts on the 1.2. Because of this, and based on print settings, I've had issues with the big nozzles where on a given layer a bit of material is over-extruded 'because reasons' (often happens with infill when you use a criss-crossing pattern that overlaps each other), hardens, and on a later pass the toolhead hits it, physically popping the model off the plate. but now you have 2x the heads hitting that stuff, more prone for error.

Like I said, just stuff to consider. And again, if anything, I'd use the big nozzle for the walls, and the small nozzle for infill and supports.

 

Good point. I don't use slic3r at the moment, but that is something to make me consider switching from S3D.

Thanks Eric, all good info to consider when my printer is fully assembled and i'm toying with different settings.

I was planning to use the wide nozzle for infill though purely to speed up prints where i'm using >50% infill (most of my prints). Was planning to have walls printed with the narrow nozzle for smaller corner radii.