Did I miss where you posted what size your motor is? Mind posting the specs again? I use a 40mm NEMA 17 (300g) for Carl's direct drive extruder at 0.6A and am curious just how light you can get with the Titan.

 

Luckily I only have a single nozzle. So I splurged and picked up both S3D and a BLTouch today. I imagine i'll be on the hunt for a direct extruder plate STL that supports both a generic mechanical endstop AND the BLTouch ... lol

 

• 13Ncm(18.4oz.in) holding torque

About 5.6 oz.

Do a Google on short body NEMA 17

 

I've just tried using different layer heights on my DaVinci Duo 2.0a. I used 'Auto-configure for Print Quality' settings of 'High' (0.1mm) and 'Fast' (0.3mm) with a brim of 10 lines. I watched as it printed and found that it printed the brim at 0.1mm around the two identical parts, this was followed by three layers of the part at 'High' quality followed by 1 layer of the part at 'Fast' quality. This continued until both parts finished printing.

I'll try and make a more extensive test using all three layer heights over the weekend and hopefully capture it on video.

 

How fast are you able to print with that setup? I have a ridiculously heavy motor on mine, and I didn't see any ill effects until printing at around 120mm/s.

 

Here is the link to the one I bought on Amazon. They are out of stock on them right now. Just bought another one on eBay for about the same price.

http://www.amazon.com/Short-Bipolar-Motor-18-4oz-13Ncm/dp/B00PNEQ79Q

 

It's a lot easier with S3D. The auto config will always give you multiples of each other, based on the nozzle diameter. It does the same thing on my Prusa i3 where I use a 0.5mm nozzle rather than the 0.4mm of the DaVinci.

 

I have been thinking about this some. What if I stacked the second extruder over the first, but offset so the tube has a straight shot to the hotend? While the tube would be longer, it would not add as much to the width.

 

So the main offset is in the Y axis and both are on the same side of XY bar?

 

It may actually account for that based on the right settings. I say may because, it has the ability to actually print multiple parts in multiple processes at multiple steps, based on the dimensions of your machine. Meaning, it'll print 2mm of partA, then move over and print 2mm of partB, then move back to A and do 2 more mm, etc. I've never tried it, but the functionality is there.

 

I have created a parametric 3 piece bracket generator for V-Slot extrusions and some handy OpenSCAD extrusion modules to accompany it.. If anyone is interested, you can use Thingiverse Customizer on it here: Parametric V-Slot Corner Bracket by spiffcow or you can visit the github repo here: GitHub - spiffcow/r-bot: R-Bot is a collection of modifications for Carl Feniak's C-Bot 3D printer

Edit:

I also added C-Bot specific corners that can be printed without supports at C-Bot Bottom Frame Corners by spiffcow

 

So I'm wondering.. How much shaking is "normal" on a typical C-Bot? Mine starts shaking pretty hard around 120 mm/s. I have it on foam pads and the print quality is still "okay" but the bed isn't shaking in unison with the frame, creating some wavy patterns. I'm considering putting a second Z assembly on the front to try to mitigate the shaking by making sure it all shakes in the same direction, but I would first like to know if it should actually be shaking in the first place.

I'm using the direct drive extruder with a very beefy motor (it's probably close to 1lb in weight). Do I just need a smaller extruder motor?

 

Duct for duel E3D extruder set up.

Let's hope I'm posting this correctly. Up until now I've been lurking.

I'm a bit more than a month in to building a C-bot and I've run across an issue.

There's a parts duct with mount for a single extruder set up in the stl files I downloaded but I can't find a set up for two parts ducts.

Has anyone designed or found someone else's design for setting up a parts duct for use with twin E3D hot ends?

Thanks.

 

Okay cool -- that may be my next project Is there reason to do front/back instead of on the sides if I have a second set of wheels on the front?

Also (and this is kinda pie in the sky, but...) if I were to redesign a bunch of parts for, say, 4040 extrusions, do you think that would make a significant difference? Or is it not the limiting factor here? Of course, it's a lot cheaper to just buy a smaller motor, but less fun

 

I will say that I will never give up my aluminum build plate.... Spreads the heat out more evenly, super flat, countersunk screws so the whole build plate is available for printing and still have my choice of print surfaces if I choose. The downside is that I don't want to run the aluminum surface naked, so I use tape which produces lines on the bottom of the prints. Not a big deal and can be mitigated with wide rolls of tape or even attaching glass to the bed with binders.

The sandwich I have, ¼ inch wood on the bottom, ½ inch real cork, ⅛ silicon, heater and then aluminum plate worked better than I expected. It's heats up much faster than my Prusa i3's 8 inch plate, which is not insulated, but will be when I get around to C-Botisizing it.

 

I have yet to get around to it based on where my printer is placed, but if I could, I'd bolt the back-top of it directly to the wall: I think that would help resolve issues you're describing immensely.

 

That's a good point on the aluminum bed.. The cost of shipping probably isn't much different, and the plate itself is dirt cheap. You'll have to have something else underneath to hold the heatbed to it, unless you give up leveling springs in order to mount directly to the extrusions like I did, you probably already have to do that.

Heh, I wish I had a concrete plan for what I want to do.. Truth is I have too many plans, but not enough time/money/skill to implement them. I was toying with the idea of trying to make an entirely parametric C-Bot derivative where you could choose your extrusion profile along with your build area and have the program generate all your STLs, BoM, etc. I figured it could include several options so you could trade off between quality/cost/convenience without having to trial-and-error it. But mainly it just seems like a fun way to learn software CAD modeling, and might look good on a resume if that skillset is ever in demand

 

Heh, I feel like an idiot.. I spent half the day trying to think of an acceptable place to bolt it to the *floor*, and it never even occurred to me to just bolt it to the wall like ever other piece of large furniture!

Update on the shaking.. I'm not printing the same thing so I can't say for certain, but I put the tiny 2020 corner brackets on the narrow corners on the corners along the sides and the shaking has reduced dramatically, along with the noise level.

 

That's a cool looking design though. I'll take a closer look at it later this weekend. Thank you.

 

I'm printing cones at the moment but once I'm done with that I'll print the fan ducts you posted and try them out. Thank you for your help. I'll also try mirroring the arm as you suggested.

My poor Two Up has been printing C-Bot parts pretty much non stop for a month now.

 

Finally got the parts to start my build today. Frame was put together this afternoon.
Does anyone have any issues of screws coming undone? What are peoples thoughts on threadlocking everything?

 

I have had some screws come loose. If I was building from the start, I would use some thread lock.