Thanks fro the feedback. I'm not having any problems with the parts pulling up off of the tape, or with the tape itself lifting off. The only issue I am having currently is that overhangs want to curl up. (Note: the curling is *just* on the overhangs. The first layer stays nicely adhered to the bed.) What I'm really asking is more general - what are the advantages/differences of using a heatby LoboCNC - General
Hmm, maybe I'm missing something. What's the advantage of using a heated bed with PLA? Or is there any? I'm getting excellent adhesion (maybe too good) on the bed printing on blue tape.by LoboCNC - General
Aside from the curling issue I mentioned, in general, I'm looking for suggestions on how printing parameters would change when using an unheated bed vs. a heated bed when printing PLA. When using an unheated bed, do you want to print slower or faster? Hotter or cooler? More or less fan cooling? In other words, what do you have to adjust when going between an unheated bed and a heated bed? Maby LoboCNC - General
Peeling up is not a problem - if anything, everything sticks too well. I'm using a 0.26mm layer height. The fan on or off doesn't seem to affect the curling. With the fan on, it still curls up but then hardens more quickly. When you say "could be the temps or flow", for my curling up issue, should I increase the temp or decrease it? Increase the flow rate or decrease it? BTW when printing tby LoboCNC - General
I'm starting to print with PLA on an unheated bed (printing onto blue tape over garolite). In general, when using an unheated bed with PLA, do you need to print more slowly or do you want to print faster? Is it better to use a higher or lower hot end temp? More cooling or less? In particular, I am getting a lot of curling up (as opposed to sagging) on the edges of overhangs. This seems to haby LoboCNC - General
If you look at the G-code, you'll see periodically an "F" followed by a parameter which is the feedrate, typically in mm/min. The print speed settings in your slicer program dictates the feedrate. Note that if you get the feedrate low enough, the motors should be able to track even if your accelerations are set optimally. One thing that is confusing is that sometimes you see rates specified atby LoboCNC - General
From the sound on the video, at times you can hear motors whining (aside form the loud extruder motor) but the pen doesn't seem to be moving. My guess is that the accelerations or velocities in the G-code program are set way too high. (Another video with the noisy extruder motor unplugged would make this easier to determine.) It also could be that the number of steps/mm is wrong, but if the axeby LoboCNC - General
Rather than a pressure sensor, I've thought about replacing the extruder stepper motor with a servo motor. You could then use the motor current as a pretty good estimate for the extrusion force. Servos also have a lot of advantages in applications (like an extruder) where the required torque can vary considerably.by LoboCNC - General
mesquka Wrote: ------------------------------------------------------- > I've just tried using a friction drive with my > Prusa Air, it works quite well actually, though I > think it's Nylon, not rubber. As stated above, the > greatest problem is filament residue. That's cool - my efforts were dismal. Do you have any more details/photos?by LoboCNC - General
I did some experiments trying to use a pure friction drive and I wasn't able to get enough drive force. I suspect that by the time you get enough compressive force with some sort of rubber drive roller, you will have either 1) mashed the rubber so severely that the drive torque is fantastically high (takes a lot of energy to compress the rubber), or 2) if the rubber is pretty hard, you will haveby LoboCNC - General
As a follow-on to my previous long-winded post on a Marlin overview (particularly as it applies to a Brainwave board), I did manage to get everything going to the point where I can drive motors. Here's an overview (also long-winded) for those (like me) who have no experience with the ins-and-outs of Arduino (compatible) controller boards and Marlin firmware: 0. The first challenge is figuring oby LoboCNC - General
thejollygrimreaper Wrote: ------------------------------------------------------- > i would suggest teaching students open-scad or a > freeware/opensource modeling program, solid-works > isn't a bad option but is only going to be > available to those who can afford it when are no > longer a student and as you know cheap it isn't, These particular kids are likely headed for engineby LoboCNC - General
Thanks for all the info. This is exactly the sort of information I'm looking for. By way of background, I am working with a bunch of high school students on a project to design and build their own 3D printers. The goal is for them to learn CAD design in Solidworks, CAM software, and then machine their own parts. They are highly motivated by the end-goal of building a 3D printer. I realize, nby LoboCNC - General
Oh, I had interpreted from the Brainwave instructions ("I am maintaining a branch of Marlin that will compile for brainwave at github...") that it was intended to run a specific branch of Marlin. That's why I was looking for a general overview of Marlin (what it does, how you communicate with it, etc.). It's great that it will also run Sprinter, Teacup, etc., but where can I find an overview ofby LoboCNC - General
vegasloki Wrote: ------------------------------------------------------- > Chris Anderson of DIY Drones and formerly a > Wired editor has a fitting quote about open > hardware/maker business models. To paraphrase, > you give away the bits and sell the atoms. I > think you might have a better understanding of the > open hardware movement by reading his book > Makers The Newby LoboCNC - General
No, the problem wasn't with the Smoothie board. The problem was that when I started thinking about switching to a Brainwave, I realized that there are significant differences between the various controllers and their firmware, and I needed to get myself better oriented. Per my original post, I was just trying to get an overview of Marlin. Regarding expectations, I have sold embedded controllerby LoboCNC - General
Just to be clear, my beef is not with the RepRap community or generally with open source technology. I'm griping about companies making money selling products designed to use open source software, but that essentially punt on documentation. That may work if the there's really complete documentation out there, but if there isn't, that's a problem. What started my ranting is that a while ago, Iby LoboCNC - General
Thanks for all the pointers. I somewhat of an old-school engineer, where its customary for any product, like a 3D printer controller, to have a big data sheet or manual where everything is laid out in one place. And there's almost always an extensive section, usually labeled "Theory of Operation", which gives a detailed overview of how everything works. That's before the specifics of working wby LoboCNC - General
Thanks for the info. I've figured out that Marlin (or other firmware variants) receive G-codes over a serial port, but is the entire file downloaded, is the code executed line-by-line, or is it buffered somehow? How is coordination handled? Acceleration & jerk? I am assuming standard G-codes have been extended to handle coordination with the extruder. And how do you get feedback from theby LoboCNC - General
Where can I find a general description of what Marlin is/does? The reprap wiki page says it is "derived from Sprinter and Grbl", which is not particularly helpful of you don't already know what Sprinter and Grbl are. There are a ton of references to feature lists and how to configure it, but I haven't found any description of exactly what does it do? (Or for any other 3D printer firmware, for tby LoboCNC - General
On a 3D printer, steppers, for the most part, work fine for the X, Y and Z axes. There is little variation in the load, and because the motors are usually stationary, you can usually just use bigger motors if you need to accelerate faster. I'd only bother using servos on a really high-performance printer. (I've worked with servo systems for years and generally dislike steppers, but I used steby LoboCNC - General
Are you talking about hobby servos (with pots for feedback, which limit them to less than 360 deg. of rotation) or are you talking about a more conventional industrial servo motor (with encoder feedback and unlimited rotation)? The hobby type are not really suitable given the limited range of rotation. There are two main drawbacks for more conventional industrial servos: 1) the cost of the feeby LoboCNC - General
Here are before and after photos of my nozzle. I, also, added a little insulation on the underside of the heater block using a few layers of kapton tape. The pointier version solved my curling. -Jeffby LoboCNC - Printing
tsb4k Wrote: > > Besides printing ABS the other constant in my case > has been a makergear nozzle (which is pretty > flat). I wonder there is more heat going back into > the print than there would be with a pointier > nozzle). I've also had problems with overhangs curling up on me, and the nozzle I made for my custom extruder was also pretty flat - flatter than the makergear oby LoboCNC - Printing
Thanks - good to know that black is a little more difficult to work with. I'll try running at 240c and see if that helps. Also sounds like a spool of a different color is in order. -Jeffby LoboCNC - General
I'm just starting to do some printing with ABS and getting parameters tweaked. One of my test cases is a 3 perimeter hollow shell, about 3" tall with a 0.25mm layers. The prints look good, but the layers are not fully fused - when I stress test the part (ie, break it) it always breaks cleanly at the layer lines. Also, it looks like the perimeters are not always fused. I'm using an extruder tby LoboCNC - General
I've actually had good luck with TrinityLabs - both with delivery and with support. I ordered a Smoothie controller board which arrived in a couple of days. I also had to modify the source to create a non-Cartesian kinematic solution, and have received quite a bit of help from Arthur at Trinity, both via IRC and e-mail. I guess their mechanical hardware is an entirely different story. Bobc isby LoboCNC - General
Thanks for the old-school wisdom. How much of the job of the heated bed is for keeping the part stuck down, and how much is for combating other sorts of warping and distortions? In otherwords, If I can keep parts stuck down without any heat, how much do I have to worry about other problems like delamination as the rest of the part cools? Mostly, I'm trying to understand what all the issues aby LoboCNC - General
billyzelsnack Wrote: ------------------------------------------------------- > As for Z.. This might be crazy, but what if you > rotated the entire thing 90 degrees so XY becomes > XZ and then have the extruder move on a belt > driven Y? Seems like that might work. My idea in having the build platform do all the moving is that you can make a build platform much lighter than the extrby LoboCNC - General
billyzelsnack Wrote: ------------------------------------------------------- > oh that's not my plotter. I've just done MCAD > experiments based on the concept from that video. > It didn't occur to me to build a moving table > though and I think your design is very > interesting. > > Is the pivot slot straight or curved? Is the point > of the pivot to gain extra "x" Theby LoboCNC - General