alaris2

that's the way - circles look even more cool than squares. how did you do the funky stress simulation thing btw?

I've added a one layer thick rectangle extending 3-4mm from each corner of any item I don't want to lift off the bed (to the model). it seems to work quite well. it's a bit like a raft I suppose, but more manly..

the roof will sag with no support. experience says so. I tried 2" with no support. first couple of layers actually worked fine and I had high hopes. then it put down a layer of infill and the zigzag motion and weight of material caused the bridge to sag. I suspect heat from the higher layers also affected this. I think I still have this model so you can see the effect. I'll try and take a photo of the lampshade tonight too.

sorry I don't have a before and after print but using Daid's settings for retraction made a huge difference to my prints. There's virtually no cleanup required now, any remaining strings are like fine hairs and are easily removed. in short, I can recommend those settings. I'm printing at 210C.

you appear to be having a conversation with yourself Ian for what it's worth, 1mm is fine for a support - any less is likely to fail. I have some test prints I did somewhere that show that. I suspect 0.8mm is actually the minimum guaranteed support. as with all things, speed matters - faster requires more support. anything that has infill requires slower or more support. it's better to have the support a multiple of the perimeter thickness is my recommendation. as an example. I printed a 1970s shatterline lampshade which I redesigned to have an extremely thin wall on one side (to let light through) and thick on the other (to reflect it). I originally tried with 0.4mm thickness, but it failed half way up. several tries later and 1mm worked fine for a 20cm high object.

I keep meaning to try the 'skin' option in Cura and not getting around to it. so you're saying that if I print a 0.2mm layer object with skin, the outer surface will look as if it had been printed at 0.1mm with only a slight degradation in printing time? I think I misunderstood the difference between that and infill every N layers then - are they not equivalent? Cura - print at 0.2mm/layer with skin = slic3r - print at 0.1mm/layer infill every 2 layers?

thought I'd see how far the competition had gotten so tried slic3r again today. some interesting observations I thought I'd feed back for Daid - 1) Cura is definitely much easier to use, and the visual feedback (model window) makes a world of difference. 2) slic3r does have some options which I would describe as advanced, but which are extremely useful and it would be nice to see them in Cura (list in a moment) 3) the print quality, trying several different out of the box variants and trying to copy my Cura settings as closely as possible, were all inferior to that produced by Cura 4) however the time it takes to slice is impressive. 33mins for a test model under Cura, 3mins 30.28seconds for the same under slic3r. 5) default start/end gcode for slic3r is pants compared with Cura. first thing it did was ram the nozzle into the bed with cold plastic still on the hotend which made a nice snapping noise. then heat the end up whilst still buried in the bed, peeing pla all over the place and going all over the fan shroud.. 6) stringing under slic3r is as bad as repg. print a hollow cylinder and it tries to take short cuts through the center leaving a nice mess to clean up afterward. Cura just printed a perfect cylinder for me with no clean up required by moving along the perimeter instead of taking short cuts. list of options that would be really useful in Cura: (in no particular order) 1) skirt in Cura joins with the beginning of the print proper. whereas there's a retraction between end of skirt and start of model in slic3r. actually this is really important since sometimes the skirt doesn't completely work and loose bits work their way onto the print head (or more usually get caught by the fan shroud) and make a mess. I therefore usually remove the skirt just after printing (ie. while printing) but I can't do that if it's attached to the model.. this should be easy to implement but would make a big difference. 2) retraction has a 'lift z' option. i can see the logical point for this, but haven't decided if it's really useful or not. mention it more out of interest than anything. under the same category is 'infill every N layers'. i'm not sure what the implications for this are (collapsing infill? structural problems?) but it can be used to make the print much faster of course. 3) can print without walls. this is quite useful for artistic prints as i mentioned in another post. (I was making a lampshade) 4) i didn't try all the fill patterns, but 'concentric' looked interesting. it might be the same as the 'circle' option already in Cura but I think it starts at the outer edge and spirals inward when filling which looks good for top surfaces. it also has a infill and top surface fill as separate options. using lines for infill and concentric for top surface would be my choosing probably. 5) first layer can have a different temp from the others. you mentioned this yourself Daid recently. 6) print speed differentiates between : perimeters, small perimeters, infill, solid infill and bridges. that's really useful when your model is anything more complex than a cube and you've gotten past the noob stage. what do others think? so far those 6 items set slic3r apart, but not far enough ahead that i'd choose it over Cura i'm afraid. that's good news for the Cura folk!

I took mine to pieces the other day to have a look at the tube. that clip has really dug in and made a circular groove in the plastic of the tube. no wonder it grips well now. this was partly caused by me trying several times to get it perfect when initially putting it all together.

so I thought, hey what happens if I print this cube with 20% infill but no walls. that would be awesome, a sort of semi see-through cube. but Cura tells me divide by zero. is it not possible to print with infill only and no walls? any workaround?

ah, maybe time to download the latest and greatest then.. I was going otherwise to see what happened if I used a raft as well since that would seem to be a workaround.

I thought I'd try printing some parts that needed support to better understand how to use this feature. So it's a Cura RC2 setup with default support settings, and I start printing. layer 0 looks great, lots of meandering wiggles. layer 1 comes along, and the head just rips up layer0 as it progresses over it and makes a nice ball of plastic for the cat to play with. anyone care to suggest what am I doing wrong? (before I randomly change parameters in the hope of finding out through trial and error) prints without support work very well, no problems - importantly the first layer sticks fairly well (not always perfect, sometimes edges curl slightly) but never had a print so consistently destroyed at such an early stage. temperature is at 210C right now, PLA is flowing very freely and has good adhesion between layers. the bed has been levelled several times (but is the next thing on my 'to check' list) thanks, nik

awesome Daid. the .stl for that must be incredibly complex I did have my speed (for the eiffel tower) set to 20mm/s which I thought was quite conservative. at that speed it would take 6300 hours to print the real tower apparently. of course, I'd need to increase my workspace slightly...

I sliced it in Cura. 50mm/sec. .2mm layer height, Fill density: 80% No support. Travel speed: 200mm/s, Retraction (2mm, 30mm/s, mim travel 6mm). There were times when I had to manually adjust (lower) the speed in printrun. Here is a short video of it printing: Will take up the challenge again some day .. - Hitesh well I like a challenge so I had a go with 20mm/s, .1mm layers, 50% fill, retracting at 50mm/s with min travel of 5mm (otherwise same as you). it gave the poor extruder motor a good workout, and printed awesomely until it got kicked off the bed about half way up. I don't know why the French didn't build it solid with 20% infill...

that's very up. when I put the blue circlip on the tube I noticed two things. 1) you can put it on and all looks good. but you haven't put it on properly - force it on with pliers until it can grip no more. 2) you know you've got it on properly because it forces the bowden tube up by exactly 1mm. originally I tried to compensate for this by pushing the tube an extra 1mm down (this actually makes matters worse) thinking it would lead to a leak, but it doesn't. I can't explain why. I've been assuming people are not putting the clip on tightly enough and this leads to bowden tubes popping off and all the other problems complained about. maybe that's not the case after all..

the eiffel tower one looks like an interesting challenge. what settings did you use for that? support? speed? I think we can't easily avoid it burning near the tip without additional cooling fans but otherwuise it might be possible.

Sorry Daid, I didn't mean to sound like I was overly criticizing and I know your prints are some of the highest quality I've seen. that red mech is especially good in fact - but let me explain by way of a photo. you see all the good looking prints don't have flat top surfaces or bottoms. that's fine for vases (as an example) and works in the case of the mech too. but take a look at http://i177.photobucket.com/albums/w228 ... 100582.jpg due to the way the Ultimaker works (most deposition style printers in fact) any flat surfaces are prone to 'tooling' marks like these are they not? or have I missed some settings somewhere? this is one of the best pieces I've made so far (but I'm happy for any constructive criticism in order to do better). structurally it's almost perfect (overhang was a bit of a problem), but it's a thing of function not of beauty. I tried elsewhere to make a keyhole, but the top surface was flat and on display. I couldn't get that top surface to look good enough for display - you always see the motion of the hot end on the last layer. perhaps there's some way to tell Cura to slice such that the top surface is drawn differently? if it hadn't drawn the walls first before the infill then there wouldn't be those crossing lines across the top surface. I note that using a hot air gun at about 200C will soften the top surface of a model and if used carefully can give a nice gloss finish to a piece. but it won't remove the tooling marks. I'm using the same settings as you are now, thanks to yourself, destroyer, kaz and others. except my value of E is rather high. the quality of prints is very good, I'm not knocking that, nor trying to start an argument - I'm just saying I wouldn't want to print anything with a large flat surface and show it to someone to demonstrate the capabilities of Ultimaker. organic models and vases fair much better at that.

good call kaz & destroyer - I managed to get a decent photo at http://i177.photobucket.com/albums/w228 ... 100580.jpg I don't think I can tighten it any further, not by hand anyway so I'll see what happens if I loosen it slightly.

is that the silver PLA that came with the machine? mine was faulty and made prints that look exactly like that.. and where did you get that fan shroud from? that's an interesting one I'd like to know more please,

PVA is an interesting idea I agree - it would avoid the scars that conventional support seems to leave. and Daid, your mech is very good, one of the best I've seen in fact, but people these days are very critical, they would say to me "but it has holes on the top surface of the feet" etc. yet if I show a functional printed piece to an engineer they start drooling. that doesn't mean that everything I've printed is 'useful'. actually most of it is experimental and sitting in a pile in front of me wondering if I can recycle it

there's a danger is there not of making software that looks like the cockpit of a boeing 767 with so many options it becomes unuseable for many. the most beautiful thing about Cura right now is the simplicity. it does what you need and hides what you don't. if it's possible to do any of what you suggest automatically, then I say it's a good thing, but if it's yet more options to add to dialogs that most people won't use, it detracts from the awesomeness of the product.

I thought the whole point of using the blue tape was the rough surface helped adhere the first layer? kapton tape is supposed to be for heated beds isn't it?

I have to agree, dual head is low in my priority list too - I'm more interested in quality. Ultimaker does an awesome job for making structural parts, but I have yet to see anything (other than vases) that I could proudly show people who aren't engineers. there's not much room left is there Daid. that might make my fan design not work for your instance since I was using a coanda effect to blow the air down the side from a top mounted fan. has anyone tried fans mounted on the (or at the edge of the) bed instead, with a shroud close to the hot end to stop it from cooling too much. actually I just had a mad idea with a bed made like one of those air hockey tables.. that would be awesomely fun but probably wouldn't work..

hey, nice cat. oh wait, that's not what we're supposed to be looking at I'm working on a fan shroud that meets your specifications Daid - hope to have it ready in a week or two.

you mean the thumbwheel on the extruder is too tight? I thought I had that set right.. with the bowden tube popped off the back the calibration (see my earlier post) gives E=844, but once I try to push filament through the hot end (as per destroyers post) I need (at least) E=1087 I've been watching the motor to see if it skips but haven't seen anything yet - wouldn't it make a horrible noise and mess of the cog?

hot diggity, that made a big difference. OK, using the E-calibration procedure from Cura gave me E=844 or so. I thought this was right on the grounds lots of other people mention numbers similar. but using the method described by destroyer only extruded 5mm or so, so I changed E to 1087 and got a much better print straight off. I'll try and fine tune it a bit more now, but 1087 seems a big number - what kind of 'E' values do other people have?