chrisr

Martins video sounds like the sound I'd imagine belts rubbing or creaking might make, could they be rubbing against the pulley sides? Any rubbery dust on top of the steppers? Just some wild thoughts... :-) but the force from the filament being pressed into the hot end will be resisted by the linear bearings and then transferred into the phosphor bronze types. Is that force a considerable one or negligible ? With all the rotations and slides the phosphor bronze bearings have to cope with, I'd want them well lubricated... more so than the recommended "just one drop of oil" I've seen some pics of owners UM's, where that part of the steel rod where the phosphor bronze spends most of its time (generally around the middle of the rod) has got a dirty black rubbed look about it. Hmmm.... I read somewhere linear bearings can be quite noisy, I found this youtube vid - linear bearing noise by itself, 0:30 onwards. "Cheap linear bearings" clicking - weird... Either way they're certainly a source of noise, perhaps depending on what you're printing and how fast?

Linear bearings?

When I switched to Anders block :grin: yay! My heating element came out ok but the the sensor was pretty stuck. I eventually managed to get it out by just gripping the small metal part of it (that was sticking out) and by gently twisting it back and forth with a pair of needle nosed pliers (the delicate type for electronic work) I eventually managed to ease it out. It came out, intact and working, luckily - as I didn't have a spare. Whatever you do, don't try and pull it out by the wires. If it's completely stuck, you may need to just scrap it altogether and buy another. Anders block holds the heater and sensor in place in a much kinder and less brutal way than UM's stock block does. Another design feature I really like. :smile:

Ah! That's the reason then... I wonder if modifying the start Gcode to "G28 (just_the_head_please_and_not_the_bed)" would fix it... I'm tempted to try but I'm wondering what then controls raising the bed to the nozzle to start the print? Is that the firmware again? That would be ideal, I guess the Gcode which controlled that raising/priming sequence could always be added to the generated prints Gcode by Cura instead of having it in the UM2's firmware.... or am I missing something very fundamental? :smile: (which is very possible!) (Edited for a bit more clarity)

I've recently been using Simpify3D for slicing with this default Gcode for startup G28 ; home all axes G1 X20 Y20 F3000 ; bring extruder to the front G92 E0 ; zero the extruded length G1 Z0.3 ; lower G1 X35 E30 F225 ; purge nozzle with 30mm of filament G1 X45 Y20 F2100 G92 E0 ; zero the extruded length again When first turning my UM2 on and starting a print, this code will try and home the bed (it already is) That's all fine. The bed will then raise (once everythings up to temperature) and the print will begin. But subsequent prints (with my UM2 remaining switched on) cause the bed to re-home twice before printing. i.e the bed will raise up, lower and then raise back up again before the print begins. It's not particulary problematic, just unnecessary and I'm wondering what's the cause of it? The ending Gcode is this: G28 X0 ; home the X-axis M104 S0 ; turn off heaters M140 S0 ; turn off bed M84 ; disable motors Any pointers? :-) Daid?

I think that may be too fast, especially at low head heights? Have you checked the nozzle temperature when the fans start up? Does it hold it's temperature ok?

The loose faberdashery filament has a natural curve to it (as so far supplied) that more closely follows the 'general' curve of the UM's bowden than the tighter coiled filament supplied on spools does, so there's less effort spent by the feeder in having to overcome the force spent in pushing ('straightening') a more tightly curved coil into following the bowdens larger curve. Faberdashery are now supplying filament on spools though, but personally I'll be sticking with the loose stuff. I've tried pushing loose faberdashery filament by hand through the bowden and it's notably easier to push through than the more tightyl coiled spooled filament was. Both times, these were filaments that had already been through the feeder so they both had the hobbed gear tooth marks on their upper surface, i.e that surface which rubs the most along it's travel in the bowden. Just as well the teeth marks appear there, as I suspect that will also help in lowering friction rather than a smooth surface sliding past another smooth surface ?

pm-dude, what fan speeds are you running with your Zetoff when you have them switched on?

I set off at 50mm/s @210C but quickly saw some underextrusion, so I raised the temperature to 217C. The actual speed gets complicated... as I reduced it in the UM2 to 88% but I think as well, I'd 85% set for perimeter outlines in S3D... (it's default is to lower this value?) so the actual speed would have been 50x0.88x0.85 = 37mm/s ish. The infill and supports were at 100% in S3D so they would have been printed at 50x0.88 = 44mm/s - although they used a thinner looking extrusion. There's a lot of settings you can muck about with in S3D. I'm still very much a novice with it!

Downloaded! Thanks :-)

Thanks Anders, it's more that I'd be able to use the custom fan shroud at higher fan speeds than anything else. I only see the safety feature kick in with models I'd previously set the fan speed to 100% (and forgotten to change it to lower) it's a pain then as the entire print stops rather than a bit of underextrusion happening. The sensor and block all work great :-) I may see if I can find another fan shroud which has a closed bottom. I'm now wondering what it may cost to have a metal custom shroud made.... locally to me there are lots of industrial estates.... one in particular has a metal working shop.... hmmm.... I'll go and have a chat with them... (Apologies Nicolinux for meandering a bit off topic.)

I'm wondering if it may be a simple job just to modify the relevant section in the source code ? My C is pretty rusty/non-existant but it looks as if the relevant bits appear in this file, lines 155-175 https://github.com/Ultimaker/Ultimaker2Marlin/blob/master/Marlin/Configuration.h I now print with fans @ no more than 40% but some models were sliced before I fitted a custom shroud and the fans were set to 100% for many of those - that's caught me out midprint more than once.... I think Daid wrote somewhere that the shrouds which have 'open bottoms' are more prone to triggering this safety feature than those which fully enclose the blocks underside. I may (just maybe) have a look at tweaking those limits a little... and...... one bricked UM2 coming up! :shock:

After printing this whole weekend :grin: (yup divorce is in the offing) I took another look at my Venkels shroud and it's just slightly buckled, in so far as you have to know where to look to see it. So in all, I'll probably leave it as it is. I did try a heat shield cut from a tin can with the Zettof. There's provision in Venkels design to fit the same. Probably something I should try. tbh I don't think Anders block affects these shrouds any more noticably than the stock UM heater block does, although granted - the front is marginally closer to the shroud than UM's stock block. One thing I have noticed -pretty quickly- with the 0.8mm nozzle is that I'm having to tweak my cooling fan speeds especially when printing at 0.6mm layer heights, as the extruded material retains it's heat for much longer staying soft, than the stock 0.4mm nozzle produced at 0.2mm heights. Hardly surprising really.... but something I hadn't factored in at the time. I am so, so loving this block! I bought S3D recently and it has provision to adjust all sorts of printing parameters, a very useful feature being to set different printing parameters across various heights. Fan speed by layer I'm finding especially useful. It's a bit of a voyage of discovery for me, just as there's so many more settings to play around with. All great stuff! Edit: My apologies for meandering a bit 'off topic'

That really is a stunning bit of work. "Awesome" describes it I think! :-) When I first read the title I read it as "Massive Divers, watch desk clock project" wondering briefly what massive divers were. It's a print I'd love to do when I have some more time. Beautiful!

Yes I agree, a metal version would be the business!

https://www.youmagine.com/designs/ultimaker-2-fan-mount-dual--2

Actually that's one other aspect I also so like about the UM, is that once you've leveled the bed, it doesn't need adjusting again. It just stays 'put' :-) illuminarti has an excellent alternate method for bed levelling over the official paper method, here: http://umforum.ultimaker.com/index.php?/topic/8330-best-procedure-for-leveling-the-bed/ Description at Post 5.

It's glass so it should be perfectly flat so far as prints are concerned. Although there have been a few forum members who received glass that wasn't perfectly level. UM as far as I know, were very good in replacing those. Have a look through the forum posts. imho the UM2 is a fabulous printer. Personally, I wouldn't hesitate. Go for it ;-)

It's superb! imho this is an upgrade I think all UM users should get. Last night printing with the 0.8mm nozzle was quite an eye opener, that 0.8mm really puts the layers down fast and being able to easily switch nozzles feels like having several printers rolled in one. Imho the v best upgrade I've got. Delighted! The fan shroud works well, it provides a more balanced flow of air from both sides than the stock metal UM shroud and it directs the air more towards where the nozzle is printing, so something like the UM robot right ear gets printed very nicely. The down side is that at low heights or large flat surfaces, you can't use 100% fan as the backwash hits the underside of the block causing it to cool and you then start to see underextrusion. I printed my shroud in PLA & with hindsight it would have been sensibler had I chosen XT or PLA-HT instead. As well, the front surface of the shroud has become slightly buckled through heat. Although that doesn't affect it's performance, it just doesn't look as 'straight' as it did before. I think it's a worthwhile addition though. Now I'm going to nurse my hangover, as one bottle of wine turned into several... :???:

Hmm... according to Wikipedia you can recycle PLA.... ? "Polylactic acid can be recycled to monomer by thermal depolymerization or hydrolysis. When purified, the monomer can be used for the manufacture of virgin PLA with no loss of original properties" http://en.wikipedia.org/wiki/Polylactic_acid

Just been looking for it... I think I may have read it on my google+ feed but I'm not sure.

Neat idea. But I read somewhere that each time you heat filament up, it looses some of it's (I think it was) elasticity, or properties or "some-such" So each time you recycle prints the material becomes further degraded, something if I recall correctly, to do about long chain molecules being cut up.... made me think of engine oil for some reason... ...let alone the dust and dirt that you'll likely be adding to the material while it's being ground? Hmm... If I can find the link to the original article I'll post it up :-) Certainly be interesting to try out though?

Ah! clearer now :smile: I don't think that's anything to do with the heated bed. I think it's possibly a couple of other things. I think you need to go hotter with your head for the red print and a little bit hotter for the blue as the layers near the base look as if you may be getting a little underextrusion there. The blue print doesn't look that bad apart from the "blobs" As well, some of the settings in your slicer may need tweaking. Are you using Cura ? If so, one setting you could look at is "spiralize" and perhaps as well your % of 'infill overlap' which if set too high I've found, can create 'blobs' in thin walls. What layer height are you printing at and at what speed? DIfferent colours can require different settings. White generally seems to be "fussy" I use Faberdashery for my PLA and I've found the settings between colours to be very consistent with little or no tweaking required. Some other slicers let you alter the order in which the perimeter gets printed, i.e the outside of your vase (if your perimeter thickness consists of more than one pass of the print head) The order is switchable between 'inner to outer' or 'outer to inner' which one you select has an impact on the surface quality. Both KISSlicer and Simplify3D have this option, I think Cura defaults to inner to outer, it was certainly using that order in the last print I did. Post the settings you're using and I'm sure you'll get some helpful advice! :smile: Edit: Ah. I see you are using Cura.

Interesting! I'm wondering whether instead of running a 2mm tube all of the way inside the existing bowden, it would be possible to cut two short sections of 3mm bowden and have those either end of the 2mm tube? Possibly they may need gluing in place... (I don't know what the fits like) you'd then have the advantage of the 2mm tube's greater flexibility than the stock 3mm with a 2mm tube inside of it. Whether that makes any difference to the general schemes of things... I don't know... but I'd imagine it's going in the right way of "helping" the heads freedom of movement at least.

lol! :-)