Dim3nsioneer

Direct drive: There is an update of the original Calum bracket which is more stable. With this bracket it's also not a disadvantage to make the new rods about 2mm longer than defined in Calum's excellent description. And find a source which sells straight rods and not bananas... Actually changing to a direct drive is relatively easy compare to the implementation of e.g. a heated bed...very few new parts are needed.

You may consider a direct drive. I just switched one axis to direct drive (I would have changed both axis but the other new rod is a banana... :sad: ) and I must say it's much easier to get smooth results with the direct drive. However as the mass-to-vibration ration is changed, I got some additional sounds...

As far as I know there is already a plugin doing this: The PauseAtZ... it's included in Cura right from the start. But to be honest, I never used it so far. If you want to pause on the fly, you anyway have to use the Ulticontroller. All plugins are 'only' post-processors up to now... If you want to write your own plugins best thing to do is probably to analyse an existing plugin assuming you are a bit familiar with Python (otherwise you get familiar while analysing the plugin). For the header, there is some information http://wiki.ultimaker.com/How_to_write_a_Cura_plugin.

Only the backlight or also the digits?

I guess it's even worse: the backpressure pushes the printed part against the nozzle. It decreases the gap for the new layer even further and if print speed is slow enough the printed part is heated up again and expands... If you have a retraction in addition creating a tiny tip then the knock-over is scheduled... I have the curling effect quite strong on the UM1 when printing an Ultimaker robot at the right ear (face to front). I always get the buttom of that ear curled up. Not for the left ear which is strongly cooled by the stock fan. I hoped to get better results one day with a different fan setup. So do you still have the same strong curling effect with the crossflow fan?

(Sorry, I have to... :wink: ) UM1 or UM2? I guess it's on the UM2... so this cancels out the direction of the air flow. Maybe I didn't get it right, but your question is why it goes up? I guess it's really just the shrinking as you thought. Why shouldn't it go up with this print? The top of the new layer cools first becoming a tiny bit smaller than the bottom of the new layer. So the direction of the curl is up... and that's why you see an influence without fan...still you have an air-flow (e.g. from the heated bed). Don't underestimate thermally induced air flows; they are very strong actually... Maybe some additional air flow below the overhang might change the situation. If you do tests, you could also play around with the bed temperature...

Saw that one too. Might be a useful gadget (depends on the price). But be aware it shows only surface temperatures not the air temperature... some ntc measurement in parallel might not be the worst idea. Cool that the iphone users will pay the engineering costs once more and the Android users will have the cheaper version... :wink: (I belong to the Androids...)

Did you see http://umforum.ultimaker.com/index.php?/topic/3406-experiments-on-bridging/? From my tests I think yours are definitively more on the sunny side already... :wink: What material did you use? There might be some tricks like changing the acceleration for the bridge layer to avoid single strings from ripping but the sticking together of multiple strings is very difficult to avoid. Maybe foehnsturm can say something about the effect of the crossflow fan onto bridging? Any difference concerning the sticking together? EDIT: If you printed it oriented as shown in the first picture (x direction) and if you use the stock fan or any other fan duct blowing from the left only try to rotate it by 90° and print it in y direction.

A turbulent airflow results in a higher heat transfer from solid to air (the coefficient called 'alpha') but is also more likely to produce a spot with no airflow at all. Crossflow fans are the 'weakest' of all fan types, having a quite low ration between pressure increase and flow, then comes axial fans, diagonal fans and finally radial fans which are used when a lot of pressure is needed and not very much flow (just for the case someone didn't know... :wink: ) But acutally one can run any type of fan in a more or less pure laminar flow range. However for applications where a large flow and a low pressure drop is needed, the crossflow fan is absolutely the right type to work with. It might be interesting to compute some Reynold's numbers for different setups, giving a more quantified image of the topic... anybody tried that so far?

That's true! I was assuming a clean head....

I do the same work-around for some months. And sometimes I miss the right time to grab the outflow with tweezers (better for the fingers). Actually, it should be possible to solve the problem as all the involved actions are in the start.gcode. So this order might solve the problem: heat up the bed (if a heated bed is present) zero the z axis lower the bed by something like 10-15mm heat up the hotend move it a small amount in x or y direction zero it again (in case you change the height manually) and from there it goes...

Did you check my age before writing about the telephone cords...? :wink: Thanks for confirming the twisting-issue. As I need my eyes elsewhere I will soon visit the next IKEA and by a 'SNUDDA'... (doesn't sound any better actually than 'lazy susan'; in Switzerland, these things do not have a special name (proving the Swiss are boring?)). I'm actually in the post-holder area. Any specific Ultimaker holder I have seen so far was not very suitable for use with a dual extruder. So I built my own one which is standing on the table close to the Ultimaker and works perfect, even with the most brittle PLA.

@Nick: If you say 'remaining', what were the other ones? You reported about the vibrations in the Bowden tube and the lubricating of the z thread. Was there something else?

I also just received my first faberdashery material two days ago and was thinking about how to handle it. Does one risk the filament to break when just lying beneath the printer? Can it be twisted and blocked? Is it an advantage to put it on some kind of rotary disk so there is a uniform tension on the filament? I was also thinking about spools but the curvature of the faberdashery filament is rather different than it would have on the spool. After experiences with other, very brittle, PLA I'm just careful.

@Ian: But don't count the lines, it's like counting sheep... ^_^ @Daid: Thanks for information. Does it have an issue number on Github? btw: Any idea when you can fix issue #636?

I'm just printing a two-piece-model, one piece after the other, using a 15 lines brim. The first brim was printed 'normal' beginning with the outermost line working itself to the center. The brim of the second object however was printed in a strange way. First the three or four innermost lines of the brim were printed, then the outer lines working from the inside to the outside. I can't remember having seen this before (maybe I was just blind up to now). Can anybody else confirm this effect? I would prefer to have any brim printed from the outside to the inside due to priming the hotend. I'm using Cura 13.12.

That would be a very nice feature, indeed! I remember Daid writing recently here in the forum that slicer engines like Cura can't do any jobs which involve more than one layer. But maybe Meshmixer goes into that direction. At least it already has a function to determine the ideal orientation of the model for printing and support generation. Maybe they could implement such a feature...

I hope you will not get me wrong, I don't mean to offend you. But if you really can measure a distance of around 10cm with a (calibrated?) set of calipers between two wodden parts at an repeatability of 0.02mm, then I really have to congratulate you. :wink: You should be aware that with repeated measurements you may reduce the statistical error but the systematic error of your measurement device stays the same. If you compare two measurements then it is even worse: no matter if you add or subtract values, the errors of the two measurements are correlated. So you have to add the individual errors which means in this case to double the error. Realistic accuracy of a caliper measurement lies somewhere in the range of the backlash you actually measured. To my opinion, most people overestimate the accuracy of calipers. Having a number of digits on the display doesn't mean the tool measures with the accuracy of the last digit. To get a real feeling about how large the backlash is, one has to compare it with the spacing of the MXL belts wich is to my knowledge about 2.03mm. So you have a backlash of around ten percent of the spacing. I think this is a bit larger than normal even when considering you have the play of two belts in series. You may try to tighten the long belts a bit. BUT: @gr5: Where do you know that from...? :rolleyes:

Smart! :wink: How did you measure it?

Let's say larger than 5cm... 1mm is definitively not large... :wink: I have the same effect as Ian. Interestingly (and fortunately!) the shift is always uniform over the whole bed size. A possible solution would be to put the z top end switch somewhere, where the leveled bed and not the z stage triggers it.

Are you doing prints with a large z dimension?

Some narrow Gaussian might do the job. Practically it would be rather a convolution of a Rectangle with a Gaussian. The smooth tip should lead to shorter print times compared to a sharp peak.

I like the idea. The calculation should not be a problem as long as the layer-to-layer-shape-change is somehow continous. Then it's just a question of curve parametrisation. But three questions popped up: - Is one layer enough to make it stable? - Is it visible on the outside of the print (there is such an effect with injection moulding)? - What is the most suitable type of oscillating curve?

I think posting your designs on multiple platforms is ok as long as the platforms stay open-sourced and independent of the printer model you use. If one of them closes to the users of a certain printer, one might have to change. Actually Ultimaker is already going further into that direction by adding the 'send to 3d printer' button (I guess it's only possible with an Ultimaker, or am I wrong?). If you want to make money with your prints you anyway have to use neither Youmagine nor Thingiverse. Edit: To be honest, I usually first have a look on Thingiverse as the chances to find a suitable design is much bigger there. They have the advantage of having started earlier.

@Ian: Did Xeno's hint work for your church print?