Dim3nsioneer

Not yet... :wink: (have a glimpse at the Wiki page...)

Uhm, I don't have it right in front of me but the width you see must be something like 5-6cm. Is that sufficient for your question?

That's actually the way to deal with mutliple current driven devices, yes. It should even be safe in terms of the controller doing still the right thing (limit the current). However it is to check if the stepper driver has components with a power limit which could be exceeded. I guess the isolation of the two coils inside the steppers against ground (casing) is good enough. Otherwise one stepper would be charged up by some volts. Any idea what voltage is needed for the typical 1.1-1.2 amps? (yes, I could measure it, but if one of you knows it already... :rolleyes: ) The two additional steppers are not the only thing which is uneconomical. But nearly any modification of an Ultimaker is uneconomical... :wink:

@Daid: As I'm not giving up so easily :wink: : What about the second theoretical possibility? I just had a quick lock at the scheme. I guess there should be no problem with the pull-ups (maybe a separate pull-up resistor for the second MS1? Or even a separate jumper block including the 4.7K). VDD, VMot and GND are anyway common to all the drivers. RST and SLP have to be connected separately for each driver. What about EN, STEP and DIR? Would these signals break down in amplitude when connected to two drivers? And last but most important question: Is there enough power left from the Shield to run additional two motors? Most probably that is the problem... @foehnsturm: Without any belts I would expect the backlash to go down to something very small. The torque per axis would actually be significantly smaller as one stepper would not have to drive two connected rods.

Is there a way to run two steppers for the same axis? I'm thinking about a all-direct-drive having one stepper on each x and y rods. Theoretically there are two possibilities: - Connect two steppers with the same stepper driver. Most likely the driver is not designed to drive two steppers in parallel, correct? - Connect one stepper per driver and connect two drivers in parallel to the Arduino Shield. Possible? I don't know the interface. Is there anybody with know-how about the UM1 electronics who could tell me something about the limits of the stepper drivers (Pololu A4988)? I'm not looking for a quick and dirty solution. It has to be safe.

After having just a very quick look at the code I think it's a nice piece of software. Thank you for sharing! Sometimes 'lifting the head' can be something nice indeed. I wrote myself a similar plugin when improving results with the dual extruder where oozing is much more visible than just with one extruder. But actually mine is coupled to retraction while yours executes the lift at certain logical points. You may add the 'help' preamble in order to automatically link the plugin in Cura to the Wiki page with the description.

It looks to me as if the material is thicker than 3.00mm which is the absolute maximum thickness with an Ultimaker. If the material is thinner, there are some ways to get also a flexible material to slip through the Bowden tube. Maybe you have a look at this thread: http://umforum.ultimaker.com/index.php?/topic/3440-advice-for-flexible-material/

Looks to me as you would have to improve some Slic3r settings. Illuminarti wrote a very nice blog about this topic: http://www.extrudable.me/2013/11/03/slic3r-strange-defaults-causing-qu-bd-woes/ Hope this helps you solve the issue!

I remember someone from Ultimaker (I can't remember if it was Daid or Sander) having written here in the forum that if they bring a heated bed for the UM Original it has to be an upgrade kit with parts that extend or even replace existing parts. So they have to design new parts, manufacture them and test them. This takes some time. When I asked Ultimaker support about the time of the release (last autumn) they told me second quarter of this year. I could imagine there is even a delay as they were quite busy with improving the UM2. Of course there is an alternative for impatient people (like me... :wink: ): Build your own heated bed...

Another possibility to drive a UM1 into the wrong z direction during homing is a customized firmware (self compiled or downloaded from marlinbuilder.robotfuzz.com) with the wrong settings at 'invert z axis'. Forget it if you have the default firmware installed. EDIT: My last phrase was maybe misleading. The meaning was: If the default firmware is present then there should not be a problem with the firmware. In this case, nothing has to be changed.

Chopmeister is right about Misumi not delivering to individuals. Fortunately there are ways around that restriction. However, they also claim not to sell to resellers which might make things complicated. And thank you also from my side, mastory! @JonnyBischof: I saw the GT2 belts and pulleys as well. :smile: However, the smallest pulley has 20mm diameter which is 3mm more than the original Ultimaker pulleys. :eek: But maybe it will work. Btw: I haven't heard anything from two of the three companies I asked for offering precision rods. The third company just sent me an offering but their axis deviation can be up to 0.3mm per meter.

No, just about 2 Swiss Francs per piece. E.g. here. Nothing compared to a spare nozzle from Ultimaker for €15. :wink:

To be a special case is not necessarily a bad thing... :wink: A relatively easy way to test it might be to slice it with Slic3r which allows for a different outermost perimeter speed if I remember correctly. Setting a very conservative value for the perimeter speed might be close to the effect the suggested extension might have. Personally, I like that outermost layer speed feature of Slic3r. It gives the print a very nice and smooth look without slowing down the print too much. Maybe a minimum perimeter time would lead to a similar effect?

First estimation was exactly that way on a work bench and a table at different locations. That was actually sufficient to see it is a banana. In addition I compared it with the original rods from Ultimaker (of which one also had a very slight bend, but not as much it has to be called after a fruit...) But for the real measurement I put the rod into the Ultimaker through the sliding block and put an indicating caliper gauge on top of the sliding block while turning the rod and looking for the highest and the lowest point. It's certainly not precise up to the micrometer but it gives an idea in which range (below or above 0.1mm) the deviation is. Another idea might be to put the rod on a very flat surface (such as the Basalt bed from QU-BD which I think is quite familiar to you) and to check with feelers how large the maximum gap is.

It might work if you buy it from Conrad. But you have to cut it. With the cutting you might deform the rod and it will not fit anymore into the bearings. Another important factor is the maximum deviation of the axis. Precision rods have something like 0.05mm which is fine. Standard rods, even with h6 toleranz have higher deviations. The company I bought my 'banana' from (@JonnyBischof: die waren von Pestalozzi in Dietikon) told me afterwards that the axis can deviate up to 1mm per meter. I had a deviation of 0.4mm in one of the rods which is not suitable for such a fine machine like an Ultimaker (imagine your print head going up and down by several tenths of mm). If no maximum axis deviation is specified I guess you have to accept such a banana. But maybe other people are luckier than I am usually... :wacko:

If you put design as first priority you probably shouldn't realise Calum's approach or any derivative... they definitively put function over design. But at least for me it works fine (well, 50% of it...I'm still waiting for some offerings of straight rods).

I agree with you. It's a trade-off between assembly costs and service costs. Another reason to apply it could be safety (some parts don't do any good if they get loose...).

Just updated the Wiki page of the 'Tweak At Z' plugin with details about V2.0 and V3.0.1, especially links to all additional versions.

In professional assembling one usually avoids using loctite due to the time it takes to apply it. It means additional assembly time which results in a higher price of the product.

Hmm...the term I would use for such a relationship between PLA and the brass nozzle is rather adhesion, not cohesion. To my experience, a piece of PLA melts easily on the outside of the nozzle and distributes over the surface, i.e. shows classic adhesion. This is quite nasty if you print one color and still have some other color sticking on the nozzle. Then it begins slowly to crawl down and suddenly you have a spot in your print. If there is such an effect as you describe it, then it should become better with an underextrusion or just smaller extrusion. I think to remember that this didn't change anything? Something else which should work against such an effect is to raise temperature as the PLA then becomes more fluid and less sticky (it certainly takes less time to get the PLA above glass temperature on nozzle contact). However, to my personal experience the curling effect becomes worse with higher temperatures.

of course... :rolleyes: I didn't see the forest, there were too many trees... :wink:

The 0.3s idle time seems quite long, but not impossible. Assuming you have to move the filament by the usual 4.5mm with 30mm/s, a quite conservative value, you would just need half of that time. Acceleration is set to 3000mm/s^2 on my Ultimaker, I think, so it takes 0.01s to reach the 30mm/s. So total time needed for priming might be something like 0.16s taking the distance driven during acceleration and deceleration into account. Is that compatible with whatever method you used to determine the approx. 0.3s? If not, where is the additional time lost? Some things I rather like not to have 'al dente', e.g. already printed PLA... :shock:

I see some chances as my backplane has significantly too big holes for the bearings and I had to wrap Teflon tape (thickness 0.13mm I think) around to fix it. I never had a problem with that fix. But it's something to have a really close look onto. Stainless steel might be an overkill for the rods (as long as you don't run it outdoor), Calum suggests C45 (1.0503 I think). Tolerance h6 is the crucial number.

Direct drive: As I maybe will have to work with the original rod for the second axis I'm currently thinking about a printed part for shifting the bearing. But it has to be shifted quite some distance for the Calum-solution. So you get in conflict with the crossing rod. The space in between them is kept as low as possible meaning the pulleys just don't touch each other. The pulleys have an outer diameter of 17mm. The bearing has an outer diameter of 16mm. That leaves you with a wall thickness of 0.5mm for an adaptor. Delicate but not impossible. Vibrations: I've put my Ultimaker on a stone slab and put some rubber feet underneath the slab. It's far from perfect but a great improvement. I did some very quick and dirty analysis with a mobile phone app analysing the sound spectrum. There are very view distinct lines at certain frequencies. Most of the noise is quite broad band... Air springs (or pressure springs) might be something to try, but they are quite expensive. There are also some elastomeres which should be suitable to put under my slab, but there more than expensive... The main problem is that all the motors are hard-coupled to the wooden frame. I plan to design a de-coupling part for the extruders. Taking away a running extruder from the frame during printing shows how large the excitation is. The very low frequencies mainly come from hard direction changes of the print head. You can eliminate them at least partially by reducing the xy-acceleration to 1000mm/s^2.

Very nice video! If I look at the video I see the main issue is that already printed layers are partially liquified again. When the nozzle moves away, this liquified part is picked up by cohesion of the plastic fluid... Why does it happen just on the overhang side? Well it doesn't. The effect is just stronger. You get the same thing everywhere if you print small structures too fast (e.g. minimum layer time below 5s). But on the overhang side the amount of material to be heated up again is limited or smaller compared to the other side. So the material temperature after contact with the nozzle is higher on the overhang side. It's quite difficult to distinguish cooling phases. I expect the temperature to drop on some kind of exponential curve starting at the very moment the material leaves the nozzle. Re-heating certainly changes that temperature slope (EDIT: and active cooling by a fan as well). I think the crucial point is that the printed plastic is below glass temperature and stays there when the next layer is printed. What if at least part of the priming after rectraction is done during the travel move? The idle time contacting the printed material would at least be smaller... But the priming process would have to be split up between the travel move and the original priming. Both gcode commands would have to be altered. It might be possible to do this with a Cura plugin.