foehnsturm

What's in the package: Flow sensor with mounted encoder, twist-lock adapter for UM2+ feeder, cable, some spare parts.

@tinkergnome, I believe incoming signals on A won't generate interrupts when the flow sensor is disabled?

I will prepare the wires in a way it can be directly connected as Sensor1 for the standard single extrusion setup.

Flow sensors are ready for shipping next week. Please send a PM with your delivery address.

So far I've noted down the following binding orders for a UM2+ flow sensor pilot: @Dim3nsioneer @cjs @fbrc8-erin @conny_g Anyone missing? As mentioned an UM3 integration is not yet available. We will see if @gr5 gets a deeper insight about the possibilities.

Cool!!?

As already mentioned firmware and electronics integration right now is only ready for the UM2+ I would provide a sensor if someone volunteers to work on a UM3 integration. @robinmdh, there's a hardware compatible variant of the encoder we are using which works in absolute mode and provides a SPI interface. Do you think it could meet the UM3 flow sensor interface?

As I mentioned in the starting post, yes we want to try that. However there is more than one setting which could be addressed. Most likely a combination of adjusting flow rate and print speed should work best. And the whole logic is not that simple. Like you have to check if an increased flow rate really has a positive effect on real flow, otherwise you already started grinding the filament.

Call for pilot users - let's make this thing see the light of day! I would like make a first small batch of flow sensors available by the end of July. Here are the details: fully assembled and tested, ready to use comes with pre-assembled cables designed for the UM2+ twist-lock mount on the entry side of the feeder works as well with Bondtech feeders based on a capacitive encoder with 2048 steps /rev full firmware integration by Tinkergnome Introductory price: € 65 (plus tax and shipping) The sensor has been tested for some 100 hrs so far. There are no known hardware issues, however this is still work under development. Especially the firmware part will see improvements over the next months. Interested? Then just post here!

Not dead at all ?. We had holidays here in Bavaria. Currently a few guys are testing the flow sensor on UM2+ (standard feeder, medusa feeder, Bondtech QR). The feedback suggests that these features already work very well Spool end detection. First layer underextrusion. Clogged nozzle Temperature limit too low ( viscosity too high ) However volunteers for a UM3 hardware/firmware integration still have to be found.

same here, maybe below 110%. The above mentioned 105 were the minimum recommendation I think.

That's what we are doing. I wanted to say, when the feeder dents dig into the GreenTec and there is back pressure the material deforms more than other PLA (dent marks in the filament soon getting closer than they ideally should be) . We already discussed the idea of a self calibration function: Do another retract before the purge / prime at the beginning of a print. Then feed the retracted length again and calibrate the flow sensor to 100%. But then this 100% would never match the requested extrusion length in reality because we're already ignoring a few percent which might be lost in the extrusion train. Or we could do it the other way round: Do the calibration and increase flow until 5mm requested feed really transforms to 5mm moved filament. Then print with the increased relative flow.

Good point. As far as I can tell that makes the e.g. difference between GreenTec and regular PLA. The GreenTec seems to deform a little more on the drive gear due to the back pressure. I actually see a few percent less extruded than with other PLA at modest speed. Which matches the 105% flow setting you recommend for it

Feeding 40 mm filament with the filament tip just leaving the feeder, no resistance due to bowden or hotend. Blue: extruder e-position = number of steps the extruder performed / steps per e Green: measured e-position = number of flow sensor steps / flow sensor resolution When looking at longer e-distances there are minor, periodically repeating deviations which indicate a slight eccentricity of the flow sensor drive gear which should be fixed with the next iteration.

We are actually working on a flow sensor upgrade for the UM2+ which mechanically also fits to the UM3. Now the big question is who wants to take care of the UM3 firmware integration?

I'm running Cura 3.2.1 with the Cura3 files from git without issues so far.

UM2+ (UM3) flow sensor topic.

This is a project by a group of community members which was also involved in the Mark2 dual extrusion upgrade. More precisely, it's me coming up with an outside the box approach / weird idea for a certain unresolved problem. Smart people like @gr5, @Anders Olsson, @Dim3nsioneer, @rooiejoris throwing in ideas and @tinkergnome who implants the stuff into firmware. My impression of the current state of development when I started this was as follows. There have been filament monitor projects since the beginning of reprap. Only very few made it to some kind of product state, like the one by Aaron Tunell. Manufacturers like Prusa and others recently introduced some kind of filament monitors, with mixed success / reliability issues. The Duet3D guys set their hardware research (laser-based and rotating) on hold because they were experiencing inaccuracies of +/-20%. Well and then there was Ultimaker ... until yesterday with the S5 All these efforts have been or still are struggling to fulfill the most important objective: NO FALSE ALERTS. Otherwise any filament sensor would quickly render itself useless. What we want to achieve Objectives, the obvious part: zero false alerts detect filament runout ("nothing there") detect filament grinding ("nothing/very little moves") Objectives, the challenging part: detect first layer issues (see video below) detect when real flow leaves a certain safe process window and starts to compromise part quality (first, inter layer adhesion will suffer, then classical under extrusion will be visible) and try to counteract, that's where the real fun starts ... Current state of development We chose an encoder and there's a reliably working prototype for an easy to attach external flow sensor, mounted to the entry side of the feeder. Resolution is in the range of 0.015 mm. It's integrated in Tinkerware with a dedicated menu and we (well, he) implemented a gcode command: M591 T0 S1 E0.5000 L0.01695 R35:130 A0.3 P100.00 I leave the parameter interpretation as a little quiz here. Right now I'm working on a modified design which, besides the encoder, doesn't need some parts which cannot be printed and are in the +30€ range to have them manufactured. But most likely some parts will still not be FFF printable. How can I get this? First give us some more time to test and evaluate. If everything works like intended we might proceed like with the Mark2 project. If we should offer this as a product I'd expect a price tag between 70-100 €. And the UM3? That's the BIG question. Like @Daid recently stated their main market is already different. And indeed, has anyone seen any kind of (hardware) upgrade for the UM3 so far? Feeders are the same, mechanically our sensor fits. Electronics, not sure. Ultimaker originally wanted to use a serial interface on the UM3. For the UM2+ we simply connect the sensor's quadrature output signal to free I/O pins, there are enough left (4) for two sensors for a Mark2 dual extrusion UM2. Ultimaker won't do anything to support a sensor on the UM3. Anyway, if a large number of UM3 users would show interest, they might at least not impede a development ...

No, I don't know the sensor on the S5 in detail so far. I was talking about our own project. But I don't want to hijack this topic so I'm going to start an extra thread soon.

I know this is a bold statement But our sensor had zero false alerts so far, by design it will always touch the filament. Now I want to see if we can achieve an accuracy of +/- 2% for 1mm of filament. The 1 mm is because rotary encoder resolutions are limited, we are in the range of 60 steps/mm now. So far 85-95% real flow seem to be the regime for good prints. Flow below 85% compromises layer adhesion, below 75% you will see the classic under extrusion pattern.

As for the flow sensor. We (the Mark2 crowd ) almost finished development for an external flow sensor for the UM2+ including firmware integration. Mechanically it fits to the UM3, but connecting to electronics and ofc firmware integration is a different story ...

Hey that's actually a great idea! As there is some distance between the sensor and the drive wheel we could postpone the halt for some time. 2-3 cms of filament should already provide enough leeway to finish a layer.

Absolutes reales Volumen, also tatsächliche Querschnittsfläche mal (kleiner) Vorschub pro Zeit ist vom Aufwand her jenseits des sinnvoll Machbaren. Es ist schon schwierig genug den Vorschub präzise UND fehlerfrei zu messen. Mit bezahlbaren Encodern ist das auf zwei,drei Hundertstel mm genau möglich. Aktuelles (erreichbares) Ziel ist z.B. das sichere Erkennen von Underextrusion innerhalb von 1mm Filamentvorschub. Das sind bei 0.4 Düse und 0.1 Layer 158 mm Extrusionslänge (ca. ein Layer des alten Ultimaker Robots)

Wir sind gerade dabei. Würden gerne aber noch mehr rausholen, als die einfachen Abbruch/Pause Funktionen. Dazu muss sich jetzt zeigen wie genau gemessen werden kann.

Hi @rhaven, Great to see Mark2 working for you so well. I've no access to my printer this week. 280W doesn't add such a great margin to the standard PSU (220W) but it seems the most you can get at reichelt and the like. There are PSUs with 24V/15A (aliexpress etc). Don't know if they are much better. Regarding he bed leveliing sensor, @tinkergnome is the man to answer. For single material prints you also can just use the standard UM2+ Extended Cura profile. But again Tinkergnome knows the details.