@smece said in mellow nf crazy hotend:

I used e3d X nozzle for this test, first time I tried X nozzle, they are support to have some polyfobic coating that makes plastic not stick to them ... well ..

I am running an E3D NozzleX in my v6 heaterblock, mainly because crashing a brass nozzle into something tends to deform the nozzle enough to throw off the alignment of the dual nozzles on the Chimera. And although these are quite pricey when compared to a brass nozzle, they are still a fairly cheap way to ensure that things will keep on working the same for a reasonable amount of time.

So far I am happy. PETG stringing makes little to no mess, have not yet seen those dreaded black blobs in a print that occur when the nozzle picks up stringing and drops it on the print when buildup has passed a critical amount. Whatever sticks to the nozzle is easy to remove.

Regarding cheap clones of whatever: you may get less than what you pay for, but you will never get more. Accurate machining and good quality base materials are often not required to make parts perform well initially, but accurate machining keeps parts performing well day in, day out. Compare a Papst fan with Chinesium. Day 1 both work well. Day 100 the Chinesium fan makes a lot of noise or stops working, the Papst keeps on humming like it did on day 1.

Frustration continues after the joy of saving a few bucks is long forgotten. In the end buying decent quality stuff saves money overall. Higher initial expense, but less money spent on failures and replacements, higher resale value, less headaches.

@dc42 said in RepRapFirmware road map as at 15 February 2020:

True; but we value our users!

And I am grateful for that!
I have become quite fond of the Duet controller in short time. Bought the Duet2Wifi out of curiosity. Toy with it, see what it is all about, sell it. Never even thought it would really be a decent contender to LinuxCNC with it's endless possibilities to make things work the way I want them to work. And the first experience was indeed like a naked plunge in subfreezing water. No conditional G-code, a weird way to use homeswitches not exactly at the end of travel, blah. But here we are, a few months later, and the water is nice and warm. Not considering moving back. Mainly because of you, your insane drive to move forward and efforts put in RRF3, and the insanely quick fixing of issues.

[rant] Also I get disgusted with kit that ceases to be fully functional because the manufacturer can't be bothered to update the firmware.

As a consumer I totally agree. Not only the software, also the actual technical life and irrepairability of 'modern stuff'. After a few years it becomes hard to get parts. Kept my old xperia X10 phone running for a bit over 6 years, cannot do that anymore it seems. Bought 10 year old motorcycles and ran them until they were 20 years old, then only sold them because I longed for something else. Not sure I can do that with my shiny new KTM; I highly doubt that the TFT screen they use for dashboard lasts that long, and build quality is more optimized towards cost and weight instead of durability.

As one of the designers at an electronics company I am not so convinced. IMHO the worst thing you can do for customers is going out of business or having to find other sources of money which lowers the amount of resources that can be put into the original product line. Given the fact that development time is a limited resource there is a point where the hours spent on maintaining compatibility is preventing staying ahead of the rest on the new hardware and just costing money. It often makes sense to create a 'light' version of the more current hardware or lower pricing on the full version a little. Which you can since you save money elsewhere. A bit on the increased volume, a bit on the development, a bit on the support. It adds up.
Also, the Duet is not a PC, phone or PVR where 3rd party software stops working due to the system being too old. If I stop updating today the Duet will happily keep printing for the next decade just like it does today. Many of your users are probably not updating the software anyway. If it ain't broken....

All this is personal opinion only, of course.

Also, Duet 3 is expensive and overkill for most 3D printing applications.

Yes, you have chosen nice and expensive motor drivers that almost no 3D printer needs. I bet a large part of the additional cost come from those
I did not check the BOM, but a Duet3 with 5x TMC2660 instead of the 5160's should not cost that much more than Duet2 to produce, and more alike platforms usually means faster development and less issues. However, I am aware that initial cost for a new board is high.

Anyway, I love what you are doing, and I am happy to get to use all the useful new stuff with a click on the 'upload system files' button.

Not much of a braincrunching project (which is usually most of the fun), but a decent option to texture 3D prints could be hydro-dipping:

It can do wood grain nicely.

Requires a suitable inkjet printer, hydrodipping sheets, activator and a bucket of water. I never actually did it, but maybe I might someday.

@weed2all said in Where's the Duet Wifi 3?:

@dc42 but we need Duet3 6hc with WIFI for cnc use case!

No, you don't. Really, you think you want Wifi, but you don't.

I have seen countless of issues with USB/WiFi and CNC machines. Mostly that is due to less than stellar wiring and insufficient use of supply filters in front of the frequency inverter or brushed universal spindle motor, but that is often the way it is and only a good electrical engineer is able to slay those gremlins. I know how to do it, I tried using an USB Pokeys57 for my lathe control panel, worked fine until the spindle servo starts to deliver more than a few Watts of mechanical output power, and no shielding, supply filtering or CM-choking the USB could stop that. Switched to Ethernet, never had a single issue since.

Second problem: if the Wifi connection drops, the CNC keeps doing it's thing, including the spindle. And you will encounter the mill pulling the workpiece out of it's clamps or simply loading up. Try to stop it using the normal interface, realise it won't work, hitting the (hardware) emergency stop, and that is 5 seconds wasted. I had a big dent in my garage door due to those precious seconds. There is a lot of energy in even a few grams of material spinning at 10000+rpm.

At least you want a very reliable stop and feed-% knob; the last one saved more endmills and workpieces than any other knob or button on my machine. Ethernet is a very reliable data transport mechanism with a robust physical layer, it's failure rate is so low you could consider that 'never', and latency is low too. USB and WiFi are not that reliable, not even close.

Most of my contacts come either directly from Wurth, or from Farnell/Digikey/Mouser.

But oh well, every crimp tool needs a bit of feeling and a bit of exercise, I am probably just not doing it enough and the Iwiss is simply more idiotproof. I suspect most people here crimped an RJ45 to CAT5 at least once. Remember how long it took before you got the first one correct?

Another sound here. I am very happy with the speed of progress. Many new releases bring features I can actually use on my quite nothing special printer.

Regarding the effort: last week I set up a Duet2 for testing a motion stage. I needed RRF3+ for that so I could use while loops to iterate the same movement tens of thousands of times. Zip-zap-zip-zap, all day long, all night long. It took me about 20 minutes going from plugging in the USB cable in a freshly arrived board to a WiFi-connected testbed that was exercising the motors running RRF 3.2. The process took upgrading the FW to 3.0, then to 3.2 (somehow going directly from 2.x to 3.2 would not work but I did not spend time on figuring out why), configuring the controller and writing a few lines of G-code.
I am very comfortable with LinuxCNC, I can do the Arduino+stepper drive stuff too, but there is no single piece of kit that allowed me to get up and running THAT fast. Which is exactly why I chose a completely-overkill Duet for the task.

Whatever you buy, you need to learn how to operate and maintain it or find someone who does it for you. Software is not different.

@dc42 said in Enhancing pressure advance:

Ideally we would measure the pressure within the melt chamber, but that's hard to do.

In what ballpark is the nozzle pressure anyway? I might have access to temperature resistant pressure sensors with an extremely small sensing head soon, and milling a hole in the nozzle to accept one would be easy. But these are for a fullscale range of 400 bar and absolute accuracy is not that high. Resolution is higher, which is probably what is needed most.

Would the curve change much between extruder brands? Would an E3D hotend with Bondtech display a different shaped curve than, for example, a DyzeXtruder?

Regarding small segments; how many segments can a Duet2+RRF3 process per second as long as no acceleration/speed limits are hit? And Duet3?

If you use cast tooling plate it won't bend as long as it can expand freely, and as a bonus it is quite flat on at least one side. If you use rolled plate it will twist or bend slightly over time.

I am using a 300x300x10mm aluminium plate with 600W Keenovo silicone heater. Absolutely no issue reaching and maintaining 150C, never tried 180C but that should be no issue; the heater is not operating near full power at 150C. Your surface is 2.8x as large, with 2kW the power density is higher.

My plate is mounted on a carrier structure with 3 PTFE spacers and stainless screws. One is fixed, one spacer moves in a slot (and thus constrained to a single axis), one can move freely in the XY plane but not in Z. This allows expansion but constrains free movement.
A couple of images can be found in this forum topic. Dutch, unfortunately.
Although I must say that the kinematic mount using a couple of balls is quite charming too.

PTFE tends to creep over time when under a constant load. I do not expect many issues with that though, and I did not yet want to spend some of my limited supply of PEEK on those spacers.

OK, granted

@Danal said in Adding a 24V safety relay for the heaters, any thoughts?:

Could you expand on that? It would seem a sprinkler requires a water supply, and it is hard to see how that is cheaper.

I think that is more applicable to my situation. Machines in the garage, and there is a water supply available.
For the price of one AFO fireball one can buy a lot of pipe and mounting clamps, and the sprinkler heads themselves are not very expensive either.

In my situation it might be a good idea. The 3D printer is not the only machine.

@deckingman said in Adding a 24V safety relay for the heaters, any thoughts?:

Better still, use a clean agent fire extinguisher as I mentioned above - much kinder to the electronics than water (or foam).

I will look into that.
I am also wondering: how effective are one-shot devices when the power is not killed? Water would sooner or later trip the ground fault interrupter, and it keeps flowing (which might be a 'small' disadvantage also)

@arhi said in Adding a 24V safety relay for the heaters, any thoughts?:

I have 750W, 1000W and 2500W silicone heaters here on some aluminium beds ... never tested how far they can go but they get up to 100C in seconds, I would never allow them to run without meltable fuse for security. Running low power beds that would settle at max power around 100-150C is safe but I don't run those and more and more printers are made/upgraded with high power beds.

Mine is a 600W heater on a 300x300x10mm aluminium plate. They can become way hotter than needed, but it lacks the power needed to reach autoignition-hot. I think the remaining risk after taking into account the overheating prevention of the Duet in combination with the regular SSR and relay is acceptably small. Can it be better? Sure.

We have local variables now. Nice!

Sure, directly painting the surface makes sense. How to get decent resolution is a good question. Inktjet gets you there. Felt markers, meh.

For occasional use hydrodipping might just be the answer. Standard patterns are available as rolls, custom can be done with blank sheets and an inkjet printer (but not any inkjet).

I might want to try it one day. UV-unwrap the object in Blender and use hydrodipping to transfer graphics to a printerd part.

Not much of a braincrunching project (which is usually most of the fun), but a decent option to texture 3D prints could be hydro-dipping:

It can do wood grain nicely.

Requires a suitable inkjet printer, hydrodipping sheets, activator and a bucket of water. I never actually did it, but maybe I might someday.

The CAN bus was made for stuff like this. There is only a delay in the transmission, and unlike many other serial physical layers that delay is fixed and known. So it is fairly trivial to synchronise a clock over all the CAN-connected boards, down to microsecond level. Once we have a synchronised clock, we have synchronised motion.

I cannot look in the head of the developers, but I am fairly certain that clock synchronisation was the first thing implemented and thoroughly tested since it is so vital.

@deckingman: Lack of thrust is for a large part gut-feeling-territory, there is little to nothing Duet3D can do about that. Sometimes it happens that products go in a direction which does not suit you. Vehicle manufacturers do that, coffee machine manufacturers do that, and so on.

If I were in your situation I threw out the Duet3 and went back to Duet2+DueX5 with RRF2.05 or investigate other controllers. Takes a lot less energy in the end.

Another sound here. I am very happy with the speed of progress. Many new releases bring features I can actually use on my quite nothing special printer.

Regarding the effort: last week I set up a Duet2 for testing a motion stage. I needed RRF3+ for that so I could use while loops to iterate the same movement tens of thousands of times. Zip-zap-zip-zap, all day long, all night long. It took me about 20 minutes going from plugging in the USB cable in a freshly arrived board to a WiFi-connected testbed that was exercising the motors running RRF 3.2. The process took upgrading the FW to 3.0, then to 3.2 (somehow going directly from 2.x to 3.2 would not work but I did not spend time on figuring out why), configuring the controller and writing a few lines of G-code.
I am very comfortable with LinuxCNC, I can do the Arduino+stepper drive stuff too, but there is no single piece of kit that allowed me to get up and running THAT fast. Which is exactly why I chose a completely-overkill Duet for the task.

Whatever you buy, you need to learn how to operate and maintain it or find someone who does it for you. Software is not different.

Nice, thanks!

Just considering options at the moment.

Say I want to control 7 heaters+sensors of which 5 are 230V/SSR, and read 9 more NTC temperature sensors using Duet3 Mini which I would want to process in the daemon task, would one or more Sammy-C21 boards connected over CAN-FD work for that? Of course that would need additional hardware such as resistors for the NTC's, a driver for the SSR's, etc. Not a problem for me.

Would the Duet3Expansion firmware on Github work for that with little or no modification? When looking at the pins in the wiki page, can I use PA[04..08] for NTC sensors and PA06/12/19/23 to control heater SSR's, for example?

So, basically, at 180 steps or so the actual vs demanded position deviation of the last motor is more than half a step with the others close to that, with zero load?

That is way worse than what I would have expected...

Basically 2 linear magnetic flux sensors oriented with 90 degree rotation. Rotating a magnet over them give a sin and cos signal from which you can calculate the angle.

Works fairly well. But usually not 15-bit well. A resolver would be more accurate.

[edit]
From the datasheet:

[/edit]

So that's 8.5 bits of precision. The extra 6.5 bits of resolution come in handy for the servo loop, but that is not precision.