Afternoon all,

Seems we are missing a section in our wiki explaining commonly used abbreviations in the forum?

On the most part I'm sure it's accidental but heavy use of abbreviations in this user help forum is counter productive. It is needlessly increasing the level of things you need to learn when we are already dealing with a complex subject matter. In extreme cases it can come across as a bit clicky and seem like the forums own language making it difficult for new folk to join in. The abbreviations are often not easy to seach for on the internet either.

I'd suggest something that searches posts for abbreviations and adds links to explanations, much like you see for many forums/sites where keywords are detected and highlighted for adverts. I do however appreciate that unless this is available as an off the shelf add on there isn't the time to develop that right now.

I have done it in my posts, but particularly when we are starting to delve into linux and single board computer lingos lets either try to keep it to a minimum, or add a page to the wiki. I will do this myself if it's not there by the time I've sorted my current headache - sorry, machine build!

Mornin' All,

Hope all is well. My printers are still running although I've dropped bay from 6 to a core of 3 P3Steel based systems with the modified Ormerod taking a back sear moving towards retirement! These are tools rather than more a hobby, so reliability and minimal faff is key. I'm sure people would cringe at the firmware & DWC versions currently running!

I'm going to be playing catch up. I've got two systems running RRF2 on Duet2 and I suspect they are heading towards end of support now? Did the filament monitors ever get to the point where they were a practical choice for calibrating the non-linear extrusions?

I'll be catching up on the last ~3 years progress on coffee breaks!

Cheers & hello to those that I know but not spoken to for an age (sorry!)

Please can you pin the most recent Firmware and DWC threads to make them easier to find? Quite often older firmware threads will appear above the most recent ones due to ongoing conversations and that's a little confusing.

Yes, to find the most recent releases I look at the github.

No category tag for threads about general website (.duet3d.com/) issues or suggestions?

Morning,

The default colour for links on user bio pages and last posts should be revisited for the dark colir scheme. They are difficult to read.

Thanks!

Reading up on this and I can see it is a mine field with huge learning curves on some bits if you let youself drop too deep!

I had heard in the past about people worrying about the failure mode of switched power supplies causing mains on the DC out but this appears to be mitigated by an internal fuse. Float between multiple PSUs would not be great but I've commoned my PSUs.

So the earth tie must be to try and stop the DC floating higher than the expected 'safe' 24VDC, but this is also potentially done internally by a similar RC circuit to that between your ethernet socket and -VIN? Tieing the earth to the -DC does potentially reintroduce the noise kicked out of the non-linear switch mode supplies to your -VDC and so screwing with your temp readings.

Are there no standards that we can look for that indicate the earth is tied with an appropriate RC circuit internally and there is no additional need to tie? Is this a product of buying cheap PSUs? Or perhaps is it my PSU which needs an RC circuit because of the noise that it kicks back to the mains that is confusing me?

Edit: I've made a few references to RC circuits (resistor capacitor), but apprecieate the internal circuits in the power supplies may be more complicated with over voltage shunts and transient suppression to mention a couple of things. I guess the main question is if it is safer to tie why don't the PSUs all arrive like that?

You said you know your system can do better. Do you mean you have seen others do better or your system did better pre Duet? With age thing do wear out, and the duet has come second! May be worth a nozzle swap if it is old.

At least 4 areas for optimisation being investigated here and improving one can easily make another look worse when all thats really happening is you are reducing a randomising effect by curing one issue which was hiding the magnitude of a second. Very frustrating, but it's the nature of the beast.

In no specific order:

• Ringing/ghosting - you've mentioned your stock pully a few times. Assume this is at most £5 to swap out with a gates model? Some other threads indicated that gates may not be the best, but at least they are respected for quality control. Creality not so much. Also try to get the belt running without scuffing the sides of the pulleys. That said as the pitch changed with speed I think this maybe a mode of oscillation in your frame somewhere. I've no experience with enders, is it easy to brace the top on the z-axis back down to the front or rear of the machine? To treat the oscillation you need to make the thing that's exciting it vibrate differently (less or at a different frequency; quieter stepper setup, belt/pulley choice, belt tension, etc), or change the natural frequencies in your frame by making it stiffer or more compliant. More drive current on the motor will likely reduce the amplitude of oscillation of the motor around it's target position. Keep check on how warm the steppers are. Ok you don't want to run higher currents than specced, but a stone cold stepper would indicate it's not working particually hard.

• Z wobble. In one of your pictures there appears to be heavy scoring on your right hand inner delrin wheel. That shouldn't happen. Check the extrusions to ensure the v-slot is very smooth. If anything that the wheels run on can scratch or be felt as uneven by your finger then it needs to be fettled or replaced. Check all other wheels for wear and that the bearings run smooth (remove wheel to check). With no z axis screws connected the axis should move up and down easy with no tight spots. The wheels should be tight enough to the rail to limit wobble, but not so tight as to overload the bearings. There is a big difference between quality bearings and wide tollerance cheap bearings. I have found heavy duty wheels (polycarbonate I think) harder wearing. Linear rail z maybe asking for trouble with an extrusion based machine as you are likely to end up spending an age trying to align the two rails close enough to each other to get the axis running smoothly. A bit like the issue Tom3D discussed on YouTube when trying a twin linear rail y-axis setup on another bed slinger. You may also need to (as far as possible) de-couple (in x/y-plane) the z nuts from the motor and idler ends of the x-axis. A popular mod on P3Steel machines. My next step is belted z-axis with a worm reduction drive to stop axis drop on power down.

• Your "///\" pattern is often referred to as "Vertical Fine Artifacts" or VFA. Somewhere in this forum there is a link to a long thread on a Prusa forum about trying to tackle them. From memory specific motors (despite similar spec sheets) do make a difference. There seem to be a few quality stepper motor brands rising up at the moment. LRO are making noise on twitter (and I think they supply E3D) but I have no experience of them. I'd be a little cautious about definitively saying it was vibrations from the fan causing issues. I'd wonder if for example it was more electrical noise? Can you check for electrical noise and would you know what to look for? Ensuring there is good continuity from your stepper motors (and maybe hotend) to the mains protective earth would be wise first principles step. likewise on the noise front can you lock your toolchanger and run with the magnets off in a trial?

• Irregular extrusion. Direct is easier as you are about to find out! Have you run the calcs to check the stepper can run at the commanded speeds? I suspect the loud odd noises you mention on some retracts are skipped steps. Have you already checked e-steps carefully (slow extruder drive with nothing after extruder), linear & non-linear extrusion correction, before doing detailed pressure advance and retraction calibration? Ideally the retracts should be minimal but slightly excessive to avoid occasion stringing.

Final point... Plan your experiments or you will spend way over the odds on this. Try to find ways of quantifying/measuring the issues you can see. Tackle maintenance issues (scored wheels, bearings etc) first and always check system for loose bolts, couplers, and signs of wear. I have - as most of us have - got history of missing a simple problem while searching for a complex one. Be warey of compairing your prints too much to others. Some are dishonest with lighting to hide artefacts etc, but to be fair I've not seen too much of that on this forum. A walk around TCT Show last year and I saw many worse examples of ringing than what I thought was critical on my machines on both demo machines and parts trying to sell commercial level services.

Your spread sheet is very similar to mine! Spookily so.

https://forum.duet3d.com/topic/5588/non-linear-extrusion/6

I fell into the same trap trying to verify the non linear extrusion. Some where in the gcode references or non linear extrusion guides it says that it is not applied to non travel moves.

Also, don't do what I did next which has to do a high feedrate test with a fraction of a mm move in one of the axis! If you do that the feed rate is only relating to the motion axis and not the extrude and so it attempts to cram 100mm of filament through the hot end in a fraction of a second! Life is generally slow and quiet while calibrating extruder. Suddenly this makes it loud and fast!

I requested a feature to allow us to allow non-linear extrusion while stationary but don't think there was much comment.

Some swear by the direct link. There doesn't appear to be anything easily to hand that confirms things definitively. In my recent searches I found that this is prescribed by code for some types of devices but not others - including some scientific instruments.

Checking schematics helps. If they have shorted the pads around screw holes to ground then you may as well do it at the psu. The Ormerod 2's external 5V regulator did this, meaning that without a ground and dc -v link any DC +v short to the chassis/ground (such as heater plate shorting to aluminimum heat spreader, through the bolts and bearings to the chassis) would then try to make it's way back to the psu terminal through the external regulator board. (Not necessarily the reason this connection was toasted on a board I recently spoke about on the forum.)

I always ground as much as possible of the chassis to earth which also includes earth bonding the stepper motors. I struggled to get or test a good bond with aluminium extrusion but realise normal multimeters aren't a great test for this.

If you do bond -v and earth use the largest connections on the earth bonding as practical so the majority of noise and fault currents go direct back to the psu rather than effecting the electronics.

Edit: The other big ones from the safety point of view is fusing and earthing. Where practical add fuses (or reset-able circuit breakers/trips). Main candidates are on the +V feeds to the hot end heater cartridge and heated bed. If possible check to ensure you have a good earth connection for your machine. If your in an old house that has never/not recently been safety checked that may be worth getting that done, and avoid long extensions or daisy chaining extension leads where possible. I run my machines after a mains plug in surge protector and RCD trip.

Edit 2: This is no religious matter where by I will stick to no link in the face of thorough evidence to the contrary. I'm not saying that I will always avoid a tie between the -V and ground (and will add it in situations like Ormerod 2) and may well someday understand it better!

People need to tread with extreme caution on this topic. As this is a Duet3D hosted site I feel the admins have the right to dictate owners of clone Duets are not welcome to seek support here, fair enough.

However in terms of the effect of clones on the original company what is the difference between me buying second hand rather than new compared to me buying a clone? For instance in the cold light of day I would have to say the logical conclusion is likely to be I am causing just as much damage to Duet3D buying second hand and asking questions on here as I would be if I had bought a clone. I would like to think I am able to pitch in and help every now and again though balancing my value to this forum.

If we support this user in their infancy in the hobby now and lightly enthuse about the benefits of original products they are far more likely to remain, become active contributors and replace their sloppy cloned parts with genuine when they can afford to do so.

In terms of intellectual property we also need to be careful. Our hobby and in some cases our livelihoods were made possible by the expiration of a patent. Is the predominant failures of the cloners is to add any innovation to the product? Cost reduction could be classed as their innovation, they after all have tooled up for injection molding rather than plastic sintering? But yes without diving too deep into politics the cloners location and legal isolation/insulation leaves our manufacturers unable to compete on a cost basis. So really you are just highlighting the failings of free market economy and blaming the end consumer who has exercised their freedom of choice rather then the governments for failing to balance this inequality. For our companies it forces rapid innovation in order to still attract people to purchase direct, and ensures they do not sit for too long. Alas without further market control the sweat shops of the world have taken the cherry from the cake for product production. Development is tough, support is tough, and selling a stable product is supposed to be the easier money bit that has now less profitable.

Bondtech essentially adapted a type of mig wire feed to a polymer filament feed. If the E3Ds Hermes (that name tickles me!) is little more than using a no-idle-roller bontech design in a re-engineered housing (the tooling for injection molding thet the cloners have done is, after all a not insignificant amount of engineering effort) are we going to be as negative about people buying E3D Hermes over Bontech?

Edit: the cherry on the cake is lost by going open source, that is the nature of the beast. But the company benefits be developing a loyal user base that in turn supports other users. When this is established the original company benefits from this free support and development that would have otherwise need to be paid for. So the cherry is not given away for free, there is a benefit.

Edit 2: This is naturally a topic that will stoke many peoples emotions and provoke strong responses. I have been wanting to raise my opinion on the matter but I do not wish to make this personal. We are free to hold whatever view on the subject that we want to! In a strange sense this is both not the individuals fault, but all of ours.

@t3p3tony could do, would a page on the wiki be easier for all to update? Link to the how to ask for help page?

The format could be similar to the gcode reference but much less wordy so that it is easier and quicker to update. Something like the following table but with the abbreviations linkable:

Common Forum Abbreviations

Additive Manufacture

Duet Specific Abbreviations

Computing

Obscure Chat

@Tricep-terry I'm guessing that work may have been to support people that are bulk buying boards for machines they are selling commercially. If the customers (rather than duet) funded the work they may not have wanted to share it. That said, They may just have their hands full!

@Tricep-terry likely stating the obvious but a CE marked board won't make the whole machine CE marked. As a community the best we could do for home brewed machines is to provide example risk assessment and mitigation documents and user manuals which can be adapted by others to suit their machines. This would result in a set of documentation that demonstrates due diligence on making a custom made machine safe for use by employees, but it would still be significant work, and only worth the MBs of storage it is written on if effort is put in.

I've got a small business spec machine that I'm now rebuilding. That could be the start of example docs if they haven't happened already in the long periods of my abscence from this forum!

Edit: I believe the best duet3D could provide with the board is a certificate of incorporation.

@Phaedrux Parsing gcode files to use M201.1 or M204 would help control acceleration on the fly. Not sure why they'd want to change max speed on the fly rather than just use feed rates?

As for variable jerk/instant speed on the fly I'm not sure there is a way to deal with this with the current gcode library?

As there are already slicers in the wild using these gcodes badly perhaps it may be easier to have new gcodes for use in config files that can't be overriden in build files?

Edit: Whats the market share of Duet equipped/reprapfirmware compatible machines like vs Prusa compatible systems now?

Thanks for the comments all. I'll take a better look on Monday, little one got turfed out of nursery with a temp. Nothing serious.

As a side note I am doing what I can to manage fire safety in the usual ways too. My larger system will have relay isolation of the heaters and separate isolation of the fans and other 24DC devices such as the steppers. Latter mostly so I can power up the machine for setup and simulation tasks without the fans running flat out! Most wires will be sized so that a fault current of up to the fuse rating would not cause the wires rating to be exceeded. Some degree of diagnostic coverage on the isolation circuits will be there if I have spare inputs on the Duet, but it is wired so that if there was a fault on the fan PSU it would take out the heater isolation.

A lot of my printers have PLA and PETG near high current (heat bed, 600W PSU, etc) supplies or devices.

In industry these devices may be subjected to glow wire testing to gain reasonable confidence that components near the wiring would have minimal contribution to a fire caused by a fault. From what I understand this is an attempt to prevent a fire taking hold should a component fail catastrophically (e.g. DC motors often die smokey deaths) and reducing the tendancy of a fire to spread through means such as dripping plastic.

So, what printable materials have good flame resistance, and would be likely to pass glow wire tests if they were subjected to them?

Glow wire testing:
https://www.te.com/content/dam/te-com/documents/appliances/global/glow-wire-testing-appliance-industry-white-paper.pdf

It also may be worth checking out "M567: Set tool mix ratios".

https://docs.duet3d.com/en/User_manual/Reference/Gcodes

Does look like there is a Gates Carbon/Volt antistatic range. Guess you have to brush a rotary part at some point to to reliably ground the rotating components. Not looked in to it propoperly yet as you can tell!

@tjhinton is there continuity between the stepper body and ground? Is the negative pole of the printers power supply tied to a mains electricity protective earth?

You mentioned static on the belt as a suspected cause. I will check my steppers to see if there is continuity between the axle and the stepper body. Antistatic belts are probably available if the gates belts aren't already so, although I do note you did check for charge build up.

@India if you want this behaviour on all builds ran on this specific machine add it to your config file. You could also add it to the custom gcode your chosen slicer puts at the beginning of a build file.

Read through the detail for M669 here:

https://docs.duet3d.com/en/User_manual/Reference/Gcodes