Missing temperature offset correction

Markus64
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Missing temperature offset correction

Postby Markus64 » Wed Nov 04, 2020 9:25 pm

Since I also print highly abrasive filaments with my Pro2, I use hardened steel nozzles. This has the advantage of not having to change a nozzle for a long time and is therefore very practical.

For some time now, however, I have noticed that I have to set the temperatures much higher to get sensible print results. This is easy to understand physically, as the coefficient of thermal conductivity of steel is much lower than that of brass or copper.
Now there is the problem of not being able to calibrate the temperatures so that - as an example - 200 ° C via software or set directly on the printer actually corresponds to 200 ° C at the hotend. This in turn means that I have to use try and error to determine the correct values ​​for each filament profile. At the same time, create a list to note how many degrees Celsius I have to set more to get the desired result.

I work professionally with the printer and can't afford such gimmicks!

What is missing is a possibility to enter a temperature offset into the printer so that the temperatures correspond exactly to the target and the actual. I'm not talking about small temperature fluctuations, but about differences of up to 30 ° C.

As I said, it's not a hardware fault! It is a mistake by the developers not to have considered this damn important point!

An "open" firmware based on Marlin is prepared for such a situation and can be adapted or calibrated by each user.
The Pro2 is unfortunately a "closed" system and my hands are literally tied to adapt my system to my needs.
I also ask every Pro2 user, should they work with hardened steel nozzles like me, to check their printer.
The actual temperature can be measured reliably via a drilled steel nozzle into which a thermistor is pushed.

I therefore urge Raise3D to add this temperature calibration option to the firmware as quickly as possible.

Markus64
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Re: Missing temperature offset correction

Postby Markus64 » Thu Nov 05, 2020 11:03 pm

Update:

I will do an extensive series of test measurements on both extruders as soon as I can.
For this purpose, a high-precision thermistor is placed inside the nozzle where the melting process takes place. The target values ​​and the actual values ​​are then recorded.

Measurements are made with an original brass nozzle and a hardened steel nozzle.
I will publish the measurement protocols here in this thread.
I set the measured value tolerances for a device in this price range at plus minus 3 ° C for the original nozzle.

If the Pro2 were "suitable for industrial use" as described in the advertising, a calibration routine and storage of min. two correction curves per extruder be possible. Once for brass nozzles, once for steel nozzles. This is the only way that it makes sense, and this is the only way to distinguish an industrial printer from toys.

But I can tell you in advance that the series of measurements will cause surprises.
Stay healthy!

Paul123
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Re: Missing temperature offset correction

Postby Paul123 » Fri Nov 06, 2020 1:15 am

I am looking forward reading your test experiences because i have the same feeling about different behavior of different nozzle materials. But being honest summing up all reactions of Raise3d, their reaction in this case will be similar: ZERO.
We are both in the lucky situation of water cooled printing, but out of the box Pro2 will have an even more sever problem with such a kind of temp correction, because the corrected temperature on the hotend will even be higher. I only found one report of HTLTP (high temp long time print) with the Pro2 in the www, but even there it was stated that there may be issues with closed hood - and the "genius" suggestion in that case was "lower your nozzle temperature" :-)))

Markus64
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Re: Missing temperature offset correction

Postby Markus64 » Fri Nov 06, 2020 3:17 pm

@Paul,
the series of measurements will be expanded:
I will also measure the respective hot end temperature and compare it with the value displayed by the printer.

In the meantime, I have secured hard copies of the advertising and printer description from the two German distributors.
Not a single word is it mentioned that the Pro2 is a closed firmware and that the buyer has no way of calibrating the system to his own needs.
Configuration includes, for example, the ability to carry out calibration measures, as required here. Temperature calibration is a fundamentally important function in 3D printing.

It is also a fact that distributors and resellers willingly sell other nozzles, including hardened steel nozzles. There is no mention of a syllable that the printer does not provide a calibration routine for printing temperatures.

According to German law, however, this information must be available, otherwise it is misleading. In addition, there is the selling price, which does not allow any potential buyer to even come close to buying an island system.

If Raise - as you fear - actually does not offer a solution to this blatant problem, I will ensure that this information must be explicitly stated in future advertising for this printer in Germany. The price should then fall into the basement.

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Vicky@Raise3D
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Re: Missing temperature offset correction

Postby Vicky@Raise3D » Tue Nov 10, 2020 6:35 pm

You'd prefer to have the value preset in motion board firmware or you'd like to have a preset configuration then manually input the offet on touchscreen when editing temperature?

For example, if you are looking for +20C offset for 200C tempearture, there are two ways to achieve:
1. Preset the offset in firmware. It will still show 200C on touchscreen but actually it has added the extra 20C when heating.
2. Or inputting 220C on touchscreen and it shows 220C.

Markus64
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Re: Missing temperature offset correction

Postby Markus64 » Tue Nov 10, 2020 7:25 pm

Vicky@Raise3D wrote:You'd prefer to have the value preset in motion board firmware.


For example, if you are looking for +20C offset for 200C temperature.
1. Preset the offset in firmware. It will still show 200C on touchscreen but actually it has added the extra 20C when heating.


Thanks for the feedback Vicky!
That's exactly what we need.
Last edited by Markus64 on Tue Nov 10, 2020 8:43 pm, edited 2 times in total.

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Re: Missing temperature offset correction

Postby Paul123 » Tue Nov 10, 2020 8:15 pm

@ Vicky
Great that you show some willingness doing something in that case. If you really are going to provide this feature in a future firmware version, you will have to provide a method finding out the right amount of offset, too, because one has to be sure, that the corrected value is really the desired value.
@Markus64: what do you think - would be a small table with different nozzle types and its offset values a simple and reliable enough solution?
2. @Vicky: if the nozzle offset is e.g. +30 you will have to allow the firmware raising the hotend temperature. Surely by now, if the Pro2 then should be running at 330 deg. C, you will have to think about the LTHT (long time high temp) issues of the Pro2!

Markus64
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Re: Missing temperature offset correction

Postby Markus64 » Tue Nov 10, 2020 8:42 pm

Thank you for your input, Paul.

I have to make it clear that this offset calibration only makes sense if every user who wants to calibrate purchases or builds the appropriate hardware. The costs for this measuring device including measuring probes amount to about 50 bucks or even less. I will publish a construction manual for this.

As shown correctly in the post above, it makes sense to store the offset values ​​and then display the temperature as the printing temperature which is actually present in the nozzle.

Since the Pro2 has two extruders, calibration must also be feasible for both extruders - independently of one another.

Since users work with different nozzle materials, it makes sense to record at least two materials: brass and hardened steel. Three configuration options would be fantastic.

However, it will not be enough to simply add a value as an offset. Since the calibration / correction is not linear, a type of table must be used to record setpoint and actual values. From these different measuring points, the firmware then calculates a calibration curve with different offset values ​​which later result in the exact printing temperature.

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Vicky@Raise3D
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Re: Missing temperature offset correction

Postby Vicky@Raise3D » Wed Nov 11, 2020 6:21 pm

Thanks for your suggestions.
We will see how we can get the proper values for this for widely used nozzles in market.

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Re: Missing temperature offset correction

Postby Markus64 » Wed Nov 11, 2020 6:49 pm

@Vicky,
Thank you for your feedback signal.

I strongly advise against entering fixed or predefined values ​​for different nozzles in the firmware.
My suggestion that every user can enter their specific measured values ​​has the advantage that the setpoint temperature and the actual temperature of the nozzles that are physically installed are determined.

The manufacturer of the nozzle does not matter. This functionality assumes that every user who wants to carry out this calibration also provides a suitable measuring device.

You also have to keep in mind that users outside of the USA rely on nozzle manufacturers who generate different measured values ​​than the offset values ​​you specify.

The version I recommend is the most professional calibration option..

Markus64
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Re: Missing temperature offset correction

Postby Markus64 » Sun Nov 22, 2020 2:39 pm

The measurement data are now available and prove that the Pro2 is only partially suitable for printing with steel nozzles. In order to arrive at the actual printing temperature, the determined offset values ​​must be added to the printing temperatures in the printer.

At 280 ° C, steel nozzles end because the firmware does not allow any entries > 325 ° C. This is not in any description of the printer and represents a gross defect. "Industrial grade" is just a marketing promise and has nothing to do with reality!

The manufacturer is hereby requested to remedy this defect. Either through the calibration option I requested, or by entering a printing temperature higher than 325 ° C.
IMG_20201120_223211.jpg

Steel.JPG

Brass.JPG

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Vicky@Raise3D
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Re: Missing temperature offset correction

Postby Vicky@Raise3D » Tue Nov 24, 2020 1:15 am

The motion board of Pro2 series won't be able to support any temperature higher than 330C.
You can find we put 300C as Max Nozzle temperature on Pro2 printer's product page. https://www.raise3d.com/products/pro2-3d-printer/

Markus64
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Re: Missing temperature offset correction

Postby Markus64 » Tue Nov 24, 2020 1:18 pm

Then you should add that these temperature specifications only apply to operation with brass nozzles and a maximum temperature of 280 ° C for steel nozzles!

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ccclarke
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Re: Missing temperature offset correction

Postby ccclarke » Fri Nov 27, 2020 2:01 pm

As a test engineer, I have seen data manipulated to satisfy pre-conceived outcomes. Where I work, we strive to analyze analyze test data objectively using as many data points as is practical before establishing performance criteria. This test appears to be something a technician would produce (simple and practical) - but it is far from conclusive, and could be interpreted as misleading (though I think of it as just incomplete) - which is what you are accusing Raise3D of: Misleading customers with false advertising followed by a demand to change their firmware.

Please note upfront that I am not accusing you of falsifying or pre-ordaining test data, but I think it is important to note your test requires further refinement to substantiate the test results. There are variables not included, like ambient chamber temp. Two data sources limit this to a very elemental test that asks more questions than it answers.

I have not seen which brand of hardened steel nozzle was used for your testing. Nozzle wall thickness is another variable.

Have you gathered any data using the (nickel-plated brass) Raise3D hardened nozzle? Obviously, brass will conduct heat better than solid steel, but would wear faster than a solid steel nozzle in actual use, making a solid steel nozzle more practical.

Another factor: You are testing with a modified printer; a more accurate test would be conducted with a stock machine. Though your cooling system is attached to the heat block throat, a (small) percentage if the heater's power is compensating within the feedback loop sensed by the thermocouple; the thermal dynamics of the chilled throat have some affect on the heat block. If you have a strong thermodynamics background, this observation must be considered.

Raise3D doesn't specifically state which material composition of nozzle its printers use for abrasive filament qualification, (other than "hardened" so the assumption is they are using their hardened nozzles.)

It would be more meaningful if your printer can successfully compensate within the parameters required to meet their advertised specification using (their) products- if you haven't tested and published this data already. If the allowable temperature compensation within the printer hardware cannot achieve the advertised claim using their products, then you are right to call them to task for it. But to do so using other manufacturer's products, does not imply the company has intentionally misled consumers with a product that cannot perform as advertised. Form and fit does not guarantee function. It is still easy for Raise3D to dismiss your claims because you are testing a printer with a modified cooling system.

What your data has showed is that Raise3D printers cannot adequately compensate displayed vs actual nozzle temperature with the present firmware using what appears to be an aftermarket nozzle on a modified printer. Correct me if I am wrong and you tested with a Raise3D hardened nozzle. I suspect, (pure speculation on my part) Raise3D opted to go with hardened, (brass) nozzles for the very reason your test data shows, rather than solid steel.

Your test is interesting and somewhat instructional, but not conclusive that the printer cannot perform as advertised. If you can repeat the test with one of their nozzles, you will have made a valid point that should spur the manufacturer to immediate action to offer enhanced temperature compensation. Using an unmodified printer, (actually several to expand the data set) would be the most accurate test sample.

Obviously, Raise3D would prefer customers use/buy their parts, and with a closed system, using aftermarket parts goes beyond their stated performance claims to which they are not bound to.

Thanks for pushing the envelope though. I enjoy reading about your mods to achieve your goals.

CCC
Last edited by ccclarke on Fri Nov 27, 2020 3:56 pm, edited 1 time in total.
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Markus64
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Re: Missing temperature offset correction

Postby Markus64 » Fri Nov 27, 2020 3:52 pm

Hi CCC, first of all thank you for your detailed posting.

My series of measurements is from practice for practitioners. The whole point is to compare the offset of brass nozzles and steel nozzles. "Hardened" nickel-plated brass nozzles from Raise3D do not interest me. Especially since Raise3D does not provide any material-specific data.
"Hard" is a very flexible term. I am a technician and I know what I am talking about.

Raise3D does not describe with any syllable in the printer properties that the buyer has to move within a closed system. This means that the machine may only be equipped with Raise3D nozzles in order to achieve the advertised services. It is also highly questionable not to be able to calibrate a printer in this price range to the nozzle used. But as we all know now, the built-in hardware is not capable of this.

The modification of my printer with water cooling makes the test even more accurate than with a standard Pro2 with thermal problems from the factory.

If Raise feels bound to a closed system in order to be able to meet the performance requirements, then, in the course of consumer protection, this information must be written in large letters in the technical data.

In conclusion, I would like to mention that my series of measurements clearly shows that the "developers" of the Pro2 never carried out such a test themselves. This is standard when you design such a device.

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ccclarke
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Re: Missing temperature offset correction

Postby ccclarke » Fri Nov 27, 2020 4:45 pm

I believe if you were to run a CAD-based thermal model, (before & after your cooling modifications, using aftermarket and stock nozzles from Raise3D) through a simulation, you would see a difference. Follow that with a current / load test to determine how the electronics is operating and the data set begins to expand. There is no such thing as too much data, but it isn't practical from a budget and production schedule standpoint.

During design, we perform these types of studies using different materials and temperatures to predict the best outcome for long-term environmental testing (aerospace environment.) Once we build prototypes, they go through extensive testing (months to years) to match the predicted performance with the actual results. Thorough product life-cycle testing uses multiple example products, not one - and there's a very good reason for that.

Our mantra is always, "Follow the data." Engineering defines the testing protocol and technicians perform them and gather the data for the engineering staff to review. (I started as a tech, so I understand where you're coming from, but the engineering world takes many more factors into account than what would appear on the surface to be the obvious.) Deep-diving into your data does not make this an open-and- shut case. Some of the tests we run take months, but end result justifies the cost of the product. Consumer-grade products are another matter, but thorough testing is still warranted if you want to compete in the marketplace.

Consumer-grade products, and Raise3D is consumer grade --as evidenced by the weakest link in the production process which is workmanship. I know a little about this subject since I train and certify all of our technicians in electronic workmanship and Raise is way behind the curve in this department. Consumer-grade products are exempt from the kind of life-cycle testing I'm associated with, though the more they do, the better they understand the product's performance and limitations.

There is no way Rasie3D can (or would) guarantee their printers will perform as advertised with modifications or aftermarket parts installed. Those types of performance and compatibility claims should be addressed by the vendors producing them. As I said, form and fit are no assurance of function.

Your limited data set is interesting, but far from compelling, and I would venture to say if Raise3D could (they likely won't) comment, they would agree.

CCC
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Markus64
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Re: Missing temperature offset correction

Postby Markus64 » Fri Nov 27, 2020 5:01 pm

@CCC,
Thank you for the detailed explanations and examples from the aerospace industry, but let's keep the ball flat.

This is not about laboratory tests or thermal models, it is more about a small and massively overpriced 3D printer that offers no possibilities for temperature calibration - POINT. It is not about changes to the hotend cooling or other improvements, it is only about a lack of calibration option.

I also emphasize it again: THAT belongs in the small print! I accept your opinion but do not share it.

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Re: Missing temperature offset correction

Postby Paul123 » Fri Nov 27, 2020 7:11 pm

@ccclarke
I agree with your description concerning aerospace grade tests. This has certainly nothing to do with the tests of Markus64, and nothing with the testing methods of Raise3D, too. I know how much a product meeting such test creterias would cost. BUT the test series of Markus64 is simple and straight forward, showing a tendency of a thermal which should and could be avoided VERY easily nearly without further development costs (the same with the whole cooling mess). Primarily its not a judicial question but a question of trying to provide de best possible product.

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Re: Missing temperature offset correction

Postby ccclarke » Sat Nov 28, 2020 11:24 pm

Aerospace testing being the upper end and @home being the low end, a happy medium that is convincing enough for Raise3D to even consider their design is flawed is what I think you're after.

Our difference of opinion is based on making a public request, (The manufacturer is hereby requested to remedy this defect. Either through the calibration option I requested, or by entering a printing temperature higher than 325 ° C.) for a condition that affects your modified machine using an aftermarket nozzle.

It remains to be proven this thermal offset condition is systemic. I am not saying your theory is wrong. I'm saying your testing methodology is not representative enough to even raise an eyebrow by the manufacturer - for that very reason. If I'm wrong with this line of thought, Raise3D has QA support working on this issue as we speak . . .

On a non-aerospace note: Change the tune on your car while under warranty and if it goes in for service and the change is detected - the warranty claim is almost certainly denied. The manufacturer can always claim the vehicle was modified from stock. (Very common occurrence here in the US.) -And that IS in the fine print.

Perform your temperature offset measurements on an unmodified machine with Raise3D parts (ie: their hardened nozzle) and you'll have a much more compelling argument.

I am not an apologist for Raise3D. They have plenty of work to do to raise their game to justify what we both agree is a very high price point . Their printers have some great features, but there isn't enough margin with their mechanical assemblies, (sag in the gantries for one) latent failures built into their wiring, (tinned leads on terminals and connectors that have to be glued together instead of positive locking bodies) and procedures that in many cases, make no sense procedurally or grammatically. The (N2 and Pro2) hot ends are on the very ragged edge of acceptability for anything other than PLA. Luckily, that's all we print at work due to the fumes - we keep a small Sindoh under a fume extractor hood in a closed chamber for ABS, etc.) Still, we routinely print for 70+ hours at a time with no issues.

Marcus, I think we can both agree we would like to see more bang for the buck where it's warranted. And there's plenty of room for it.

Cheers!

CC
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Markus64
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Re: Missing temperature offset correction

Postby Markus64 » Sun Nov 29, 2020 9:56 am

@CC,
I am glad that at least you, along with Paul123 and me, are actively dealing with the subject. That we have different opinions doesn't matter to me.

Since you repeatedly refer to the original, hardened nozzles, I would like to go into this. These nozzles are offered in the Raise3D shop. However, there is no further description of what degree of hardness this material corresponds to. Raise3D has two distributors in Germany. One in the east makes Raise3D the same and does without further information, the other actually lists values ​​on which, however, are unusable.

As a technician with a background in mechanical engineering and development, I naturally choose the product that is best for my project and, above all, has all the technical details that I need. This is the case with the nozzles I use.

Since Raise3D cannot or does not want to deliver exactly this data, I deny Raise3D any professionalism in this regard. Criticism is not seen as an opportunity. There is no will to improve the product in dialogue with the user.
It starts with Europeans being denied support. For me a form of discrimination, marginalization and unbelievable arrogance.


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