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I decided to buy an UM2 once a working (soluble) support material solution was there. It seems this is not going to happen!

I regularly see a Dimension Elite printing. It is amazing to see how effortless and without any problem this thing works. It "just prints". No delamination, stringing, dripping, oozing, warping, clogging, ringing. As many are wondering how a soluble support material solution could be designed (which I think makes it a tool instead of a toy), it is worth looking at how for example this specimen does it - an almost a decade old design! Maybe others can share their obervations as well.

Of course this Stratasys machine is in a different league, but I don't see a natural law prohibiting sub-$10k machines from proper printing.

I don't own this machine, I have no schematics or internal documents. I read the manual, watched maintenance videos, observed it when printing, read some patents and talked to the operator. So everything is AFAIK or IMO, if you know better, feel free to correct me!

Find the manual here. The machine prints 0.178 mm layers from two materials - ABS and soluble support. Layout is pretty standard, platform is Z move only, print head moves X/Y. Print quality is excellent, limited by the 0.178 mm layer thickness.

Material: Comes in cartridges (CHF 550 here, approx, EUR 500 for a 0.9 l cartridge, build and support each). Cartridges are hermetically sealed with locking pin for transport. They contain a desiccant and must not be opened; the machine keeps track on how much material is used by an EEPROM on the cartridge (maybe also copy-protection). There seems to be a feeder motor directly at the cartridge. Material lifetime in cartridge is 30 days, when cartridge case is broken (eg. when the end of the filament slipped inside or you are overly curious), it must be used within days. There is one single material you can use (different colors though).

The soluble support mostly breaks off easily, the rest is removed in the water based solvent in a heated ultrasonic cleaner. The machine never prints build material on the base, it always starts with a layer of support material.

The machine prints on a non-heated, removable plastic base. The build chamber is closed and heated (patented). There are no tilt adjustments for the build platform.

In general, the machine is very solidly built. It weighs 120 kg, everything looks precisely machined, no play on any bearing, no user adjustment screws. Z move is via a ball screw, X/Y move via stepper motors and belt drives. The print head looks quite heavy, even the X stepper motor is located on the print head.

Search videos on "dimension elite maintenance", you'll find a couple of close-ups on the print head. The print head has two fixed nozzles quite close to each other (10 mm?). It has two feeder motors - geared brushed (?) DC motors from Faulhaber with an additional reduction gear, located just before the heated nozzles. The feeder wheels look quite solid and seem to make deep notches in the material - no slipping here. There is a fan in front of the heaters. Strangely the material makes a 90° bend from horizontal feeding to vertical extrusion - the designers seemed to want to keep the height low. Because of the 90° bend you can't clean the nozzles, the specimen I watched needed a replacement (the complete head was changed) after a few years as one nozzle started clogging (not bad for mostly nonstop printing).

There is a scraper/metal brush head cleaning (also patented IIRC) station at the rear. Behind it is a waste bin. After each material change (at each layer when printing with support, which is 90% of the time) the printhead goes over the cleaner and extrudes a bit in the waste bin.

Quick summary on the most interesting points:

- heated, closed build chamber, non-heated platform

- closely controlled quality, dry material out of cartridge

- print head cleaning station with waste bin

- geared DC extruder motors - higher power density, much higher torque than stepper motors

- extruder motors directly at the nozzle - more precise material control than with remote feeder via bowden tube

- very close spacing between nozzles, nozzles fixed

- extremely solid, heavy build quality

and: It just prints. No webcam for supervision, load the file and get the model hours later.

Any other ideas? Anyone else observing other types of printers? In addition, there are some quite interesting ideas in Stratasys patents - another time.

- Martin

 

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The price tag of the stratasys and the size of the company makes any comparison to the Ultimaker unfair.

I consider my Ultimaker a tool, not a toy, even if it does not print soluble support structures. It still prints a lot of beautiful and/or useful stuff.

Right on topic, I found this article of particular interest: http://www.tridimake.com/2014/03/quick-comparison-pro-versus-low-cost.html

 

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If you show a printer like UM2 to an expert on CNC machinery, immediately he is going to appreciate lots of deffects on the printer. They talk about "closed loop", better motors, warmed controlled area, filament counter, lots of detector for everything (is it extruding, is the motor running or stopped, which the actual speed?,...). Of course software can be improved too. Why not evaluate the whole object and optimize printing for each area instead of printing everything with the same settings?.

These are some questions I remeber from friends who have worked on high dollar CNC machines.

The answer to most of these questions is: add more money to the bill, If you add some thousands to an UM2 you will have an improved printer, but probably you wont be able to purchase it.

Other than this there are patents that prevent some features to be added. For instance, the way to prevent seams to be seen. The solution is almost trivial but is patented. Until recently the FDM process itself was covered by a patent. Until 2014 the SLA process was covered by a patent. Small companies cannot pay expensive patents (well except the Chinese perhaps).

Makers like Stratasys deal with patents every day. They own patents and they must pay for patents. Some patents even prevent them to make some new and significant advances that would benefit the customer.

 

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MMartin, very interesting post, thank you for sharing!

I think that if you have a lot of constraints like in the dimension machine, only ABS, a very tightly controlled environment like with the heated chamber, the exact same type of materials etc, it gets a lot easier to get consistency and reliability in output.

The openness and flexibility (open filament system, both ABS and PLA) of the Ultimaker 2 that makes it great, at the same time makes it a lot harder to get consistency and reliability out of it when trying to develop dual-extrusion for example.

But of course good designs and ideas should be reused, however I think that the lightness of the head of the Ultimaker family makes some of the solutions working for the heavy printers impossible to use on the UM. I think that new ideas like Foehnsturms magnetic cartridge might be the way forward...

Just my 2 cents :)

/Daniel

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by considering complex sensor systems please do not run into the Makerbot 5th gen problem where you have more false positives then real problems...

btw my Ultimaker hand never skipped an step in X or Y axis so why closed loop? maybe for the extruder but if you do not have the stock feeder it isn't a problem ether

 

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FYI, My girlfriends work just got one of these machines as a trial, just 2 days ago. Right now they are not impressed, as a support engineer took 5 hours to unclog the nozzle. As replacing the nozzle would have been 1000 euros. He used up 20% of a roll of material during this cleaning.

The solvable material is NOT water solvable. It's most likely PLA with an additive, as it's dissolved in drain cleaner at 70C.

Each spot on the build plate should only be used twice, and if all spots are used up, you need to replace this part.

And for the price of the machine alone they can put an Ultimaker2 on every persons desk at her office.

Their software is greatly limiting the possibilities.

And the support engineer was down-talking Makerbot all the time.

Is that the way Ultimaker should move? Because that's not the way I want to move.

 

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@ Daid, I think that´s alt least not the way anybody like to go...

I have some very bad experience with a Z18 at work and I have to say for app. 8000€ euro they could buy at least 3 UM2 and would be more happy. My cvolleagues decided to go with a "industrialized" machine, but had up to now no really good print. further the closed SW makes some troubles too.

As usually, just my 2 cents...

 

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Prior to getting my UM2 I seriously considered the Stratasys uPrint Se Plus. I had some meetings and demonstrations and was very close to placing an order. Then I got back some trial prints with times and material costings. I could not believe the material cost. This just killed the project until I saw the UM2 at an exhibition. The Stratasys material, which has to be used on their machines, is ten times the price of the filament used on UM2 type of printers.

In addition to this, MMartin states that the material has a use by date once opened! I did not realise this and there was no mention of it at any point when being told about the machines by their reps. So glad I found out about the material costs in time and got the UM2. The material cost saving makes trial and error printing more feasible and more than compensates for a bit of messing around with the UM2 settings and post printing finishing.

Having said all of that, I get that MMartin is only trying to point out what can be learnt from the bigger companies and incorporated in the UM3 of the future. When I got the UM2 the second nozzle (for support material) was promised for mid 2015. This upgrade was a big factor in my purchase decision and I am very disappointed that it is not going to happen. So it is definitely worth looking at other good machines which do have two nozzles and see what can be learnt from them.

 

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Thanks for the detailed report MMartin! Very interesting insight for me - I've never seen a "pro" 3D printer before...

I know a thing or two about state-of-the-art industrial machines (made my apprenticeship in electronics engineering at Besi Switzerland, formerly Esec), but not 3D printers in particular.

Being an electronics guy, I'd mostly pick up on the differences here:

The Ultimaker (including most RepRap printers) uses a very low-end electronics platform. Sure, it works (and not that bad either!). But it's really a primitive thing compared to professional electronics.

An update here would be highly valuable, but takes considerable effort in firmware programming. The beauty of it is - once that development is done, the new platform won't cost much more than the old one. Imho this is just a matter of time. Shortly there will be further improvements in this field. Maybe already on the UM3? ;)

It doesn't take a mammoth-setup using a host-computer, a slave real-time computer, and high-end motor drivers for every driver. It just takes a bit more CPU power, better motion control planning & execution, and a clean stepper driver setup with good drivers.

The stepper motors used in RepRap printers are the ideal choice imho - they're cheap, and they do their job very well when they are driven by a good driver. Closed-loop is not necessary because there is no demand for higher motor velocity than what's possible with simple stepping. I don't see any benefits from 5-phase steppers. There is no demand for more accuracy, and none for more power.

Another necessary improvement is to get rid of NTC "thermistor" temperature sensors. PT1000 sensors are much more reliable and accurate, given you have a good measurement circuit.

EMI, ESD immunity and machine grounding are also very important considerations that the RepRap printers fail to address. Afaik, the UM2 made a lot of progress here, but it's not quite there yet.

Everything I've written about can be improved if enough effort and knowledge is put into the project. In the end, there won't be a significant increase in costs (there will be somewhat of an increase, of course). Just use different, more suitable parts.

Then there's the mechanical aspect - high-precision shafts (not regarding diameter tolerance, but straightness which is usually not specified, or not kept up to spec!), good pulleys, couplings, gearing and so on.

This is pretty simple - you get what you pay for.

And finally, there are all the little design details that make the difference - and make the reliability of the machine. Good hotend design, good material feeders and so on. These things are continually improving thanks to the open-source development scheme.

At some point, the RepRap printers will surpass professional grade printers due to one simple fact:

They are open-source, transparent (value to cost), understandable, modifiable, user-serviceable, and much more affordable. Just take the printing materials - 500 CHF FOR A SINGLE ABS CARTRIDGE??? That is 10 times more than high-quality material for reprap machines. 10 times is a lot!

Even if you can afford to buy one of these professional grade printers - you'll always have to calculate if it's worth printing a part or not, because the part will have a significant cost (not even mentioning that you need to replace build plates often).

The real beauty of RepRap printers is that you can just print something and wonder if what you designed works or not when you hold it in your hands. Then make 10 more prototypes until it works. Who cares? The process cost you only a few bucks...

 

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Another necessary improvement is to get rid of NTC "thermistor" temperature sensors. PT1000 sensors are much more reliable and accurate, given you have a good measurement circuit.

FYI, The UM2 uses PT100s, which is a godsend compared to the older methods.

 

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Build platform: The manual says replace it regularly, but in practise, it lasts a long time (not only printing twice).

The solvent for the soluble support is water based, not water. But not limonene either (which I find nasty). Anyway I think if it is saturated with plastic, it needs to be disposed of properly (not by pouring into the drain), so even if the solvent would be pure water, I wonder if you could pour the saturated solution simply into the drain.

Actually, it is much more difficult to build a €2k printer instead of a €50k printer. Only lightweight parts, low precision components, no fancy manufacturing. So one of the very interesting questions is: Can a top quality printer be built for €3k? (I mean with support material and out-of-the-box reliable printing)

Stratasys went the easy way for some design decisions. The Dimension Elite print head holds two massive extruder motors and a huge X drive stepper motor. I guess it's over 1 kg. This will cause high reaction forces on the base with vibration transmitted to the build platform. So they added a 100 kg base, the 1:100 ratio reducing the reaction displacement by 100. This certainly works, but it is kind of a sledgehammer design.

Interesting question: Will top quality printing ever work with remote extruder motors (not at the print head)? I think no as material control is too loose. The smarter way (talking of the Dimension Elite) would be to reduce print head weight. Use one instead of two extruder motors (there is a nice Stratasys patent on this) and have a stationary switching mechanism. Move the X motor onto the Y rails. Use smaller, higher geared (to improve motor efficiency) motors for the extruder.

Next interesting question: Will sticking to open loop stepper motor drive be sufficient? For XYZ it seems so. But for the extruder motor inside the print head, the power density of stepper motors is pretty low. A geared (BL)DC motor would be better here, requiring an encoder and closed loop motion control. But this might get expensive. Maybe a small, highly geared miniature stepper motor with 48V drive (or higher) might do as well.

A note on closed vs. open loop motion: Stepper motors can be reliably driven "open loop", which means there is no position feedback except for a reference switch. This is done by massively ovedriving the motor with a regulated current that results in a torque being much higher than the torque ever present in the driven system. Together with a simple linear accceleration profile, this is cheap, computationally simple and reliable. The drawback is the motor is huge for the usable torque and the slow speed, resulting in a low power output at high weight.

EDIT: The main problem is that forces in the system might be higher than planned. Dirt on a bearing, a misaligned axis... The other issue is that if something goes wrong with the step pattern generation (interrupt during move, software bug) and the resulting acceleration would exceed the available torque. In both cases you lose a step, possibly accumulating over time. So steppers are fine if everything goes as planned. You can add encoders to make them more robust, but this negates the cost advantage.

Torque at a given motor size is more or less limited by the magnetic properties of stator and magnet material, so the only way to increase power output is to increase speed. This is what DC motors do, running at up to 100000 rpm. This usually means gears (unless you want to build a dentist drill). In additon, a DC motor needs closed loop position control (which means an encoder for position measurement and typically a PID position controller). The advantage is that you can use all coil current for moving your system, not having to overdrive the motor so it doesn't miss a step.

Nowadays DC mostly means BLDC (or, close, "servo motor"), where the brushed commutation is replaced by a digital commutation, either six-step or field oriented control, depending on requirements. The bottom line is you get higher dynamic motion, higher power density for higher sensor cost (encoder) and higher computational complexity (PID position control, PI current control, FOC commutation, jerk limited trajectory generation).

I am with Jonny here: When can we get rid of the pathetic Arduino platform for control? Closed loop motion control (maybe FOC BLDC, maybe vibration cancelling) requires more computational power. I don't see a reason why a modern control system design does not use a Cortex M4F, take an STM32F4 for example (180 MHz single cycle floating point multiply...). On the other hand, for simple trapezoidal open loop stepper motor control, even a poor 8 bit controller might do.

Coming back to print head weight, UM2 is a clever design, in its way: By having the heavy extruder motor stationary, the print head is very lightweight and an enables the use of small diameter bearings and low volume/weight base parts, all reducing cost and keeping high tool path fidelity.

Another question: Will two fixed nozzles work? The Dimension Elite says yes, but it is built like a tank (reducing vibration), has a layer height of 0.18 mm (not 0.1), meaning increased spacing and a heated build volume, reducing warpage. Certainly placing the nozzles much closer to each other will help - why not 5 mm apart? This will reduce tilt sensitivity. Maybe given higher tolerances, more warping (unheated), more vibration, lower layer heights of a low cost printer will just not work without a nozzle lift. But this adds cost and weight and reduces accuracy.

And when we're at it: Will an open material (as opposed to fixed, maunfacturer provided) printer ever work reliably? I think no. The obvious reason is that for every material, the print parameters need to be tuned. But much more severe is the fact that maybe no pamameter set exists for making the mechanism work 100%. Remember what everybody writes after a failed print: "I probably need to tune the parameters a bit.". With a fixed material, the manufacturer would be forced to provide a working parameter set - and perhaps discover that no set perfectly works. Maybe other deficiencies exist, too much play in the drive system, too loose temperature control, too much material shrinkage... With an open material choice, this will hardly happen, as all deficiencies are masked by material variations. And here is the dilemma: Imagine the UM3 came with a closed cartridge (with desiccant and all), chip protected. I'd accept that (up to say double the material cost), provided prints work perfect with this. But I guess the community here would sink UM in a shitstorm.

 

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Concerning open material printing and parameter sets:

Existing recommended parameters from filament-manufacturers could be implemented into a well-updated software.

Some eventually influencing data like room temp could be added too.

Another thought, maybe still a little futuristic:

Today, a well experienced printer owner knows the needed parameters for the specific geometry of a model. The print will come out well. I read about people in this forum who reached a success rate of 90something percent.

In the moment (correct me if I'm wrong), software is able to create quite reliable support structures. I can't see why it should not be able to deep-analyse a model in a way that even considers variable parameters during print, like print speed or temp.

In fact, some complex models require exactly this.

Sorry for being a bit OT, cause this thread is more about the hardware.

Also sorry if I wrote complete bull...dung, as I know nothing about software...

 

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...

Imagine the UM3 came with a closed cartridge (with desiccant and all), chip protected. I'd accept that (up to say double the material cost), provided prints work perfect with this. But I guess the community here would sink UM in a shitstorm.

That would definitely be the worst thing they could possibly do ;)

If people would just not buy cheap-ass filament and instead use high quality brand filament, there wouldn't be that much problems about material profiles and all that. I've been printing several kg of different PLA colors from Diamond Age Plastics. There was never any issue at all. The stuff prints perfectly, just the way it's supposed to be. The very moment a manufacturer limits filament choice by making proprietary cartridges, you will have to live with what they feed you. Either it will be cheap standard material sold for a lot of money, or it will be good material sold for even more money. And what if at some point they change their policy and get sloppier with the material? You'll be helplessly dependent on them...

Seriously, just buy good filament. I'm paying less than 60 CHF per kg for the best PLA there is, (thanks to Dim3nsioneer's efforts ;)) and I know that I will never have a problem with it and get great print results throughout.

Hint to Ultimaker: Don't get me wrong, but if I were you I'd stop selling the filament that you have now. Either don't sell filament, or only sell the good stuff. You could team up with Colorfabb who have a good name (not a fan of their PLA personally, but lots of people are), and you're both based in the netherlands which would facilitate logistics... I don't know if you're actually making a lot of income with the filament or not, but I'd consider that as a necessary way to further improve your recognition of a "manufaturer of high quality 3D printers". Because that's what you are!

I've tried several rolls of UM filament (both ABS and PLA) and they were all low-grade. That's a pity because people will have a bad first impression of their new printer.

About building a 3k $ high-quality printer - I've actually been working on that for a long time now. It will probably be more like 5k$, but that's still much less than even entry-level "pro" printers. Progress is slow, because I have a daytime job to do, but I believe I'll be getting there pretty soon.

Right now I'm finishing a new interim electronics platform using Trinamic's new TMC2100 stepper drivers in combination with the standard Arduino & Marlin platform. The difference is promising (see here) and it's actually a very "cheap" upgrade. Cheap meaning it doesn't take much time to develop because it works almost the same as the previous drivers. The parts themselves are a bit more expensive, but still playing in the same league.

My next step will be a Cortex M3 (eyeballing the NXP LPC1789 at the moment) paired with an FPGA motion controller and TMC260 stepper drivers. But that's a completely new design, meaning it will take a long time to even become a beta-testing prototype...

Another thing about materials: I won't use ABS anymore. It's just not a good plastic. It's toxic, warpy, gives weak prints compared to PLA (as long as we're talking room temperature) or PET and it's a real pain to produce nice prints with. And damn it, IT'S TOXIC!! People are putting their open-frame printers on their desks and let them print for hours and hours, inhaling the fumes and nano-particles this sh%%t produces without thinking anything by it. A few years from now, this could turn into a serious shitstorm when people start getting sick... (or not, but I'm not taking my chances...)

Whenever my parts don't need to be temperature-resistant, I use my trusty Diamond Age PLA. For higher temperature stuff, I use Colorfabb XT which is a bit more challenging to print with (although most problems with it are solved) but gives extremely durable results. I can send you a print sample if you want to compare it to ABS ;).

Besides that, XT also doesn't cost more than 50 CHF per kg. (34 EUR for 700g iirc). It's limited in color choices (transparent is stronger than the new colored versions as I've heard), but still the best material for technical prints that I know of.

Both PLA and PET have very little warping & shrinkage, so that there is usually no need to take these factors into account when designing models. That is another huge advantage, especially if you're not an industrial designer and don't have access to professional CAD software that might help you with these questions.

/edit

Thanks to the free choice of printing materials in RepRap 3D printers, there is a lot of development going on. Carbon-fiber and even metal enhanced materials are sprouting, as are things like PA6 and POM. Who knows what more is to come in the next few years. This takes place while the big companies would rather like to sit by idly and let the customers buy their overpriced filament cartridges because they don't have any other choice.

/edit2:

Forgot to add the link above...

 

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Patents: I'd like to encourage you to look out for interesting patents. I'll give a short introduction - I'm no expert myself (in the industry, you always need a patent attorney, it's sufficient if he knows the fine print), feel free to add your own suggestions.

Reading patents can be fun. They are a treasure trove full with ideas that were deemed working and bring some benefit. Although some might seem cryptic at first, this is not intentionally so. In fact every patent must be a blueprint from which the average but non-inventive ("skilled in the art" is the legal term) Joe Engineer can build your invention.

How are these finds relevant? Of course it means no commercial machine can use them, so you can trim down your UM3 suggestion list. But noone prevents you from experimenting yourself, create a single motor dual extruder head, a tip cleaner, a filament box with desiccant... An interesting question (again) is how far one could "approach" patents. Let's consider the heated build chamber. UM can't sell this because Stratasys holds the patent. But UM could prepare the machine for it - make everything inside temperature-proof, add sensors and relay outputs for the heater, maybe even (as accessory) a hood in Makerbot Replicator 2x style. Fans, sensors and heater would have to come from a different source (Farnell, Digikey or an affiliated reseller). This would be no direct patent violation, but might be asking for legal trouble. Or the tip cleaner: Provide mounting holes and a check box for path generation in Cura, but leave the rest to the customer...

My favourite access is the European Patent Office "Espacenet" patent search (just type "espacenet" in google). Go to the Advanced search and type "stratasys" in the Applicant field. In the worldwide data base, this gives you 515 patents. Many are duplicates in different countries ("patent families"). You can narrow this down by entering "US" in the publication number field, but some US patents don't have the full data in the database - try a "also published as" patent, preferably an european (EP...) one.

The quickest way to get an overview over mechanisms is by looking at the drawings. From the patent list, hit a few times "load more results for export" and press "Download covers". This give you a list with all covers you can flip through.

Also, when you opened a patent from the result list, select "mosaics" to get a overview over the drawings. You can press "next" on this page to flip quickly through the result list.

It's a bit hit and miss. Keyword search might work or not because for example Stratasys speak is different - "liquefier" means hotend for example.

Interesting patents: See the list at Scott Crump's Wikipedia article

Purge towers

Head tool changer

Single motor dual extrusion head (nice)

How to handle moisture sensitive material

Tip cleaner

Other finds?

 

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Tools: I found the patent list a bit depressing. There's tons of great ideas, but none will make it into an UM! So here some ideas on what can be done, specifically what tools are worth using in development. I hope this does not go too far OT.

With any motion system, the question is how closely the "tool" follows the path you commanded. For an UM style layout, it's the position of the nozzle via the topmost layer of the print on the build platform. All mechanical systems show play and vibration. If after a move, the build platform wiggles too much, it might collide with a (2nd?) nozzle and rip of the print, or it might give you zigzag surface patterns.

Generally industrial sensors are expensive, but an engineer costs a firm easily a six-digit figure per year. It's an easy calculation how much time he can spend on building measurement tools himselv vs. buying them off-the-shelf (making such stuff is often apprentice work - they have fun and need practise projects anyway).

High speed camera:Together with a macro lens a great tool for seeing what's going on. Some compact cameras offer super-slo-mo and there's a startup trying to lower costs. Expensive otherwise.

Capacitive distance sensors: From Micro-Epsilon and such. Typically you measure settling to a fixed positon, connected to a scope. If it must be DIY I'd look at CDCs from Analog. Also an option for DIY are slotted photointerrupters. Depending on beam width, you get an OK resolution, but only a very short useful range.

Acceleration sensors: Have the advantage they need no counterpart, but can't measure relative movement. Brüel&Kjaer is the Rolls here, but there's tons of MEMS sensors from smartphones that might work as well. Note that double integration of the acceleration gives the displacement.

FEM (modal and static): Finite element is the method of choice for analyzing stiff structures. I guess an FDM printer is a poor application as it mostly consists of bearings and drive belts - lots of play, generally nonlinear and unknown stiffness parameters.

Motors: Open loop stepper drive is rather easy and seems to be no problem. If you still think you are using steps, you can connect a logic analyser to the step signals (like a cheap saleae logic), record a ten hour print and then write a python script to sift through the data and check for glitches or too high acceleration. For debugging, you can even connect a high-res encoder to the motor in doubt (Nanotec provides this as an option) and log those signals with the logic analyzer as well. You can then measure the actual motion of the motor and compare it to the step signals.

Simulation: For anything more complicated than open loop profile generation, Matlab/Simulink is invaluable. If you want to get started with BLDC FOC for example, it's great to play through in simulation. You can simulate play, encoder resolution, sampling time or whatever and see how the final system would work even before starting it. Consider this question as an example: Let's assume we want to place the extruder motor into the print head. As it has to be lightweight, we use a DC motor (say from Maxon if we ignore the cost) with a multi-stage planetary gear. As it is a DC motor, we need a closed loop control. Where do we place the encoder? At the motor shaft - the gear has play so we don't know exactly what the output does. At the extruder wheel? This might be problematic control-system wise because of the play...

Having mentioned "

again). I wrote Stratasys went the straightforward route with the Dimension Elite. They made the system stiff enough for the required dynamics, ending up with a 120 kg machine.

 

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"Although some might seem cryptic at first, this is not intentionally so" <- Yes, yes they are. they are intentionally vague in order to 'catch' uses of the technology that the author did not think of originally. This is why, if you want a patent, hiring someone with experience is a good idea. This wil generally allow you to get away with patents that are just vague enough that you 'catch' more, without being to vauge so it could be invalidated by a judge.

Also; A normal consumer is alway allowed to use the information in a patent, as long as you don't sell it. A patent gives the ability to prevent someone from selling your invention, not someone from making it (and a patent does not give you the right to be able to sell it either; which can cause problems in some cases).

As a final note, always keep in mind that patents get public after 1,5 years in europe. This means that there are -tons- of patents that are basicly mines; You give an idea to the office, that date counts. Once you see that someone uses 'your' idea in that time, you pay the rest of the fees in order to sue. If noone uses it, simply don't pay and noone gets the patent.

Patens are a horrible piece of law that forces everyone to use these kind of tactics.

 

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Just because it's published somewhere does not mean it's accepted as prior art. Not everything on the internet is accepted as prior art; it needs to be distributed enough (in order to prevent modifiying the dates afterwards).

I'm not sure if github is enough to be considered as prior art, so you would have to be carefull with that.

 

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