Trying to decide on the Ultimaker 2 - some help please

[yellowshark 153]

Hi, a newbie here. I am on the brink of buying an Ultimaker 2, I am just awaiting prints from some .stl files I have sent to Ultimaker for final decision making. I have a few questions.

 

1. I have searched everywhere but cannot find a specification document or comments as to the extruder size, i.e. 3mm or 1.75mm? If the former can one successfully feed 1.75mm?
   

 

 

1. If no, is the size mandatory or is it optional, to be specified at order time?
   

 

 

1. With the research I have done on 3D over the past couple of weeks I get the impression that for PLA you want an open design to aid cooling and for ABS a closed design to maintain a consistent temperature.
   

If that is the case than how does Ultimaker 2 fare with PLA? Does one take off the 4 side panels?

 

1. Does Ultimaker 1 have two fans for the cooling? What does Ultimaker 2 have?
   

 

 

1. I am confused about retraction. I can understand physically what it is but I do not understand why and when you would use it?
   

 

 

1. I wonder if there are people on the forum who have experience in other print methods, e.g SLA, DLP and have either moved to FDM or use multiple methods. How have you found working with plastics?
   

 

 

1. Can the Ultimaker 2 work with nylon?
   

 

 

1. Is there a detailed specification document anywhere? I cannot see anything on the website.
   

 

 

1. Finally and this may be a bit controversial but I hope I can get some objective opinions. One of the comparison reviews I read noted that Ultimaker had a great and active community. I have been following the community for the past week and have learned a lot and have been very impressed by the tenor of the forum and the wealth of expertise that is has.
   

On the negative side though and almost unavoidable, I been struck by the number of people and the number of problems they have experienced. We are a start-up company and will be producing product. My son is an engineer and I have years of experience in software development, so we have no concerns about getting the system up and running and optimised. We realise and plan to start with a testing phase to determine the optimum settings for the PLA/ABS materials we intend to use, i.e. the specific product coming from a specific supplier.

 

But once bedded in I do not want us to be spending 5 hours a day solving problems when we should be producing. From the forum I have started to harbour some doubts as to whether the machine is up to production work or is the reality that it will fall over most days?

From personal experience I know that on technical forums you will always get these “negative” subjects, that is what the forum is there for; there just seem to a be lot of them!

 

 

Thank you

Pete

 

[gr5 2,072]

 

1. I have searched everywhere but cannot find a specification document or comments as to the extruder size, i.e. 3mm or 1.75mm? If the former can one successfully feed 1.75mm?

 

 

1. If no, is the size mandatory or is it optional, to be specified at order time?

 

For UM1 and UM2, the feeder only takes 3mm filament. In fact 2.9mm is ideal as 3.1mm is too wide for most bowden tubes (the tube at the top of UM1 and UM2). The nozzle hole diameter is .4mm which is maybe a more important specification.

People have gotten 1.75mm to work in UM1 but it requires changing many parts. Some people have done it with stock UM (no changes) but it doesn't work very well.

3mm filament is easy to purchase and available at many places around the world and in many types of plastic (PLA, PLA45 PLA90 ABS, flexible PLA, much more).

 

[gr5 2,072]

s I get the impression that for PLA you want an open design to aid cooling and for ABS a closed design to maintain

 

ABS is difficult to work with because it shrinks more than PLA. This sounds simple but causes many problems. PLA also shrinks but not as much. PLA45 doesn't shrink. One way to deal with shrinking is with a heated chamber so that the shrinking isn't occurring as much *while* you are printing but after you are done. A heated chamber helps both PLA and ABS but isn't really needed for ABS. An open chamber is helpful for being able to see what is going on and so that you can reach your hands in from more directions. But an open chamber is not necessary.

Also there is a patent regarding a heated chamber so even the UM2 comes without a front and top (you have to build your own).

The side panels on the UM2 appear that they might be easy to remove but I'm not sure.

So a heated chamber is not bad for PLA other than being able to stick your hands in more easily if it is open.

 

[gr5 2,072]

Does Ultimaker 1 have two fans for the cooling? What does Ultimaker 2 have?

 

UM1 has a single fan that cools the part. Most importantly the top layer. It is controllable in software.

UM2 has 2 fans for the same purpose plus a third fan inside the print head to keep the heat from travelling up into the more sensitive parts of the print head.

 

[gr5 2,072]

But once bedded in I do not want us to be spending 5 hours a day solving problems when we should be producing.

 

fyi - I don't work for ultimaker. I just own one.

Shouldn't be an issue. The printer is complicated and you will have many problems with it at first. There are so many issues. For example you can clog the nozzle if you leave the nozzle hot without printing for an hour. Or the fact that levelling is amazingly important and takes a long time to really get it in your head how perfect it needs to be and how printing too high or low by .1mm can mess up the bottom layer of your print.

So it is frustrating for some people. For me it was just a puzzle to solve.

And everytime I think I am a master at this machine I try some new part that has all new challenges. But if you keep printing similar parts you will have all the issues worked out within a month. Of course if you change to ABS you will have to learn all over again.

The UM2 will likely prove to be much more reliable both in electronics and in the feeder mechanism and ease of levelling and consistency (wood platform droops lower from day to day whereas the steel one I'm sure won't).

 

[Nicolinux 288]

Pete, if you need another point of reference - here is my experience with the Ultimaker 1.

I have this machine for roughly 2 months now. I spent the first few weeks exclussively with tuning. While frustrating at first, it payed off afterwards. Right now I have a few remaining problems (z-stage and issues with blobbing) but comparing with my experience with another printer and looking at some pictures of objects made by others on Thingiverse, I'd say the Ultimaker is an awesome machine once dialed in.

As George said (and by the way - he and Simon (illuminarti) are a great help here on the forums), if you print the same part over and over again, you will find the optimal settings pretty soon. The most important concept to grasp is speed vs. temperature.

Regarding the spec sheet for the Ultimaker 2 - that's what I'd also like to see. I guess the Ultimaker folks are very busy right now to prepare for the new release, but they will surely release it soon.

 

[yellowshark 153]

Thanks for your advice guys, most helpful.

Nico (?) when you say speed vs temperature, could you expand on that please.

My understanding is that reducing the speed used will reduce problems and increase quality; additionally one should be printing at an optimum temperature for the material. But I have not considered how the temperature is controlled.

Is it “controlled” by the speed used or is there a thermostatically controlled heater in the printer?

 

[gr5 2,072]

I think nico is referring to the fact that if you print too cold *or* too fast, you get underextrusion because pressures are too high in the nozzle.

It is true that lower speed tends to result in better quality mostly because of extrusion control. Every time the movement accelerates, the extruder accelerates at the same rate but because of delays you get slight under extrusion when accelerating and slight overextrusion when decelerating. This is minor but makes a slight difference in quality.

Anyway you will learn all this after you play with your printer and have watched it print for hours on end.

 

[LePaul 315]

Pete,

I've posted a great deal with my kit, build and subsequent frustrations along the way to getting quality prints.

As others have said all along, 3D printing (rapid prototyping) isn't turn key. While many will make it sound like you simply load the PLA/ABS material and just go print, I've found that isn't the case with any of them. When I bought my Ultimaker kit, my friend ordered a Solidoodle 3. His arrived, assembled and ready to go. He was up and printing before me but has had a number of issues and malfunctions along the way. The support he receives from them is essentially a short sentence and that's it. Here, I can go directly to the forums or post a support ticket.

I wish I had gone with the assembled kit, and had I known the Ultimaker 2 was waiting in the wings, would've bought that.

However in hindsight, building the printer has helped me understand it, learn how it functions and be less wary (i.e. scared) to get in there and adjust things. I'm an IT guy who deals with mainframes, servers, desktops, etc...but I was really leery of building a 3D printer out of wood, a stack of stepper motors, belts and pulleys. I've had all sorts of interesting issues along the way and managed to get thru them.

Since you are leaning to the Ultimaker 2, it would seem a lot of the hurdles you have read about will be reduced since it comes pre-assembled, heated bed and many enhancements from what us Ultimaker 1 owners have. Nancy has been posting a lot about her experience with the one she has had on loan for the past few days.

What sold me on the Ultimaker was the print quality and also the community support. I followed these posts for months and while I had concerns like you did, I was intrigued and impressed how many minds came together to resolve and improve the product.

 

[Daid 304]

Nancy has been posting a lot about her experience with the one she has had on loan for the past few days.

 

It's not on loan, it was a preview model sold at NewYork. 5 UM2 machines where sold at NY. These where from the "zero series" intended for demos, they miss some minor things like a few stickers and will need a firmware update soon.

They where sold at NY because people really wanted to have them, and they could not wait. It was also crazy expensive to ship them back, so double win for all of us.

The UM2 is quite a step up from the kit. But as LePaul says, I do not think it's 100% care free printing yet. However, the forums and our support desk are ready and waiting to assist with any problem.

 

[nancy 8]

Yes and no. The Ultimaker 2 I "have" actually belongs to a friend of mine who purchased one of the prerelease units at Maker Faire. I'm printersitting while she's in San Francisco.

And regarding the original question, I'm posting a lot because I find the people here really responsive, knowledgeable and nice. It shouldn't be misconstrued that there are so many issues with the printer, at least as compared to other models. The bed is staying fairly level which is a step up from the UM1 that I borrowed for Maker Faire, though that UM1 was in a pop up store printing nonstop for 6 months. Come to think of it, I sure borrow a lot of printers! The extruder isn't jamming and cutting into the filament, which is a problem I've found with other machines. The factory default settings that come with Cura actually prints very accurately!! That's the best part for me. I printed a 3 piece flute and I didn't have to readjust the flow setting, temperatures, or any of that stuff to make sure the pieces fit.

All that said, what do you intend to use the machine for? You can "producing product" but I have no idea if that means you are expecting one day turn around on these machines, or whether your printer will be used for prototyping. If prototyping, the accuracy is definitely a plus. If you are expecting to churn out batches every day, that's a different story.. it also depends on if the products you churn out every day are the same or completely customized one-offs. Generally, I find that after a week of getting to the know these printers it gets a lot smoother.

 

[yellowshark 153]

Hi Nancy

What do we want to do? Well two markets. First is prototyping, for local engineering and manufacturing companies. Certainly we will use the UM2 initially but medium term I am sure we will go further up the range of printers. Speed i.e. turnaround and reliability will be major factors in developing/maintaining such a customer base and I do not think you can achieve that with printers at the price point we are talking about.

Our second area is niche consumer products and yes I am planning that we will produce every day. But each print job will be to a single custom order; customisation is predominantly by colour although one product is customisable by height, although the profile stays the same.

In essence once we have the optimum settings for each product then that is it, as far as I can see. There is certainly an element of risk here as we are unlikely to hold stock, but we have some techniques in mind to control demand, will be building some failures into our production capacity planning and hopefully within the first month or so will buy a 2^nd UM2 to give us back up.

 

[yellowshark 153]

Bump

I am confused about retraction. I can understand physically what it is but I do not understand why and when you would use it or would not?

Also I have just realised I do not know what the connection is - nothing I can see on the web site. Is it usb from the computer? Standard size or mini size connector at the printer end?

Can one also use a USB stick or card reader?

SD card?

 

[gr5 2,072]

Retraction: You just enable it in Cura (the slicer) and you don't have to worry about it. Depending on your part shape a layer may have islands - for example if you print a chair, while it is printing the legs, there are 4 distinct areas of printing with nothing between each leg (until you get to the seat part). If you don't have proper retraction, some filament leaks out while the print head is travelling to the next lag and you get a thin "string". The strings are usually easy to remove but quality is much better if you get no stringing in the first place which is quite possible with retraction.

connection: The um2 has a usb port on the back which you really don't need to use except to upgrade the firmware. But there are 2 ways to print: through usb or though SD card. The sd card method is strongly recommended. So you put many parts on the SD card (thousands?) as needed and you can have folders on the sd card to organize it. Then you select the item to print from the front of the UM. If you need a new design then when the UM isn't printing, you remove the SD card and put it into a "real" computer and copy the design onto the UM card. The "real" computer can be running linux, windows, or mac operating systems.

Alternatively you can never use the SD card and always print through the usb port. This isn't recommended as you need to keep your PC running all the time and if you crash the PC, the printer will stop printing also and it's tricky to continue (but possible).

The USB port can be useful for debugging things (I rarely do this). Like if you want to move your z drive up and down by 10mm over and over for some kind of test or calibration, it would be much easier to do this from a computer keyboard than from the knob on the front of the UM. But it really isn't all that bad to do from the UM knob.

 

[Daid 304]

(Small extra comment on the USB printing. If you select the UM2 in Cura, it defaults to "never USB print". As we found USB printing to be too unreliable for the UM2 target audience)

 

[yellowshark 153]

Thanks guys that is perfect for us as I suspect the design PC may not be co-located with the UM2.

Thanks for the answer on Retraction George, understood. Are there any disadvantages in leaving it turned on - just wondering why there is a parameter for it if one would always have it turned on.

 

[gr5 2,072]

>why there is a parameter for it if one would always have it turned on.

Well it's slower. The printer stops, retracts, moves, then stops and unretracts (primes?). It can add about 1 second to every move across open space. For a two column object that's no big deal. Printing a hair brush with 300 bristles would add significant time. Some people don't care about the strings so much. If you are printing a part that is hidden within some mechanism maybe you don't care. And printers without the bowden tube (basically I think all printers other than the Ultimaker) don't need retraction as much.

Personally, I always keep retraction on.

 

[Nicolinux 288]

Another alternative for printing is OctoPrint. This is a small application that can run off really cheap computers (like the RaspberryPi). It has a very nice web interface where you drop the .gcode files (Created by Cura) and start the print process. It also has support for webcams which is perfect if the printer isn't at the same location as the computer.

Cura and OctoPrint are somehow connected. The developer of OctoPrint uses an Ultimaker and also forked a part of Cura.

 

[umuser 0]

What is it about a bowden that makes retraction more needed?

 

[gr5 2,072]

With the UM you have the feeder mechanism pushing on the filament from the back of the machine and then through the bowden tube. Most machines have the feeder mechanism on the print head. This is the biggest difference between UM and other printers. It means the print head weighs much less and can move much faster. The downside is that when the feeder stops turning, the filament still has pressure from the pressure/flexing of the bowden. Like a spring. But you can undo that pressure very fast with retraction.

Non UMs benefit from retraction also but don't need the feature nearly as much.