I have just been playing an evening with an Ultimaker2 I'm fixing for someone else.
I have been building and using Makerbots from the first Cupcakes up to the Replicator 2X's
(I have several of them in my lab)
I though I'ld share my impressions, as I liked the Ultimaker 1 but had heard mixed reviews on the Ultimaker2:
-I like it! It's beautifully engineered.
With the Makerbots the next versions have not always been improvements (the 2X has lower quality bearings than the 2's and more backlash. The Replicator 1 print head was more reliable than the newer ones)
This is definitely not the case here: this is the same design, but better.
-I think marketing this as a 'trouble free' printer is a mistake. nobody has been able to deliver on this promise, and it is the reason I had heard some nasty things about this printer.
-I love the fact the company sticked to their story and has open-sourced the U2. It's all there on Gitbhub: solidworks files + a BOM. I'm a fan & converted.
-at first I didn't like the fact that everything was hidden away. To reach the steppers you need to remove some panels. This turns out to be trivial as everything can be disassembled easily. The print head looks too slick & delicate to my taste, but disassembles by removing the 4 main screws. Elegant.
-in general it is easier to disassemble and repair than I had expected based on the pictures I saw and the reports I had heard from other people using them.
-temperature settings are not done in Cura, but are set in the machine per material. I found this annoying and weird. However, I considered that this means you could print a single file on the SD-card with whatever material is loaded, withou regenerating the file. That is a nice feature.
-I have been printing with PLA and ABS and find the default settings for both materials a bit strange:
-PLA has the build platform set for 70°. I always had good results printing on cold blue painters tape, and so did the Ultimaker1. So why change this? Heating that bed takes a long time. For small parts this significantly increases print time.
-ABS has the cooling fans on. They shouldn't be. I find the default settings cause warping in flat prints. I turned of the fans, and increased minimum layer time to 25 s. This gives much better prints for my test objects
-ABS has the temperature set to 260° I've always printed at 230, and don't see why it is set so high.
-I don't like the fact that the LCD does not show actual temperatures for the bed & print head. You can monitor it in the 'Tune' menu but I'ld rather see it on-screen.
-though I always liked the Ultimaker 1, I decided against it for my lab, as we need high-strength parts for our robotics classes. I wanted to have the ability to print ABS.
If I would compare the Ultimaker2 to the Replicator 2x today, I would say the U2 is a better designed machine (easier to disassemble, lighter, better focussed design), with better parts (no plastic cantilever arms, no cost-savings on bearings, better cable harness,better high-temperature capability)