RepRap Prusa Mendel Iteration 2 Complete 3D Printer Kit

I'm only at step 15 in the video series describing how to put the thing together. So far I'm happy with one exception. The parts have changed since the videos were made, I've been able to get around this so far. Step 14 had me stymied today (a Saturday) so I called the support number. To my surprise I actually got a person on the line. He was able to point me to a few pictures to help me out and I did make it through to the next step. I would give 5 stars for the experience so far however there needs to be documentation included for the places the videos differ from the currently shipping version of the kit.[Edit] I've completed the build using the videos as my guide and had to call support a couple of times. If you get this kit note that the RAMPS 1.4 connections are not shown in the videos however they are pretty straight forward and looking at some pictures and the wiring diagrams I was able to get it hooked up. Every time I called support I got a human being, which is a GREAT thing these days. I think I blew up the motor controller board (because I wired the power supply incorrectly, make sure to use the square plug wires with two green wires and two black wires from the PS) so I'm about to find out if the 90 day warranty is correct. It took me five days from start to finish working through several steps per day.[Edit 2] The new RAMPS board is on the way, they gave me no problems at all with the replacement so I'm changing my rating to 5 stars.[Edit 3] I've found that putting blue painter's tape on the heat bed glass fixes many issues. The glass I got with the kit was warped so I went to lowes and picked up a small piece of flat glass. The thermistors are tiny and fragile, I replaced mine with larger REPRAP thermistors (had to drill out the hole on the J-head hot end). I've run into a lot of issues with my printer but this isn't due to this kit, it is due to design flaws and #D printing still being in the early stages. I still recommend this kit just be aware you WILL have issues and you will have to work through them.

All the parts were there in the kit except for the measuring tools (but that was easy enough to make). None of the printed parts were labelled so it took a while to determine what everything was. Also, some of the printed parts were not printed correctly which made the building process much longer and frustrating at times. I had to modify some of the parts to make it work which required a lot more tools than expected. Additionally, the videos they have for the instructions have some different parts to the kit but if you identified for the beginning what the parts were, it was easy enough to follow along. I would recommend getting all the tools you will need which the video does state what to have. In the end, it was a lot of fun!

I bought this printer kit because it was available for immediate shipment. I had been considering the more expensive Makergear M2 kit, but they were back ordered for two weeks, plus it was more expensive.That said, the Prusa Mendel Iteration 2 from NWRepRap arrived as promised. I generally prefer to work from written instructions, but I was able to assemble the printer using the on-line videos from NWRepRap without the need to call factory support. I was able to figure out the differences between the machine shown in the video and the kit I was shipped on my own.The most difficult part of the assembly was leveling the bed. I discovered that the threaded rod frame is not that rigid. The printer must sit on a flat surface for good results. The instructions for leveling the bed did not work well for me. I got the best results by laying the glass on the heat bed but not clipping it in place. Next I did a rough adjustment of the Z-axis limit switch. Then I moved the carriage to each corner and adjusted the nuts on each corner of the red heat bed until the glass was just touching the hot end nozzle and a bit of resistance was felt when sliding the glass a bit. If the settings were not correct when going back to a previous adjustment, it meant that the surface the machine was on still was not flat enough.To get USB drivers that worked, I had to go to the Arduino web site and download drivers from there, the drivers on the NWRepRap site did not work. HOWEVER, the later version of the Ardunio software itself would not compile the code. So I used version 0022 from the NWRepRap site and I was able to configure, compile and upload the firmware to the Arduino board without further problems.The shaft couplings for the Z axis motors were problematic. The plastic tubing kept slipping off the motor shaft, spoiling the print and one time causing the print head to crash into the glass. Fortunately the tempered glass did not break. I had better results using the outer jacket stripped off a piece of RG-6 coax to resize the Z-axis motor shafts. That got the machine working long enough to print out better Z axis couplings that I found on the Thingiverse web site. The rigid couplings from Thingiverse do require more care in adjusting the Z axis lead screw alignment so that they won't bind.As assembled according to the video, the machine has a print area of 180x200x100 mm. I needed a 130 mm height for one of my projects. I tried printing the object on its side, but that did not work well for the cylindrical portion. I reassembled the machine with the Y axis smooth rods under the support rods. This configuration gives a 180x120x130 print area which so far is adequate for my needs. In the future, I may use this machine to print the parts to build a Prusa I3, then use the stepper motors and metal parts from this I2 to build a complete I3 which has a print area of 200x200x270 if built with a box frame.The most critical thing that I have found to get PLA prints to stick to the glass is the Z axis limit switch adjustment. A fine adjustment can be made by rotating the switch on the rod it is mounted on after moving it up and down for coarse adjustment. It is better to err on the side of being too close, even though this will make your object a millimeter or less "shorter".Small parts will distort during the print, because the previous layer does not have enough time to solidify before the next layer is placed. The best work around that I found for this problem is to print two parts at once. The software prints a layer on the first part, then moves to print a layer on the second part, giving the first copy a chance to cool before the next layer is applied.Bottom line: This is a good kit to get started in 3D printing, but the technology as it stands today is still a bit of a "hot house flower" and it takes patience and fiddling to get usable prints.

The printer never worked. The owner kept sending me replacement ramps boards that either did not work or kept frying itself. The printer ended up destroying a perfectly good laptop, as well as costing over $800 in repairs on a desktop as well as destroying itself. The 90 day warranty ends immediately after 90 days regardless of issues. No effort was made by the owner to fix any issues or reimburse the cost of damages caused by the printer. The kit that was ordered came with numerous parts that were wrong and/or broken, and the advertised filament on the website was the wrong size filament for the extruder being sold in the kit. $2,000+ and 4 months later, I still only have a doorstop. Would not recommend this manufacturer.Edit: I forgot to mention, the printer also caught fire at one point.