New Build - First Thoughts  

New Build - First Thoughts

First off, I'd like to thank the Prusa team for a quality product. Everything is well thought out. I love the assembly handbook and the 3d printing handbook. I also really like the attention given to wire routing, it really makes it look much better. The customer service has also been excellent.

That being said, I do have some comments I'd like to make regarding assembly instructions and design. I'm not complaining, just giving some constructive feedback.

I got hit with a COD duty tax from UPS when the kit arrived. Obviously, this depends on the country you live, but I had totally forgotten about duties. US customs charged $18.57, and UPS charged a $7 disbursement fee. So Americans, keep this in mind when you buy a kit and have your checks ready.

My first issue with the instructions is that there is nothing in the text or pictures to differentiate the y-stage motor and endstop. Unless you read through the rest of the instructions thoroughly, you might not notice that each motor is different and so is each endstop. Choosing the correct one is explained in all the later sections but the first. I some how choose the right motor (20% chance!) but I choose the wrong endstop and had to take it off and replace it with another.

As far as required tools go, it's great that you include the necessary ones with the kit, except one that is very very important, a ruler! I also cringe when using pliers to tighten hex nuts. The M3 nuts are 5.5 mm, so I used a 7/32" socket instead.

I was going to say that the pictures didn't match the text in Step 4 of Y-Axis, but I see that has been remedied!

The smooth rod doesn't seem to be as smooth as I would expect it to be. If you run your fingernail across it, it will feel very rough, and your fingernail will catch. Good quality rod is cheap, and should be ground to a smooth finish. For example, Misumi sells identical smooth rod for $10 each, and it's ground to a 0.4 micrometer finish! Realistically, this probably doesn't make a huge difference toward the finished product, but I would expect smoother rod to last longer and be quieter.

I found when inserting the belt into the holder in Y-Axis Step 32, it was helpful to put one tooth in the middle of the holder so that I could get easy access from both ends with a screwdriver to push the belt into position. It also makes removing the belt much, much easier if you screw up.

I'm not a huge fan of the Y-Axis motor mount. The belt tension puts a moment on the motor, and the mount can't react it, so it rotates. A better design would add a 2nd leg that also slides on to the threaded rod and triangulates the mount. The simplest way to do this would be to simply slide a piece on that shares a face with the rear of the motor, so it can't rotate. Again, probably doesn't affect the finished product much, might impact belt life by putting the pulley at an angle to the belt.

I don't agree with putting all the parts on the frame first in Z-Axis Step 4. The rod is a tight fit as it is, and if you put those on first, you are forced to insert the smooth rod at an angle later. I found it much easier to only attach the bottom printed parts to the frame. Then I could slide the top parts onto the rod first, maneuver them into position, then bolt them to the frame.

Z- Axis, Step 14 - what is the purpose of the heatshrink?

I would add another step to Z-Axis that says to measure from the X-carriage to each Z endstop. That way you know the X-carriage is exactly horizontal.

I also plan to print and add a shroud to the extruder fan. It will add a few grams to the extruder, but it will protect the fan. I was trying to grab some ooze off the extruder and managed to hit the fan with my tool, breaking a few blades off in the process. It still works, but makes nasty sounds.

The slots in the printed LCD supports were too small to get over the PCB. I ended up taking a piece of sandpaper and sanding down the slot until it was large enough to get on. It was due to a print defect, not a design defect.

Depending on the print and the speed, the heatbed sometimes struggles to keep up to temp (I had this problem printing Marvin in a large room). I plan to build an enclosure to keep it better insulated.

I'm also kicking myself that I didn't purchase a 2nd piece of glass with the kit. They are so cheap, and it would really speed up printing if I didn't have to wait for the glass to cool each print.