Friday, May 25, 2012

Printrbot arrives...

Yay, my printrbot has arrived.  At the end of last year I came across a neat kickstarter project by Brook Drumm for a simple 3D printer.  I was ready to get a Makerbot at the time (which looks quite good and has been refined a lot over time), but there was something about the way Brook wanted to do the project that appealed to me -> so I decided to back him.

The project ended up drawing a lot more interest than he originally expected...  This is a great thing when starting this type of business (more customer interest, more initial capital) but it meant that everything had to be scaled up fast.  Of course this led to delays in the kickstarter rewards, but so what... the goal is to get a business off the ground not to get rewards out fast.  It's been interesting to see how Brook and the community as a whole communicated about the changes in the design, the release of information about business decisions, design files, product revisions, assembling the printrbot, and of course the very few complainers about the delays.  I'm rather pleased with the way things  have developed and think it's likely Brook will end up with a nice little business and a happy community of customers.  There is an unofficial discussion board at that has been very helpful.

Opening the box is always interesting... Every company has a different character in how they pack things, and how the quality control is done before shipping.  I knew there would be a lot of light objects and a few heavier ones and that if the packing was wrong lots of damage could occur in transit.  Happily they did a very good job - exactly the right type and size of packing material and positioning of parts - there is no way to tell after opening if the box and actually shipped across the country or just sat on a table... perfect.  So let's see what's in the box...

There are a few lasercut pieces.  The larger one is for mounting the heated build platform (attaches to parallel rails on one axis and drive belt connectors).  The two smaller pieces are used to mount the electronics board.

A standard atx power supply.  Not exciting, but it will be fun to look at the quality of the output later.  Sometimes they can be unexpectedly good, sometimes not.  This project shouldn't come close to pushing the limits so it ought to be fine.

A big spool of ABS filament (about a pound I think).  The motors are off to the left - nicely wrapped in foam.

There are 5 motors in total.  The two smaller ones are wired together (z-axis intended to run in parallel).  All have connecters already attached - connectors look good.  I'll measure the resistances later.  All five turn nicely and the detents feel good.  (with the parallel wired little ones a cute thing is that turning one by hand will cause the other to turn as well).

The heated bed (6 inches by 6 inches) is already wired with a connector.  I'll measure the resistance later - it's a long pcb trace as a resistive heater strategy.  Board is very flat and not warped - mounting holes in each corner.  There are also 3 endstop switches and a thermistor already attached to individual connectors.  Solder joints are good but no heat shrink - not certain why but maybe there is a reason I will discover later.  A couple of extensions for the extruder finish out this bag.

This little bag has 6 bearings (they look like standard skate bearings), 25 little zip ties and 5 pairs of linear bearings for the smooth rods.  The packing list says 11, but there were only 5 pairs.  It's not a problem since there are only 10 needed in the printrbot.

In the white cardboard box we have a jumper (I think for enabling the atx powersupply), a usb cable, a spare extrusion nut, the hot end and the electronics board.  There are two connectors on the hot end - I think one for the heating element and one for the temperature sensor.

There are four 10 inch threaded rods, two 8 inch threaded rods and six 10 inch hardened steel rods.  It's always a good thing to check whether the cut threaded rods are straight (all six were good).  It's also good to run a nut down the threads to see if there are any binding areas (all six were good).

There are lots of little hardware pieces: screws, nuts, washers, strings, tubes and belts.  Everything matched the packing list.  When I have lots of parts I prefer to lay them out on paper with labels - of course as I build things get all messed up, but it helps when making certain all the parts are present.

The printed plastic parts are of a better quality than I expected.  There doesn't seem to be a lot of cleanup needed.  The side that was on the heated print bed is a bit shiny and a few have little bubbles on that surface - nothing to cause a problem. Here we have two base pieces, a mount for the extruder, a mount for the carriage, a mount for the motor (x-axis I think) and a mount for the idler.  They all seem to be both lighter and more rigid than I expected.

This group of printed parts is interesting.  The most complicated piece is the extruder (top center).  There is another piece right below it that helps tension the filament into the extruder.  There are two herringbone gears, two drive belt gears, a bearing mount for the y-axis I think, a mount for a limit switch, two belt clips, two pairs of sandwich clamps (I think for the z-axis) and four clamps (3 the same, 1 with a slightly longer segment and an extra hole, I think for mounting the bed to the rails.

Now we know what came in the box and checked everything off the included BOM (missing one unneeded bearing) -> we can start to build.