My Folger Tech Prusa i3 Experience

After playing around with the 3d printers I have access to on campus, I decided to order my own. I went with the Folger Tech Prusa i3 because I'm a cheap bastard and building a printer from a kit would give me a better understanding of its functions and deficiencies. I knew going in that the kit had some issues. I like modifying things - it wasn't a concern for me.


The kit arrived on time - took a few weeks but that was forewarned in the ebay listing. One of the top Z axis mounts had a corner broken off, and I was missing a jumper. Minor issues - I snagged a jumper from an old graphics card I had laying around. I ran into several issues in assembly and calibration. I'll try to detail the problems and fixes below so anyone else purchasing this kit can save some time!


Electronics:

The RAMPS board and Arduino board did not fit together perfectly - there was some interference from some solder on the underside of the RAMPS board that was hitting a connector on the Arduino. I shaved it down. I was a bit rough with both boards, but thankfully had no issues upon startup.

I didn't like how the manual specified the end stops should be installed - solder on the underside of the end stops prevents them from mating flush to their brackets. I flipped the stop to where they would fit flush, with the connector at the opposite end of what the manual specified.


Assembly

The lower X axis rod did not fit snugly in the carriage ends, and would move side to side. Temporarily fixed that by making some burrs in the hole with a knife so it would hold position. I plan on designing and printing a new pulley side carriage with a tensioner for the belt - I'll permanently take care of this issue then.

I didn't have any problems with the acrylic cracking. YMMV as this is a commonly reported issue. Either my frame came out pretty strong or people are REALLY cranking down on those screws!

Belt installation and tensioning is a bit of a pain. Easiest way is sliding in both belt ends at the same time. If you didn't get it tensioned enough the first go, unbolt the idler pulley and move up one belt tooth at a time. Easier than trying to pull them taut and cram them in the slot.

I did have some tolerance issues on the X axis idler. Needed to file the sides of the carriage a bit to get it to move smoothly.

Don't tighten anything down too hard until you confirm that it's in the right place. I left a lot of things finger tight at first since some parts of the guide weren't clear. Saved me some time later when I needed to flip some things around. Seek out multiple guides and build videos.

Calibration

Had some issues with the end stops at first - there are several threads on this that you can search. Make sure you know whether your endstops need to be set as max or min position, and you have the home direction and axis orientation set properly in the config file. Also, you need to set the bed size and home locations in Repetier for manual mode to work properly.

EXTRUDER CLOGGING / SKIPPING

This is an important one as I've seen a lot of other people with this issue! I had some PLA and was having soft clogging issues left and right. When I say soft clog, I mean that filament was still being extruded, but very slowly, and the extruder would skip when trying to feed at normal speed. If I let the nozzle sit for a few seconds, I could extrude a bit without skippage, but there was a significant delay between extruder stepper actuation and plastic extrusion. Looked like it was overcoming significant pressure.

On Monday I recieved the Taulman Bridge Nylon I ordered, and tried to clear up the clog with it. I set the temperature of the extruder to 245°C in Repetier based on information from Taulman and other users. The Bridge Nylon clogged, and was turning black on the nozzle. The thermistor on the extruder was reading low! I reduced the temperature to 230°C, cleared the clog with some guitar string and a needle, cleaned off the tip of the extruder, and got my first successful print. No skipping. VERIFY YOUR EXTRUDER AND HOT BED TEMPERATURES

I'll post some of the mods I have planned as I do them in this thread. I've got an older gaming computer I can gut for some fans and heat sinks. I've seen some extruder upgrades - I'll be pursuing those too.

As a bonus, here's some of the PLA parts I was messing about with on campus: (The 3d sys printer is pretty meh, especially for the money. I'm not responsible for that purchase. I did recommend a Form Labs Form 1 SLA printer for some of the high tolerance high precision stuff one professor wanted. It's pretty cool, I'll get some footage of it.)

Caliper adapter bracket for bolting on front e36 M3 brakes on an e30. For you non-car folks, the former is a BMW M3 1995-1999 stateside, the latter is a BMW 3 series from 1984-1991.

[timg]http://i.imgur.com/C8z9i58.png?1[/timg]

[timg]http://i.imgur.com/d6fH9Qm.jpg?1[/timg]

[timg]http://i.imgur.com/dAjYMSh.jpg?1[/timg]


Rears:

[timg]http://i.imgur.com/L3QNoFA.png[/timg]

[timg]http://i.imgur.com/zWbx8RL.jpg?1[/timg]

[timg]http://i.imgur.com/JCvB0pI.jpg?1[/timg]

[timg]http://i.imgur.com/20TvaYn.jpg?1[/timg]


Next project is printing some intake runners for an individual throttle body setup on a BMW M52b28 inline six.

[timg]http://i.imgur.com/UHRYywY.png[/timg]

I've got to do some testing to see if Bridge is up to the task. Taulman's got a few different types of nylon. Engine bay temperatures can see 100°C, so the Tg has me a bit worried. A phenolic spacer and ceramic coated headers can help mitigate the temperature issues. It should be resistant to oil and gas. The part will not be load bearing, and it won't see high pressures as this is a naturally aspirated application. Just needs to be air tight!

This one was not available assembled, correct?

No, they only sell it as a kit.