Sunday, April 26, 2015

Misadventures with the Prusa i3

The Prusa i3's nozzle had come loose and we had determined this by the fact that hot filament was oozing out of the top of the nozzle. To remedy the situation, the hotend needed to be removed and soaked in acetone. This also meant that the thermistor had to be reattached. This created a new problem: by screwing in the hotend tighter than it had previously been inserted, the hotend was higher up off the heated bed. This meant that the extruder had to be closer to the hotbed on the z-axis, so low, that it was jumping on and off the couplers that attach the z-motors to the threaded rods. Okay, "easy" fix, raise the heated bed off of the build plate using our adjustable spring loaded screws that we had added in a previous upgrade. Oh, wait, while installing that upgrade my husband had destroyed one of the screw holes partially by impatience and partially by Makerfarm's optimistically tight tolerances. Welp, guess I had made it a whole month without going to Home Depot.

FIELD TRIP!

Went to Home Depot for a piece of plywood, hoping for the smallest piece available as we only needed at 8" x 8" section for the build plate. They were out of 2' x 2' x 0.5" pine boards, so I delegated the task of tracking down a store associate to said husband. Here's a neat tip, if Home Depot is out of a particular size package of goods, they'll generally give you an upgrade for the lesser price. In this case, no 2' x 2' x 0.5" pine plywood, but they did have 2' x 4' x 0.5" pine plywood AND 2' x 4' x 0.5" birch plywood. We requested that they cut the larger board in half for us, but their saw was down for repair, so they were nice enough to give us the $17.50 piece of birch for the price of the small pine board ($7.14). Keep that one in the back of your head, you'll thank me later.

It should also be noted that after going through half a gallon of acetone (yay, ABS!), we finally decided to supersize it and move up to the much cheaper gallon can of (industrial solvent) acetone. The gallon cans cost like $4.25 a quart, whereas the quart sized cans cost nearly $8/each.

After escaping Home Depot (and forgetting to get the Dremel, d'oh), we made our way back home where my husband was impeded by the childhood top on the acetone. He eventually gave up and passed it off to me. Obviously I couldn't do it either, and thought, "hey, I should pop this plastic sleeve off the top and see if I can open the can that way," but did not for fear of breaking this thing that I kinda wanted to return. So no go on the acetone. Off to the return pile.

Back to the repairs: My husband got to work on cutting down a new buildplate. "This should be easy," he thought. "Just put in some new screw holes and it'll be good to go!" Oh, wait, the y-idler is tenoned to a laser cut mortise in the buildplate... Hand drill probably not going to work. After rifling through the workshop for 5 minutes, he found a chisel, and proceeded to fix one the world's most advanced manufacturing tools with a Bronze Age tool. With some wood working skills and the new Dremel (which we remembered on the return trip, hooray!) he transferred the hole template from the old buildplate to the new one. Then he was kind enough to reassemble the printer, leaving me with the joyous task of recalibration.

Joy.

See my enthusiasm there? If not, you can see it here: Calibrating a Prusa i3.

Two weeks after determining the nozzle issue, a calibration cube printed out perfectly.


No comments:

Post a Comment