Hey, Slab!

Today, I decided it was time to reduce the noise of my printer.

First I did some measurements. I created a single-layer print of pure infill, increased first layer speed, and adjusted infill angle to make the printer move X, Y, or diagonally. Sure, I could have done a custom gcode sequence to just move the axis, but I didn't feel like digging into that. The first print was quite difficult to get off, so I moved Z adjustment from -0.8 to -0.6.

For each test, I used the Sound Meter app, first right in front of the printer, then on a separate table across from the printer, taking the average after about half a print. 

Y movement: Near printer 56 dB, other table 46 dB

X movement: Near printer 54.3db, other table 37.2 dB

Diag movement: Near printer 57 dB, other table 45 dB

Y movement is far noisier than X movement. There's some suggestions in this thread: Lubricate bearings, oil axis, add motor dampers. Oiling is an easy step, let's try that. After oiling, Y axis movement is 56.7 dB near the printer, 46.7 dB on the other table. Louder. Huh. Could be a measurement error.

I don't feel like taking the printer apart today, but I did get a slab of granite, and I have plenty of foam. So let's do some tests with them.

First step: Put pieces of simple camping foam under the feet of the printer. This reduced the noise level of the Y movement to 48.3 dB near the printer, 35 dB on the other table. Already noticeable! And this foam is pretty stable, so shouldn't make the printer too wobbly.

There's also a sound coming from the power supply, probably the fan there. Slightly irregular, not that loud yet.

I took the opportunity to fasten what bolts I could get to. I tried to open the power supply, but wasn't able to without taking more apart than I felt like. I did however notice a small piece underneath it that wasn't fastened correctly, so I fixed that. After that and putting the printer on a slab with soft foam underneath, the test print measures 40.4 dB near the printer, 31.5 dB on the other table. So this shaved off in total 15 dB, impressive! Even the power supply fan seems quieter.

Of course, I should have measured between fastening bolts and putting it on a slab, but I didn't. Maybe another day.

Luckily, the filament spool just fits under the cabinet above

I might want to have the filament spool mounted separately, possible between the two edges on the sides (you can see one in the picture). I would need a setup where the holder was easy to remove, though. I suspect some of the noise from fast moves is from the filament spool.

Clearly, this merits printing a really nice McBenchy!

There's a smidgeon stringing (that I have cleaned off), and the Z level is not quite perfect, but overall it's super smooth.

The first layer of the McBenchy had an average noise level of 34.9 dB (measured in front of the printer), the second one where the usually noisy bed fan started got up to 39.5 dB - that's not just the fan, though there were also some fast zig-zag moves that were somewhat noisy. Apparently moving the printer about has at least temporarily fixed what was wrong with the fan. Later layers averaged 37.7 dB, though there were places that were somewhat louder, it seems to occasionally hit a resonant frequency. Measured on my chair arm, so at normal distance for me, it's 29 dB, at the other table 28.2 dB.

All in all, I am satisfied with this noise improvement. In fact the power supply is not responsible for a fair amount of the noise, maybe I could dampen that by adding some rubber washers to the various screws.

Obligatory Borderlands 2 reference:

It moves! It lives!

Having mostly dealt with the problems from last post (Flimsy wiring? Get the right jacks. Overheating driver? attach driver directly to frame. Loose coupling? Tie down coupling with hose tightener (which required dremelling a hole for the screw to rotate through), I have been able to make both X and Y stages move! The whole setup also looks much tidier now.

The stages can move for a seemingly arbitrarily long time, but they still overheat if standing still for about 30 seconds. Have to find a solution for that. I don't know if thermal paste will change much when I've already bolted them tightly together.

Major problem: Both stages have a tendency to switch between running smoothly and getting stuck, depending on exactly how the rod is aligned. I'm guessing the guiding bolt is a little loose, and can change between perfectly aligned with the rod and not quite perfectly aligned.

After cutting off superfluous edges and cutting a notch on the Y stage for the tube tightener screws, I have about 11x16 cm of writeable area. Not a lot, but enough for tests and for a RepRap, should I go that way (requires a plastic extruder, though. First some 2D tests!)

Softwarily, I have refactored the little test program to where I have two functions: move(dir, axis, len) and pauseSeconds(seconds). The move() functions is almost calibrated to move in cm.

For playing around, I am tempted to hook up three three-way switches so each axis can be controlled independently. Or maybe get a mini joystick controller:)