Dwagon comes back to 3DP after a move:So after moving, my Diggro sat pretty much unused for several weeks while we got things semi-livable in the new place; last week I picked up some Dell AA23300 server PSUs cheap, and after modding them to turn on when NOT shoved up a Dell server's arse, I decided to work on some plastic bits to tone down the screaming fans and tidy the things up, as I want to trade a few of them with a fellow eevBlogger.
Well, the printer just repeatedly
for the better part of a day; eventually I deduce that when the layer fan kicks on, it's just cooling the nozzle too much and causing the filament to cool inside the nozzle; as long as it remains off, while manually feeding the filament the extrusion feels normal with little backpressure. As soon as I turned the layer fan on, extrusion slowed to a crawl with lots of backpressure. Temp shown on the screen does not change appreciably.
I tried raising the hotend temp, but decided there had to be something seriously wrong when 235° barely made it extrude at all, and then only with the layer fan at 60%. I tried lowering the the layer fan so it didn't blow right on the block, but due to the geometry of the CR10 printhead, I simply could not get it low enough to be just a couple mm above the work as the 'fang instructions say to do.
I get to thinking... one of the mods I bought for the Diggro at the outset was a MicroSwiss heater block for CR10; I found it on sale, and it comes with a silicone sock that better covers both the block and part of the nozzle. A few quick measurements show that assembled with the original Diggro heat-sink, the overall height is ~4mm less than the CR10 hotend.
Plus, the heat-brake tube is all metal, while the one from the CR10 hotend is bored hollow, allowing the Bowden tube to contact directly with the nozzle. This combined with the Cap tube is probably why I've never had a clog; but it does limit me to PLA.
So begins another adventure in 3DP; I get the new hotend built, set the nozzles on the 'fang so they're just 1.5mm above the work, and it seems to work right off the bat... 200° with layer fan off & 220° temps with layer fan on and I've never had a smoother feeling extrusion by hand. No bubbling, no smoking, and the extrusion with layer fan on is like making rods it's so straight.
But of course this joy did not come until after I had a penis fingers event with the new heater cartridge and blew up my mainboard; requiring open-heart surgery and a dragon-sized FET bodged in place.
No, you may not see pics of THAT crime.
Why the sudden change in extrusion behavior? I had no idea. Hindsight says it may be ambient temp tho; one of many things I plan to try is a big box over the printer as an experiment once I find my monitor cam.
1) After some small amount of misery and self-mutilation (more love nips from a hot MOSFET), I finally wake up to a semi-successful print this morning. Looks a little fuzzy around the edges, but it did at least complete the print. I'm pretty sure that once I dial in the temps, it'll print better than OEM, and not just on square things with PLA.
2) For a change, removing the supports did not fight me at all; they pulled out easily and in one piece. I was quite surprised by this, given how deep inside the piece they extend.
C) Print quality is
"Ehhhh..." at best; calling it a successful print is probably pushing it. Most of the fuzzies will go away with a little fire tho...
4) Okay... make that a lot of fire. And a zip-tie.
But still... good enough for Proof-of-Concept on my muffler tailpiece.
5) Money shot...? Taking measurements. Qa-plahh! Okay...
6) Side By Side with stock unit. Well, it did work as intended; I was able to fit the tailpiece on the PSU, and overall appearance is as intended. A successful print would tidy up the look of the PSU without adding appreciable length with a stock IEC cord; however 90° cords are right out. And left out. They're just... OUT.
TL/DR: Installed, the tailpiece does make a noticeable reduction in the perceived noise level with it sitting on the desktop. The higher-pitched elements are reduced quite a bit; but it is still somewhat distracting in a quiet workspace. While my tailpiece does tidy up the look of the unit (and I do have plans to make a similar front piece) and makes a 3-5dB difference in noise measured at the back of the unit, the single most effective noise abatement attack was to throw the whole thing under my desk. We'll see what difference, if any, adding the frontpiece makes; as muffling the inlet area did make a noticeable and measurable difference with the unit on the desktop.
Details of that adventure can be seen in the TEA thread.mnem
*back into the suck*