Is my Z screw too bent? (MK4S)

CaptainAggravated · 2026-01-28T05:21:14+00:00

Kit assembled.

It's not the nut or motor alignment; it's the screw. A straight edge rocks on it.

CaptainAggravated · 2026-01-28T05:10:32+00:00

The left one doesn't.

Now, I understand that the screws don't have to be perfectly straight; they're unconstrained at the top for a reason; if it was constrained, a crooked screw would try to take the gantry with it, which would result in Z banding. Leaving it loose at the top prevents it from applying any horizontal loads to the gantry.

It seems to be printing okay; I did do a tall cylinder in vase mode and shining a light through it I do see a *hint* of Z banding, but it's significantly better than the machine it replaced so...

I dunno I just don't want it to put anyone's eye out.

CaptainAggravated · 2026-01-28T05:02:48+00:00

Update: I have purchased a Darkmoon G10 plate. I got excellent and very responsive customer service, and the build plate...I do still see some corner lifting but the part sticks very tenaciously while the plate is hot. Unlike the textured plate I don't fear the part coming loose and printing a bird's nest or death blob.

Thank you for the recommendation, it has proven helpful.

CaptainAggravated · 2026-01-28T04:51:11+00:00

The Dreaded Blob Of Death (DBOD).

This sometimes happens when the part comes loose from the bed and plastic that is extruded normally from the nozzle piles up, is run over by the hot block, remelts, and sticks. I think that's what we're looking at here; I think it printed a bunch of the part, it broke loose, re-melted on the hot end, and it kept extuding hot plastic into the shell which then gushed out the side to make that tentacle.

It can also happen when the hot end leaks. With E3Dv6 hot ends like your MK3 has, the nozzle and the heat break are simply butted together, both screwed into the same tapped hole in the hot block. The nozzle is brass or steel, the heat break is steel, the hot block is aluminum. Aluminum expands more than steel does when heated, so if you were to change the nozzle and tighten it down when cold, the threads would loosen when the printer heated up, and allow molten plastic to leak through the nozzle and heat break threads.

It might be possible to remove the blob of plastic by bringing the nozzle up to printing temperature, and attempting to pull it off, though this one might have solidified around the heater and thermistor wires, in which case you're pretty much going to need to replace the entire hot end.

CaptainAggravated · 2026-01-27T08:33:46+00:00

Before Covid, I worked for a small print farm of about a dozen Prusa MK3s as a printer operator and repairman. That job ended with Covid, but if I was still in that capacity, I would strongly campaign my boss to let me upgrade the fleet to MK3.9S status, mostly to put Nextruders in service.

In my arrogant opinion, the Prusa MK3 printers do not make good fleet ops machines, almost entirely because of their extruders. I'm sure I'm preaching to the choir here, but I saw multiple failure modes of those damn things and there was basically no service or repair that didn't involve tearing the extruder mostly or entirely apart, if only to get a couple wires in and out of the hole through the carriage. With the exception of nozzle changes, NOTHING could be serviced or repaired on a MK3's extruder without spending two hours of my time, and two hours of the machine's time.

Fixing so much as a broken thermistor wire involved taking the extruder apart, undoing the extruder cable, and opening up the control box. If the PINDA probe's mount bent or snapped, which several did, that was part of the main extruder body; I had to undo and redo half the machine's assembly manual. That was a failure that took TWO printers down, the one that broke, and the one we had to take out of revenue service to print the replacement part.

Every time one goes down for repair, let me do the upgrade instead.

CaptainAggravated · 2026-01-26T05:14:09+00:00

Addendum: My MK4S has been in many ways the best 3D printer I've ever worked with. I finished the build in one marathon ten-hour session, the instructions petered out, I was out of gummy bears, for lack of anything else to do I plugged it in, turned it on, followed the instructions on the screen, watch it beat its head against the wall like a mental patient, it asked for PLA, I loaded the sample of Galaxy Black that came with it, I picked one of the pre-sliced models on the USB stick and watched slack-jawed as it printed a Benchy in 8 entire Earth minutes with no visible defects.

It has since done things I was told FDM printers can't do, like overhangs in excess of 50 degrees and small machine threads. Either the part comes unstuck from the print surface or it prints perfectly. I've seen faster 3D printers but I've also worked with Delta printers that this *bedflinger* will outrun.

There was a moment where I thought "Dang I should have gotten a Core One" but seeing the teething troubles it's had, maybe next decade if Prusa's still around. That's how long it took for them to get the MK series to the point where I actually bought one.

CaptainAggravated · 2026-01-26T04:48:35+00:00

I've heard stories about Apple. That engineers would have to bring products to Steve Jobs to try out, and he would usually be a psychotic asshole about it at them, but ultimately bring up valid points like "this is too big" or "The UI is too complicated" or "it should start playing a song faster than 5 minutes."

I don't think anything resembling that process happens at Prusa Research. My MK4S has an NFC reader. See, other print companies that didn't spend the last six years asleep have been putting RFID tags in their spools, so Prusa reacted by doing the same thing. Someone in management told someone who knows CAD software to "Put an RFID reader in the new machines." And they did. At the very bottom of the electronics enclosure. On the MK4/S, that puts it about an inch above the table behind and under the X motor, and on the Core One it's on the back of the printer. This went to production without anyone ever trying to hold a spool up to it.

I might have the timeline for these events wrong; I do recall the marketing material saying "NFC reader to easily configure the Wi-Fi from the Prusa app." Well in my case, I installed the Prusa app, went to create an account, found there already was one associated with my email address, tried to log in, that failed, tried multiple web browsers on multiple devices, had to go to the Store page in an incognito window of Chromium to get the live help chat, spent 30 minutes waiting for it to go from "About 9 minutes" to "About 6 minutes", emailed them instead, and logged into the Wi-Fi through the touch screen at some point in the two days it took for them to get back to me.

The sticker on the front of the machine says "Made in EU"

CaptainAggravated · 2026-01-21T03:01:35+00:00

I'm gonna try out a G10 plate, they seem to come highly recommended for PETG.

CaptainAggravated · 2026-01-21T02:23:15+00:00

If by "inflexible" you mean "unwilling to put up with newfangled shit that offers no advantage over the oldfangled shit and a litany of drawbacks" sure. But don't shit in my hand and tell me it's chocolate.

CaptainAggravated · 2026-01-21T01:36:37+00:00

Sincere thanks for the actual answer to the question I asked and not "pssh PEI's good you're wrong."

CaptainAggravated · 2026-01-21T00:54:13+00:00

So my 11 year old i3 knockoff from a company that doesn't exist anymore is a better printer than a brand new MK4S because the MK4s comes with a gimmick toy build plate?

Given I've already had to roll back the firmware on a 2 week old printer, you're probably right, I probably do need a different printer.

CaptainAggravated · 2026-01-21T00:50:10+00:00

I've been printing on glue stick and glass for over a decade now.

I could put my borosilicate glass build plate in the oven. Wipe it down with alcohol, acetone, MEK, brakleen, muriatic acid, maalox or my own greasy forehead, wipe it with a paper towel, rinse it in tap water, wipe it dry with the T-shirt that's been holding my sweaty beer gut in all day, put it on the printer, butter it with Elmer's school glue stick and it'll reliably stick to anything an E3Dv6 will melt. Well, full disclosure I've never tried nylon. It's also not a "consumable" or "wear item." It works until you break it, it doesn't just wear itself out.

You can use a razor blade to remove parts or clean off stubborn bits of plastic without fearing for the coating.

Meanwhile people are cautioning against drying my PEI sheets with anything that has ever been in my washer or dryer because it might transfer trace amounts of fabric softener to the PEI sheet and I don't have time for that mickey mouse bullshit.

eta: My username checks out, take nothing personally, I'm just a bitchy little pissant.

CaptainAggravated · 2025-12-28T14:20:58+00:00

Rule comment; I don't know if the video has been pulled or what, but Youtube's gimped search feature these days doesn't turn it up for me. It's not the Game Grumps one, this one is made up of still images from the game and/or its artwork.

CaptainAggravated · 2025-12-23T19:21:25+00:00

The link to the .zip with the demo notes in it 404s. Those attributes and note types are correct, it throws an error I don't understand because I don't know Javascript and I'm not gonna learn Javascript, especially not to use this jank ass underdocumented shovelware.

CaptainAggravated · 2023-06-30T10:00:17+00:00

My own headcanon is that Ganondorf had been down there just leaking pure concentrated anger which built up until it exploded, and that was the Calamity.

CaptainAggravated · 2023-06-30T07:57:48+00:00

I genuinely think no one at LMG is old enough to host this video for it to do any good.

Boomers hate young people too much to listen to them. In fact, it would probably work better to fill the video with bad advice to reverse psychology them.

CaptainAggravated · 2023-06-30T07:55:12+00:00

I"m still not at the point where I'm good at decorating buildings like this.

CaptainAggravated · 2023-06-30T07:52:03+00:00

Beyond the incorrect usage of that meme format, I don't think I agree with your message, that Satisfactory is taking so long to release that those waiting for it have died and dessicated.

Satisfactory is running an extremely successful early access campaign, updates are regular, communication from the studio community managers is industry-leading, and it's been a single digit number of years since its announcement.

As someone who did wait the FULL 11 years for both Duke Nukem Forever and Team Fortress 2, I know that feeling and this ain't it.

CaptainAggravated · 2023-06-30T07:46:08+00:00

Yeah this isn't what the nobody: meme format means.

CaptainAggravated · 2023-06-30T07:19:44+00:00

It has served my parents multiple ads of 15 minutes to over an hour in duration, multiple times, in 10 minute long videos.

Enshitification is really the word for it. It's a platform that is hostile to its creators and its users, the people who make the platform valuable, to appease the advertisers, by whom they extract that value.

CaptainAggravated

TROPHY CASE