From 9b8528eeb562c8f084762d90a8e58eb7b84f4209 Mon Sep 17 00:00:00 2001 From: Pim van Pelt Date: Wed, 4 Sep 2024 22:56:40 +0200 Subject: [PATCH] Add Tuesday: Printer-day --- content/blog/wk6day2.md | 162 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 159 insertions(+), 3 deletions(-) diff --git a/content/blog/wk6day2.md b/content/blog/wk6day2.md index 837e1c4..9120e19 100644 --- a/content/blog/wk6day2.md +++ b/content/blog/wk6day2.md @@ -1,7 +1,163 @@ --- -title: "Week 6, Tuesday:" +title: "Week 6, Tuesday: Prusa MK4S" date: 2024-09-03T21:55:00+02:00 -draft: true --- -{{< image frame="true" width="17em" float="right" src="/img/headline/todo.png" alt="Credit: " >}} +{{< image frame="true" width="17em" float="right" src="/img/headline/harrymack-02.png" alt="Credit: Harry Mack, YouTube" >}} + +This morning I got up by a, what do the normal people call it?, "alarm clock" at 08:00. I did not +like being woken up by such a device, and I begrudgingly turned around a little bit. The person next +to me was also not really ready to get out of bed, so I did something that is somewhat unique in our +house: I got up before Marina did! And made her coffee, oh what a loving spouse I am. + +I have an appointment at the Stromvelo shop at _Zurich Buchegg_ which is not too far away, and I +bike past there several times a week normally as I commnute from Brüttisellen to Google in the +city. I remain worried about the Stromer ST5, as it keeps on randomly failing its torque sensor, +which renders the bike pretty much unridable. But, the Deity of Cycling is smiling upon me this +morning, and after my morning coffee I hop on the bike -- which works!! These last few months, it's +been either 'not working at all', or 'super sensitive and immediately wants to go full power'. This +morning was the latter situation, so biking to Buchegg was ... not a problem. + +I arrived there at 09:05 or so, while the shop opens only at 10:00. I locked the bike and dropped +the key in the mailbox, and decide when I get home, that I will give them a call to confirm. It's +about 2km from here to Oerlikon train station, and I'm very close to Bucheggplatz which is sure to +have a few _Bolt_ or other electric scooters. I grab one at the tram stop at Bucheggplatz and make +my way to the train station. It's kind of fun to have one of those 45km/h (28mph) bikes and then +crawl forwards at 19.9km/h (12mph) on the scooter. It's sooooo slow. I manage to even take a selfie +of myself on the scooter, which of course doesn't reveal that I'm on a scooter at all. But, I scoot +my way to Oerlikon, grab the train and then the bus home. + +While I'm in the bus, I get an e-mail from DHL that they have dropped off another package from Prusa +Research in Prague. Huh? Did they send me _two MK4S_?, I think, and I make myself ... promise ... +myself (hint: that was an Austin Powers wordplay) that I will not give it back if it's another MK4S! +But Marina quickly puts my greedy mind to rest - it's merely the second half of the package that was +already underway. Yesterday the MK4S was delivered, and today it's the MMU3 and some heat elements / +parts for my currently not working MK2.5S. Fair enough. + +### The Prusa MK4S + +Building the Prusa MK4S is a treat. Except, I'm a dunce so I download the MK4 (not MK4S) build +instructions, and about halfway through it asks me to grab some plastic part or other, and I spend, +I kid you not, a full hour looking for this part. I go through the box, maybe 4 times, inspect each +part, also look through my trashbin, and pull out a few hairs, lose a few years of my life, only to +conclude: oh, this is the MK4 manual, and I'm building an MK4S. Whoopsie. First, I backtrack a bunch +by reading the MK4 to MK4S upgrade guide. Later still, I find that, yes, you dumbass, there's also +just an MK4S assembly manual. People can be so stupid some times. + +Apart from my inability to read instructions or navigate the Internet, the build is a really great +success. I get most of the way through, and spend most of the afternoon being absolutely impressed +with the progression of the _technology_ of these printers. I started using Prusa in 2017 with +the Original i3 MK2, which I later upgraded to an MK2.5S. Then I built and used an MK3, which had a +lot of clever upgrades. There are a feww upgrades on this MK4S that I am most happy with: + +1. Instead of an inductive sensor, called a PINDA (**P**rusa **IND**uction **A**utoleveling), not +to be confused with the Dutch slur for Indonesian people, there is now an actual loadcell attached +to the printer nozzle tip. Before, the PINDA would scan for the metal in the plate, and if the +Z-distance between the PINDA and the nozzle tip was known, it could be pretty accurate. However, +a perhaps better way is to use the _nozzle itself_, and measure the pressure as it bumps into stuff. +Using a very sensitive [[loadcell](https://www.prusa3d.com/de/produkt/hotend-heatsink-xl-mk4/)], +(which is also found in kitchen scales), it will gently bump into the print surface -- regardless of +how thicccc or thin it is -- and use up to 49 measurement points to do a direct mesh leveling +calculation. Result? Absolutely flawless first layer thickness and adhesion on the entire build +surface, not just the middle. Winner winner, Chicken Dinner! + +1. The hotend is now a +[[Nextruder](https://www.prusa3d.com/de/produkt/nextruder-hotend-brass-0-40-mm/)], where the whole +thing is one piece that can be inserted - and released! - using two thumb setscrews. Before, +removing the hotend and replacing parts within, was a matter of disassembling the entire print head. +Now, I can replace the hotend + nozzle for different diameters, by simply disconnecting the hotend +heater wires, and the thermocouple connector, on a daughter board called a +[[LoveBoard](https://www.prusa3d.com/de/produkt/loveboard/)] for a reason not entirely clear to me. +But with this new cable, the filament sensor, loadcell, extruder stepper motor, thermometers and +fans are all connected in the print head, with shorter wires that travel through a cavity in the +print head PETG parts. It's really clever, and I'm looking forward to changing the hotend more +easily in the future. This hotend is "high flow" with a 40W heater element, and a 0.4mm nozzle, +which can push out a huge amount of 1.75mm filament. The flow rate can be very precisely controlled +by a new planetary gear system in the extruder feeder. It looks very fancy! + +1. Although it's a small thing, the stepper motors are a huge upgrade. They're first of all _much_ +faster than the MK2.5/MK3, and they are also a fair but more precise (0.9 degree steps instead of +1.8 degree steps - which means 400 steps per revolution). They say it's going to reduce the smaller +layer offsets called _VFA_ (Vertical Fine Artifacts). Honestly, I never really had issues with the +MK3 printer, but it's a good benefit. + +1. Finally, the Einsy board has been replaced by an xBuddy board, with a much faster processor and +more IO. It also couples with an NFC reader (which I think is pretty useless), and a WiFi based off +of ESP32! (which I think will be super useful). It also has ethernet by default, and the screen has +advanced from the classic dot matrix LCD display, to a 64k color touch screen. I decide to try out +Prusa Connect, where the thing connects via wifi to a service Prusa provides, and I can also make +the Prusa Slicer on my Mac connect to the same service: hence, I can print directly from the slicer, +and skip my [[Octoprint](https://octoprint.org/)] running on a [[PC Engines](https://pcengines.ch/)] +machine. Talk about fancy! + +1. A super small detail, but these things really matter. Belt tension has always been somewhat of +a dark art - I have some experience in this because of my RC Helicopters, some of which also use a +belt to drive the tail rotor. _Feeling_ how much tension to add, so that the belt doesn't skip, but +also not that it's so tight that it creates friction on the stepper motor, is pretty difficult. +Prusa added a really cool progressive web app that asks you to put your cell phone next to the belt, +and then strum it (sort of like a guitar). It then measures the resonant frequency of the belt to +figure out if it's too tight, or not tight enough. I've seen a fair amount of cool shit, but a _hat +tip_ to the engineer(s) who created this. + +After dinner, we watch one episode of V-Wars after which Quinn decides to skedaddle. Instead of +watching some more TV, I retire downstairs with a bottle of Red wine, and finish the printer. I +completely nailed the belt tension using the app - the X axis at 84Hz and the Y axis at 94Hz, smack +in the middle of the green. You rock, Prusa microphone webapp! I'm really, really impressed by what +you've done. + +### The Results + +If you're not into printing, [[3DBenchy](https://www.3dbenchy.com/)] was kind of +a torture benchmark, which would test fine layers, some overhangs, some very small cavities and +holes, etc. Early printers would often freak out on this, and create spaghetti, push the thing over, +fail to print the holes, or the overhangs, etc. + +It's a little bit of a humblebrag, but the folks at Prusa ship this printer with two _Benchy_ +printer objects. The first is called BenchyRules which is a 14 minute print. The second is called +BonkersBenchy which strips out lots of the insides, turns the object a little bit so as to minimize +the head movement, and is meant to print in 7 (yes, seven!) minutes. On my MK3, it'll take about an +hour to complete. + +Now, normally, when the printer is built, the annoying task of doing calibrations, printing a few +first layers to calibrate the layer heights, doing a bed mesh tweak to make it as flat as possible +(mostly so that the objects on the outside of the print surface also stick to the bed!), flow rates, +you know all of that stuff. The Prusa MK4S? Uhh, I turned it on, let it do its self test where it +makes sure all the sensors and stepper motors are connected to the correct ports, and have +reasonable measurements. It asks me to tap the hotend tip (while insisting that it'll be turned +off), and I _tap-dat-ass_. It says things are all OK and that's ... it? In the menu, I click 'Load +PLA', which it does. Then I click "Print BenchyRules", and I am *fully* expecting it to either +yell at me "you did not calibrate yet", or just completely destroy the print, but it does neither. + +Here's my unfiltered, unscripted POV reaction a few seconds after it started printing: + +{{< video src="/media/vdo/IMG_1116_22.46.16.mp4" >}} + +The first thing I notice is that the whole workbench / table starts shaking under the violence of +the steppers, which are not even making much noise. The second thing I notice is that it is *so +fast, daaaaryum* this thing flies. People have asked me if this is in real-time, and yes, I can +confirm this video is directly from the iPhone with no editing, no speedup at all. This thing is +quick as a hare! + +OK, while the BenchyRules and BonkersBenchy are cutting a lot of corners, it was an absolute _treat_ +to build this printer and see it fly. It completed the benchy in 14 minutes, and the speedy +BonkersBenchy in 7 minutes. So much fun! Before I go to bed, I put on an 8 hours print on ABS +material to refurbish the MK3 into an MK3S; and for good measure I also put on an 8 hours print on +the MK3 to refurbish the MK2.5S with a new set of parts for the print head. + +This was a fun day! + +## Pictures of the Day + +{{< gallery-category >}} + {{< gallery-photo fn="2024-09-03/IMG_1102.JPG" caption="After dropping off my bike at the shop, I grabbed a Bolt scooter to transport myself to Oerlikon station. The scooter doesn't go very fast, so I manage to take a scooting-selfie." >}} + {{< gallery-photo fn="2024-09-03/IMG_1105.JPG" caption="The Prusa MK4S printer is halfway done. The Z and X carriage and the bottom parts are done. This is about 1/3 of the way through the build." >}} + {{< gallery-photo fn="2024-09-03/IMG_1106.JPG" caption="For lunch I treat myself to a Smos Gezone (a healthy sandwich) with cheese, ham, lettuce, carrots, tomatoes, a bit of mayo and mustard." >}} + {{< gallery-photo fn="2024-09-03/IMG_1111.JPG" caption="The electronics part of the Prusa MK4S showing its xBuddy board and lots of wires for sensors and stepper motors." >}} + {{< gallery-photo fn="2024-09-03/xbelt.png" caption="The Audio Sensing application on my cellphone allows me to get perfect belt tension by measuring the frequency. Such a clever idea!" >}} + {{< gallery-photo fn="2024-09-03/ybelt.png" caption="The Y belt tension is perfect when it hums at 94Hz. OK then!" >}} + {{< gallery-photo fn="2024-09-03/IMG_1115.JPG" caption="The printer is done and booting for the first time. Literally 3 minutes later, I printed the Benchy in the videoclip on this journal. I don't think I've ever been up and running so quickly. So cool :)" >}} + {{< gallery-photo fn="2024-09-03/IMG_1117.JPG" caption="The (modified) Benchy is printed in 14 minutes instead of 60+ on my Prusa MK3. There's a bit of trickery going on, but the end result is actually really good!" >}} +{{< /gallery-category >}} + +{{< gallery-modal >}} +{{< gallery-script >}}