Prusa Mk3 buying guide - New to prusa  

RE: Prusa Mk3 buying guide - New to prusa

Hi John, 
Before starting assemble of the printer I cleaned all of the tapped holes in the Main Frame, and the Y axis Carriage plate, using an M3 Drill/tap and a spot of oil... this makes assembly MUCH easier!
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I started printing in the early days of Prusa research, so I got my Mk1 Prusa, played with the included filament and bought 
Acetone (to make ABS Milk for the glass Build plate)
Painters tape, for the glass build plate,
Assorted filament. ABS and PLA, because PETG and TPU were not common in those days
a smaller nozzle,
A spanner for the nozzle. https://www.ebay.co.uk/p/4-Way-Cross-Wrench-Socket-Spanner-RC-Car-4mm-5mm-5-5mm-7mm/1334345955

I soon found that the ABS fumes affected my chest causing breathing problems, so I got rid of that....

I personally found a glass bed to be a pain in the bum...

The Mk1, came with an ABS filament cable support, which broke and caused spot flexing  on the cable  bundle. 

So I bought some 16 awg Flexible Silicone wire,  to repair the heat bed cabling...

later I upgraded to Mk2, with the PEI bed surface, and I bought
Isopropyl alcohol for cleaning the bed...

later I found that Dish soap and water did a better job,   BUT on the Mk2, you have to be very careful witht he water, because the Heatbed is not removeable

I found that Blobs of doom can damage thermistors so I got a couple of hot end thermistors and a bed thermistor.

Fans,  heaters, thermistors,  Pinda probes and filament sensor wires can fatigue with repeat flexing,  so they are worth having in stock...

I have never had an extruder wire break on me (YET!)  ((Probably Jinxed myself) watch for my followup post when all of the extruder wires break over the next couple of days!)
I had an X axis idler bearing fail on me, so I initially replaced the bearing, and later replaced the single bearing smooth roller with a toothed twin bearing roller. Not specifically necessary but it pacified my concern about squashing the belt teeth! .
PTFE Liners in the extruder DO wear out, so I have spare PTFE, sharp knife for chamfering the bottom of the PTFE and a reamer for the internal chamfer at the top.
I also got a set of screwdriver handle Allen Keys.as they make maintenance easier.

I also got Braided Cable sheath to replace the spiral wrap that Prusa used to supply, but that's not necessary now, because Prusa supply Split Braided sheething.

Additionally I HATE the way that the X axis Motor sheething just hangs on the wires at the motor end, so I make a TPU strain relief to support that end. no doubt there are more items
and more recently I bought a 'Slug Slime' Pen oiler (precision oil dispenser).

this hobby has a tendency to grow arms and legs... 

Joan
.

RE: Prusa Mk3 buying guide - New to prusa

Xanax. 

Filament.

Heater block sock and some small fine wire to attach to securely. 

Magnifiers, both the hand kind and the mirror kind to inspect the nozzle from below without causing cervical injury.

Gloves. lots of gloves. Otherwise the demons of adhesion will haunt you.

Dawn dish washing liquid detergent. Paper towels. A sink with running hot water. For when you forget to wear gloves.

Four liters of 91% isopropol alcohol. To waste your time trying to clean the bed when a little soap and water would have done it better.

A liter of acetone. For when the bed actually oxidizes.

If you print PETG, ABS, Nylon, PC, consider the PT100 upgrade to the hot end. And an enclosure with vent system so the bad vapors go outdoors for your neighbors to enjoy.  Remember to keep the enclosure wide open when printing PLA.

A fresh set of bearings and rods if you follow Prusa's advice and install them without grease.

A bottle of 18 yo Scotch to celebrate that first good print.  And a gallon of cheap rum to drown the sorrow of the next 50 bad prints.

Probably forgetting a few things ... but I have to go have a dram of rum ... my new bearings just arrived.

RE: Prusa Mk3 buying guide - New to prusa

Haha nice. Thanks

RE: Prusa Mk3 buying guide - New to prusa

John,

On the more serious side, and nothing I said above is untrue, the MMU is a project, expect some tweaking to get it to work well. But once working those that own them have printed polycarbonate to soft flex with one.  A recent post shows a gear with five different materials printed at five different temperatures, and it looks like it turned out pretty well. 

Upgrading to the PT100 for the increased temperature range requires additional hardware in the form of amplifier boards, and probably a firmware mod to select a different lookup table.  Not really plug and play.  But the thermistor in the E3D-V6 is only good to 300C, and some say 280 should be respected.  But if you start with lower temp material and work your way up, it will allow time to learn the forum and find resources, folk who have already done the higher temp mods and can steer you in a better direction to ease steep learning curves. E.g., the MK3S is showing serious problems for folk printing at high temps, especially inside enclosures. Nothing catching on fire, but parts deforming or melting. A solution is being worked on by many... why no one has printed parts on the SL1 is for this is curious, since those parts would be impervious to the heat of an FDM printer... So a good solution is possible, just not yet available en mass.

Bearings and rods shipped with the MK3 are serviceable: they do work well and aren't a limiting factor to print quality.  But they should be cleaned and packed with grease before they are installed.  Just common sense.  For the most part, even the motors, belts, and gears are all fair quality and won't limit what you do.  There are forum threads for eeking out that last 1% ... but the cost/performance trade-off seems slim. Folk are printing 0.02 mm layers with 0.1 mm nozzles, and getting great results. But the stock printer will handle 0.05 layers and 0.25 nozzles out of the box, and I wouldn't be afraid to try 0.025 layers with a 0.25 nozzle.

The MK3 is a capable printer for a reasonable price. You'll be happy with one.

RE: Prusa Mk3 buying guide - New to prusa

Posted by: j.henrikb

So after hours and hours of research, Prusa seems like the obvious chose to buy as my first 3d printer for home.

I bought a MK3 as my first printer and have been thrilled with it. While capable of doing it myself, I opted to have Prusa build it for me and I'm also glad I did that. By doing so it let me get started right away and be reasonably sure that any issues were not build related.

As I gained experience it became obvious that Prusa didn't put the time and attention they should have into it (ex: 2mm swing from on corner of the plate to the opposite corner), but it was still plenty good enough to get started.

So to all you Prusa buys and girls, what did you end up buying short time after getting the prusa? That you thought "Well i should have bought this straight away".

Honestly, nothing.

I put somewhere between 4000 and 5000 hours on it before I did more than fine tune the Live Z. The thing just worked.

At that time I had jam issue that had me considering replacing the extruder with a different design, but my MMU2 finally showed up (ordered with the printer, but it took about 6 months to show up) so I opted not to do that. I did, however, do the Nyloc mod to the Y bed for better leveling (now all 8 points are within 0.006mm of the center point) and I tried Drylin bushings for the carriages (happy with them for the X and Z, but they were garbage for the Y and I went back to the factory bearings).

I was planning on making an enclosure for it. Saw someone on youtube who had to replace some parts because the original parts melted/deformed. 

Get experience printing materials that don't require an enclosure first. I had also planned to do an enclosure, but I'm glad I never did as it would have made my life miserable (see comments below).

I think it's best to spend time with the printer in your environment to get used to it and understand what it will need from you before considering an enclosure as it can make things more difficult if you need to get to the printer.

I want to print lots of exotics like PC, Nylon, CF and other very strong materials.

It will do all those things, but as this is your first printer I highly suggest that you start with the less advanced materials (PLA/PETG) to build up basic experience.

What about the Multi color kit? Is it possible to use it for more than colors? Like supports in PVA?

You absolutely do not want to get ahead of yourself with an enclosure if you are considering the MMU. Spend some time in the MMU forum and you will see that it is NOT the plug and play option that the printer itself is. It is a finicky beast that can take time and effort to get working properly. If you have it buried in an enclosure it will make your life more difficult as you will need to get to the unit frequently while working the kinks out. Even once it is working "smoothly" it is going to need you to lay hands on it from time to time and any enclosure needs to account for this or you will hate it.

As far as getting the MMU, I would recommend waiting. Again, get experience with easy/simple printing first. When it's cooperating the MMU is a good tool, but when it's not it can be a frustrating PITA (ex: mine was perfectly working until I had to rebuild the extruder this weekend, now the IR sensor is refusing to play nice again). Pick it up after you gain general printing experience and have specific needs for it.

RE: Prusa Mk3 buying guide - New to prusa

Definitely some sort of lube for all bearings and friction surfaces...  Your choice, I chose white lithium per a discussion with the bearing supplier for the company I work for though many here would dispute the use of white lithium...   A year and a half later my bearings are still fine, touching wood.  Otherwise, I'd say run it as it is for a while before tweaking any further.

As an aside, I'm under the impression Prusa now supplies some sort of grease with their kit.   Does anyone know what type of grease they supply?

RE: Prusa Mk3 buying guide - New to prusa

Posted by: j.henrikb

So to all you Prusa buys and girls, what did you end up buying short time after getting the prusa? That you thought "Well i should have bought this straight away".

Filament is the only thing I purchased right after the MK2 printer was assembled. Everything else came over time. Like IPA from local store, filament sock from Amazon.

For new users I would always recommend to just print some kg PLA with the stock printer. IMHO the call for mods is usually happening too fast for the original Prusa machines. There are a lot of parameters which can be used and tweaked without replacing the actual parts. Most of the time newcomers learning the machine by replacing the parts and realizing afterwards that the original parts are pretty good.

Don't rush for exotic materials. Gain some knowledge first before wasting time/money with those expensive filament. 

... and welcome to the Prusa community!