Upgrade recommendations during initial build?  

Re: Upgrade recommendations during initial build?

Bearings / Rods:
X: RJ4JP, AWMP-08 370mm
Y: RJ4JP, AWMP-08 330mm
Z: LM8UU stock or equivalent (I suggest you to choose the best ones from the stock bunch, as you'll have 6 more when replacing x/y with igus), SWM-08 320mm

Alternatively:
Y: RJZM-01-08, mounting clamps (but you need them in advance...), AWMP-08 330mm

All other solutions are too complex, overengineered, expensive, too much hassle or unreliable. Note that you'll need perfect assembly, or plastic bearings will bind.

Dampers:
X: NEMA17 Damper (Astrosyn or EMVIO)
Y: NEMA17 Damper (Astrosyn or EMVIO), motor bracket (search on thingiverse)
Z: (untested) cork dampers
E: (untested) cork damper
Base: >1cm foam + heavy tabletop + sorbothane pads + thingiverse mini dampers

Fan:
Add JST or equivalent plugs to either replace the fan with a 40mm one or add a 100ohm resistor.

Re: Upgrade recommendations during initial build?

Maarten

Always best to build as supplied initially and use it for a couple of weeks, then if you have any problems they are much easier to diagnose.

Then you can decide what upgrades are required for your printer.

Peter

Re: Upgrade recommendations during initial build?

Hi Maarten,

i am also waiting for my MK2 and was thinking to make some changes from the beginning.
Lot of your ideas i also have on the list, BUT as Peter wrote, maybe it is the best to assemble the original and do a change later. And we can print our own parts needed.

I really like the Prusa i3 MK2-X http://www.thingiverse.com/thing:1692666 idea. I will see where/how to improve and then getting IGUS bearings, etc...maybe 10mm but for sure longer X-Y IGUS rods, I don't like that the bed holder bearings need cutout in the corners and/or the bearing holders.

But if you want to start here my thoughts:
The RJMP-1-8 are 1mm larger in diameter and 1mm longer. You should be able to use them for the heated bed holder, the bed will be 0.5mm higher. Maybe you have to adjust the firmware to get the auto calibration running nicely.

Using RJMP-1-8 for the X-axis you will need to print a new x-carriage, best in ABS (i got the Safety Orange ABS in my order 🙂 ). But if you don't have a 3D printer where to get? Chicken Egg problem.

I am not sure about the Z-axis because this is not moving a lot and just safe the money here.

I think the IGUS rods are a good idea, they don't cost that much compared to the bearings.

Waldemar

Re: Upgrade recommendations during initial build?

Hi all,

Apologies for taking so long to respond, with the year end festivities and all.
Thank you all for you thoughts, really helpful.

I think at first I will follow Peter's advice and build as stock, just to see how it performs. Especially since it's my first 3D printer and I have no idea what to expect. I can then use the printer to make the necessary replacement parts in stead of having to outsource that.

I was just a little weary of building and then rebuilding, but come to think of it: that's part of the fun and learning process!

Patrizio, thanks for your input, I think I will eventually follow your advice, but then with the ability to print the necessary brackets for the Y axis with RJZM-01-08 .
As many people state, the Z axis doesn't move that much so stock bearings should be fine.

Waldemar,
I hope you get your's soon, I'm hoping I can place my order soon too! But when I decide to upgrade, I will probably spring for the Igus rods where I use the bushings as well. The cost would be negligable.
PS: I'm also looking to get that same orange ABS. Are you sure it's the same orange as they're using for the stock parts?

Thanks again

Re: Upgrade recommendations during initial build?

Hi Maarten,

I really like the Prusa i3 MK2-X http://www.thingiverse.com/thing:1692666 idea. I will see where/how to improve and then getting IGUS bearings, etc...maybe 10mm but for sure longer X-Y IGUS rods, I don't like that the bed holder bearings need cutout in the corners and/or the bearing holders.

But if you want to start here my thoughts:
The RJMP-1-8 are 1mm larger in diameter and 1mm longer. You should be able to use them for the heated bed holder, the bed will be 0.5mm higher. Maybe you have to adjust the firmware to get the auto calibration running nicely.

Using RJMP-1-8 for the X-axis you will need to print a new x-carriage, best in ABS (i got the Safety Orange ABS in my order 🙂 ). But if you don't have a 3D printer where to get? Chicken Egg problem.

I am not sure about the Z-axis because this is not moving a lot and just safe the money here.

I think the IGUS rods are a good idea, they don't cost that much compared to the bearings.

Waldemar

RJ4JP-1-8 are drop in replacements for the LM8UUs. Anything with a 1mm larger diameter will cause clearance issues in the Y-corners and possibly with the zFrame on the X-axis.

Re: Upgrade recommendations during initial build?

After looking over the various topics on the bearing replacements, I'm not sold on a bearing that is without its own sheath.

I'll elaborate because I'm a lifelong machinist and used to working with very fine tolerances. Ive watched enough of the videos on bearing installs by end users and I see a constant issue cropping up- too easy to over squeeze them or under. A solution is to introduce a bearing within the design that removes that.

Hence my choice being the RJZM-01-08. http://www.igus.com/wpck/3663/drylin_r_rjum_01?C=US&L=en

Now, having said that, I already looked over the PRUSA parts, and retooling for the additional 1mm isnt that big of a deal. I'm working on a bigger side to the project for later (machining metal parts for mine) so accounting for the change isnt that big of a deal and I'm doing a printed version to start with, and thanks to some of the work already done by the community I didnt have much to do.

Another user here put up pics of his stock MK2 using these already and he hasnt encountered any issues. The Y carriage has ample room for a 0.5 (1mm both ways) alteration. Otherwise, theyre the same size as the stock bearings. The X and Z carriage only needs to have accounting for an additional 1mm in the diameter, which is painfully easy and a 30 second change in (laughs) even Tinkercad. These mods are simple and can be easily done while still maintaining the design structure already in place.

I want to add David already did most of the work, the link to the thingiverse files are in this thread: http://shop.prusa3d.com/forum/improvements-f14/where-can-i-find-stp-files-t2721.html#p21294

Re: Upgrade recommendations during initial build?

Ancient wolf, let me recap. You'll have three problems with igus bearings:
1) they are more tight and allow less tolerance;
2) the plastic part is compression dependent;
3) their performance is weight/load dependent (only relevant for y).

Let's focus on problems 1 and 2 for now.

RJ4JP-01-08 with zip ties will work as long as you have a decently aligned X/Y axis (to mitigate problem 1) AND they are correctly tightened (that is, "not too much" - to solve problem 2 and further mitigate problem 1). The trick is to tighten the zip ties with the right strength just to keep them in place, and although not "measurable" it is rather easy to do in practice - just have many zip-ties spares to learn and do it with the rods in place. Once tightening is right, it usually helps to glue the bearings to the zip ties to avoid rotation and linear shift while still keeping the needed out-of-axis movements. Just a drop a glue, so you will be able to remove and reuse it in the future. I tell you that it is way simpler to waste 20 zip ties doing that alone in your working room than trying to be professional with a webcam pointed at you.

RJZM-01-08 will indeed solve problem 2 by design, but problem is that for some reasons you'll be going to use printed adapters to mount them instead of zip-ties. Maybe for X there are modified parts which still use zip-ties, but i've not tried them. So you will have to solve/mitigate problem 1 entirely by assembly accuracy, because the bearings will be fixed in place. My opinion, in this world that I admit is rather new for me, is that many expert machinists have experiences based on precisely machined equipment, that is not the case of this printer, which is entirely held in place by zip-ties and cost-saving design solutions. I mean, just look at how the frame is fixed or how the X is supposed to be kept straight. So, ok for the RJZM-01-08 to avoid problem 2, but if you have experience with small tolerances, i assure you that it is way more simple to find the right zip-tie tightening than to have the entire rest of the printer perfectly aligned to support a bearing that is firmly attached to its carriage. (...and +0.5mm; you may think that's the only drawback, but look at the feet and at the Y endstop and you'll find more problems there).

After tinkering with all of these, i'm now with zip tied RJ4JP-01-08 for X/Y and LM8UU on Z. Should i ever develop a printer to be sold with the same market talk of the Prusa's printers, i would use neither of the above, but RJZUM-03-08 for all instead of cheap LM8UU and proper mounts instead of zip ties - that would solve problems 1 and 2 and just put OCD to sleep.

BTW, if you want to solve problem 3 (e.g., you print heavy things) or just want an higher quality hardware with no specific noise requirements, go for higher end linear bearings such as misumi etc.

Re: Upgrade recommendations during initial build?

PS: I'm also looking to get that same orange ABS. Are you sure it's the same orange as they're using for the stock parts?

The Safety Orange ABS should be the same. I'am checking the online shop everyday for in-stock filament and other parts. I got already 3 additional PLA s, which were not available when i ordered my MK2 :-).
The great thing is, that you get a free shipping voucher to add these to your MK2 order.
The support and service is just great! They do everything possible to answer your questions and help with the orders.

Re: Upgrade recommendations during initial build?

The support and service is just great! They do everything possible to answer your questions and help with the orders.

Indeed it is, I placed my order yesterday and the safety orange ABS was not in stock. I checked with chat support and they were able to book some back in stock for me. Really appreciated the effort on their part.

To start out, I just added that safety orange ABS and a blue PETG.

I found some other filament suppliers I'm keen to tryout based on reviews made by Thomas Sanladerer.

Rigid ink. ASA filament seems very interesting

https://rigid.ink/products/asa-1-75-mm-0-03-mm-tolerance-filament

After getting to know the printer a bit more, I'll try some of those.

Re: Upgrade recommendations during initial build?

Ancient wolf, let me recap. You'll have three problems with igus bearings:
1) they are more tight and allow less tolerance;
2) the plastic part is compression dependent;
3) their performance is weight/load dependent (only relevant for y).

Let's focus on problems 1 and 2 for now.

RJ4JP-01-08 with zip ties will work as long as you have a decently aligned X/Y axis (to mitigate problem 1) AND they are correctly tightened (that is, "not too much" - to solve problem 2 and further mitigate problem 1). The trick is to tighten the zip ties with the right strength just to keep them in place, and although not "measurable" it is rather easy to do in practice - just have many zip-ties spares to learn and do it with the rods in place. Once tightening is right, it usually helps to glue the bearings to the zip ties to avoid rotation and linear shift while still keeping the needed out-of-axis movements. Just a drop a glue, so you will be able to remove and reuse it in the future. I tell you that it is way simpler to waste 20 zip ties doing that alone in your working room than trying to be professional with a webcam pointed at you.

RJZM-01-08 will indeed solve problem 2 by design, but problem is that for some reasons you'll be going to use printed adapters to mount them instead of zip-ties. Maybe for X there are modified parts which still use zip-ties, but i've not tried them. So you will have to solve/mitigate problem 1 entirely by assembly accuracy, because the bearings will be fixed in place. My opinion, in this world that I admit is rather new for me, is that many expert machinists have experiences based on precisely machined equipment, that is not the case of this printer, which is entirely held in place by zip-ties and cost-saving design solutions. I mean, just look at how the frame is fixed or how the X is supposed to be kept straight. So, ok for the RJZM-01-08 to avoid problem 2, but if you have experience with small tolerances, i assure you that it is way more simple to find the right zip-tie tightening than to have the entire rest of the printer perfectly aligned to support a bearing that is firmly attached to its carriage. (...and +0.5mm; you may think that's the only drawback, but look at the feet and at the Y endstop and you'll find more problems there).

After tinkering with all of these, i'm now with zip tied RJ4JP-01-08 for X/Y and LM8UU on Z. Should i ever develop a printer to be sold with the same market talk of the Prusa's printers, i would use neither of the above, but RJZUM-03-08 for all instead of cheap LM8UU and proper mounts instead of zip ties - that would solve problems 1 and 2 and just put OCD to sleep.

BTW, if you want to solve problem 3 (e.g., you print heavy things) or just want an higher quality hardware with no specific noise requirements, go for higher end linear bearings such as misumi etc.

Nice insight Pat, thank you. I'm pretty confident in my ability to work precision into a +- design like the MK2. The bearings I chose to work with already have sheathing so Im comfortable with making sure the rest is aligned- I had to work with constant QC tolerances far tighter than what we have here, so its all fun for me really. The Y stop was the first thing I looked at.

I should have probably mentioned that I'll probably get matching rods for the bearings but IGUS assures me I wont have to. Not totally removing the need for zip ties, but minimizing them over time is part of my own challenge- without trying to sound snotty, my machinist OCD cringes every time I look at one. The Y carriage could easily have 0.5 milled off the bearing points and that would 100% allow zip ties too, but again I can machine my own parts and a bearing clip with even a lower profile than the zip ties is possible. It is also very possible to get the MK2's alignment square enough for a cretin like me to be happy, it just takes patience and good tools.

I love the MK2 in its present form, its working flawlessly for the most part so as a matter of my own tinkering interest the step up to as near a no degradation as possible scenario is the next step in my boredom. I'm putting together my own MK2 farm because it serves my needs and Im more than happy to continue to contribute to PR by using their stock machines; Ive already been blasted with requests for machined parts and frankly, Im not interested in doing that. I'm just lucky enough to have the right shop equipment to make these mods myself and really, I would rather be printing than making changes hehe. I just cannot justify only going slightly better if I'm replacing the bearings at all- yes, they are more expensive but I'm not in this to be cost effective with parts the solid ones are just cheap to me and doesnt solve my issues of fire and forget. We have IGUS here in the US too and its cheap enough to afford a few styles if you really want to experiment.

The same guy who I linked the 16mm mods for the bearings also has a good functional frame mod (MK2-X I think?) that has about all the things Id look for in really tearing the MK2 up, but keep in mind I would only go that far as long as I made sure I kept buying the stock from PR. I'm dedicated that way. 🙂

Re: Upgrade recommendations during initial build?

I recommend build as provided initially with any kit. Then look to improvement. If you change things before the Genuine Prusa I3 MK2 kit build, you are moving the goalposts and will not have a common starting point. There lies confusion, and complaint by you possibly about support. Just my opinion.

Re: Upgrade recommendations during initial build?

I recommend build as provided initially with any kit. Then look to improvement. If you change things before the Genuine Prusa I3 MK2 kit build, you are moving the goalposts and will not have a common starting point. There lies confusion, and complaint by you possibly about support. Just my opinion.

Hi Nigel, thanks for your opinion. Peter said basically the same thing.
However interesting the various upgrade ideas are, I think you are right to suggest first building as supplied to get a good base for comparison.
Especially since it will be my first printer and all the knowledge I have at this point is second hand.

Still have to wait some time, if Prusa's timetable is accurate, i won't be getting the printer any time sooner that February 20th 😥
But all good things come to he who waits.. 😉

Re: Upgrade recommendations during initial build?

The support and service is just great! They do everything possible to answer your questions and help with the orders.

Indeed it is, I placed my order yesterday and the safety orange ABS was not in stock. I checked with chat support and they were able to book some back in stock for me. Really appreciated the effort on their part.

To start out, I just added that safety orange ABS and a blue PETG.

I found some other filament suppliers I'm keen to tryout based on reviews made by Thomas Sanladerer.

Rigid ink. ASA filament seems very interesting

https://rigid.ink/products/asa-1-75-mm-0-03-mm-tolerance-filament

After getting to know the printer a bit more, I'll try some of those.
Hi Maarten,

Congrats that you ordered the printer and great they could get you the Safety Orange ABS, even it was not in stock now. So you start with ABS, PETG and the free Silver PLA.

I live in Belgium so the shipping costs are quite high if you order just one spool. Today i was looking at https://www.filaments.directory/ and https://www.filaween.com/#/home for companies in Belgium and Netherlands. Colorfaab ships to Belgium for free but the price is around 43€/kg. But i found ICE Filament from Belgium with a price range of 26€/kg and i can pick it up close to my place (30 min drive) for free. Still looking for ICE Filament reviews. DAS Filament from Germany Thomas Salander already tested costs around 30€/kg including shipping costs if i order 2 spools. I would like also get some rigid.ink but the shipping costs are quite high on small volume. I will see.

Waldemar

Re: Upgrade recommendations during initial build?

Hi,

regarding the main topic I'll add my voice to the chorus:

Built stock first, learn to use your printer and to understand how it behave, then consider which upgrade may be usefull for you 🙂

Regarding the Orange safety filament, is there a RAL référence (or Reichsausschuß für Lieferbedingungen for Germany ). for more information on RAL check this: https://en.wikipedia.org/wiki/RAL_colour_standard

I found a ABS producter in France that provide the color number of their filament and order one pool of RAL 2009 (to be specific it's this one: http://www.sovb3d.fr/abs-175mm-standard-1kg/12-fil-abs-orange-175mm-1kg.html ), I should have it for this week-end, hope it match !

I tried the ICE Orange PLA from amazon, but it's not the same Orange.

Re: Upgrade recommendations during initial build?

Hi,

regarding the main topic I'll add my voice to the chorus:

Built stock first, learn to use your printer and to understand how it behave, then consider which upgrade may be usefull for you 🙂

Regarding the Orange safety filament, is there a RAL référence (or Reichsausschuß für Lieferbedingungen for Germany ). for more information on RAL check this: https://en.wikipedia.org/wiki/RAL_colour_standard

I found a ABS producter in France that provide the color number of their filament and order one pool of RAL 2009 (to be specific it's this one: http://www.sovb3d.fr/abs-175mm-standard-1kg/12-fil-abs-orange-175mm-1kg.html ), I should have it for this week-end, hope it match !

I tried the ICE Orange PLA from amazon, but it's not the same Orange.

Hi Christophe,

Thanks for the tips! Regarding the safety orange, I found a ral reference on wikipedia which says RAL 2005.
https://en.wikipedia.org/wiki/Safety_orange
When checking here I found it to be close to the Prusa orange. (keeping in mind that screen colors may deviate a bit)
RAL 2009 seems a bit less bright. But I hope for you it's still close in real life.

Waldemar,
I'm from Belgium too! 🙂 I'm compiling a list with suppliers I found. I'll gladly share it with you.
Thinking of starting a new topic in the general forum with them. I'll PM you the link when ready.

Re: Upgrade recommendations during initial build?

Nice finding, I didn't assume that the term "Safety Orange" was a standardized color !

And there's no hope to compare on a computer screen, it's out of the sRGB gamut ...

At least it should be ok for the enclosure I'm building right now 😉

Re: Upgrade recommendations during initial build?

I think building it as-prescribed is fairly reasonable advice, but if you've got time to burn, then you should look ahead at certain *sore points* on the printer. Your list is mostly pixie dust and pie-in-the-sky kinds of things that aren't really upgrades, they're just alternates. Like taking another bearing and zip-tieing it back to the Y assembly and fretting about compression is nonsense because IMO the real problem is the zip tie mount style.

Go over the build instructions and look at all the parts and go through the exercise of "What if this breaks, is printed really sloppy, or is just plain defective?"

For instance, how painful is it to replace bearings after the printer is assembled? The Y axis bearings are pretty easy to replace. But the X/Z bearings are a PITA to replace because you have to go through an inordinate amount of disassembly to get to them.

What about the Y belt holder? What if you think it sucks and want to replace it? How much disassembly of the printer will you need to go through to replace it?

And so far there has been no mention of the electrical nightmare.

What if one of the parts on the X carriage breaks? What if your layer cooling fan dies? How much disassembly will you have to go through to replace it? Will you literally have to disassemble the majority of the carriage and unwrap the entire goddamn cable bundle just to replace it? Maybe consider some connectors at the X carriage end to make life easier. Yeah, it's not as glamorous as fretting over the specific color of ABS that you buy, but it might save you a lot of time down the road.

And how are you driving the printer? The Mk2 was my first SD based workflow experience, and hands down it has been awful. Apparently the firmware is more Octoprint friendly now, and that is a better interface to the printer by many orders of magnitude.

Re: Upgrade recommendations during initial build?

gz1 you've definitely got a point here. Have you developed any solutions for the design limitations you mention?

Re: Upgrade recommendations during initial build?

Hi gz1, as stated by Andre, you do raise some valid points.
And the reason for the initial question was that would have liked to prevent disassembly when not absolutely necessary. (i.e. 'nice to haves').

This design might indeed have some inherent shortcomings, but as I am a complete novice, those concerns are not as easy to address for me without any first hand experience. Plus actually having a working printer (stock or 'enhanced') is the only way I could print replacements or upgrades. (for example bearing holders in stead of zip ties, to name a simple one)

I will just have to tackle them whenever they occur. Luckily there is a very active and knowledgeable community.

I do like the idea of connectors at the x carriage, I will look into that.

Thanks for your thoughts

PS: indeed we got a little side tracked with the discussion about colors, maybe best saved for another discussion to keep this thread clean