10mm Rods for all Axes  

RE: 10mm Rods for all Axes

From mechanical aspect, it is reasonable to change/modify the rods that can impact on performance/stiffness on specific axis. There is no need to change all if no mechanical benifit behind it. 

RE: 10mm Rods for all Axes

Yes, but that is the question, does it give any benefit or does it not?

I would assume they had made it if there is a benefit, but it also can be a matter of costs.

RE: 10mm Rods for all Axes

It would benefit, but 10mm rails and bearings will chew up a lot of space and a new frame would be required. I think if looking at using larger rods, then going with rails would be a better option. 

RE: 10mm Rods for all Axes

On Y that surely will cost buildroom, but it still would be more than the MK3. I could live with that.

On X it should not make a differenz as long as there is enough material left in the printed parts after opening the whole from 8 to 10mm.
Let's see how the printable parts look, hope they publish them soon.

I already tried rails on my MK3, but was not able to get that working. Rails do not forgive as much as normal bearing, even for a desk worker like me 😉.
I did not try Hiwins, I took some from Igus.
Meanwhile I am with sinter bearings from Igus on Y, that works good enough.

The i3 is an established product with about a third of a million in use, this is the fourth major revision.

Any change is incremental, relatively minor, and as a result of extensive testing and user feedback; one of the advantages of the Prusa style support system is they get to know about the average user's experience as well at the millions of in house print hours.

They are addressing VFA's for example, something that 90% of users probably never notice.  I print a lot for engineers and have never had them queried.

You can safely assume that many different sizes of smooth rod have been tried on all axes.  If they change one to 10mm then it is because they discerned an advantage, that they don't change the others then presumably they decided that they are already at the sweet spot.  I'd hazard the extra weight cancels out any increased precision on X.

If you have a Mk3 in good order then don't expect a Mk4 to print significantly better, it won't.  Expect it to be a little faster and a little easier to use but that doesn't excuse you from maintenance.  Just now I changed nozzles to print some copperfill parts, the nozzle change on the Mk4 will be quicker and there's no need to recalibrate the first layer but that only saves about 10 minutes and many users never change nozzles so would get no benefit...

I assume the main drivers for the revision are:

User expectation; we are too used to fashions changing every year so a period without change causes speculation *even if there is no need to change.*.

Einsy limitations:  There's just no room for software to further exploit the hardware.

Exploiting the 32bit controller:  Several features that were limited by software can now be exploited including newer hardware.

- and there may have been increasing difficulty sourcing some components.

Although the machines are designed to be open for user modification the great majority of those mods don't actually make much difference.  Why? because the i3 is an established product with about a third of a million in use and this is the fourth major revision.

Cheerio,

RE: 10mm Rods for all Axes

As with most such decisions, my guess is that the benefit didn't justify the increased cost and the need to redesign to accommodate the larger rods.

Posted by: @stefan

Hi,

is there a good reason for using 10mm rods only on the Z-Axis?
I would expect that it would also be an advantage on the other two Axes.

While thinking about buying an MK4 I wonder if I should change all Axis right from the beginning to 10mm.
Mainly in the hope that it will make the printer even more silent, at least when the firmware allows higher speed some day.
Hope the printable parts are out soon so that one can try to start with some modifications.

Stefan

RE: 10mm Rods for all Axes

Thanks to all for your comments.

@Diem
You surely are right that Prusa must have made their own thoughts about this issue, and decided for good reason as they did.
I did not want to blame Prusa do do any stupid stuff or so. There are to much people with useless comments on that all the news features are present in other printers since long. Yes, may be, so what? Think they do a good job there, hence I would not think of buing one more machine.
May be a part of my intention also was to have a reason for doing some modifications just for fun 🤤.

I in fact do not expect too much better prints from the MK4, just a bit regarding those vertical fine artifact (do not like them) which they claim to reduce with the VFA-Motors.
Printing faster would be good to, but as this only works in a later firmware I do not know how much that would be at the end.

The main thing ist the bed calibration, which is a work I do not like, and the much easier way to exchange parts on the extruder.
Indeed I often unmount the fans to clean them and therefore build my own way to make this possible on the MK3, witch a simple micro plug I added into the wire.
May be I want to change a nozzle from time to time with the MK4. I did avoid this on the MK3 as it is much to much effort to me.

Well, must be a "I must have this" thing 🤩 
How should one live with two MK3s only ..... 😉 

RE: 10mm Rods for all Axes

Input shaping should dramatically reduce ringing. On the livestream, they said you can expect an increase in print quality as well as speed.  The print quality of Mk3S+ is already pretty terrific, so that's exciting. 

The main thing ist the bed calibration, which is a work I do not like, and the much easier way to exchange parts on the extruder.

The first layer calibration gets easier with practice.  For the last couple of years I've been annoyed if I fail to get it right in one pass of the built in routine.  Quick nozzle changes would save time but that's not a good enough excuse to buy atm.

Cheerio,

RE: 10mm Rods for all Axes

Posted by: @diem

The main thing ist the bed calibration, which is a work I do not like, and the much easier way to exchange parts on the extruder.

The first layer calibration gets easier with practice.  For the last couple of years I've been annoyed if I fail to get it right in one pass of the built in routine.  Quick nozzle changes would save time but that's not a good enough excuse to buy atm.

Cheerio,

Don't you destroy my creed 😉 😉 😋 

RE: 10mm Rods for all Axes

I mean, yeah?  But the closer we get to fire and forget, the better.  I've gotten fairly decent at it, but I'd rather NOT spend my time doing that.  And occasionally, I forget to change which sheet I'm using in the menu, or even accidentally select teh wrong one. It'll be nice to not have to worry about that. But, I mean, if the upgrade doesn't make sense for you, that's cool.

Posted by: @diem

The main thing ist the bed calibration, which is a work I do not like, and the much easier way to exchange parts on the extruder.

The first layer calibration gets easier with practice.  For the last couple of years I've been annoyed if I fail to get it right in one pass of the built in routine.  Quick nozzle changes would save time but that's not a good enough excuse to buy atm.

Cheerio,

RE: 10mm Rods for all Axes

This, basically.

A lot of people seem to be under the assumption that every change to the mk4 has some amazing and notable improvement to the final product - but the important changes are the new extruder and the 32 bit board with input shaping, everything else is marginal at best.

The 'stiffer frame' exists because they're going to a die-cast process to make frames now and can design a marginally stiffer frame - not because the new frame design has an amazing improvement on prints.

They're going with the new heat bed because its a marginal improvement for the same cost - not because it has an amazing affect on bed flatness.

They're going to stiffer rods on the Z-frame because they noticed a slight issue with the 8mm rods that this corrects - but an issue that wasn't apparent on the X and Y axis.

RE: 10mm Rods for all Axes

In general I agree with what has been said so far: with Mk4 we shouldn't expect "that much" difference in print quality and speed. Fact is, changes (i.e. Z-rods) have relative small improvement impact. But then, big majority of Mk3 owners never complained about print quality (as long we have reasonable expectations).

Still I think, that Mk4 became much more user friendly by having new 1st layer calibration solution. Yes, we do it manually for years etc., but let's be honest: it's not something one would enjoy doing -especially not on Mk3 (Mini is better in this regard, because we can actually see what's going on under the nozzle).

Will I upgrade my Mk3S+ Bear to Mk4? Well, 640€ is a lot of money for an full upgrade... even 550€ option (without motors) is a lot! I honestly don't know yet.. is quite possible.

Just sharing my thoughts,
Bogdan

RE: 10mm Rods for all Axes

Is there a current parts list for the MK4 available?

RE:

You mean the printable Parts?

Am also waiting, but there is nothing yet.
Hope they come out next few days.

RE: 10mm Rods for all Axes

Posted by: @bogdanh

Will I upgrade my Mk3S+ Bear to Mk4?

Just sharing my thoughts,
Bogdan

For me the price between the Upgrade and a MK4 Kit is by fare to low to aven think about it.
I would rather sell my "old" MK3 or keep him just in case of need.

RE: 10mm Rods for all Axes

I'm actually trying to find the bearing part number used on the Z 10mm rods.

Thanks

RE: 10mm Rods for all Axes

That should be four LM10UU then.

Or twice LM10LUU if the design has changed from the MK3.

The latter is already used in the mini printer.

To the bearing .

RE: 10mm Rods for all Axes

At 1:56 from this Youtube Video you can see that they use the long version.
So LM10LUU ist the right one.