3D Printing Forum

Anders Olsson wrote:- Do not over-tighten the nozzle! It should take about 3 Nm before it breaks compared to 5 Nm for normal nozzles, but 0.25 Nm is normally enough for it not to leak (use the printable torque wrench).

Do you recommend this? Given the fact that most buyers would just screw it in(like I always do and was planning to do ?)
I might have to change plans then

I used the printed torque wrench at the beginning until the inner part broke. Since then I use a standard wrench. I don't know what exact torque I apply but it's much less than the originally mounted 0.4mm nozzles have seen back in December.
Other question: What about cold pulls with the ruby nozzle? Yes? No? Big No?

I only used the new ones for a week but so far I done 20-atomics. No issues.

Cold pull / Atomics should be no problem for the ruby nozzles.

Titus wrote:

Anders Olsson wrote:- Do not over-tighten the nozzle! It should take about 3 Nm before it breaks compared to 5 Nm for normal nozzles, but 0.25 Nm is normally enough for it not to leak (use the printable torque wrench).

Do you recommend this? Given the fact that most buyers would just screw it in(like I always do and was planning to do ?)
I might have to change plans then

If you use the tiny wrench that comes with the UM2+, i doubt you will achieve enough torque to destroy the nozzle.
However, if you are using a large adjustable wrench, you should be a bit careful.
That is valid for all nozzles of course, but the ruby is a bit more sensitive.

I did over-tighten the first ruby nozzle in this batch badly just to see what happens, and when I unscrewed it and tightened it again with 0.25 Nm it did in fact leak. I haven't had time to investigate this further yet though, but all other nozzles that I made so far (and tightened with reasonable torque) has been working fine.
So over-tightening issues is not fully explored yet, that is why I warn you

I have a very basic question re. nozzle changing on UMO...

When you follow the build manual, the process for mounting the hot end is:

1. Tight the nozzle on the block
2. Tight the brass pipe (which then comes against the nozzle)

Now when you swap nozzles, if the threaded part is not of the same size you are in trouble:

1. If it is shorter, it will leak from the brass pipe (happened to me the first time)
2. If it is longer... well I don't know, I haven't tried that, but that might work...

So... Are you always re-adjusting the brass pipe after changing nozzle? (which makes the swap a bit of pain)
Or have all your nozzles exactly the same thread size?
Or are you locking the nozzle on the brass pipe instead of the opposite?

On umo I hate to change nozzles, I have break 3 original umo alu blocks by doing it so. But. I never touch the barrel. And if posible, I don't do atomic. Take out the nozzle at 90 so there's filament on the cold area. I know it isn't ideal, but...

When I done it without residue sometimes when tightening the nozzle the barrel rotates, and that can make (if hot) that the barrel goes up a bit and marks the peek, pushing the coupler.

Anyhow, after 10-12 nozzle swaps I start to have the barrel tilting because the alu m6 screw dies soooo fast. With the um2 hotend it's just a walk in the park. Now I understand why people don't mind changing the nozzle from one print to another. On umo it sucks to hold the block with one wrench and take out the nozzle hoping all its tight and doesn't leak...

When changing a nozzle in the UMO I hold the block with one wrench and unscrew the nozzle with the other, at 200 degrees.
When I install the new nozzle, I always just screw that in by hand, at 200 degrees. I learned this from Joris, that if you do it normal, i.e. fast enough, the nozzle will remain cold until tightened.

The ruby nozzle however is smaller to hold, and will probably heat up faster. I wonder what the best method for that will be

I just printed out the "click one" when I got the first olsson block and have been using that one to great satisfaction ever since. Dunno how much torque that one skips one but it seems to be enough

What I want to know is when these nozzles go live? It looks like they will produce a higher a degree of accuracy over the standard brass affairs, and I print some very high precision components (very high for 3D printing anyway) and anything that helps towards this is a boon!

The next batch might be ready in a month or so, but it depends a bit on the results from the testers that has received the current nozzles.
If you want a test-nozzle, danilius, I can probably send you one form the current batch.

The difference in printing quality will probably not be huge, the main feature with the ruby is that it generally does not wear.
Some types of filament seems to print significantly better with the ruby though, so the potential for improved quality depends on what you print.

I did some tests on using steel wool to clean the ruby by the way, it seems safe I would say.

Nozzle after 40 hours of ABS-printing: Regular steel wool, nozzle heated to printing temperature: Nozzle after cleaning: Closeup of ruby: What appears to be a slight wear of the outer edge of the shoulder is just a reflection I think, will have a look on in a better microscope another day.

Anders Olsson wrote:The next batch might be ready in a month or so, but it depends a bit on the results from the testers that has received the current nozzles.
If you want a test-nozzle, danilius, I can probably send you one form the current batch.

Decisions, decisions. Yep, that will do me fine. Can I pay by PayPal?

Anders Olsson wrote: The difference in printing quality will probably not be huge, the main feature with the ruby is that it generally does not wear.
Some types of filament seems to print significantly better with the ruby though, so the potential for improved quality depends on what you print.

Well, there is only one way to find out. Since I print things that simply do not look like anything else I see on various forums, my assumption is that I might get some unexpected results. Whatever results I do get - good, bad or ugly - will be reported here, or wherever you prefer. I think you might be onto something that's useful beyond abrasive materials. Especially because of the external geometry.

You can clean the nozzle with ABS. Heat it up and push some filament on to it. Allow the nozzle to cool and yank.

Hi Anders, how do you want us to communicate our findings, open on the forum or private message? So far it's the "mutts nuts" on PLA, just testing some XT.

Easiest for me is if you post your results here, good or bad

Posting things in a thread like this saves me a lot of time compared to trying to communicate through individual emails.
As I am fairly busy already and likely to be even more busy soon, this is the only way for me to run product development like the ruby nozzle.
I risk giving away secrets to competitors and I am giving away lots of things for free, but the time I save by doing it this way is more valuable for me.

It is likely that you will have a slightly harder time getting nice top layers with the ruby by the way, while overhangs generally looks a bit better.

Performing external cleaning of the nozzle with hot plastic is one thing I did not try yet. It might potentially pull the ruby out of the holder, but please feel free to try. I have already improved the mounting on the next version.