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Re: Testing for the new shroud?

Posted: July 17th, 2016, 5:17 pm
by Neotko
LePaul wrote:I'm not sure I understand the gap you guys are commenting on? A few months when I adjusted it and the new ruby nozzle, everyone said it was perfect?
I said perfect to this photo

viewtopic.php?f=9&t=4&start=240#p3329

But on that photo I didn't saw the upper side. That should look like this

viewtopic.php?f=9&t=4&start=225#p3314

The gap between the alublock & peek on your photos it's too small. That affects the hot/cold zone making weird stuff like blops or inconsistent printflow. Also, the hole of the fancap it's too big allowing air to hot the alucap.

Re: Testing for the new shroud?

Posted: July 17th, 2016, 6:11 pm
by LePaul
Alright well I can't print another shroud for a while since I'd have to print a replacement

How do I increase the gap?

Re: Testing for the new shroud?

Posted: July 17th, 2016, 8:54 pm
by LePaul
Okay I'm looking at the gap you say I should have there.

Now my brass pipe is fully threaded in as it should be

To compare I have a spare hot end kit. Apart and assembled are just like what I have installed....
image.jpeg
image.jpeg

Re: Testing for the new shroud?

Posted: July 17th, 2016, 10:55 pm
by Neotko
Example of how it should look like from amedee img

download/file.php?id=487&mode=view

Wiki explained very well how to assemble it
https://d2py9w124w2itd.cloudfront.net/p ... .36.17.png

Re: Testing for the new shroud?

Posted: July 17th, 2016, 11:17 pm
by LePaul
Hmm, so is isn's supposed to thread all the way inside? That explains why my nozzle isn't flush since you guys suggested tightening it up. Ah...tweak and re-tweak

I changed the acceleration to 2000....see how that goes

Re: Testing for the new shroud?

Posted: July 17th, 2016, 11:22 pm
by LePaul
I did remove the shroud earlier and try to loosen the brass pipe from the heater block. Maybe that requires it to be hot...it wasn't moving.

I did an atomic before removing everything and double checked the extruder feed side looked ok. It's clean.

If I was certain the heater block and sensor would come out clean, I'd just install the new one

Re: Testing for the new shroud?

Posted: July 18th, 2016, 8:19 am
by gudo
LePaul wrote:Okay I'm looking at the gap you say I should have there.

Now my brass pipe is fully threaded in as it should be

To compare I have a spare hot end kit. Apart and assembled are just like what I have installed....

image.jpegimage.jpeg
Hi LePaul
My 2 cents if that can help !
your pic shown the Peek screwed fully in the alu heat block,for getting the good position,
does that to be screwed after the nozzle in place on the heat block :?:
Image
Image

I made a virtualy assembly from the Ultimaker UMO+ step files, so it reveals an inconsistent point compare with some part sizes done
May be it would be have to check the deep of the 6.3mm hole Peek :!: :?:
Image

Re: Testing for the new shroud?

Posted: July 18th, 2016, 9:54 am
by LePaul
Visuals are good!

Well two points...

1) As it is now, with the fans tuned to 12%, I am getting good prints. I also lowered Acceleration in the firmware from 4000 to 2000 and my overnight print came out very good, the banding/ringing was not present

2) I could take apart the print head and make the changes shown above. But...I am also concerned about damaging the heater and sensor from the block. If those are damaged, I am unable to print until replacements arrive. Being months behind on printing, I think I am going to try to remove the heater and sensor...and if they come out easily, I can replace with my space block/PEEK and brass coupler. If there's resistance....I may keep things the way they are for now.

Re: Testing for the new shroud?

Posted: July 18th, 2016, 10:11 am
by Neotko
Nice one gudo. The ptfe coupler it's 5.1 length not 5. And indeed there's a 0.2-0.1 gap on the design that on the reality isn't there (no clue why)

Lepaul if you try to take out the sensor/heater the only way to do it it's by hammering the oposite side to push it (specifically because you had some leaks in the past and material will be there). If your prints are ok leave it for now.

Low aceleration downside it's:

- Worse toplayers because when going on a corner the shift in speed will make weird stuff on the feeder, unless you print at 20mm/s
- Slower prints, with higher quality.
- Small toplayers that have zigzags will get errors if you print faster than 20mm/s

So yeah, it can work, but some prints will get weird stuff (that probably isn't a problem if you are going to paint the parts layer).

Re: Testing for the new shroud?

Posted: July 18th, 2016, 10:16 am
by Neotko
Gr5 50% answer it's to print slower. If you print slower with low aceleration you ofc will get good prints. I'm more focused on printing at no less than 70-50mm/s all the time and getting decently looking prints.

A um in good shape can print quite ok at 50mm/s and fantastic at 30mm/s. At 20mm/s almost any printer can print

Re: Testing for the new shroud?

Posted: July 18th, 2016, 10:31 am
by LePaul
What acceleration setting would you suggest?

I would like to print faster (50mm/sec)

I have been using 40mm/sec @ 210 for quite some time now. If I went up to 50mm/sec, should the temp go a bit higher?

Re: Testing for the new shroud?

Posted: July 18th, 2016, 10:45 am
by Neotko
Well I can't tell you much because I use 1.75mm and it needs less heat than 2.85. I print 70mm/s at 210-215 for 0.2 layer height. I use standard aceleration 3000 (um2 uses 5000 because his more stable frame and lighter hotend).

To print faster you need to have a perfect hotend assembly so there's less weird preassure changes. But if your prints look ok for now just keep them going until you get free time to adjust everything.

Re: Testing for the new shroud?

Posted: July 18th, 2016, 10:59 am
by LePaul
3000? Okay the firmware default was 4000 I can try 3000

Good point on the hotend. Maybe I'll do a Ultimaker robot at 50mm/sec and 210 and see what happens

Re: Testing for the new shroud?

Posted: July 18th, 2016, 11:51 am
by Neotko
Don't use 210 for 2.85mm filament & 0.2 layer. That's for 1.75mm filament. As I said for 2.85 I don't have the recipe.

True 4000 it's the default. Seems UM2 default it's 3000. Weird, that's what I use on all my machines.

Re: Testing for the new shroud?

Posted: July 18th, 2016, 11:56 am
by LePaul
Neotko wrote:Don't use 210 for 2.85mm filament & 0.2 layer. That's for 1.75mm filament. As I said for 2.85 I don't have the recipe.

True 4000 it's the default. Seems UM2 default it's 3000. Weird, that's what I use on all my machines.
I wonder what the recipe is! :)