Can your UM2 printer achieve 10mm3/s ??? Test it here...

[mr.-waldorf 0]

Hi Skint,

Congratulations! You have the best printer on the Market and is working well.

I know that you have your printer at short time but it seems that some users report problems after some use, hopefully this is not the case and that you have a perfect condition printer

Many thanks for the tests and the posts

Cheers

 

[skint 62]

Hey Mr W.

Im hoping that its just not beginners luck. Infact, knowing that some users have reported degradation over time, I have just placed notes in my diary to re-test this piece once every two weeks....forever, until I see a noticable difference.

 

[Nicolinux 288]

One thing I want to do is replace the nozzle block. l posted a support ticket this morning asking for a replacement nozzle and teflon part. I'll pay for them if needed. I also pm'd the request to Sander. No response from either as yet.

 

This didn't change anything for me.

I did replace the teflon piece and also made sure the nozzle was not clogged or otherwise damaged. You can simply test it by removing the bowden from the head, heat up, insert filament, let it cool to 90° and pull it out. If the nozzle shaped filament tip is smooth, then your nozzle is fine.

 

[shurik 87]

That's how it came out for me:

Looks pretty much perfect.

Then, what does that mean? We can print at blazing 100mm/s for 0.2mm layers and wholly 200mm/s for 0.1? Is that so?

 

[mr.-waldorf 0]

Hi Shurik,

Congratulations, your printer rules! The extrusion test is with 0.25 layers.

For 0.1mm layers:

3mm³/s = 75mm/s

4mm³/s = 100mm/s

5mm³ = 125mm/s

6mm³ = 150mm/s

7mm³ = 175mm/s

8mm³ = 200mm/s

9mm³ = 225mm/s

10mm³ = 250mm/s

Thank you so much for the post. I was convinced that your printer would be in the problem list, I am glad that is not

 

[IRobertI 521]

I repeated the test and it worked the second time as well so it wasn't just a fluke. I did however look at the finished print a bit more closely and it's apparent that around the 7-8 mark the temperature is a bit too low. The surface is no longer shiny like the lower parts and I think it's probably under extruding a little bit. Raising temperature to compensate could likely cure that. But for me personally I'm very happy as this means I should be able to print at around the same speeds as my old UM1.

 

[shurik 87]

Oh, I thought for whatever reason that the test is with 0.2mm layers. Thanks! So it seems, 0.2 at about 60 mm/s should be just good.

BTW -

 

I was convinced that your printer would be in the problem list

 

Why? I'm not a big troublemaker usually.

 

[mr.-waldorf 0]

Hi IRobertI

Thanks, that is very important data. For you, increase the current delivered to the motor solved the underextrusion.

Congratulations, you have the best and most beautiful printer on the market. (I love your spool holder) :wub:

Damn, it seems that UM2 underextrusion problems are becoming a urban myth. Only 3 users reported problems

 

[IRobertI 521]

I should probably switch back to the old feeder as well and try that with the increased current. I'll do that tomorrow.

 

[woofy 12]

This didn't change anything for me.

 

@nicolinux,

I know you replaced the teflon part, but did you replace the nozzle as well? I've followed your thread but may have missed that.

I am simple not able to get the extusion rates others are getting and I need to to eliminate suspects.

 

[mr.-waldorf 0]

I should probably switch back to the old feeder as well

 

Why? I'm very pleased with your results.

Your spool holder is very usefull to avoid under extrusion on longer prints. I printed one for my printer, but I am not using it just for test purposes, otherwise is one of my printer bests friends.

 

 

[gr5 2,230]

let it cool to 90° and pull it out. If the nozzle shaped filament tip is smooth, then your nozzle is fine.

 

I disagree. I mean you might be right. But also I think it's possible that the gunk on the inside of the nozzle - although very thin - could cause problems. When I got a brand new nozzle it was so shiny I could see inside it easily. My old nozzle is so black I can't see anything in there.

I did the 90C pull, look at shape test and got some beautiful results but that doesn't mean there isn't something inside the nozzle that is - well - sticky?

 

[mostlyatomicbob 34]

So, I printed this https://www.youmagine.com/designs/um2feeder-v3 over night on my trusty UM1.

and here are my results:

 

The print on the left was with the stock UM2 feeder mechanism, and on the right with the new 'improved' mechanism.

 

not much difference really.

 

I would be interested in being able to tweak the current to the extruder motor, but being a bit of a luddite i am not sure how to do this!

 

Bob

 

[Nicolinux 288]

@Woofy: No I didn't change the nozzle.

@gr5: I'd imagine that if there's something inside the nozzle, you'd at least feel it when you touch the filament tip. And if the "gunk" is that thin, then it wouldn't impair extrusion.

 

[takei-naodar 0]

So, I printed this https://www.youmagine.com/designs/um2feeder-v3 over night on my trusty UM1.

and here are my results:

 

 

The print on the left was with the stock UM2 feeder mechanism, and on the right with the new 'improved' mechanism.

 

not much difference really.

 

I would be interested in being able to tweak the current to the extruder motor, but being a bit of a luddite i am not sure how to do this!

 

Bob

 

That is only natural.... the point in the new feeder was to create less points of contact with the knurled material and more importantly change the Material that would get abrased. You should try out my Spool/ Feederholder. Also a good tip would be to get a tiny tiny tiny drop of oil on the ball bearing. I noticed earlier that it did not spin very good so i lubricated it a bit.

 

[woofy 12]

Hi Bob,

The gcode file is just a text file that you can edit, I used Wordpad.

Here's my hack (highlighted in Red) to increase the motor current to 1500mA (1.5A).

;Generated with Cura_SteamEngine 13.12

;FLAVOR:UltiGCode

;TIME:1041

;MATERIAL:6167

;MATERIAL2:0

;Layer count: 320

;LAYER:0

M107

M907 E1500

G0 F4500 X89.56 Y87.02 Z0.25

;TYPE:SKIRT

G11

G1 F1800 X91.88 Y84.90 E0.31448

G1 X94.36 Y83.00 E0.62680

G1 X97.01 Y81.31 E0.94125

 

[mostlyatomicbob 34]

Thanks Woofy.

But I think I might have found the root of my problem:

 

The teflon part has a fairly large deformation which I am sure is inhibiting the flow of the PLA.

 

I will open a support ticket and see if i can get a replacement

 

[IRobertI 521]

So, I printed this https://www.youmagine.com/designs/um2feeder-v3 over night on my trusty UM1.

 

Just a note on this one. That's a modified version of my very first draft of a new feeder design, it was completely untested by myself when Takei put it up on Youmagine. I'm actually a bit surprised it works at all

 

[gr5 2,230]

The teflon part has a fairly large deformatio

 

Your picture is a bit blurry but is there a dent in the top left region? Does that impair filament?

Did you try sliding some filament through there to see how much force is needed? Typically the extruder can push 5kg of force. The resistance would need to be at least 1kg to notice much difference in printing ability.

 

[rabanwin 0]

Hi Everyone,

OK, I can reach the 10mm²/s , but at 9mm²/s there are occasionally problems. At 10mm²/s I can hear the extruder spring click every 4 seconds and there are small gaps in the print. The result sound pretty good for me.

I'm a bit confused. The extruder have always problems when printing the first Layer of a large surface. (0.3mm initial layer thickness, 20mm/s bottom layer speed, PLA at 115^oC). The extruder spring clicks and I don't get a regular surface. The building plate leveling looks OK for me.

I thought the extruder is not strong enough to handle that - but after the test I would say it should. Any Ideas?

 

[mostlyatomicbob 34]

gr5.

Yeah the photo is a bit rubbish.

The inner surface is deformed, it buckles inwards and outwards.

When it is assembled with the hot end i can feed filament through but I can feel it catching.

I think the problem maybe that when I am printing and the filament is retracting, the PLA is still soft and it forms into the deformation, then it jams into that shape.

When I have been cleaning my nozzle i have noticed an extra blob on the filament that looks roughly like the shape of the deformation int the Teflon part. I will take a photo later.

Out of interest is this part Teflon or PTFE? As i have access to a good lath and both materials, so it maybe fast for me to make one of these parts.

 

[gr5 2,230]

The extruder have always problems when printing the first Layer

 

.3mm at 20mm/sec with .4 nozzle is 2.4mm^3/sec which isn't excessive even for 215C you should be fine. I'm sure you are just a tiny bit too close to the glass when you last leveled. If you are off by even a half width of paper (too close) then you are putting .3mm height PLA into a gap of .25mm.

Repeat the levelling procedure but don't touch the 3 screws. Instead only adjust the height at the rear point and adjust only electronically by turning the dial. Put a piece of paper in there and it needs to be a little looser than you did in the past.

Also if you level with the bed and nozzle "at temperature" you will get a better result as both of these expand when hot. 180C is close enough for the nozzle and safer temp to leave just sitting there than say 240C which will conver PLA into brown gunk.

 

[mostlyatomicbob 34]

A couple of marginally better photos:

 

[Nicolinux 288]

Hey, I had the same problem. I then filed the inside of the teflon coupler a bit but it didn't change anything.

 

[gr5 2,230]

is this part Teflon or PTFE?

 

I sure dont' know. I don't know the difference. I think probably PTFE though.