Stickyness of the MK2-bed  

Re: Stickyness of the MK2-bed

From my little experience, you really have to wait until it's cold (room temperature) for large pieces.
I always use a spatula to unstick the pieces.
If it's really too sticky maybe your first layer is too squished.

Re: Stickyness of the MK2-bed

Hi darknico,

Thanks for sharing your experience.

The bed cooled down completely at room-temperature abput 25°C.
And the model was a figure on a plate, 5cm diameter, and it was absolutely fixed.
I finally used a very long knife to avoid to damage the bed.
And so I got a little between model and bed, which broke the stickyness.

My old bed was much easier in that point. After cooling down, it popped nearly by itself from the bed 🙂
When it was conditioned with steam and cleaned.

But perhaps there is another trick with the mk2-bed?

Re: Stickyness of the MK2-bed

Hi Daniel,

just curious, what do you mean exactly by conditioning with steam ? Using an steam iron to project steam on the surface ?

Re: Stickyness of the MK2-bed

😀

No! 😀 Conditioning in that case means, that you had to heat water to boiling, and hold the PEI-plate over the steam for about 10 minutes.
That's all. After that, the plate was sticky when hot, and not sticky when cold.
Worked with ABS and PLA. Very nice.

Re: Stickyness of the MK2-bed

Ahh, ok !

interesting, I wonder how well it could work here.

Dismantling the hetbed is a bit messy, you have to remove some cable management, but it could be worse. I'll probably have a look at that when I'll make an underbed cork insulation.

Re: Stickyness of the MK2-bed

Hi,

I use this one:
http://www.mtplus.de/Dauerdruckplatte0.html

And it's really well working. I placed it on an aluminium-headbed for a constant heat all over the plate.
It was held by four brackets. Easy to remove and maintain.

Re: Stickyness of the MK2-bed

Ok, back on topic 🙂

Does anybody know how to reduce the adhesion of the bed?

Re: Stickyness of the MK2-bed

Do you try to make your 1st layer less squished by adjusting Z?
At first I was too high and it was not sticky enough, so I lower Z just a little and it give me the extra stickiness I needed.
The other way should work too.

Re: Stickyness of the MK2-bed

Ah, I see.
I guess my first layer is really squished too much.
I'll try this. Thanks.

Re: Stickyness of the MK2-bed

Hi there,

It's me again.
I have superb results with the mk2, it's great.
But there are still some things I don't unterstand regarding the heatbad.

First, all PLA was that strong on heatbed, that I had problems removing it.
But that was ok. I followd the tip of darknico and I could countinue.

Since 3 days I try to print a special model. A robot with joints, printed in one piece, without support.
http://www.thingiverse.com/thing:539127
It worked 2 times with transparent pla. Then I tried it with the silver pla which came with the mk2.
Did not work. Nozzle at 200-215°C, Bed at 55°C, bed cleaned with aceton, alcohol, window-cleanser.
Did not work. Some of the elements warped up, blocking the nozzle in the next layer and causing a layer-shift.
I tried to use a 2layer-brim around it, no effect.

After all these tests I noticed, that the bed isn't as sticky as before.

Is there a way to refresh that?

Could anyone please try to print that robot with the mk2 and share the results?

Thanks for reading and thanks in advance for any help or idea,
Daniel

Re: Stickyness of the MK2-bed

Hi,

I've printed this one : http://www.thingiverse.com/thing:331035
Seems to be the same.
A first I tried without support.
But it failed like you. The nozzle touched the "warped" corners and unstick the piece.
Then I understand It was caused by the overhang so I added supports and flip the robot (face facing the back of the printer) to have the fan blow more efficiently to the overhanged harms.
It worked beautifully!
Mine didn't mention the supports but yours is mentioning it on the title.
Why print without it ?

Re: Stickyness of the MK2-bed

That's the "quest". It has to be printed without (additional') support. Only the support included in the model shall be used.
It's a test for the printers quality. If it works, it's ok.

The point is, the mk2 is able to print it fine. For most of the printers the accuracy is the problem. So the joints don't work, or related problems occur.
The mk2's accuracy is fine, but it fails in my case, and it seems to be the same problem that you describe, because the pla is warping in one point of the model causing the nozzle to "collide" with the model.

What's the cause of this warp?
I often read about to big temperature-differences.
I noticed this problem with my old printer too, with mk2 this problem is rare.

And you noticed that the direction of the second cooler is important?

Re: Stickyness of the MK2-bed

Hi,

I just finished to print it.

I saw that when printing the arms, it tend to warp a bit, and after a delicate phase where I helped a bit by pushing back some debris that were accumulated on the warping side of the right arm, everything was then completely fine.

I just used PLA standard setting from Slic3r with ZHop, with 0.100 mm resolution, and didn't add any brim or additional support.

But maybe my magical hat helped to avoid the pinda to hit the warping things as well ? (this one http://shop.prusa3d.com/forum/improvements-f14/pinda-hat-mk2--t1020.html ) because I was focused on the right arm (printed on my left) and not the other side which should had the same issue.

PLA used is the everyday PLA from E3D.

Re: Stickyness of the MK2-bed

Hi christophe,

Thanks for sharing the result.
I even lost a print exactly because ob what you described.
Some PLA of the joints of one arm (the other one was fine) seemed to be collided and kicked the arm from the bed. :-/ bad.

I designed a new cooler-output für the nozzle cooler, to cool from all sides instead of only from the front.
This idea follows the hint that darknico described today.
The result is a little improvement, perhaps, but not the solution.

The next try will be a print with reduced speed. Perhaps this is the trick.

What bed-temperature did you use?

Re: Stickyness of the MK2-bed

Hi Daniel,

I just used a very standard 55°C for the bed.

The issue I presume with the arm is the angle of the arm have in this position, while printed there is a very acute angle, implying a big difference of cooling capacity between the front side and the back side, provoking warping even if PLA is not very prone to warp.

Another model that make my day is a voronoi Klein bottle (this one: http://www.thingiverse.com/thing:145694 ), with local warping ruining a lot of my tentative. And since I want to mold it with acetone, ABS is almost mandatory :/

Re: Stickyness of the MK2-bed

I tried this robot in ABS -- the warping is awful so far (the overhanging arms are the problem). Other parts work and will move, I guess, but I crashed something (either nozzle or pinda) into the print, breaking off an arm one time, and hence producing spaghetti there. Also, the Y axis went out of sync everytime due to crashes, several times by 2mm or so, so the result was totally messed up.

Thanks to this thread, I have a few ideas how to print this, and I *will* manage to print it in ABS! 🙂 Against crashing the pinda, I'll use Christophe's protector, against crashing the nozzle, I'll use a larger zlift in slic3r, and I'll turn the model around and use the nozzle cooling fan. Let's see!

Re: Stickyness of the MK2-bed

Just keep us informed 🙂