How do you level the nozzles??

[rhymeandreason 2]

I'm assembling the dual extrusion kit, and got almost to the finishing point with the instructions in the Ultimaker wiki, but then got stuck.

In the instructions, it says that the new nozzle (placed behind the new nozzle), should be just a little higher than the old nozzle.

No matter how I try, I can't get that to happen.

It seems impossible, since I can't even get all 4 of the long screws to go in evenly.

Is there something I'm missing to this?

I looked around for mods people have done, and only found this:

http://www.thingiverse.com/thing:169888

It looks like a different printhead mount for the 2 nozzles, but don't know where the thermocouples would go in that design.

And I don't know if that would help with the leveling issue.

Plus, why is the new nozzle supposed to be a little higher? I thought you would want to make them both exactly leveled.

Any help is much appreciated!

 

[drayson 75]

Hi!

As far as I remember, for leveling the bed the first time, the second nozzle should be a bit higher but after, you have to set them equally as they have to have the same distance for printing layers.

I have choosen a different setup so I can't give you more detais on the original setup... :-(

[Dim3nsioneer 557]

As drayson pointed out, during bed levelling, the second nozzle should be a bit higher up in order to avoid collision with the unlevelled bed. After having levelled the bed with the first nozzle, you adjust the height of the second nozzle with the long screws. Be aware that by turning one of the long screws you might also change the height of the first nozzle again. A perfect levelling procedure is therefore iterative.

One important thing: Both nozzles should have the same temperature when you level them against each other. I recommend bed levelling with a cold but clean nozzle. I level them to a distance of 0.06mm (in the meantime, I do this by eye in most cases). Together with the thermal expansion of the hotend in z direction by 0.1mm between room temperature and 200°C this gives a very nice first layer thickness which adheres nicely to the bed.

Other people recommend levelling with a hot nozzle. You can do that but you would have to really put it down to the bed surface in order not to get a too large gap between nozzle and bed.

Another thing you should be aware of: If you have the standard plexi bed, don't be confused if you perfectly levelled the two hotends against each other in one position of the print head, move the print head to a different position and realise that your precious mutual levelling has gone. The plexi bed is not flat. However, I usually managed to have a resonable mutual levelling. A small trick of mine: I once printed a three or four layer area on the plexi bed. The surface of such a print is quite even if you used correct print parameters. Then I did the mutual levelling (after letting the nozzle cool down) on top of this printed surface and it was perfect.

I guess this is more information than you actually wanted...

 

[3dcase 37]

Hi,

the original design with the bended extra washers is pretty smart I still think, (using standard parts).

You have to play with the tension of the 4 long bolts to do the adjusting, while it swivels around those washers.

It can be done, just try and experiment some more I guess.

But in my humble opinion, the levels changed to much, due to temperature? and even the filament pressure

In fact he entire printhead, all the wooden parts are only clamped together by the force of the 2 washers, is almost 'falling' apart.

The second nozzle a little higher? perhaps to keep it from hitting the previous layer?

You could try and keep them the same level, seems more logic to me. Haven't tried dual printing with the new cura 14.03 yet, but the Z-hop function could be a nice feature in dual printing.

The printhead you linked in your post? I would go for this one personally . https://www.youmagine.com/designs/dual-printhead#!design-information

You might achieve the same effect, by adding 8 M3 nuts to the standard setup.

2 on each bolt, in between the lowest thicker wooden part and the part the 2extra washers hit.

Leave out the washers, and use the upper nut to clamp the printhead/bearing part and the lower nut to clamp the nozzles and do the levelling with.

Because of the thread in the Alu plate the levelling might be difficult. If you dare, dill out the thread and use an extra nuts on the bottom alu plate instead.

Lot of luck and wishdom!!!

Kees

.

 

[rhymeandreason 2]

Thanks everyone for your tips!

After trying lots of times, I think it really is that the design is too wobbly and not stable at all. The whole thing only has the bottom aluminum plate to grip on to, and the 2 wood plates in the middle that actually hold everything in are completely loose.

I tried putting in 2 nuts on each one, between the wood plates. That worked, and I got it leveled, but as soon as I put filament through, it pushed the whole thing out!

Now I'm printing some extra parts to clamp the bottom pieces all together. Looking at the UM2, the bottom part is where all the important stuff fits together, and it needs to be a fixed height.

Thank goodness this is my second printer. Not sure how you would manage to do it without another printer to make extra parts.

If it works, I'll post what I come up with. *cross fingers!