What are the exact distances required for bed levelling with the Olssen block and different nozzle sizes?

[shaund 0]

Hi,

Coming from a print background where 'level the bed with a sheet of paper' gives a huge scope of variety, I'm coming to the conclusion that my best bet would be to use a metric feeler gauge to get the exact distance set.

So, my question would be, does anyone know the required distance from nozzle to bed required to get the .25mm, .4mm and .8mm nozzles to work without playing the 'adjust it when it's starting to print' game - something that I really dont want to do with the .25mm nozzle in case I crash into the build plate..

Is it dependent on the first layer height and so depends on this or is this an absolute value and the printer takes care of the rest?

Regards

Shaun

[DidierKlein 729]

Usually i don't relevel the bed when i change the nozzle. Some users do some don't.

What i do personnaly when i change the nozzle:

During the printing of the brim or the skirt (i usually go for a skirt of at least 3 perimeters.

I fine tune the level of the plate with the 3 level screws.

You want your first layer to be squished but not too much, if it's almost transparent you are too close, if the layers is not squished and are "rounded' then you are too far.

If your first layer is 0.3mm then the bed must not be perfectly leveled

[kolia 31]

S/He said s/he doesn't want to adjust it while starting the print, in fear of damaging the nozzle.

I'd be curious too.

Since we want to squish the first layer and we send the equivalent of 0.3mm, then I would suggest you to try to level and print at 0.2mm gap to start and then adjust by +/-0.05mm according to the output.

And if you can, maybe go for a dial gauge? There are easy fixtures to set it up on the print head to check this. Because with your feeler gauge you basically fall back to the paper trick: what to decide if you can slide your gauge but it's kind of scratching ? (especially since the bed is on springs).

[gr5 2,225]

I believe Daid once said that when you level the bed with the official procedure it assumes you are leveling it such that the head is .08mm above the bed. So you could use that value if you have a feeler gauge at that value. Using a 0.1mm gauge should work well also.

At various times I have had to unbox 5 brand new ultimakers and get them printing quickly. I have learned to use the leveling procedure and to it by eye. I try to get it so the head is just visibly touching the glass. It's extra easy to do in the front corners because you can tap the bed a bit and watch and feel and hear it move up to hit the nozzle if it isn't quite touching the nozzle. With the rear screw that doesn't help.

This procedure seems to give fantastic results first time every time.

However another great option might be to install tinkerGnome's version of Marlin. That actually tells you the offset that is stored for leveling and you can adjust it by any amount. So if you are changing nozzles often you could level them each perfectly once and write down the final value (but you would have to level without *ever* touching the screws). Or alternatively you could keep track of the *difference* between the 3 nozzles and adjust leveling by the correct amount.

you can get that version of Marlin (which is really fantastic version of Marlin!) here:

https://github.com/TinkerGnome/Ultimaker2Marlin/releases

[shaund 0]

Thanks for your responses so far - I must admin that I am a bit surprised that for something as exacting as getting the prints to stick to the plate especially with the .25mm nozzles that the whole affair is so hit and miss.

I'll give kolia's suggestion a try and I'll feedback when I get the chance

Shaun

[gr5 2,225]

Hit or miss? Really to get it exact you just twist the 3 screws as it's printing the skirt. And once you get it absolutely perfect it stays that way for months despite hammering prints off the glass hard enough to have the glass slide out or the printer slide across my table. I mean by eye I can get it within about .1mm of desired final height but when I print the skirt or brim I can get it much closer. These are tiny adjustments.

[KevinMakes 22]

I also level teh bed with a feeler just because...well Im a bit of a control freak... Anyway I find that it is a good measure to print at about 1/\4th of the diameter of the nozzle...so for my massive 1.6 mm It will be .4 mm off the buildplate...this tends to squash and spread the first layer (also good for first layer adhesion if you don't want to do a raft or skirt)

[KevinMakes 22]

I also level teh bed with a feeler just because...well Im a bit of a control freak... Anyway I find that it is a good measure to print at about 1/\4th of the diameter of the nozzle...so for my massive 1.6 mm It will be .4 mm off the buildplate...this tends to squash and spread the first layer (also good for first layer adhesion if you don't want to do a raft or skirt)

 

The main reason for the exactness is because I am testing printing on top of, inj molded, and pre printed parts.

[kolia 31]

The main reason for the exactness is because I am testing printing on top of, inj molded, and pre printed parts.

 

That's interesting. On what kind of injected material do you print? ABS? PA? PC?

[Labern 775]

When I first started I thought that leveling had to be perfect every time. I quickly realized that it doesn't matter that much. The smaller the item you are printing the less important it is.

I agree with Gr5, I don't touch the bed level for months and don't bother changing between nozzles.

It shouldn't scratch the glass unless its a big difference as the pressure of the plastic pushing out should help push the glass down enough and not scratch. I did it once by accident and there are no scratches but cant guarantee yours wont scratch.

When using the 0.25mm nozzle you normally wouldn't print a large item, just something small. So as an example if the bed is out 0.1 from back to front then over the tiny print surface in the middle it might only be out 0.01

I have the first layer at 0.05mm for that nozzle so that's plenty of room to flatten out.

On larger nozzles, yes they will normally be on bigger prints that would cover more area and could be out the whole 0.1mm, but your first layer will also be thicker so it still doesn't matter that much as long as it has enough squish to make it stick.

[KevinMakes 22]

That's interesting. On what kind of injected material do you print? ABS? PA? PC?

 

I have done some testing with printing on top of a few vinyls, polyprop, and a "carbon fiber"(graphite)

All scored (roughed up) and or with a epoxy brushed on.

[Coni 1]

That's what I also always wondered

According to this manual Cura expects a 0.1mm offset from the nozzle to the bed after calibration.

The sheet of paper that I use right now has 0.11mm