Movement across bed before printing

[Oj00 5]

Hi Guys,

I've been wondering for a while now why once the bed calibration has been completed, the head moves to the front, the bed drops and heats up. Then the bed rises and the head moves to a point half way back on the right hand side, once the bed has stopped the head rapids to the front left side to do its initial purge.

Often however during the rapid to the front left a trail of plastic can be left across the bed or a blob if some has leaked from the print-core while hot for calibration.

Anybody know why this is?

Thanks,

[robinmdh 100]

short answer: It works and nobody has asked for it to be different, so why change it?

long answer:

"Then the bed rises and the head moves to a point half way back on the right hand side" is one of the probe locations.

And this is left over from when setting the bed level (after measuring or when starting a print using measured data or user calibrated data) could not be done at any height/location so it had to set the height that has been measured at one of the probe locations.

We've changed some things in how we store/calculate the hotend height so now I/we can change it fairly easily but it hasn't been an issue as far as I know for anyone, you unique butterfly, you ^ ^

But it was one of the things I still had on my not important should still do it sometime list in the back of my head... I'm working on Cura connect in the mean time and there are bigger things missing there

So please let us know how big of an issue it is?

[ultiarjan 1,223]

It's an issue, it can cause color pollution on dual prints. Not a big issue, but still something to fix. And someone has asked before pretty sure I mentioned it a long time ago in some beta test report....

[cjs 34]

Yes please change it to not move to the probe location. It can be quite annoying from time to time.

I'm happy to know that Ultimaker is working on new features to increase the possibilities of my printer but I would also like to see Ultimaker working on those small things. For sure they can't be marketed as big improvements but I think they can make the user experience better. I also think that people sometimes don't ask for it because they have accepted the fact that the UM3 does it this way.

[neotko 1,417]

I also think that people sometimes don't ask for it because they have accepted the fact that the UM3 does it this way.

 

Indeed, also I don’t think that UM has much spirit towards letting people change what they define (and of that I’m sure)

Adjusting this thing could be easily done by the user if access to the machine jsons wasn’t limited to ssh or aigned firmware updates.

If changing the machine json would be accesible the chances of getting easy updates from the community to improve little things would be faster

One could rearrange the prime areas

Change steps of the motors

Play with the hardware to make modifications (like 1.75)

But atm the risk to brick the printer is very high when changing the machine json that controls all that information. IMO the biggest issue the um3 has. One typo on the json comas or dots and you get a white brick that doesn’t boot up.

[robinmdh 100]

I also think that people sometimes don't ask for it because they have accepted the fact that the UM3 does it this way.

Indeed, also I don’t think that UM has much spirit towards letting people change what they define (and of that I’m sure)

Ouch, why do you think that? Change whatever you want, that why the SSH option is there we also do intend to open source a whole bunch of it so that people can change it more easily. The advantage of SSH is that there is a little bit of access implies a certain level of know how and If you know how you can probably also unbrick your printer if something goes wrong, without too much trouble.

But perhaps a web UI to change machine settings, or maybe just a web based file editor with some pre-set files, so that all of the python code is accessible? This could be of use to our own experiments as well, Having spend the 5-10 minutes to set up persistent (after updates) changes to the machine json for someone else (discovering there is a annoying bug in the file parsing) recently I Feel some of what you say. Then again there is only so much time in our day. And if someone wants to build something like that before we manage to get to it I'll gladly help them.

BTW: This specific movement behavior is not something you can influence that easily and the prime locations can be changed in Cura, not everything is in the machine json.

Edited December 11, 2017 by Guest

[cjs 34]

@robinmdh May I ask if the movement across the bed will be addressed with the next firmware update? It's a big problem when you want to print on fabric and it also "damages" print adhesion sheets. 

 

BTW: I actually do think the SSH option is a good thing but it's a bit problematic as there is no documentation available. There are a few guides on this forum which aren't always easy to find. A web UI would be terrific! But let's not get off topic  

 

[WesleyE 14]

I'll check our backlog and put it on there if it is not already on there. No promises on if/when it will be in the firmware though! 

Edited February 27, 2018 by WesleyE

[cjs 34]

Thank you @WesleyE for your response. I really appreciate it! 

 

Hopefully this community requested change will make it's way into the firmware soonish 

[cjs 34]

Any news regarding getting rid of the movement? 

It especially gets really frustrating with adhesion sheets as you will shortly see a dot with the last used filament color at this spot, which will make the underside imperfect. 

[robinmdh 100]

On 4/17/2018 at 3:48 PM, cjs said:

Any news regarding getting rid of the movement? 

It especially gets really frustrating with adhesion sheets as you will shortly see a dot with the last used filament color at this spot, which will make the underside imperfect. 

It's gone AFAIK though with "big news" you can maybe imagine it'll take a little while yet, I think it'll be when you can update to version 5.x.x

[cjs 34]

Thanks for the update @robinmdh  Let's wait and see what the "BIG" news is all about. Excited for what Ultimaker has planned for version 5.x.x. Hopefully it's not to far away