Cura Print Speed vs UM2 Print Speed

[closedcircuit 1]

I have (yet another) beginner's question :???: :

Does the "Speed" setting in UM2 replace the "Print Speed" setting in Cura, or do they multiply one each other?

In other words, if Cura's Print Speed = 50 and UM2's Speed = 90, will the resulting speed be 50, 90 or 50x90=45%?

Thanks!

 

[Daid 306]

The speed in Cura is in mm/s, the speed on the machine is a % on top of that. So, 50mm/s in Cura, with 90% in the machine, gives 45mm/s

 

[closedcircuit 1]

Thanks Daid! Makes sense...

 

[closedcircuit 1]

Is there a more-or-less scientific way of deciding how to change these settings, or is it really trials and errors?

 

[Dim3nsioneer 558]

Is there a more-or-less scientific way of deciding how to change these settings, or is it really trials and errors?

 

I have no idea if you work in science or not, but if you don't, I can tell you that you might be surprised how much trial and error there is in science...

With every reasonable filament you buy you get a recommendation for the temperature range it has to be printed in. The lowest temeperature (e.g. 190°C for PLA) usually is for very slow prints such as 10mm/s. The highest temperature (e.g. 220°C) is for the highest speed. With today's printers, including the UM2, reasonable quality can be achieved up to about 100mm/s. That's the basics. The rest is indeed trial and error. You may find that a few degrees higher or lower is better or worse for a specific print. You will find that filaments from different manufacturers, even different colors of the same filament, behave differently in terms of temperature.

 

[closedcircuit 1]

@Dim3nsioneer: Thanks for your reply - its' really appreciated. I don't work in science, but read mathematics at university. That's where other scientists would come when they couldn't solve their own equations

What I was wondering (albeit in a not terribly well written way) was if there is a protocol that one should follow when troubleshooting a difficult print. For example, do I start with constant temperature and vary speed or the other way round? What about retraction length, bed temp., etc.

At the moment, I seem to be shooting in the dark because of the sheer number of permutations (say 3 or 4 temperature settings x 2 or 3 different speeds x 2 retraction settings x 3 different bed temperatures = a lot of opportunities for a failed print)...

 

[Dim3nsioneer 558]

What I was wondering (albeit in a not terribly well written way) was if there is a protocol that one should follow when troubleshooting a difficult print. For example, do I start with constant temperature and vary speed or the other way round? What about retraction length, bed temp., etc.

At the moment, I seem to be shooting in the dark because of the sheer number of permutations (say 3 or 4 temperature settings x 2 or 3 different speeds x 2 retraction settings x 3 different bed temperatures = a lot of opportunities for a failed print)...

 

"Don't tell me the odds!" :mrgreen:

You don't need to test everything at once. You will soon find a reasonable setting for a temperature-velocity match (if you're far off from that, try 50mm/s and 210°C). For the heated bed, maybe start with 60 to 65°C, not higher (as gr5 continues to point out; and he's bloody right about it...)

Then maybe find a good setting for a higher speed and a lower speed. And then you're done. And now the most important thing: If you have a new filament which seems not be working with any settings, bring it up here in the forum... :-P

About retraction. I can't give you a straight number for a good setting on an UM2 as I have an UM1. But I think there should be some information here in the forum.

You may develop your own test procedure with every new filament you try. Someone has started a thread about that a few months ago. Due to the extremely miserable search function of this forum (@UM: any chance we get something better soon?) I cannot find the thread anymore.

 

[closedcircuit 1]

@Dim3nsioneer: There are many great things about 3D printing. One of them is to see all these kind souls taking the time to patiently share their knowledge and explain basic things to complete n00bs such as myself. Many, many thanks!

 

[Dim3nsioneer 558]

@Dim3nsioneer: There are many great things about 3D printing. One of them is to see all these kind souls taking the time to patiently share their knowledge and explain basic things to complete n00bs such as myself. Many, many thanks!

 

And it's very interesting to see people which called themselves noobs at a time giving very good advice to other people after a few weeks/months! So, prepare yourself being an Ultimaker expert one day...