[Chiuso] What print speeds do you use?  

Re: What print speeds do you use?

David

It depends on what I am printing. There are also volumetric melt limits to the hot end to take into account (somewhere around 10mm^3 per second - I don't have time to get the exact figure).

At 0.2mm layers, my perimeter speeds range anything from 20 to 100 mm/sec and infill from 30 to 150mm/sec but those figures are quite meaningless unless you significantly increase the acceleration parameters.

Print speeds by themselves do not tell the whole story - in fact they are quite meaningless.

Peter

Re: What print speeds do you use?

Interesting. By 'meaningless', do you mean they don't actually make much of a difference, due to acceleration being a large limiting factor? Do slicers like Cura not adjust those settings automatically when the speeds are changed?

Re: What print speeds do you use?

David

In my opinion, although some slicers do attempt to handle acceleration, it is still a function that is built into the firmware and best left to the printer to resolve. It is possible to change the printer's maximum acceleration rates via GCode.

The problem with talking about speed as a single entity is that it quite simply it is not something that can be discussed as a stand-alone parameter.

For example (with stupid values), what is the point in trying to print at 1000mm/second at a layer height and line width of 1mm when the extruder can only melt 1mm^3 of filament per second and the maximum acceleration is set to 50mms^-2

All these factors (and a few more) need to be considered as a whole.

I found the communication with E3D regarding the V6:

Printing with a V6 using pure MG94 ABS 1.75mm which we know the characteristics of very well and has a melt flow rate of 11.7g/10 min, running the HotEnd at the normal print temp for this material which is 240C we found the following:

11.5mm^3 per second is the max comfortable flow rate, you can go a little faster but extrusion is not as optimal.

This means an extruder feed rate of 4.8mm a second is easily achievable. These numbers are very conservative and are only a measure of max steady state flow.

Explanation:

Feeding 4.8mm of 1.75mm filament is 11.5mm^3 which will print a line (approximately) 143mm long at layer height of 0.2mm and width of 0.4mm, hence a maximum theoretical limit of 143mm/sec with that filament at those temps, subject to the possible acceleration and settings of the printer.

I hope this helps.

Peter

Re: What print speeds do you use?

Last night I have been printing the Marvin file over and over again trying out different parameters. When I turned the speed down to 20% and it printed really well. I didn't modify and of the other default parameters in that program.

A question though when I open the program .gcode I am assuming when I see F1000 that is 1000mm/s? Is that correct?

Re: What print speeds do you use?

Did you have the cooling fan on full blast for all of those Marvin prints? I've found that has a ridiculously pronounced effect on their quality.

Also, i believe the F1000 is indeed a feedrate command as you suspect, but i think it is in units of mm/min instead of mm/sec as 1000 seems way too high for mm/s. So it would be like 16.67 mm/s, which should be the z-axis speed.

Re: What print speeds do you use?

Yes, the G0 and G1 commands specify the feed rate in mm/min: http://reprap.org/wiki/G-code#G0_.26_G1:_Move

The axis/axes to which this refers is/are determined by other parameters in the command.

If the command only contains Z or E, then the movement will be with that axis only at the specified speed.

If an X and/or Y parameter is specified, then the movement in the horizontal plane will be at the specified speed and the movement of the Z and/or E axis will be proportional such that all moves start and end at the same time.

The little processors controlling these printers really have to work extremely hard to earn their keep!

Peter

EDIT: Jeff - a word of caution here. There is a minimum speed at which material can be extruded. When printing at 100 microns at an already slow speed and reducing that speed by a factor of 5, you may be getting very close to the minimum and print quality can suffer.

Re: What print speeds do you use?

"Did you have the cooling fan on full blast for all of those Marvin prints? I've found that has a ridiculously pronounced effect on their quality.

Also, i believe the F1000 is indeed a feedrate command as you suspect, but i think it is in units of mm/min instead of mm/sec as 1000 seems way too high for mm/s. So it would be like 16.67 mm/s, which should be the z-axis speed."

mm/min makes more sense. I didn't have the cooling fan on, I don't even know the M code to turn it on yet. I see faster cooling is a key to better printing. Thanks for the advice I have homework to do.

Re: What print speeds do you use?

"EDIT: Jeff - a word of caution here. There is a minimum speed at which material can be extruded. When printing at 100 microns at an already slow speed and reducing that speed by a factor of 5, you may be getting very close to the minimum and print quality can suffer."

I appreciate the advice, so far in my very limited experience that has yielded the best result so far.

Re: What print speeds do you use?

Currently for PLA I am using 100mm/s print speed with 150% flow of filament, results are faster and quite similar to 50mm/s print speed with 100% flow. Nozzle is 0.4mm and layer height 0.2mm, just hoping that such fast action does not burn down electronics, I have added Mosfet to bed & nozzle.

Re: What print speeds do you use?

Currently for PLA I am using 100mm/s print speed with 150% flow of filament, results are faster and quite similar to 50mm/s print speed with 100% flow. Are you using Slic3r? If so, slice and save the file, then click the Preview button at the bottom. Select Speed in the View drop-down at left. Go through the layers of your model and see just how close to those settings you're actually getting. Depending on the size and complexity of your part, there may be a very good reason there's not much difference between speed settings. The actual speeds may not be anywhere near your maximums. This could be due to hitting acceleration limits on smaller surfaces, or as PJR notes limits on maximum volumetric speed built into Slic3r, in particular the per-filament limits set in the Prusa profiles. You can change these all you like, but you're not going to push filament through quicker than the E3D V6 (or your chosen replacement) extruder can melt it. Up the limits, and you may run into extruder kicks, clicks and jams. You may also encounter limits in how fast the filament itself can be pushed. Most are limited to 50-70mm/s for guaranteed results. Beyond that, you're on your own in terms of robustness and finish. You likely won't damage anything, but your efforts may be for naught.

Re: What print speeds do you use?

I am trying to figure out the maximum print speed for PLA on my Mk2. Rather than figuring out all the various settings by myself, I would prefer to start with a set of values that have worked for somebody else, but no one ever provides a complete set of values!

What values are you guys using? Any chance somebody could provide a Sli3er configuration file with values that have worked for you?

Re: What print speeds do you use?

I am trying to figure out the maximum print speed for PLA on my Mk2. Rather than figuring out all the various settings by myself, I would prefer to start with a set of values that have worked for somebody else, but no one ever provides a complete set of values!

What values are you guys using? Any chance somebody could provide a Sli3er configuration file with values that have worked for you?

I think Peter explained it already pretty good that there is no magic max print speed number.
If you want to test higher speed, take your default PLA setting. Double all speeds. Verify in the Slic3r preview that the model you're printing can do this speed. Then just try to print and see what the printer/firmware is doing. If that worked out, go ahead and increase the speed by 10%-20%. At some point the hardware/firmware will limit it pretty fast.

Re: What print speeds do you use?

[...] What values are you guys using? Any chance somebody could provide a Sli3er configuration file with values that have worked for you?
Just adding to what nikolai and PJR have stated: You're going to run into the limits of the E3D V6 extruder, which is something like 11.5mm^3/s. Speed is only one factor that affects this. To answer your question, we'd have to know what extrusion widths and layer heights you want to work with. My linear speeds working with a 0.80mm nozzle are less than half of those I use when printing with a 0.40mm nozzle, but the print may well finish up much more quickly depending on specifics of the model. It's not how fast the nozzle zips around, it's how much plastic you push as it moves that matters.

Re: What print speeds do you use?

Just adding to what nikolai and PJR have stated:..

I get all that, really I do, but it's a standard Mk2, nothing exotic. What's the harm in sharing settings that were used to print a high speed Benchy, for example. Or a high speed Batman, or a Marvin or whatever. I'm not looking for a guarantee, just a starting point so I don't have to experiment with 20 or 30 settings by trial and error.

Re: What print speeds do you use?

I get all that, really I do, but it's a standard Mk2, nothing exotic. What's the harm in sharing settings that were used to print a high speed Benchy, for example. Or a high speed Batman, or a Marvin or whatever. I'm not looking for a guarantee, just a starting point so I don't have to experiment with 20 or 30 settings by trial and error.
There are plenty of settings being shared out there. Chris Warkowski's are perhaps the most famous and are very good. Mine are in the pages linked to at the bottom of every one of my posts. I've got a whole page devoted to speeds. To really answer your question, you're going to have to tell us what materials you're printing, and what layer heights and extrusion widths you want to work with. These factors are all inter-dependent.

"Speed" makes the most difference with external perimeters. Too fast and you'll get an uneven appearance. Going slower fixes a myriad of problems. In general, you can get away with higher speeds for anything inside the perimeters you'll be seeing. I did post above telling you how to view the actual speeds you're printing at. You can select speeds of 200mm/s (e.g. Prusa's default infill value) but may rarely get that high. Your actual speeds are going to be highly dependent on the model, material, and print settings you use.

The fastest I've been able to print a Benchy in 25m, but I'm thinking the results aren't what you're after.

Re: What print speeds do you use?

What's the harm in sharing settings that were used to print a high speed Benchy, for example. Or a high speed Batman, or a Marvin or whatever. I'm not looking for a guarantee, just a starting point so I don't have to experiment with 20 or 30 settings by trial and error.

The reason why I'm not sharing my high speed settings because I don't have them. My approach is always to go with the default settings and modify those for the specific purpose. The key factors were mentioned here.
So basically the same approach what you have already done with 80mm/s. At the end you have to experiment with your filament and the model you're printing. Slic3r system settings are providing already a pretty good starting point.