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Print times between Cura and Slic3r (in Repetier) 5x difference

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I did some searching around and couldn't find any reference to this subject. I just moved from an Airwolf 3D printer running Repetier Host and Slic3r. So when I started using my new UM2 extended and Cura I noticed a serious uptick in print times. If I use the same settings on Cura and Slic3r, I see a 3 - 5 X print time increase in Cura. I have gone over the settings several times and I cannot figure out why this significant difference. Except for the filament diameter difference of 0.4mm vs. 0.5mm that should only account for 25% difference, not 400%.

For all intents and purposes the machines operate identically.

I do know that Slic3r super-fills the part by over extruding material during infill. This speed things up considerably. Perhaps because I primarily use 100% infill this would account for it. And in that case, would using Slic3r on UM2 speed it up also?

I initially tried setting up Repetier to create GCode for the UM2 but it is not actually extruding material and seems to over retract so the filament eventually sucks up into the Bowden tube. I can't seem to find anyone with a clear setup for UM2 on another slicer so I feel like I am trapped with a slow Cura solutions.

I really love the UM2 otherwise. The hardware is amazing! I just hope I can get the print times down to something more manageable.

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>So why is Cura the software coming up with print times 3X as Curaengine in Repetier?

About a year ago the print times that Cura claimed were way off. It would typically print much slower - especially if there were many short moves because the printer has to slow down on each corner - each vertex. Cura fixed this about a year ago and now has pretty accurate print times. I don't think slicer does this. So the print time out of slic3r may be innacurate.

Anyway, I suggest you try a large cube which has lots of long straight lines and maybe try 50mm/sec. Try doing only single pass shell width (.4 and .5mm) make sure layer height is the same, turn off infill for both, turn off top and bottom. See what you get then turn things back on one at a time to see what's different. There's other things like "min layer time" that can really slow down a small part but doesn't affect a large part (say 100mm cube).

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.15 mm is a slow print? I really wish that someone would have told me that in the beginning. my makerbot rep 2 can rip guts at this layer height ( .15 mm) So I am just shocked. Thanks for the update. I really appreciate it. Do you think you can guide me to the forum where people are using larger diameter nozzles.

.65 mm and .8 sound pretty rad. Do you already have a setting sheet that I can borrow?

Thank you so much.

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Well with the .4mm nozzle I think of .1mm as slow, .2mm as fast and .15 in between. There's a tradeoff of speed and quality. If you want extra high quality you have to print extra slow - not just thinner layers but actually move the head more slowly as well.

It's hard to compare makerbot to ultimaker speeds because a 50mm/sec print on ultimaker goes much faster than 50mm/sec on makerbot - this is because the acceleration values are much higher. The acceleration values are higher on ultimaker because there is no feeder on the head so the head is light weight.

This high acceleration means that a 50mm long trace of plastic at 50mm/sec actually prints in about a second on UM but the Makerbot never gets up to speed so prints much slower.

Cura now takes into account the acceleration of the UM in it's calculations as of about a year ago.

If you have a UMO then there are lots of resellers for nozzles. Ebay is okay. Some of the nozzles have too large or too small of a "shoulder" and so the quality isn't always great. If you have a UM2 then you should get the olsson block which lets you change nozzles and you can use any standard e3dv6 nozzle with um2. I'm not sure if the e3dv6 nozzles work with UMO. I think they do. The ones from UK are very good quality. 3dsolex also has very good quality nozzles.

For the olsson block and e3dv6 nozzles, if you are in usa go to my store at gr5.org/store/. If not in usa start at 3dsolex.com. If you buy e3dv6 nozzles from UK seller make sure not to get the 1.75mm filament nozzles - get the 3mm filament nozzles.

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You are right about the being able to compare but I have unfortunately gotten my maker bot replicator 2 to go so fast on Architectural models ( Buildings, Facades, Sculptures). I brought 2 of the UM2's into the studio and have not gotten them to be able to print fast enough to kick out the makerbots rep 2's. I will try with a .2mm layer height. When I go into the direction of layer height I get really sparse printing layers. Sometimes it seems perforated.

I am in the US and need to pick up some nozzles with different diameter. I should make a decision by the end of the day. I really am in need of spunking up my machines to go faster. If you could share with me your advanced setting for the .2mm layer height and the type of material that you use I would be so great full.

The Olsson Block looks pretty lovely. Do you have any insight as to why Ultimaker 2 prints with 3mm filament?

If you have any influence on this I could use help.

If Cura had hexagon infill patterns it would be heaven.

Thanks again.

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hexagon infill prints slower than lines.

If you want to print fast with .4mm nozzle try no infill, 2 shells (architectural stuff prints pretty good with no infill and it's so much faster). So .8mm walls/shell. 0.2mm layers. Do 240C and print as fast as you can without underextruding. Around 50 to 75mm/sec.

Make sure ALL your printing speeds are set to the same speed - by default I think infill is much faster - maybe 80mm/sec? Having different speeds causes problems.

If you get a .6mm nozzle then you can do a single pass wall instead of 2 passes. And again print .2mm (maybe .3mm) layers but now you can cool it down to maybe 210C.

Quality won't be as good at these higher speeds but it will probably be as good or better than the makerbot.

If you want high quality slow it down to .1mm layers, 35mm/sec, 210C. 2 shells (.8mm shell) .4mm nozzle of course and be patient. Good quality takes many horus.

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I think I figured out a good portion of the issue.  For some reason Cura doesn't acknowledge the 80mm/s infill.  It appears to be closer to 20mm/s.  So I am using Curaengine on Repetier host to slice the model and then saving the gcode out as Ulitigcode flavor.  So the UM2 recognizes the code as cura driven and all of the built in firmware is intact.  I get nice startup and finish sequences but I get better control of the speed during print.  I'm back to being happy with my printer.  I just don't understand why Cura wasn't working for me.  Oh well, I'm happier with Repetier controls and part management anyway.  So Win Win!

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