Cura jerk/accel for cr-10 s5 too high?

[fael097 1]

Hi, my models are always getting knocked over if I have more than 1 piece printing at the same time, sometimes even if it's just one piece. I always use rafts and hairspray and even so prints get knocked over.

 

is this because of acceleration and jerk? cura defaults for this printer are 500 for accel, 5000 for travel accel, 20 jerk and 30 travel jerk.

 

I used simplify3d before and it didn't have accel and jerk controls, and printing seemed waaay slower, even if I set printing speed to 120mm/s (double of my cura which is set to default 60mm/s). I get kinda tense watching cura gcodes print because it seems just too fast, since I'm used to simplify3d (not sure which accel/jerk values it used, I suppose it uses my firmware defaults)

 

I never had much knocking over problems with simplify3d, however I always had stringing issues, which I don't with cura, and I feel like cura has way more control of everything, so I decided to stick with it, but I can never rest when I'm printing multiple pieces at the same time. 

 

could accel/jerk be the issue? any suggestions for accel/jerk values for this printer?

[burtoogle 513]

Do you have z-hop enabled? If not, perhaps you need it?

[fael097 1]

1 hour ago, smartavionics said:

Do you have z-hop enabled? If not, perhaps you need it?

well, so the thing is I have this printer for like 2 months and I've experienced a bad case of stringing out of the box. I've been playing with every possible setting, reading everything about it online, forums, articles, guides, trying to fix stringing. changing temperature, retraction, coasting, calibrating filament diameter and extruder steps, nothing made a meaningful difference.

 

I gave up at a certain point and accepted that either the extruder or the filaments that I have access to are bad, until I tried to go back to default settings and disabling z hop, and for my surprise, no more stringing whatsoever.

 

after experimenting some more, I realized that the Z axis speed is too slow in this printer, it makes it impossible to break the filament string with a travel move because by the time the printer is done lifting the extruder for the z hop, the pressure relief from the retraction is over, filament has already started oozing again, and travel moves no matter how fast, are not enough to break the string anymore.

 

and not by coincidence, that's when I started having these knocking over problems. so basically I can have pancakes or spaghetti lol, can't get rid of both.

 

so that's why I was wondering if I could somehow get rid of knocking prints over without z hop, because I tried everything I could to get rid of stringing with z hop enabled and failed, now I'm trying to get rid of knocking over with z hop disabled

[gr5 2,172]

I also find zhop to be bad for my ultimaker printers but I think it's really helpful on delta printers.

 

Regarding knocking prints over - I find when I have overhangs, say at the bow of a boat, I also get raised edges that the print head can later bump into.  The primary solution is to get your parts to stick like hell.  My parts stick so well they don't get knocked over no matter what.  The advice to do this super well is long and involved and takes 20 minutes to get all the important details.  But if you are patient (feel free to watch it at 1.5X of course) I strongly recommend you sit through the entire video linked below.

 

The other way to reduce raised edges is: "more fan".  You want as much fan as possible.  I've also found that higher print temperatures can help (210C was better for me than 195C).  I don't know why.  Maybe it's easier for the nozzle to push the edge back down?  Maybe higher temp only works with slow print speeds (like 35mm/sec?).  But what I *do* know is more fan helps a lot.  So if you can add another fan to your printer that will help as well.  Or use a blower instead of a fan.  These fan's are a bad idea and Ultimaker finally figured that out with the UM3 - the um3 uses blowers, not fans.

 

 

[Jhawk6553 8]

On 1/23/2019 at 12:26 PM, gr5 said:

I also find zhop to be bad for my ultimaker printers but I think it's really helpful on delta printers.

 

Regarding knocking prints over - I find when I have overhangs, say at the bow of a boat, I also get raised edges that the print head can later bump into.  The primary solution is to get your parts to stick like hell.  My parts stick so well they don't get knocked over no matter what.  The advice to do this super well is long and involved and takes 20 minutes to get all the important details.  But if you are patient (feel free to watch it at 1.5X of course) I strongly recommend you sit through the entire video linked below.

 

The other way to reduce raised edges is: "more fan".  You want as much fan as possible.  I've also found that higher print temperatures can help (210C was better for me than 195C).  I don't know why.  Maybe it's easier for the nozzle to push the edge back down?  Maybe higher temp only works with slow print speeds (like 35mm/sec?).  But what I *do* know is more fan helps a lot.  So if you can add another fan to your printer that will help as well.  Or use a blower instead of a fan.  These fan's are a bad idea and Ultimaker finally figured that out with the UM3 - the um3 uses blowers, not fans.

 

 

Can you explain why Zhop is bad for ultimaker printers?