Retraction

[destroyer2012 0]

The FW (marlin) has it capped at 45mm/s

Well I set the max speed higher (to like 10000) using Daid's build me marlin website. So rest assured I am actually running 70 mm/s (or at least trying to, skipped steps aside). So could it be that everyone else is running 45mm/s?? That would make sense...

[alaris2 1]

it's possible - I haven't messed with the FW at all.

Thanks Flo, that's an interesting line of experimentation there.

I can recommend Daid's Ultimaker feet for experimenting with dwindle. I don't think it's just speed that makes the print better (but you're right that prints will take longer with dwindle and the slower speed at extremities is bound to be improving quality there).

The feet consist of several layers of 45 degree lines that decrease in length - without dwindle, those shorter lines move the same speed as the longer lines and the PLA is oozing out the nozzle the whole time leading to excess material being deposited at the shorter lines which makes a mess of the print.

with dwindle on - the problem disappears and I get a perfect print. I'd take a photo, only it was printed in black and it just doesn't show well.

the thing i can't explain is why dwindle should work - I had expected it would print slower on the short lines now. That calibration pyramid works well for retraction but I can recommend Daid's feet for dwindle testing (and I'd love someone to explain to me why it works, or even if anyone can reproduce what I'm seeing here)

cheers, nik

[mariuszem 4]

My idea, to not use Clamp on extruder side. Perfectly fit. No move.

[maxy 0]

The FW (marlin) has it capped at 45mm/s

Well I set the max speed higher (to like 10000) using Daid's build me marlin website. So rest assured I am actually running 70 mm/s (or at least trying to, skipped steps aside). So could it be that everyone else is running 45mm/s?? That would make sense...

Reading this thread made me curious... I tried Florian's settings above and got a nice string-free print. But I realize now that I was retracting at 45mm/s (which actually results in longer pauses while retracting).

You can change the maximum without recompiling Marlin. Use the M503 command to list the settings (the defaults stored in flash I think). The command "M203 E1000" removes the limit. It may be worth to try decreasing the extruder acceleration limit too (not sure if this one actually has an effect, but it's extremely high compared to the other motors).

I have my extruder stepper current turned down to get a more quiet machine (it was WAY too loud and rattling in the beginning). I can hold the wheel steady with a little bit of force to make it miss steps (with the default motor current I could not do that). So I had to quickly test the real 70 mm/s retraction - sometimes it did miss steps, sometimes I think it actually worked. I should mention that I have

http://www.thingiverse.com/thing:25490

installed to reduce extruder friction.

I could turn up the current to make it work, but it was too loud for my taste already. I'll stick with 45mm/s, which isn't exactly quiet neither, or maybe with something lower.

[jcosmo 5]

Hi Alaris,

The Cura's retraction function gives very good results.

Since I replaced the bowden tube with a tube with ann inner diameter of 4.0mm instead of 3.2mm, it's even better than before!

++

Gaël

Re your comment on replacing your Bowden with a 4mm ID tube.

I'm interested in trying that also and was wondering where you sourced it, and what the OD is?

Thanks for any help,

James