Retraction for E3D Volcano and Direct Bondtech BMG

zzing

I have exactly the same setup on volcano with 0.6mm nozzle - yet using a titan aero.

I almost settled on something, but I definitely have to take another look at it.

There are two methods I usually go to:

the four cubes https://www.thingiverse.com/thing:1159886

the pointy things https://www.thingiverse.com/thing:909901

But I haven't heard of this 4 to 7mm thing.

LHelge

I have a P3Steel with Bondtech BMG and standard E3Dv6 (0.4 mm) and a Hypercube Evo with Zesty Nimble and switching between standard E3Dv6 (0.25 mm) and Volcano with 0.6 mm nozzle. I run 0.8 mm retraction at 40 mm/s on all three and it seems to work fine.

I would guess the BMG and Nimble are quite similar since they are both geared direct extruders. But the Nimble is set up with much lower jerk and acceleration.

dc42

@saffi said in Retraction for E3D Volcano and Direct Bondtech BMG:

I ran something like 0.8mm retraction on a standard E3D, but now I'm using a Volcano with a 0.6mm nozzle and have no idea where to start testing retraction settings. I've read 4mm to 7mm, but that seems quite high.

That sounds like the retraction you would need for a Bowden extruder, not direct drive.

saffi

@dc42 Thanks, I'll bump it back down to my standard 0.8mm settings and try again. Maybe I need a bit of coasting or negative restart distance to get rid of the small defects near retraction points.

Phaedrux

From what I've been able to gather 2mm seems to be a good starting point for a direct drive volcano.

o_lampe

It's an old thread, but my own retraction test was based on this thread, so I want to share my findings here

I ran several retraction tests with PETG and retraction length between 0.4 and 2.4mm. Forget it, stringing here, stringing there... well, you know the song

Then changed to PLA and I was able to see differences.

But I got by far the best result , when I canceled Z-hop.
It was set to Z0.2. My Z-axis is slow with low acceleration, so it takes a while to raise the nozzle.

I thought, it was worth mentioning...

Phaedrux

@o_lampe said in Retraction for E3D Volcano and Direct Bondtech BMG:

But I got by far the best result , when I canceled Z-hop.

Makes sense to me. When it lifts it pulls a little string with it. Wipe on z hop could maybe help. But best to avoid z hop if at all possible.

o_lampe

@Phaedrux said in Retraction for E3D Volcano and Direct Bondtech BMG:

But best to avoid z hop if at all possible.

I haven't found a way yet to use Z-hop only on first layer. At least not in RRF.
Suggestion: adding a taper off parameter for Z-hop, like in mesh compensation.

Veti

@o_lampe said in Retraction for E3D Volcano and Direct Bondtech BMG:

I haven't found a way yet to use Z-hop only on first layer. At least not in RRF.

use firmware retract
then use prucerslicer layer change g code to disable z hob via g code after the first layer

o_lampe

@Veti
Nice workaround!,
I've thought about using z-hop option from slic3r, but then it wouldn't lift and retract simulanteously. Your idea is better.