Tuning extruder jerk when using an LDO Orbiter

rilot

Hi all
I've recently changed my extruder on my large CoreXY from a BMG to an LDO Orbiter. So far so good except my acceleration is now being limited by pressure advance and extruder jerk.
The recommended value for jerk for the Orbiter 1.5 is 300mm/min which is really low. With the BMG I was running over 1500.
My PA is set to 0.055 which is pretty close to where it was with the BMG (0.06).

My question is, does anyone have experience with this extruder and setting jerk values above the recommended?

I see there is a new version 2.0 out that pushes this up to 600mm/min but I can't for the life of me find any information on why the 2.0 can have higher jerk than the 1.5 when the motors are largely identical and the gear ratio is roughly the same too.

Phaedrux

@rilot said in Tuning extruder jerk when using an LDO Orbiter:

does anyone have experience with this extruder and setting jerk values above the recommended?

Well you can, but it's not recommended.

You can test during a print, just send the command to increase jerk slightly a bit at a time from the console and watch and listen for the change.

oliof

I must say that I have setup maximum jerk for E to 3600mm/min on the Orbiter1.5 in complete ignorance of the recommended value and it seems to work fine (combined with a Dragonfly BMO hotend). I guess I should reduce this value quite a bit?

CabalSoul

I've got an Orbiter 1.5 @24V LDO-36STH20-1004AHG
Jerk 1800
Accel 6000
current 750ma

it's working like that for at least a year no problems yet. I have the same questions as yourself regarding why the 2.0 got better specs.

rilot

OK, last night I changed it to 1000mm/min for jerk and other than my print time dropping drastically and my accelerations looking like they did before, I couldn't see anything bad as far as print quality is concerned. That was printing at 120mm/sec. No funny noises from the extruder either.

oliof

@rilot I just switched extruder jerk from 3600 to 300 and it didn't affect print time at all. Maybe my E acceleration value of 6000mm/sec^2 is enough to just run with a low jerk? One thing I can say is that retracts now don't sound like the machine has a hiccup anymore.

rilot

@oliof Right. Could be. I'm going to have to go back to basics and tune it all from scratch, ignoring the numbers that the Orbiter reckons are right.
Thanks for that.

Adrian52

@rilot I have orbiters 1.5 and 2.0 which have the same ldo36sth201004ahg(xh) steppers; they have the same recommended steps/mm, so the gearbox is the same too. I used the 1.5 with a bowden for a while, then added a 2.0 as a direct drive - using them in tandem off e0 and e1 drivers at 850mA, 24V. I am using 300 jerk (with P1) , 7200 max speed, and 10000 acceleration. They run very smoothly and quietly at up to 250mm/sec with 0.4 nozzle.