Flying extruder vs acceleration marks

Hi,

I recently upgraded my Delta with a flying extruder. I used model balloons for springs and hung it between the carriages, much like the WASP setup. It worked really well right out of the box and I had only some very slight acceleration ripples behind the corners.

I also upgraded my arms with magnetic ball joints and longer carbon fiber rods and now the extruder setup changed slightly and the acceleration marks are much more pronounced now. Obviously longer arms means also a longer stretch of the model balloons and I have the feeling that the extruder wiggles more than before.

I cant really tell if the extra wiggle is the sole cause of these ripples and wanted to start a little experience exchange for flying extruders. So how are the flying extruders treating you when it comes to performance in general and acceleration in particular.

Cheers

I just saw a video someone posted of the Wasp Delta and the flying extruder does seem to be a great solution keeping the bowden tube very short and the mass/inertia on the effector as low as possible. Quite keen to try this. Did you print modified carriages to attach the elastic supports?

The only thing is I just ordered a flex3drive as an alternative solution to getting better filament control without the mass of the motor/extruder on the effector. Maybe Ill try the flying extruder first and keep the flex3drive in reserve.

You lose stability with longer arms. You have to increase the parallel spacing to get a more rigid effector.

Im still undecided on the flying extruder. In the meantime I switched to cura slicer and quality really improved, so I have to reset all my expectations about quality and how the frame reacts to different speeds. But sooner or later I have to test a bowden setup.
Layer stacking is very good but I still have some slight ripples in the wall but they dont look like acceleration more and corners are also sharp and ripple free. Im printing at 60mms at the moment, but I hope to increase that .

So you're using cura now what we're you using before? When you say you have to test a bowden setup, do you mean you haven't tried one before? Or haven't tried it on this particular printer? What printer is it?

Slic3r 1.29 just the retraction control is so much better in cura I was really surprised.

Yes When I build the delta I didnt have long enough bowden tube so I just model balloons and it worked well just from the start. My bowden length now is ca 10cm.

My printer is selfbuild a bit cherry pi a bit kossel but nothing out of the ordinary.

Slic3r 1.29 has an issue with over extrusion, I highly recommend you go back to the earlier ones like the stable 1.17

Well I can certainly see the attraction of a 10cm bowden tube, my kossel mini had an 80cm tube when I bought it and the filament control was very poor. I reduced it down to about 55 cm by moving the extruder and set the retraction to around 3mm but at 100mm/s (/min?) which works well and the print quality is much better. So I think you can get reasonable print quality from bowden setups but you have to tinker.

I ordered a flex3drive as I loved the really high gearing and moving the extruder onto the effector but without the motor's mass, so I will have practically no distance between the drive gear and the hot end. But I haven't got it yet and saw the flying extruder which seems so simple a solution, if it works on a £2600 commercial printer it must have some merit. I will give the flying extruder a try before the flex3drive.

This is my attempt at a flying extruder. I remade the carriages with loops on them and then made an extruder bracket to "fly" in the centre of them. Attached at the moment with just sewing elastic, but the bowden tube certainly provides some support also. I might try some silicone material once Ive got a handle on how much tension they need. Already printing a lot better my bowden tube is now 10cm instead of 66cm. Just getting the extruder dialed in now then on to some retraction tests to see how much of a difference it really makes.

Might add a filament guide from the extruder up through the top of the printer as the filament kinks a bit when the printer homes after printing.

But so far so good.