Hello
is there PVA filament (water soluble filament for supporting structure) from Velleman K8400 to buy?
I doubt it as they don’t recommend using PVA with the Vertex (due to clogging issues).
But this should actually work, I have especially for this purpose mounted the second extruder and wants to print parts that are otherwise difficult to achieve.
sorry for my bad English
You can try but be prepared to have to clean your nozzle many times.
Chances of success depends on a few settings like a slow speed, the lowest temperature possible, no retraction (pity you can’t cancel it for one nozzle and keep it for the other) but it probably will make a mess with the other nozzle.
It’s best to make some test prints with PVA alone on your left head to tune the parameters until it prints with a decent result and without clogging every 5 minutes. Then only you can try with both heads.
PVA you can find on many on-line shops. It doesn’t need to be Velleman’s.
[quote=“reno”]
sorry for my bad English[/quote]
Not so bad actually 
Thanks for the tips, will now 500 gr order and test,
will then report the result 
Hi all,
I bought some PVA from UK.
It is really expensive, act 35EUR/500gr and 12EUR shipping to Germany.
First print went fine, or let’s say acceptable.
Second one got stuck and I had to remove everything to clean the mess.
Main prob is the 1cm from the extruder drive to the push tube fitting.
There the filament curls in and will not be transferred to thru the tube.
I will make some checks with the extruder housing. My intension is, to have a little PTFE tube from the very close of the mechanic of the extruder
up to the push tube fitting.
Will drill a larger hole thru it an glue some PTFE tube into it.
So the distance will be almost less than 1mm.
Will be a project for the next weekend I guess.
Keep you informed.
Fyi there cinyas has a nice extruder design on thingyverse which actually does pretty much the same. I’m using it for months now and can say it’s a pretty solid design. I’ve not used it with pva but it does work well with flimsy pla in my heatbox (when it gets around 40 degrees it pretty much curled up every time around the pulley)
Kind regards
JeAfKe
Hey JeAfKe,
I have found a few replacements and was going to invest those changed extruders.
But thanks, for the info, that they are working, in the meaning of “I tested them myself, and they are working”.
So I will have a closer look on them.
UPDATE 2016-01-29-1200:
Printing them at the moment, got some additional info about PVA from Cinya
Thanks
Best
Frank
Only tricky part is getting the pulley aligned. I first mounted it with the pulley loose and inserted some fillament. Measured the depth from top of the pulley to the top of the axle. Disassembled it again and tightened the pulley with the numbers I’ve measured.
Kind regards
JeAfKe
[quote=“jeafke”]Only tricky part is getting the pulley aligned. I first mounted it with the pulley loose and inserted some fillament. Measured the depth from top of the pulley to the top of the axle. Disassembled it again and tightened the pulley with the numbers I’ve measured.
Kind regards
JeAfKe[/quote]
Thanks for the hint…
saves me time, I guess.
Best
Frank
I made a 0.3 print of the new extruder, just a test case.
The holes are not aligned so I had to drill them with 4mm bit.
The alignment of the pulley was made easily. Thanks to JeAfKe…
And I had to modify the push tube fitting’s bolt. It was slightly misaligned
The part itself was working properly, could make my first PVA support print without probs.
For PVA I used some very slow settings, received from Cinya at Thingiverse.
Details for PVA can be found there.
The only issue I have at the moment is the litte rest of the outcome of the PVA, this is mixed in some cases with the PLA.
Bu tI guess, it is only a question of speed, if I reduce the PVA extrusion speed just a little more, it might work, but that is fine tuning.
So I will go to print the left and right extruder with 0.21, for the final version.
More details will be provided here
Best
Frank