Dear customers,
It has come to our attention that in the latest batch of K8200 printers there is a slight problem with the manufacturing finish of our nozzles. Some have a slight chamfer (see picture below) on the orifice, this can result in a bad surface finish of your 3D prints.
In case your nozzle has this problem you can start a support ticket here:
support.velleman.eu/
And get a free replacement nozzle.
We are sorry for the inconvenience
Sincerely
Velleman
Is it possible that the nozzle set for the k8400 has the same problem? Ik checked everythig with my printer: allignment filament, replaced the extruder wheels and lastly the nozzle. After around 20 hours of printing the extruder starts ‘clicking’ now and then and the surface finish looks underextruded. In the first ± 20 hours there isn’t any issue. This issue came up with both nozzles from the set.
I bought the NOZ8400, M.07.RE
With other nozzles I bought earlier, I could print easily for 300+ hours.
Just wondering
Are you printing with ABS or PLA?
The best temps for
ABS 220C
PLA 190C
Did you change the retraction distance and speed?
Distance 4mm
Speed 110mm
I only printed with PLA on my K8400, at 200 degrees.
My settings are:
I’m prety familiar with the K8400 and resolved a lot of issues during the past year. That’s why this is new for me. Tommorrow I’ll replace the current nozzle with a new one, which I’ll buy at the store. I’ll let you know what the results will be.
I’ll have to pick up a print as well, to show the difference between two prints, and around 20 hours of printing between them. I’ll keep you posted.
As promised an update with photo’s. I’ll show you the history of the past 20 hours of printing with this nozzle.
After the I replaced the first nozzle from the kit (because of the same issues), the printing went very well again. I was very happy with this stormstrooper (3 hours printing), printed with the above mentioned settings at a 0,2mm resolution:
After the stormtrooper I decided the printer funtioned well again, so time for a customer print. A building, also 0,2mm resolution, around 16 hours of printing. Results very nice and good top finish.
Then I wanted to print the next building (11 hours, same settings). The extruder started to ‘click’ again, like there was some kind of blockage. Although the printer underextruded the outerperimeters where fine. So no retraction failures there.
The outsides are more or less fine. A bit underextruded:
But the roof is terrible:
So after reading this line: (I qoute the original post)
“…this can result in a bad surface finish of your 3D prints.”
I thought I recognised the same issues with my nozzle set for the K8400.
For a last comparison the good and bad stormstrooper and around 30 hous of printing between them:
Good trooper:
Bad trooper:
As a last remark: I bought a new nozzle today. I’ll replace it tonight, so I can see if these specific set of nozzles are causing my problems.
You should really drop your temp to 190C and retraction to 4mm then try it again.
Pff, what kind of answer is that. I printed tons of good qualtity prints with my settings.
Maybe you can explain me what the big difference would be according to you.
I’m just trying to help.
Your retraction is still to high.
If you pull the melting plastic to far back into it will cool in the isolation tube and clog it.
190C is a good temp for PLA.
You don’t have to change anything it’s your machine.
But these are the settings that I have used on my machine when they first got to the USA January 2015 and print with it every day and I have not had any issues.
Thanks for your help ans sorry about my tone. Your explanation is clear.
I find it weird that the problems come up after 20-30 of printing. I would expect that failures due to settings should come up ealier. Nontheless will I change my settings to your recommendation.
I installed a new nozzle and switched the hotend isolator with printhead 2. After a good review I had the feeling that te little ptfe-tube inside the isolator is a bit twisted at the and and causing blockage. Problably caused by locking down the nozzle to tight. I’ll have to check this weekend with printhead 2. Right now I’m printing OK again with a new nozzle.
Maybe you have some experience with removing a ptfe-tube out of the isolator? I think drilling it out would be best, but then I can’t check if the tube was twisted…
Again, thanks for your input.
No problem.
A few years back I purchased the VTSA from a local Velleman dealer.
http://www.vellemanusa.com/products/view/?id=351294
If you go to this link and click on the picture the 3rd tool down is what I have used to remove PTFE tube
When I first built it I didn’t cut it right so I had to replace it.
You will need more of the tubing because this will destroy the old one.
