K8203 bad quality print

K8200 3D Printer K8200 - Issues while printing
1

Hello,

I do not get an acceptable print quality with this kit.
Moreover I encounter erratic feed (as if the E motor tries to push too much filament…)

I have placed the new driver card.
I have checked the voltages of the drivers (Z 0.434 changed to 0.558, Y 0.443 changed to 0.550, X 0.439 changed to 0.549, Extruder 0.5 changed to 0.91)

After installation all this I have downloaded the slic3r_175_pla_config.zip from Velleman website.

In Slicer : File - Load Config - I select this file.

Filament setting - Diameter is set to 3 mm. Logically this parameter should be at 1.75. (the filament’s diameter)
Printer settings - Extruder1 - Nozzle diameter 0.5 mm
If these parameters are false, perhaps others parameters are also false ?
Captures of parameters can be seen here : http://www.verticam.be/FR/PGPHO.php

Does someone knows where I can find a correct ini file compatible with this kit ?
Thanks for your help.

Velleman support should have more empathy for users who are not always 3D printer specialists … and are spending a lot of time to use their kit. :frowning:

Repetier : 1.6.1
Slic3r : 1.2.9

2

Hi Dakota88.

Join the club… I have had similar problems see my topic ‘K8203 Extruder feed erratic’

I ignored the downloaded config files and entered 1.75 and .35. I had great difficulty starting as I was using a new board and (as usual with Velleman) there were no instructions of how to set it up or even that it needed setting up. ‘K8203 Upgrade printing faulty’ sorted out by 2 very helpful contributers - although by then I had returned the board for checking

I still had the original board with a dodgy USB port. Managed to get it working (with BluTac) and had 10 hours of printing - almost as good quality as the original 3mm set up.

It then started erratic feeding as described. I’ve spent a week trying to find the cause to no avail (and little help from Velleman) I am left with trying to get some info which must be easily available

Set up with Z rail about 100mm up and extrude filament manually. What is the extruded filament diameter? This would give a clue as to whether the nozzle is partly blocked (the only possible cause I can think of left)

I reckon I will be back to 3mm fairly soon and have to write it all off to experience (unless I can get some recompense from Velleman)

3

Hello Fafnir,

It is incredible to spend so much hours trying to solve such type of problem.
I have done some tests prints with other printers and it seems much more simple and the quality is much better.

It is strange that you managed to get it working for 10 hours…
I understand that you use your computer to print. I use the SD module.
I have also this erratic feeding. I have tried to decrease the pression on the filament using an elastic and the erratic feed is disappeared (see the photos). But it is not a solution.
I have also changed the config file manually but I don’t know if there are other parameters to change. (filament diameter is 1.75)
The print quality is my actual problem. http://www.verticam.be/FR/PGPHO.php

I will try a print and change only Filament setting 1.75 and Nozzle diameter 0.35 mm and will post photos.

4

Hello dakota88

This is link to a couple if items printed in my 10 hour window dl.dropboxusercontent.com/u/181 … sK8203.jpg

The rectangular item is a support for the control board. The best surface is in the bottom right. The fan would come on quite unexpectedly with full force and cool the extruder below the ‘cold extrusion’ limit and shut down. In this case I didn’t notice for some time. I’ve now made a diverter like yours.

5

Hello Fafnir,

Could you give me a link to download the support for control board stl ? (I didn’t find it on Thingiverse)

I will print it to see if I obtain the same quality as your.

Thanks
Mario

6

Hello dakota88 is Mario your real world name?

in file dropbox.com/sh/drlwbzs7yrtf … D-eia?dl=0

The 2 stl files are 1/10th scale. They are my own done in Blender. 1/10th is more convenient basically the native dimensions.

The pic shows the 2 holders keeping it in place

I have rarely used thingiverse - make all my own files - like the Celtic pattern on the previous post

If you have an accurate caliper gauge would you try measuring the extruded filament. Set extruder up about 100mm and extrude filament. then measure the diameter.

7

Hello Fafnir

Thank you for the files. I will print them tomorrow.

I get much better results : I have printed the fan nozzle. Happy with the result. See photos here :

http://www.verticam.be/FR/PGPHO.php

The extruded filament is 0.36 mm

I don’t understand with the erratic feed has disappeared…

I suppose you have mesaured the voltage of the extruder driver ?

8

Just realised my request wasn’t clear. Is that the diameter of the solidified filament after extrusion? If so my nozzle must be partly blocked

9

Yes Fafnir it is the diameter of the filament after extrusion.
Mario

10

Hello Fafnir

In your Dropbox there are not stl files.
Only Jpg.

Thanks
Mario

11

Mario,

Sorry I thought you had got them replaced with files for Velleman

dl.dropboxusercontent.com/u/181 … Board2.stl
dl.dropboxusercontent.com/u/181 … older2.stl

Alec aka Fafnir

Edited Added dl.dropboxusercontent.com/u/181 … Holder.jpg Pic of set up

12

I will try to help as much as I can.
Did you load the firmware for the K8203?
This link is for the firmware for just the K8203.
This version supports the K8203 DIRECT DRIVE EXTRUDER and the VM8201 LCD and SD card controller. DO NOT FORGET TO RESET YOUR EEPROM SETTINGS AFTER THE UPGRADE!. Copyright © 2011 Camiel Gubbels / Erik van der Zalm.
http://www.k8200.eu/downloads/files/downloads/firmware_k8200_v2.2-marlinv1.zip

This link is for the K8203 and the K8204.
This version supports the K8203 DIRECT DRIVE EXTRUDER and the K8204 Z AXIS UPGRADE ROD AND COUPLER FOR K8200 and the VM8201 LCD and SD card controller. DO NOT FORGET TO RESET YOUR EEPROM SETTINGS AFTER THE UPGRADE! ©2011 C. Gubbels E. van der Zalm
http://www.k8200.eu/downloads/files/downloads/firmware_k8200_v2.3-marlinv1.zip

Here is the link to change the firmware.
http://www.k8200.eu/manual/printing/?c=007

When changing the firmware use the Arduino software 1.0.6 or lower anything higher will not work correctly.
You can download it in this link
https://www.arduino.cc/en/Main/OldSoftwareReleases#previous

Do not forget to short the JPROG pins while uploading the firmware.

13

Hello,

I get much better results now.

http://www.verticam.be/FR/PGPHO.php

The quality reached is now enough for me. :slight_smile:

Thanks a lot for your help.

Mario

14

All,

A few weeks ago I decided to upgrade my belt driven extruder (upgraded with an E3D hot-end) by the direct drive extruder as offered in the Velleman K8203 kit. I did not install the included hot-end but modified the angular mount to fit the E3D hot-end.

Before:

98hljl.jpg1600×1200

After:

309jz1i.jpg1600×1200

In the past I printed magnificent pieces and since the upgrade the quality of the printed parts went heavily backwards. It looks like the extruder steppermotor was missing steps and has not enough torque to turn smoothly. As a result the extrusion looks like a cobblestone path.

The force required to push 1.75mm PLA through a 0.35mm hotend at 190° Celsius is between 15 N = 1.5 kg (slow) or 25 N = 2.5 kg (fast). The Nema17 steppermotor is able to produce 30 N, so there should be something else wrong.

I’ve spent at least 3 nights browsing the web to find a solution and another 3 nights with trial and error:

[ul]- steppermotor driver set to 0,75 - 0,80 - 0,85 - 0,90 volt

  • multiple adjustments to align the filament pulley
  • PLA extrusion temperature set to 170° - 175° - 180° - 185° - 190° - 195° - 200° - 205° - 210° - 215° - 220° - 225° - 230°[/ul]

Nothing helped !

After some more sleepless nights, I noted the following facts:

First of all it feels the driver spring is way too strong and pushed the filament too hard between the bearing and the filament pulley. I could barely push the filament by hand. As a result the Nema 17 steppermotor floats betweens microsteps and nervy skips.

This issue was easily handled: I grinded off one resolution of the spring.

After reading an in depth description how steppermotors works, I concluded the 1/32 step modus as default set on the high power DRV8824 driver wil not do the job. As test I replaced the DRV8824 driver by the original A4988 board with default 1/16 step modus and guess what: the extrusion was as soft as a baby’s skin !

Of course the A4988 driver is not able to deliver enough current as needed in direct drive modus for a long time without getting extremely hot, so this solution was only a temporary one for test purposes. Next I cutted the M1 and M2 traces on the backside of the controller board and inserted the high power DRV8824 driver over again. Cutting M1 and M2 forces the DRV8824 in 1/16 step modus with the same extrusion result as with the A4988 board, but now able to work for a longer time.

Sorry for the double post, but perhaps this is also useful for you…

15

Hello Fitchie,

Thanks for your comment.
I had the same problem as you and also concluded that the spring was too strong.

I have disassembled all parts, reassembled them and reinstalled Marlin, and now I get good prints.
The configuration ini file downloaded from Velleman site had errors :
I set filament setting diameter to 1.75. and Nozzle diameter 0.35 mm

Just for information my driver is DRV8825.

I do not understand when you say : “Next I cutted the M1 and M2 traces on the backside of the controller board”

What does that mean ?
Thanks

16

[quote=“dakota88”]I do not understand when you say : “Next I cutted the M1 and M2 traces on the backside of the controller board”
[/quote]
On the backside of the controller board between the connectors of the stepper motor drivers, you’ll find 3 bridges between solder pads. By default they are closed (aka low), if you want you can cut the traces (aka open) and solder some jumper headers in. With these jumpers you can select the micro stepping each motor.

M1 (PCB) = Mode 0 (DRV8824) = MS1 (A4988)
M2 (PCB) = Mode 1 (DRV8824) = MS2 (A4988)
M3 (PCB) = Mode 2 (DRV8824) = MS3 (A4988)

For the DRV8824 driver:

29xc084.jpg968×614

For the A4988 driver:

9giopf.jpg810×420