CDC DIY Printer Problems

[Niall]

I have a CDC DIY printer. This is a low cost FDM printer, which is assembled by the owner. I got several good prints of using the PLA filament that came with the printer. When this ran out I used a different brand of filament and vertical faces have a regular ripple. I tried some scraps of the original filament and it does the same thing. The manufacturer's customer service is useless - they actually blocked my e-mail address after I asked them a question!

 

I cannot get Cura to see the printer when connected to my PC, Windows does see it. How do I solve this? Cura's support "says ask the manufacturer"

 

Looking on the internet I have replaced the links between the lifting stepper motors from plastic tubing to metal junctions and the bed, extruder moving and extruder steppers with new ones with no success in solving the problem. I have used 2 of the replaced motors to change out the lift steppers.

 

I am now completely stumped, does anyone have any ideas?

 

Thanks in advance

 

Forgot to add a photo of a 10mm test block - Top of the print is to the left -

Edited June 7, 2022 by Niall
Added more information

[Schwarz-Brot]

There are two things that come to mind seeing this:

 

First possibility: backlash in both, your X and Y Axis. Every few layers it seems like the printer changes the direction of laying the filament - or maybe every layer, depending on your layer heights. This might be anything from a loose connection between your driving shafts and (if applicable) the pulleys for the respective belts to ultra cheap belts which do no longer match the pitch of the pulleys due to having been overly stretched in the past or worn out over time. Anything in the Drivetrain that shows a bit of backlash is a problem in this usecase. Go and wiggle every part to find it. Including the extruding head!

 

 

Second possibility: A periodic distortion of the printers frame coming from the movement of the Z-Axis might lead to the same stepping effect. Most likely to happen if you have a lead screw for z-movement. In this case the screw probably is bent or runs excentrically and transfers force via mounting points or bearings. This can lead to a periodically distorted frame which effects the placement of the X-Y Drivetrains relative to your printbed.

[Niall]

Thanks for the reply. I'll do some checking out.