S5 Z-AXIS squeaking and grinding noises - Repair and some teardown comments

[mkaj2019 41]

My S5 started to make some unpleasant noises when the print bed moved up and down. The issue was in my case that the white plastic cover at the back of the print bed carriage has deformed over time. One of the through holes in the plastic cover moved and was now touching the z-axis rod.

This could also happen to your S5 printer over time. I will try to explain what I did to solve the issue. I also took some pictures from the parts inside with some comments.

 

Before the repair:

https://www.dropbox.com/s/nt96xhdoyvbb1ex/Before_repair.mp4?dl=0

 

After the repair:

https://www.dropbox.com/s/21xoipf9ls8r62b/After_repair.mp4?dl=0

 

To remove the squeaking, I needed to drill the through hole of the plastic cover bigger:

 

• Remove everything from the backside of the printer (Spool holder and Filament Spools from the back, Cables…)
• Lay the printer with the backside on the table
• Remove the bottom panel of the printer (bottom panel is mounted with tamper proof torx M3 Torx screws) and break the warranty void seal (mine was already broken although I have never tried to open the printer before). I am also very surprised that the bottom panel is cheap plastic not metal and has big holes for the speaker. I highly doubt that this is according to instrument safety regulations.

 

• Unplug the speaker from control pcb (Wow, that is one big speaker for a 3D Printer, can be maybe used in the future for spotify music playback)

 

• From the bottom you can see two stainless steel sheet metal plates holding the z-axis rods in place. You have to remove everything in front of it so that you are able to pull out the rods through the bottom.  In my case it was only the outlet fan on the left side.  The fan close to the control pcb sucks the air in and the fan close to the power supply blows the air out

 

• Once you have completely removed the z rod you can turn the printer back on its feet. You have now access to the plastic cover through hole.
• I carefully used a step drill to enlarge the hole diameter. There is some kind of dirt gasket underneath the cover to prevent dirt coming into the linear bearings, so be careful not to drill into the gasket or the linear bearing.  (The hole on the picture looks a bit horrible because I tried to use a scalpel before to cut away some material, which did not work.)  I would not recommend a normal drill for steel. It will suddenly dig into the plastic and most probably damage the linear bearing.

 

• Then I removed all plastic chips with tweezers out of the linear bearing and blew it out.
• I applied some new oil on the bearing  
• Put the printer on the backside again and carefully insert steel rod again. It must move freely through the linear bearing otherwise you have not removed all chippings.
• That’s it. I mounted everything back together (Make sure that the fans are oriented correctly, and the speaker is connected again, and the job was done.

 

Some interesting side notes:

 

• Good Meanwell PSU USP-500-24 (Scheduled for obsolescence and will be discontinued by the manufacturer). Will most propably be replaced soon by something else.

 

• Great Trinamics TMC 2130-LA Stepper drivers (Heat from the drivers and the whole pcb is transferred by a thick silicon pad from the pcb backside to the aluminium dibond panel)

 

• Motion Control is still done by the classic 8-Bit ATMega2560

 

• The rest of the firmware is running on this Olimex A20 OLinuXino Lime 2 board

 

• SparkLAN WUBA-171GN WIFI Module

 

• Great MOSFET for the 24V heatbed. Very low on-resistance of 0.4 mOhm

 

• Not that great: Power Cables for the heatbed are heavy stranded cables, not very flexible. I wonder how long they will last before they break. (Good thing: the WAGO Connectors for the heatbed wires on the PCB are great (I think they are rated for 30A or something)

 

 

• Some components are not populated on the PCB. Which could be a hint for future 3D-Printer design plans e.g.  a second heater connection (Maybe the next printer will have active heating for the build chamber. There is also a connector for another temperature sensor)

 

• Not so nice: Some cables are not assembled that great e.g. the heat shrink tubing was pulled off on one fan cable. The soldered cable shielding was exposed.

 

• And The USB cable for the wifi module is too short and under tension.

 

Overall, I can say: Very good, and high-quality electronic components like the above-mentioned parts but also e.g. the SUNON Fans or the MOONS Stepper Motor. The assembly is good but could be a little bit better. The mechanical design could be definitely better and is a direct result of excessive cost-cutting measures. I am confused that the electronics where not affected by these measures.

 

 

Edited April 21, 2020 by mkaj2019

[anbat8 1]

I have the same issue, Thank for sharing this with everybody. It's really appreciated

[UlrichC-DE 114]

Thanks for the info and pictures! I've always wanted to take a look.  👍

Now some things become clear to me.

 

 

On 4/21/2020 at 3:48 PM, mkaj2019 said:

I am also very surprised that the bottom panel is cheap plastic

 

Speaking from experience, if you use a metal plate in a design like this, you will have even more interference on the unit.