Question This is not good

[Ho-whizzle]

Printer Model

LDO Trident 300mm

I was level my bed then the left corner platform rod slipped and wont stay in place. Does anyone know why and how this happened and what I should do before I have to take it apart?

I have attached a video.

 

[Ho-whizzle]

https://imgur.com/a/KooZmPK

 

[Sanity Agathion]

This looks to be the same case?

LDO Trident POM nut ground down

After 600 hours my Trident met a major failure with the POM nuts, where one got ground down until it completely lost the grip: This "shouldn't happen", but there were at least two others who reported the same issue in Discord so I thought I'll start a discussion here about it. Maybe...

forum.vorondesign.com

 

[Ho-whizzle]

This looks to be the same case?

LDO Trident POM nut ground down

After 600 hours my Trident met a major failure with the POM nuts, where one got ground down until it completely lost the grip: This "shouldn't happen", but there were at least two others who reported the same issue in Discord so I thought I'll start a discussion here about it. Maybe...

forum.vorondesign.com

I think you’re right which is a shame but good to know. Thanks! I wonder why LDO does not provide stronger or metal lead screw nuts instead?

 

[Ho-whizzle]

This looks to be the same case?

LDO Trident POM nut ground down

After 600 hours my Trident met a major failure with the POM nuts, where one got ground down until it completely lost the grip: This "shouldn't happen", but there were at least two others who reported the same issue in Discord so I thought I'll start a discussion here about it. Maybe...

forum.vorondesign.com

Also, do you know the specs for replacement lead screw nuts so I can quickly purchase them.

 

[Sanity Agathion]

Also, do you know the specs for replacement lead screw nuts so I can quickly purchase them.

Honestly I don't know from top of my head, Most probably some TR8x4. It may be best looking into specifications for that motor and/or kit BOM.

 

[netzwerg]

I had the same happen on one trident printer, the other trident is fine.
Turned out I greased the rods on the first printer with Liqui Moly LM47 (https://www.liqui-moly.com/de/de/lm-47-langzeitfett-mos2-p000371.html) which contains Molybdänsulfid (MoS2) particles, which don't get dissolved in the grease and probably did grind on the POM nuts longterm.
On the other printer I used Liqui Moly LM50 (https://www.liqui-moly.com/de/de/lm-50-litho-ht-p000370.html#3406) grease, that is pure lithium based greased and everything looks fine.

HIWIN recommends using grease without particles such as MoS2 or PTFE on their linear rails. So it's probably a good idea not to use it for greasing metal vs. plastic contacts.

 

[majic79]

Isn't a POM a self-lubricating material? I thought that the point of it is that you don't need to add any lubricant to the nut - they are also somewhat vulnerable to chemical degradation depending on the lubricant

 

[jonhi]

Huh. I started the other thread, but I also used some kind of lubricant (probably too much).

 

[netzwerg]

Isn't a POM a self-lubricating material? I thought that the point of it is that you don't need to add any lubricant to the nut - they are also somewhat vulnerable to chemical degradation depending on the lubricant

It has a high lubricity and is rather abrasion resistant and has a low coefficient of friction and is therefore often mistaken as "self lubricating". Lubrication will extend the service life though.

 

[m00dawg]

Oh wow I hadn't thought SuperLube (which has PTFE in it) might be problematic. Yikes I might need to find another lubricant for those. Or...nothing? In terms of the POM self lubrication point, I never lubricated my threaded rods up until recently on any of my printers. My first Prusa which is several years old now is still running with the same POM nuts.

 

[majic79]

I did some digging, you can use lube, but you have to be careful to avoid some specific acids (it's not chemically resistant) and also to avoid powder (dry) lubricants as it may act as a grinding powder instead. Silicone lube seems to be recommended. Moly-disulphide I know is popular in high-wear metal on metal, but is specifically recommended NOT to use on plastic components (including POM)

 

[Sanity Agathion]

Hi, contact seller of your kit and ask them for leadscrew replacement. See one thread over linked in my first post here.