Ender 3 V2 bad thread

[terrypin]

Removed the two bolts securing the hot end assembly a few days ago, first time in the six weeks since I received the printer. When replacing them this morning I found the LH bolt could not be tightened. It’s fine in the other hole. So obviously a bad thread, which I find surprising; are these often encountered?

Much rummaging found a bolt of about the right length with diam of 3.01mm, slightly larger than the original 2.89mm, and that works.

It seems to me (novice) that the hot end was therefore only secured firmly by one bolt, yes? So do you think that could be behind the disaster I had on Friday causing the small project (80x40x25 box) to get stuck on the nozzle, and the area around that to be totally gunged up with PLA? I should add though that, after about 10 successful prints (mainly boxes) I’ve recently had other failures, with lifting filament apparently being the main symptom.

 

[ScoobyDoo]

Lifting filament? Do you mean it's not sticking to the build plate and lifting away when printing? If so make sure your bed is clean and maybe raise the bed temperature slightly.
I print all my pla at 65 bed temperature, if there's grease from your fingers etc on the bed then you'll have issues with the filament sticking so give it a good wipe down after each couple of prints

 

[terrypin]

Lifting filament? Do you mean it's not sticking to the build plate and lifting away when printing?

Yes, thanks, that’s what was happening. I’ll clean more regularly. Is methylated spirits OK?

 

[gitbags]

If printing with pla you maybe better off turning the bed over and using the flat glass side. Clean with isopropyl alcohol, or hot soapy water. Take care with alcohol on the textured side, there are reports on Reddit of people damaging the coating.

If you're having issues with adhesion after cleaning and your sure your bed is level with the right amount of squish for your first layer, you can add a brim to your print or use glue stick, or hairspray to reduce lifting.

 

[terrypin]

Thanks, very helpful.

Soapy water sounds the better option after looking at prices for isopropyl alcohol.

I’m surprised that plain glass could improve adhesion, compared with the ‘textured glass’ side?

 

[roman59]

Thanks, very helpful.

Soapy water sounds the better option after looking at prices for isopropyl alcohol.

I’m surprised that plain glass could improve adhesion, compared with the ‘textured glass’ side?

The best upgrade I did with my CR10 V2 was replace the stock bed with a borosilicate sheet of glass & use an Elmers purple glue stick on the bed, perfect bottom layer and no need to print a brim or raft, adheres to the glass perfectly with no curling or lifting.

To clean the bed after printing I just use a wet paper towel to wipe off the glue & a dry towel to finish cleaning.

Cheers All