PVA going thinner during printing (big size model)

[sol_1234 0]

Hello I'm Ultimaker 3 Extended user.

I want to ask some questions about problem during the printing.

Like this picture, I try to print big earthen pot(pottery) model, it takes full size of build plate.

It would have been takes 5 days if it had succeeded. 

 

1. I put glue on bed, so it can be a problem about lost G-code in later (steadily)?? 

2. It was unreasonable size for printing?(fit in build plate narrowly, I tried small size the same model and it was succeeded. )

3. The long time printing does not easy to succeed?

[gr5 1,762]

@kmanstudios has done many 5 day prints on his UM3 printers.  Any suggestions, kman?

 

My first suggestion is to change the angle on support from 50 to 60.  This will reduce the amount of support needed greatly.  Also for this print it looks like you can set the "support horizontal expansion" to zero.

 

In general ANY problems you have with PVA are very likely caused by moisture in the filament.  Unlike ABS and PLA, PVA and Nylon absorb water quite quickly (e.g. 60% humidity for 2 days is probably enough to partially "ruin" your PVA).  So I recommend you put the spool of PVA on your print bed, set the bed temperature to 80C, put a towel over it and let it sit overnight like that (10 to 20 hours).  Also loosen some of the pva a bit on the spool so the outer layers can dry even more (typically I would expect only the outer 10 meters of filament to be exposed to moisture).

 

When done and it cools below 40C, put it back in a sealed bag with desiccant (it's good to buy those rechargeable boxes of desiccant - around 250 grams is good).  When printing things that are longer than 24 hours or when the humidity is above 50%, keep the filament in the bag while printing with only 3cm unzipped at the top of the bag and with desiccant inside the bag.  Keep the bag and filament sitting on a table behind the printer in a small area so the spool can't fall over.

 

[kmanstudios 1,116]

ou pretty much covered it.

 

I would just add that the OP needs to do a series of hot and cold pulls before starting the next print just to really clean out the nozzle.