HELP! My support material won't still in one location

[jill_henderson 0]

Hello Ultimaker community,

 

I am relatively new to 3D printing and I am having trouble solving this problem! Below is an image of an assistive device I am trying to print but i am having trouble trying to print the support material! Within the blue circle there is supposed to be a layer of support material but for some reason it will not stick to the initial layer, and in red on the upper half of the green boarder the support material is very blobbled and not working well where on the lower half its working great! MY original print worked well then i made some edits and tried to reprint it i started having these problems. 

 

I have already tried drying out the PVA support material, and i am unsure if it is the nozzle bc some parts are printing cleanly?

 

 

[gr5 2,224]

1) What is the green material?  PLA?  Because PVA doesn't work with some materials such as ABS.

2) Yes the PVA needs to be very dry.  You can tell if it's very wet because it will snap and crackle and sizzle and you can even sometimes see puffs of steam coming out of the nozzle.  This may not be your issue - I don't know.

3) This is a UM3, right?

4) Is the PVA directly on the build plate?  I hope so.  If not then this is a bug in Cura.  I may have seen this bug.  I think you could just turn off brim completely - this part might not need it.

5) Assuming PVA is directly on the build plate, try cleaning the bed very well, then put a few inches/cm of pva into a sealed jar with some water and let it dissolve for a day (or use wood glue - 10 to 20 parts water to one part wood glue and no waiting needed).  Then paint this slurry on the *clean* bed. 

6) Does your part really need any support?  I don't know what is going to print next so I don't know.  Maybe you can just turn the feature off.

 

Do not leave PVA on the back of your printer when not in use.  It needs to be stored in a sealed bag.  I recommend buying a few of these rechargable dessicant packs:

https://www.amazon.com/EXMAX-Indicating-Rechargeable-Functional-Microscopes/dp/B00YS3AFAA/ref=sr_1_50?dchild=1&keywords=dessicant+rechargeable&qid=1596215672&sr=8-50

 

Or you can get a gallon of the stuff and make your own packs.  They change color when they absorb water and then you can microwave them back to dry again.

 

This won't be enough to dry PVA that is already wet.  For that, put it on the bed at 70C with a towel over it for a minimum of 8 hours but 24 hours is better.  Or just unspool a few meters (if that's all you need) and dry that for one hour at 70C on the bed with the spool on top (no need to cut the PVA) and a towel over that.

[jill_henderson 0]

@gr5

1) yes its PLA

3) yes its the ultimaker 3

4) yeah i read that PVA doesnt stick to other materials very well so i made the brim made from PVA

6) It does need support, it is not far enough into the prin to show, but the places that are forming support will be support some "hovering" PLA

 

I will try to cleaning the bed and removing the brim thank you!  

[gr5 2,224]

Well the other thing to try is level better.  The bottom layer PVA should be squished really well.  For the second layer not to stick to the first makes no sense as PVA usually sticks to PVA.  Reasonably well.

 

PVA is not as nice as PLA to print.  It doesn't stick to itself when molten.  Liquie PLA is like snot, like mucus - it sticks to itself like a liquid rubber band.  PVA is more like concrete - it falls apart in separate pieces.  But still - it should stick to itself enough that this is the easy part.  The hard part is getting PVA to stick on top of PLA.  But you aren't there yet.

 

When you next print, listen while printing the PVA.  See if you hear snap/crackle rice cereal like noises.  If so then it's time to dry the PVA.