PVA - what's the highest someone has printed with this?

[FalmouthLouis 3]

I hate printing with PVA though it is sometimes necessary. Just recently, I have had to print a structure which needs 6 separate columns of PVA along the lines of what you see in the attached photo. I needed these to go up to about 60mm height at which level they would do their support work. The problem is that half these columns were knocked off the vertical before they had got higher than 20 mm. This is a new reel of PVA with no obvious signs of having taken on moisture. I was using a prime tower to avoid uneccesary stringing etc. I couldn't use Breakaway as this is a fragile structure.

 

I think the highest I have ever gone with support material was around 150 mm using Breakaway, but this wasn't in the form of columns like this, but was one solid scaffolding structure which was not sensitive to sideways knocks. I don't think I've ever tried going higher than 30 or 40 mm using PVA.

 

So my question is: just how high have people managed to go with PVA? With my immediate problem, might I get better results by printing very slowly? ...or is this something to do with the quality of the calibration of the machines concerned?

[geert_2 558]

As I just said in another post. I don't have dual nozzle machines, but due to the lots of reports about PVA-problems, if I had dual nozzles, I would custom design and print most of the support in PLA. And only do a small interface in PVA in-between. And I would use a dovetail to let the PVA grip well into the PLA-support.

 

Like this concept. Then you can design the PLA support structure economically but still very stable.

 

Test this concept on a small test piece first, before doing a large model. And stay with the printer to see what happens during the first attempts.

 

 

[FalmouthLouis 3]

Geert - given the complexity of support issues (and wider dual nozzle coordination) it would be good if you could get a dual nozzle machine off Ultimaker so that you could put your massive expertise into helping us from direct experience with these systems.

 

I understand what you are saying above, but I am generzlly taking other people's designs and creating bespoke support structures for each project would drive me insane and would be financially unsupportable.

 

I've been poking around Cura's preferences for the support function, and there are a mind-boggling array of options. I've identified an option which allows one to create a brim around support structures, which might help my specific problem where I have narrow support towers. But I have other problems, such as difficulties in getting Breakaway to come out of slots and crevices. There seem to be options which allow one to widen the z gap between support and supported surface, but I have no idea how this will work in practice. Someone from the Ultimaker/Cura team needs to point us to settings tweaks which are most effective in getting over problems with producing effective support structures.

[geert_2 558]

3 hours ago, FalmouthLouis said:

...

I understand what you are saying above, but I am generzlly taking other people's designs and creating bespoke support structures for each project would drive me insane and would be financially unsupportable.

...

 

Yes, I can see your viewpoint now. To be honest, I hadn't even thought about existing models from others, it simply didn't cross my mind.  🙂

 

I design mostly for internal laboratory or hospital use, and 95% of the models don't need supports anyway. So I can design towards easy printability, and I wrote the above from that perspective.

 

Also, I am not using the latest Cura version: for my older UM2 machines, the older versions still work fine, so I can't say much about the latest settings.

 

[e23 1]

I have wondered about this kind of stuff myself to as well.

 

Not a fan of PVA and I don't think it's great to print with alone.

 

I have to use breakaway now since PC White (what I use) isn't compatible with PVA.

 

 

[RudydG 62]

I use pva all the time, no issues with it. But the main precaution, is keeping the material dry!!! Drybox, only take the amount needed out off the bag, and reseal the rest.

My make is Polymax polydisolve S1.