Separate names with a comma.
Discussion in 'BigBox General Chat' started by Spoon Unit, Aug 31, 2016.
I'll bite.. what are they?
Looks a whole lot like this: http://www.thingiverse.com/thing:60778
Yep. I have a feeling my bed adhesion isn't going to be good enough though. I can see a couple of parts beginning to bend. First layer looked just fine though...
That's pretty cool, hope it turns out OK.
So far, I have about 5 parts that will be non-viable. 3 have been ripped off the bed and it'll be interesting to see how it copes with the spaces. I'll post an image of the build plate once it's done. Note to self: If you're going to set this much stuff to print in one go, a clean bed and fresh adhesive would be good (or maybe that PEI Alu build plate).
Well, I did lose a few pieces. The total print was 84 parts and I think I lose around 7 parts. I suspect I've counted something inaccurately, but nevertheless, I have more than enough track stands to be going on with.
In my experience, printing less parts usually ends up in shorter print times and less waste. I have been using only PLA but even then I had warping a lot when printing two semi large parts together. Just doing them single would have been better and turns out also shorter. The travel time between parts adds up crazy.
Was there any pattern to the parts that came unstuck? (eg near the edge?)
Well, many pieces had an external and internal edge. I'm sure you're going with uneven heating, and I think that's at least partly the issue. One way to counter that would seem to be to warm high enough that the external edge has the heat you want. Another observation is that these were thin pieces with no bridge until the final three layers, so I could probably have dropped all cooling until that final layer to reduce the impact of a gale force blowing again a relatively small and thin piece of plastic. I just abandoned a print of 11 corner pieces as I had a number of those pulling away. I'll probably swap the bed for a clean one in the morning and re-UHU. I'll then adjust S3D so the (50%) gale doesn't blow until we reach the first bridge.
Once you have a piece came free it can become murderous for the rest of the pieces, partly because the second print head and can give the extra tug required to pull things apart.
I'll bet if someone does a thermal photo of the Aluminium bed that the corners are not 10C cooler as on the PCB backed glass one. (It's a great conductor.)
I didn't realise it was 10; that's a lot, and certainly enough to cause issues if you don't take account of it. Perhaps this could be a reason to actually allow the heated bed to sag a little in the center, and use supports around the edges.
At first glance, the changes to fan speed and bed cooling appear to have been sufficient. The first overhang in the next set of models appears on layer 17 (at 0.3 height), so I'm keeping the fan off until then. I'll also maintain the bed temp at 75 throughout. So far, the print is going well with zero lifting even at the edges.
That printed just fine then:
These look great @Spoon Unit
Did you have any warping on them?
zero warping on those ... or the next set of 12 straights
Nice large part. Again zero warping. Painful however that the bearing that's supposed to fit in the center drops straight through. I think older designs are just not setup for accurate printers.
Loctite do some great stuff for locking bearings in place....... I will dig it out to let you know what it's called, it's a nice green colour too !!
I redesigned it so the bearing would be a nice tight fit. Much better. At the same time, I drafted the holes so that the ball will sit nicely in the holes without any need to have the whole contraption angled.