The care & nurture of a 3d printer...

[Wulf]

The Blitz's turned out lovely.

Looks like playing around with the Interface settings will pay off. Although, note the separated slats above the sides on the leftmost truck, those printed without support!

The Luchs just wanted his photo taken, 'cos he's cute.

[paulr]

 

A really interesting thread

One of the stalls at our recent nationals was selling files for 3d printing

[Wulf]

A really interesting thread

One of the stalls at our recent nationals was selling files for 3d printing

Yes, I have paid for quite a few files myself. I even backed a Kickstarter for Dark Ages terrain, buildings, walls, etc, mostly because you could get cheap copies of previous Kickstarters, including some WWII stuff along with it. I have a 13 hour print of a ruined Russian factory lined up now from that...

[Wulf]

I wish I'd taken a picture of this, but I was a bit worried & a lot angry when I discovered that a reprint of the Blitz's failed in a very peculiar way...

Originally there were 4 lorries, but one failed with a flat - oval, in fact - tyre. The print hadn't stuck to the print bed firmly on that corner and had printed, but risen up. The printer continued to print on top of it, and by the time it reached axle level it was all straight again, but the diameter of the wheel below the axle was about half the diameter above it. It's happened a few times before. I decided to reprint, and add in a couple of other Blitz variations.

About an hour & a half into the print I realised the print was looking messy. I then realised that, sitting off to one side of the build plate, there was half a front axle... This time, it had printed up to axle level, but hadn't quite reached the chassis, when the axle part came adrift. At this point only the tiny point of contact between each wheel & the surface had held it in place, and the supports were not binding enough to... support. My efforts to make the support easier to remove have come back to bite me...

Worse yet, the print head seems to have actually got stuck on the axle, as the entire print had 'shifted' off to one side at that point. This was the really interesting bit. When it tried to move over the axle it got stuck, and the belt feed that moves it has slipped (which is WAY better than getting any kind of mechanical jam!), but then carried on printing about a centimetre off to one side. I noticed this about another millimetre of print later. I realised it had failed, aborted the print, then set the print head to Auto Home, which moved it off to one corner of the build plate, where it hit the end stops which automatically recalibrated it. It's started up again on the same print. A couple of hours and about 5p worth of filament wasted...

It's never a simple task this.

[Wulf]

Here's a common oddity I meant to mention before. It came to light again while testing the print time of a single Pz 35(t) for Leon on another thread. Look at these shreenshots:


Notice the oddity? The track treads show up on layer 2, but not on layer 1 - the tank actually 'hovers' a fraction of a millimetre above the buildplate! That happens quite a lot. Remembering that the extruded filament will droop & adhere anyway, and that Support should hold it in place, it's sometimes not an issue, but I have taken to checking every model on every print before starting, and lowering it just a fraction until I do get a decent contact. One weird one was these guns, where the tracks touched the buildplate, but the recoil spade did not. The spade was almost a half millimetre above the buildplate, which is huge in this scale. Not certain if this was intentional or not, but I adjusted by rotating the gun rather than sinking the tracks into the ground, as a half millimetre would make the tracks excessively thin, or even not print at all. Anything below the plane of the buildplate just doesn't print, by the way, it's a common way to reduce the height of, or eliminate, bases, etc.


As I am dependant on the work of others supplying these meshes, I'm happy to spend a few moments in preparation.

[Steve J]

The quality of the cad data can make a big difference to whether a build works or not. We know this form bitter experience at work . Another major issue can be temperature, especially during Winter as if the room cools over night, it seems to always cause problems. Then there are the occasions when for no obvious reason, the build crashes .

[andys]

@wulf - pm sent. I think, can't see it in the outbox thing!

[Wulf]

@wulf - pm sent. I think, can't see it in the outbox thing!

Reply sent...

[Wulf]

The quality of the cad data can make a big difference to whether a build works or not. We know this form bitter experience at work .[/q]
Yes, I've seen all kinds of weird anomalies in the meshes on Thingiverse. Hovering tanks (and other things) seem to be quite common, or things that do touch the ground, but only with the tiniest sliver of contact.[q] Another major issue can be temperature, especially during Winter as if the room cools over night, it seems to always cause problems. Then there are the occasions when for no obvious reason, the build crashes .

I seem to be OK overnight, strangely enough, nothing has failed overnight. Usually while I'm awake - but a few times when I'm at work.

[Wulf]

Here's an interesting one (and an in-action picture too):


While printing a whole load of parts for a ruined factory, really overloading the build plate, the print at one corner came loose. Rather than restart the whole print (for the third time...) for the sake of one part, I waited until the print head was at the opposite corner of the build plate printing the part over there, then gently raised the magnetic mat that comes on the Ender 3 pro and inserted a piece of kitchen foil, while it continued printing. The thickness of that was enough to raise the bed to compensate for the lost print layers (the fluff/spaghetti they turned into isn't seen here) and allow the rest of the print to adhere and continue. It'll finish in another 12 or 14 hours...

Note that this is using a Brim for bed adhesion, thus the grey 'halo' around all the parts. A brim will support the more vertical parts, like some pillars & the chimney. Assuming it doesn't all go wrong, I'll post a pic of the finished print tomorrow.

[Wulf]

Here's the completed kit of parts for the factory (with StuG for scale):


Everything printed nicely, I'm glad to say. The 'Venetian blind' effect vertical pillars are the supports, a side view of the zig-zags visible in the previous pic. Sadly, I realised when I looked at the previous pic that I'd forgotten to set the support to break into 'clumps' which simplifies cleanup. Never mind, the shapes of this print are relatively simple, so as long as the support doesn't bind to it it should be fine.7

However, my gout is playing up today, and while that doesn't stop me sitting at a table cleaning up the print, it dampens the enthusiasm, so it may be a day or so before I post a pic of the assembled piece.

[fred.]

I'm really enjoying the detail you are providing in these posts. While the results from the printing are good it does feel an art to generate the right settings and tweaks to produce them.

[Wulf]

I'm really enjoying the detail you are providing in these posts. While the results from the printing are good it does feel an art to generate the right settings and tweaks to produce them.

You can approach it methodically and produce consistent results, but unless you only print one sort of model (tanks, armoured cars & trucks, for instance, have different problems with support) they'll have to be decent rather than good. Most of my issues have to do with getting stuff better, not with getting stuff printed.

[Wulf]

The gout is still playing up, but these proved far easier to give an initial cleanup than I had feared. Unfortunately that's partially due to having been printed with thick layers, and far too fast. The undersides of the outer roof supports are a mess of hanging filament thread thanks to inadequate (but easily removed...) support. However, it looks pretty good from tabletop distances...



Lots more cleanup to do, and plenty of filing cutting & sanding on those overhangs... Then it needs a base & lots of rubble & fallen roof structure.

[paulr]

 

I'm definitely learning lots