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I have a couple of prints with severe overhangs that end up needing support material, which requires a lot of work to clean up and then leaves artifacts on the finished print which require sanding and filling to eliminate. I was able to tune the overhangs and add fillets and slight slopes to the overhangs to get them to almost print without the overhangs, but I still get some droopiness in some areas, or a bit of extrusion that squirts out of place and sags. I can't quite get it 100% perfect.

I had a crazy idea of turning the printer upside down and trying the same print without support in the inverted position. I have this idea that gravity will hold the extrusion in place longer and it won't slip away from the nozzle and pop out of position and it will adhere better the the previous layers (above it) and it might solve this problem.

Has anyone ever tried inverted printing, or using gravity assist to help? I can envision being able to do a perfect 90 degree overhang by laying the printer on it's side so the overhang is perpendicular to gravity.

Is there something I am overlooking?

Make sure you take photos when you try!

There was a 6 axis 3d printer that had almost the same effect of what you describe.

I am a bit doubtfull that it will work as you hope. But give it a try. And for all we know next year this time it could be the next big mod to our printers.

Have you tried tuning the bridge flow parameter, as well as changing the cooling on those overhangs?

Got a pic of the problem area?

You can print upside down, yep.
https://www.facebook.com/themakerhive/v ... permPage=1

I've done inverted printing breifly with my Bukito Printer. Only to show off that it would work that way. wouldn't recommend it as a regular thing.

Just turn the camera 180 degrees, mine works fine.

If you were on the space station, you could do zero-G printing. Best way I can think of to eliminate support requirements.

Eric wrote:If you were on the space station, you could do zero-G printing. Best way I can think of to eliminate support requirements.

Wouldn't have to worry about a heated build chamber either. Just let the air out of the chamber and the plastic won't cool off due to convection. Just have to keep the build platform heated.

Even zero-g wouldn't free up unsupported configurations as much as one might think. Bridging would be easy but larger overhangs don't fail just because of gravity. They also fail because the extrusion needs something to stick to in order to deviate from a straight line.

IMBoring25 wrote:Even zero-g wouldn't free up unsupported configurations as much as one might think. Bridging would be easy but larger overhangs don't fail just because of gravity. They also fail because the extrusion needs something to stick to in order to deviate from a straight line.

I'm not suggesting that you can print in thin air this way, only that the appearance of overhangs and bridges could be improved with this method. For example, bridges tend to sag a tiny bit on the first layer, and subsequent layers have nothing to adhere to, so the bottom of a bridge surface takes the appearance of loose pasta. If the print were inverted, the bridge layer would droop towards the nozzle, and the next layers would lay down extra firmly on the previous one, giving a good adhesion.

Just mount the printer in a 2 axis gimbal. Rotate the whole printer so the bridge runs vertical. Once it's a couple layers deep, go back to upright. Easy peasy!

Printing upside down. Isn't that how it works out anyway for you Aussie guys?

Just like the toilet flush swirling the wrong way!

gary

nitewatchman wrote:Printing upside down. Isn't that how it works out anyway for you Aussie guys?

Just like the toilet flush swirling the wrong way!

gary

Good one!

Instead of printing upside down why couldn't you turn the filament inside out?

Eaglezsoar wrote:Instead of printing upside down why couldn't you turn the filament inside out?

That's just crazy talk!

barry99705 wrote:

Eaglezsoar wrote:Instead of printing upside down why couldn't you turn the filament inside out?

That's just crazy talk!

Thank you! Some things i write are supposed to make someone laugh.

Mounting the printer in a large gimble is something I have been thinking about building for quite a while. ....gimble would also have stepper motors and read same gcode simultaneously to tip printer in optimal direction on the fly.
My Maker buddies think I am crazy and think it won't help anyways.
That's enough reason for me to try it! now to find the time