Printing methode for 'endless' objects

Hi all,

... i have an idea for printing parts that can have any length you want to have ... this can be many times longer than the building area!

For this you need a conveyr belt and a print head skewed 30 to 45deg to one side, so you can print either as normal 'sheetwise' - or vertical slices by adding lines to a vertical surface, starting at the bottom and then stack line on line until you reach the top.

You have first to print an endpiece of the object, so you have a stable vertical surface you can print on, then the printer moves only in two directions, e.g. X and Z, while the conveyr will move the width of the filament in Z after a vertical slice is ready.

So you can add as many vertical slices to the 'endpiece' as you want with moving the object in Y until you're ready.

The slice'n'dice will be the 'as normal' for the endpiece, but for the rest of the object it has to slice vertically ...

Some other ideas?

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

That's a very neat suggestion. When you print each vertical slice, you'll have to make sure that the bottom filament adheres both to the printed object behind it, and to the conveyor belt. It would take some precision, and perhaps the nozzle would need to be cut with a bevel.

The conveyor belt would become the new "z" axis, since it would move slowly and in only one direction. The other two axes would need to be made fast and low-backlash.

It might be nice to have some kind of vertical surface that is placed to start the process off, instead of printing the first layer normally and then switching to use it as a base.

If the endless object becomes very long, you might need some kind of rollers to support it, or else the cantilevered weight could tip over the reprap.

I've been brainstorming that idea. The biggest problem I've run into is that you would have to move against gravity at the same speed and precision you normally move horizontally.

Seems workable to me, especially as the Mendel extruder appears to work fine at odd orientations. I think jbayless' suggestion of a rigid vertical "floor" is a good one. If you were hoping to make this an "endless" printer, you'll have allow the "floor" to disconnect from the belt and slide along a table with the emerging model. The friction from pushing the model out along a floor might cause issues with z accuracy. You could overcome that with a longer conveyor belt, but that would defeat the purpose of an "endless" printer (that would be the same as simply building a taller mendel or Darwin).

Why angle the extruder at a shallow angle? Wouldn't it work at 90 degrees?

Yeah, the 'floor' would need some way of disconnecting once the model has been securely anchored to the belt by enough printed layers. As for makeme's issue, that could be resolved either with a constant force spring used to counteract gravity on the vertical axis, or by flipping the whole printer sideways (eg. mounting the printer to a wall instead of on a table), so that gravity once again pulls in the direction of the conveyor belt motion.

I'd hate to ask, but do you have a picture to reference your idea? thanks

... attached a sketch of my idea ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

You mean like this?

[www.youtube.com]

Like that, only without the vertical limitation of having to go back over the same area again. That way you can print something long and tall, instead of long and thin. You have to tilt the extruder so it's out of the way of the tall part, tho.

The limitation is that layers will regularly need an edge that contacts the conveyor belt. So you couldn't print, for example, a very long cone.

Yeah, support structures would be more important.

What about heating? Large objects would crack from thermal stress.

You only need to worry about that for the layers which are close to the construction, once it's hit the conveyor it can be allowed to cool.

Actually that process might very well create some interesting warping.