How is this done

I have seen files that are complete assemblies...do they work right out of the machine.
I can't think they would

Another example confuses me

a section of linked chain how is the image made so that it does not actually permanently connect the links of the chain together where they touch.

for example how would a small version of say a shaded floor lamp be drawn I can see the main body of the lamp just a straight column but when it comes to the shade which extends out from the column both x and y how is the bottom line laid down and then built upon to create the shade itself. It can't just float there.

Sorry if these are basic questions but I am very new to this.

 

Cool, pun intended, I hadn't thought about that aspect.
Thanks

Still wondering about the floor lamp model Best way would be to print it up side down that way everything has a base but if I was forced to print it right side up how can that be done?

 

Good point

 

That is good to know thank you very much I wasn't aware the software had this possibility.

 

One question how much horizontal movement do you think is required before a support column needs to be put in place. In Ahmed's image it shows small gaps between the support columns.
So how big can these gaps be?
Even the 3d tornado is an expanding ring which has now supports so there must be some horizontal movement that does not need support

 

I understand that I guess what I should have asked was
How much of the extrusion is required to be on a lower level before a support is required?
Would half the nozzle width be Ok or would we be able to squeak out 1/3 on the lower lever and 2/3 hanging.
I guess it would depend on the viscosity of the melted filament.

Is something like this built into the software used. Is it a definable value or is it simply static?

I am asking because I was thinking about placing actual SUPPORTS for a cover piece and if I used a fillet I may be able to create the the actual SUPPORTS without having to use the breakaway support.

IF the fillet had enough area in it to allow for the overlap to exist then it could be printed without the need for the support.

The beginning of this support would just be an added width of the wall it is not separate just wanted to show the layers and overlap.

 

It depends on the viscocity of the filament is a pretty good way of saying it. Plastics are viscoelastic materials, so when they are 'melted' they still exhibit some solid like properties, which is why this whole 3D filament printing thing works! You can tweak this with machine speed, temperature, and material type.

The rule of thumb here is 45degrees. If you go with a 45 degree incline, you're probably going to be fine with just about any settings. Completely horizontal features like your cover need to be supported all the way across. Not to harp on the 'it depends' point, but horizontal features are occasionally OK if you don't mind stringing on the bottom.
The part you have drawn should just be printed 180 degrees from what you have shown, then there is no need for any support. The other thing you can do is print in pieces and glue together.

 

The piece was a sample box and this was one of the side this would be the only real way of printing all four sides at once.

45 degrees being the 'rule' is what i was wondering about.
So a hollow pyramid with 45 degree slope walls would be able to be printed
Thanks

In this example the cover would have been printed separately.

 

If you don't want to have to deal with calculating it yourself Autodesk Meshmixer has an overhang analysis that uses the 45 degree 'rule'.

 

that begs the question if the design uses something greater than the 45 will it automatically add supports. When I made that drawing I just used a simple fillet it was based on distance not angle I had no idea what the angle was. I would think that most slicing software would have the ability to add supports where needed is this not the case???

 

Exactly. I think that the automatic supports go by the 45 degree rule very strictly. You can adjust what the criteria is for deciding when to support, but you can't say, "put supports here, but not there".

It's a tradeoff. You either spend the time designing your own custom support that only fills in exactly where you need it, or you spend extra time printing and then cleaning support material.

 

@3D Printing ROBO your bringing up very old topics. Its absolutely a good idea to read through them but please try to refrain from posting on them as it brings an old thread up to where new threads are. Makes the forum very confusing.
Thank you