Adding a Raft doen't add more layer

[jweaver 2]

I have been playing with Rafts and Brims and looking at the "layers" in Cura rather than printing for real.

And I am confused.. If I start with a model which has 99 lines.. And then I add a raft of 3 lines.. You can see that the first layer of the model now gets pushed up to layer 4.

But the model is still 99 lines tall, so the top gets cropped off.

This can easily be seen by exagerating the number of layers, to say 50... And then looking at the "layer" view.. The model is now sat on a thick raft, but the top is now missing.

What gives? Is this right?

Jon

 

[gr5 2,070]

It's probably just not displaying the top - I'm guessing it still creates the gcode. You can test this by opening the gcode file in repetier host which has a better "layer view" than cura does and it's free.

I've never used raft feature by the way. It's kind of an old technology that isn't needed so much anymore as there are now other techniques.

 

[jweaver 2]

It's probably just not displaying the top - I'm guessing it still creates the gcode. You can test this by opening the gcode file in repetier host which has a better "layer view" than cura does and it's free.

 

I've never used raft feature by the way. It's kind of an old technology that isn't needed so much anymore as there are now other techniques.

 

Cheers.. I was just playing about, trying to work things out.. What othrr techniques are there?

I had to do a couple of prints tonigh with small areas of contact.. One fell over (one the last layer) and one moved during the print...

I looked at Brim, but this would be added to the bottom of my print, so i felt a "raft" was the better option... What else is there?

[gr5 2,070]

Does your printrbot have a heated bed? What is your bed like? aluminum? acrylic? glass? Are you printing PLA or ABS?

 

[jweaver 2]

I am ruinning PLA onto blue tape over aluminium (non-heated)

I don't have a problem getting the first layer to stick.. But this project has 2 shafts.. And I have scaled the whole thing down to print a small version..

The shafts are about 6mm which means that there is almost no surface area.

I have managed to print the 3 that I need with no problems (although the first fell over on the last layer)..

But I was just wondering whether Brim/Raft might help me in cases like this.

Jon

 

[Daid 304]

100% sure the layers will be in the GCode. As the raft is seen as negative layers in the engine code.

So most likely this is a problem of the GUI not showing the layers because it miscalculated the layer count.

However, a brim is usually a better option then a raft. It uses less plastic, less print time, sticks better on small prints and leaves no surface scars.

 

[jweaver 2]

100% sure the layers will be in the GCode. As the raft is seen as negative layers in the engine code.

So most likely this is a problem of the GUI not showing the layers because it miscalculated the layer count.

However, a brim is usually a better option then a raft. It uses less plastic, less print time, sticks better on small prints and leaves no surface scars.

 

Cheers.. Will try a brim.. My only fear was that it extended outwards from the bottom layer, so I assume would be visible.. Where as the 'raft' implied that it was a totally seperate structure which could be removed.

It doens't really matter too much.. I will give a Brim a look to see how it turns out.

Cheers

Jon

 

[gr5 2,070]

Brim is easy to remove afterwards. It's a fantastic feature and I use it on 80% of my prints. It helps parts stick to the surface - especially if they have sharp (square) corners.

Make sure you clean your blue tape with isopropyl alcohol. Blue painters tape comes with a waxy substance that keeps the tape from sticking to itself. isopropyl alcohol (just put it on a tissue or cotton and wipe for a few seconds) removes that. Other solvents might also work - not sure. But rubbing alcohol works great. Found anywhere bandages are sold: