You have to see this. How to make peelable raft!

[mrbi11]

http://zavax.wordpress.com/2013/04/24/h ... th-slic3r/

[geneb]

He's begging for multiple hand injuries.

A MUCH safer way would be to use a small desktop vice (clamps to the table), a razor saw to cut the perimeter and a good, thin metal putty knife (1" would work) to pry the support off. You can find a razor saw at any good hobby shop.

g.

[mrbi11]

He's begging for multiple hand injuries.
.

not sure you got down to the easy part. I think he is making the point you are about how impossible or dangerous removing current raft tech is.

At the end, he inserts a small GCode software change between raft and print, that amounts to 1 layer height change and 1 temperature change.
He prints the connecting layer much cooler, then heats back up for the print.
The main downside is it takes minutes to cool down and heat back up.

The last bit he shows is taking a cool plastic print and peeling off the raft cleanly with no tools at all.

[626Pilot]

What's the motivation to use raft instead of adhesive or Kapton?

[mrbi11]

In spite of my many posts, I'm a novice. I'm posting a lot because I have lots of questions and very few answers.
Questions because I cant get some difficult prints to print. So take anything I say with salt.
By difficult I mean objects that are large round and flat, up to 138mm in diameter touching the print surface.

I believe the main purpose is to deal with shrinkage during cooling.
Large round objects want to contract after the first few layers, because those are cooler than the bottom.
This pulls up the edges.

The raft idea, is that it isn't solid, so has some give. It is a screen sort of shape, although it can be set solid.
I believe however, that a lot of folks make a solid raft, which as near as i can tell serves no purpose.

It isnt a replacement for hairspray. You still have to make your surface sticky somehow.
Its a remedy for the curling effect, which gets bigger with diameter of solid bottom layers.

I have been avoiding them like the plague, because of what GENEB points out in his comments below.
You have to whittle a giant flat piece of plastic with something very sharp and with lots of force.
Even if your fingers survive, the thing looks like hell and has a lot of damage.

If I cant get my prints to work any other way, I'm going to try rafts again. I will first learn the peelable trick,
which i think mainly depends on printing a connecting layer at cooler temperature. So I need to find out how cool my abs
will still reliably print. It takes advantage of poor adhesion. He also change layer height, which I do not understand.

[cope413]

If you haven't used abs juice, then stop making this more difficult than it needs to be. A good abs juice mixture will eliminate most curling issues. Most people around here avoid it because it's messy and a pain, but it's absolutely the best way to get good bed adhesion.

[mrbi11]

Lol.
Whats abs juice?

[cope413]

Dissolve 7-8 inches of abs in acetone. The more abs you dissolve, the stronger it will be. Once fully dissolved, brush it onto your glass and let it dry. You'll be left with a thin layer of Abs on the glass that your parts will stick very well to.

[cope413]

Start with 2-3 ounces of acetone...

[626Pilot]

Here's a 30 pack of Elmer's school glue sticks. This is enough to last until we are all brains floating in jars and it costs $12. All you have to do is lay down a thin layer, wait a minute for it to dry (unless your bed is already hot) and go. Best thing I've used so far and I've tried Kapton and hairspray. http://www.amazon.com/Elmers-Washable-A ... lue+sticks

[mrbi11]

I hate to sound offended but I'm fairly certain my brain is too full of weighty notions to float.
(joke)

[AndThenSome09]

I have to agree with cope, ABS juice is the best in my opinion, as long as your machine is calibrated so the nozzle is close enough to the build surface all you need is a very thin layer. I use whatever color ABS I'm printing to make a batch of juice, my parts come off with that thin layer attached and I just clean up the edges with a razor and am left with a nice glossy finish for the bottom. I think you should make a little for each color you print in because it will become part of your print!