Top tips for how to get a flat base ?

[printbot 1]

Hi,

I'm still learning how to use my new Ultimaker - starting to get some great results :-)

I'm currently trying to figure out, with out success, how to get the base nice and flat - at the moment the base curls up at the edges...... which causes a couple of problems:

- The print is not properly fixed to the bed which means the print can become detached from the base when the printing gets to height - the leverage gets too much and the print head pushes the print over.

- the bottom is not flat giving a distorted base layer.

I'm guessing these issues have been solved & wondering if anyone has some top tips to share on the subject ?

Cheers.

 

[illuminarti 18]

See my post here, earlier today:

http://umforum.ultimaker.com/index.php?/topic/1944-just-assembled-great-machine-try-to-improve/?p=13613

 

[gr5 2,173]

1) print on blue tape cleaned with isopropyl alcohol. This is by far most important.

2) Try not to print solid upper layers, or add holes in your cad part or whatever it takes so the upper layers aren't pulling so hard on the sides of your print (as the plastic cools it shrinks and pulls very hard)

3) Do not put sharp corners on your parts where they meet the print bed. Either round the corners, or add a 1 layer thick skirt. Some have said you can use the skirt option with 0mm distance. Haven't tried it.

4) If you print with ABS 1,2,3 isn't enough and you have to get a heated bed. With PLA a heated bed is waste of time.

 

[baasb 6]

I don't agree with you that a heated bed is a waste of time when printing PLA. A couple days ago I've added a heated bed and it's a HUGE difference. I only print with PLA and all the parts come out 100% flat and with a better bottom structure since I print directly on smooth aluminium rather than the blue tape which leaves marks.

 

[printbot 1]

Hi Folks,

Thanks for all the pointers, I will do some more tests and see how flat I can go :-)

I wonder when the official Ultimaker heated bed will arrive......? :-)

Much appreciated - cheers.

 

[printbot 1]

Hi,

A quick update....

I stripped off all my 1" blue tape and cleaned the bed with Isopropyl. Replaced the tape with 2" blue and really rubber it down hard onto the bed followed by cleaning with Isopropyl. I then printed the first layer at 230C followed by 210C for the rest of the print. I slowed the printer down to 50% for the 1st cm of height and then back to 100% to finish.

Wow, talk about stuck !!! I had to really try to get it off the blue tape. The base is much flatter but still room for improvement - I think I'm going to try and lower the first layer temp to 210C, same as the rest of the print - more later.

I suspect I will jump on the heated bed when it comes out :-)

 

[gr5 2,173]

FYI - it's important that the first layer is *pushed* into the tape slightly. The initial string of PLA coming out should be wider than it is tall. If it looks cylindrical then you need to raise up the bed slightly. You don't want the first layer sitting slightly above the tape.

Next time just *barely* clean the blue tape with isopropyl so it doesn't stick so well. lol.

Also you only have to use higher temp and slower printing on the very first layer. The rest doesn't make any difference. PLA sticks to PLA just fine at any temp >=190C and any speed. In fact people who use heated beds often turn the bed *off* after the first layer is done printing.