AAAArrgghhhh ! Need stickum advice

[curious aardvark]

So I'm trying to print a couple of pretty basic files. They're the biggest and longest prints I've tried so far. But very simple.
The part on the print bed are hollow rectangles 52x42 mm with 5mm walls on the bed.
Not enough to warp and should be plenty too keep them stuck to the bed. Both are just about on the max printheight - around the 140mm mark.

But should not be difficult prints.

I'm currently using pet tape heated to 60c and pla. Which for any print under about 3 hours has been very very good.
This is the first real issue I've had with the tape and sticking.

What I'm finding with these big prints is that the bloody things are detaching from the build plate at about the 4-5 hour mark (judging by what's printed and the amount of loose plastic in the case).
It's not the pla. I switched from cheap ebay pla to polymakr polyplus - with not real difference (less warp, but same final result). There was minimum warp, the bases are super flat with a very slight squish - proving the calibration is super tight.
I've tried slicing with simplify 3d and makerware - doesn't make any difference.

So how do I make the tape more sticky. Think I read you can use a gluestick on pet tape. Are standard gluesticks okay (pretty sure I've got one in the 3d printing bits and bobs box). Or do i need some kind of special stick ?
And what temp works best for them ?
I don't care if I have to remove the tape with the print, just so long as I can actually print it.

Help ! :-)

[ssayer]

Standard glass and glue stick with the bed at 60 degrees. I've printed plenty of 30+ hour PLA prints and never once had one come loose (though I have had to stick the plate in the freezer for a couple of minutes to be able to have them come loose)...

I would think that the glue stick on your tape would work as well, but I don't use tape.

[LambdaFF]

Hi, I'm using the typical schoolboy glue, from the UHU brand. http://www.uhu.com/en/products/paper-glues.html
My longer prints are over 5hours, and if I did have problems sometimes, nothing to do with the glue. It cleans super easy with a microfiber cloth and water.

I smear it evenly on the PEI tape as if I wanted to glue two sheets of paper and then heat the bed at ~50°C. For PLA, that's it for me. When it's finished let it cool and work the angles with a spatula.

[curious aardvark]

well I've had think, and I reckon it's the vibration caused by the infill that's probably working the prints loose.

I can get rid of that for one part but not the other.

I'll dig out the glue stick and see if it makes any difference :-)

Failing that I'll stick blue tape back on. It might pull the tape off the bed, but the model being printed never came off the tape :-)

It's kind of got to the stage now where I don't care what the bloody things cost, they will be made !

[Marm]

Try adding littel discs to the corners in your design. That will increase the area of adhesion to the bed, and if the edges of the discs pull up, oh well. Just sand them off later.

Uhhu, Elmers, and Hercules glue sticks have all worked well for me.

[curious aardvark]

That wouldn't have made any difference. Initially I laid the foot flat - so massive surface area.

The blue tape worked a treat. The difference between active grab and vacumn grab on a smooth surface did the trick.
Just wish I could use s3d so I wouldn't have t babysit it so much.

So here's the foot. If it would print laying down I can make it a lot longer. Hopefully it'll be long enough.

planterfoot_800x600.jpg

And the whole thing assembled.

assembled leg_800x322.jpg

Now I just have to try it on the planter lol

If you're wndering about the angle of the foot. The planters legs are crossed so hit the ground at 45 degree angle. The feet will be flat on the ground when it's installed.

[Hugues]

Been printing on this in the past few months, heated to 65 degrees, PLA, never had any lifting, cool down to pop the part off:
http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1

Glued the sheet to my alu bed with this tape:
http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1

[Davo]

well I've had think, and I reckon it's the vibration caused by the infill that's probably working the prints loose.

I can get rid of that for one part but not the other.

Why not just slow down your infill speed?