raft sticks to perfboard, but part lifts up from raft (ABS)

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bschiett
Posts: 2
Joined: Fri Jan 23, 2015 1:55 pm

raft sticks to perfboard, but part lifts up from raft (ABS)

Post by bschiett » Sat Jan 24, 2015 11:14 pm

Hi All,

I just got a pp3dp up mini printer and I am trying to get consistent ABS printing results. I am printing in normal mode with 0.25mm layer resolution and I haven't changed any of the standard settings. The only calibration I did is the 9 point calibration which I took care to do carefully. I found the point where the nozzle is closest to the bed and then moved the bed up so it just touches the nozzle and then went to the other locations and did the paper trick to figure out how much space there was between nozzle and bed. In my case only the 2 front rightmost positions have 0.2 and the other positions have 0. I do not do any special bed heating except when the print starts and it heats automatically. The room I'm in is about 21 degrees C in temperature and there shouldn't be any cold drafts. I have closed the wind barrier. I am not using kapton tape or glue stick or anything like that and I'm printing using the included white ABS. The perfboard is secured with clips to the heat bed to avoid it bending upwards as it gets heated which is something I noticed on earlier prints. One weird issue is that the metal tab that holds the perfboard at the right hand side in the front seems to be bent further than the 3 other metal tabs holding down the perf board, so if you would be on the perf board and walk from the left hand side in the back to the right hand side in the front, you would be walking down a path that goes down slightly. I've kept the front door of the printer closed as much as possible during printing.

My problem is that each print the raft sticks very well to the perf board but the part lifts off the raft. I don't understand what's going on here. It's a square part of about 4 to 5mm in thickness. I first tried to print it flat on the bed but it always lifts off in the same corner (in the back left hand side) and I had to stop the print. I then tried to print the part vertically and this gives better results BUT the edge that sits on the raft is still warped and the corners of the part still seem to lift off from the raft as the print progresses (not in the beginning when i've only printed 5mm of the part, it happens later as the part is printed). Here are the photos of the two prints: http://bit.ly/1GPswMD (dropbox gallery)

I like the up mini but really don't know what to do with this. How do I make sure the part does not lift off the raft? Should I print without a raft and somehow get the part to stick to the perfboard by using a glue stick or should I use ABS slurry or some other trick? I am looking for an easy way to produce consistent prints and an easy and quick way to get the part of the building platform, each time I try to get the raft off using the provided tools I ask myself if this really has to be this hard and if there isn't a quicker and easier way to get the raft off so I can do another print ....

Thanks for helping!
B

yo3ggx
Posts: 11
Joined: Sun Nov 23, 2014 8:10 pm

Re: raft sticks to perfboard, but part lifts up from raft (A

Post by yo3ggx » Wed Feb 11, 2015 1:08 pm

Hi,

Same problem for me. If you print without a raft you will get the same warping and the surface will look horrible because of the perf board. The only solution was to build the bed temp mod for 100degC. After that everything was perfect. You need to wait a lot till the bed reach around 85degC before starting to print. For me this mean even more than 1h. The heating pcb does not have enough power to heat it faster.
You can check the bed heating status if you are building the same mod as mine.
I've posted it here:
http://www.thingiverse.com/thing:662388

Good luck.
Dan

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