Raft Warping/Not Sticking to Plate

[pg353060]

After a string of failed ABS prints using my company's new Makerbot 2X (due to not sticking to the build plate), I've switched to trying to print parts with rafts (0.3mm air gap, border extended 10mm from the edge of the part). The 110C heated build plate also has kapton tape on it, so I think it's odd that I'm having stick issues (I've spent so much time troubleshooting failed prints the 2X that it feels like a full-time job at this point. Definitely not for first-timers..). I've got extruders set to 230C, but have really only been using the right extruder because we haven't needed anything duel-extruded yet.

During printing, the raft warps (always on the front-lefthand side) and either detaches from the build plate entirely or causes the print to have less depth on the warped side. Since we need fixtures and parts that are uniform, I need to figure out why this is happening. The front door of our 2X doesn't close fully, leaving a thin gap for cool air to enter from; it's not a huge amount of ventilation, but could this be the reason for the warping?

I'm new to 3D printing, so it's likely simple that I'm missing here. Any help would be appreciated!

[fred_dot_u]

I have a sigma 2016 dual extruder model with no enclosure, although there are walls on three sides and an open top. When I print ABS, which has been quite a bit recently, I place a piece of cardboard over the front opening. There's always a gap, but I have no real external airflow generators (fans, a/c ducts) that are a factor.

I'm using 100°C for the bed temperature, although the FLIR device for my iPhone shows about 10° colder. I've been running 245° on MatterHackers economy filament. If I run too cool, I get delamination.

It's a tough call to address the warping, though. I've been using Wolfbite on the bare glass bed and it's been incredible. Not a warped part if I do everything else correctly. Early batches of Wolfbite had some chemistry problems, which garnered it a shaky reputation right at the start, but the new batch is great. It's marked for 30 day expiration after opening, but I've been using a food-sealer vacuum and sealing it after every use. It's been three months and the handful of prints I've done today are holding great. I re-apply every five or six print jobs, but it barely makes a dent in the bottle.

I had been using brims of 2mm, single layer, but lately dropped to no brim, no raft, unless it's a tiny footprint.

I've never heard of a too-hot bed causing warping, but it's not out of the question either.

[pg353060]

I'll try blocking of the gap in the front door somehow. My worry is that this part of the building can run cold at times (for certain manufacturing processes) and, though the gap isn't huge, that cooling could be the source of the bulk of the warping. This is the first time I've heard of applying Wolfbite; I'll look into it.

I would think that the bed being overheated would result in it being hard to take prints off the bed, not the opposite.

[Davo]

For ABS prints up to 4x4", I use Aqua Net, bed at 85C, head at 230C, 2mm brim. For larger ABS prints, I use an enclosed model with the chamber temperature at 50-55C.

A warm environment is key for larger ABS prints - and other materials also benefit from this, to differing degrees.