MakerBot Industries

MkB ToM #5510, recently assembled, MK6+ extruder, HBP, newb.

My first prints went well with raft and default settings, but I would notice that the first raft and fill layers seems to extrude more material than necessary. I was investigating and realized that the nozzle settings were 0.5mm instead of 0.4mm. I changed this and saw a noticeable improvement in build quality.

So I went to print with a raft and saw that the raft printed perfectly and sticks to the platform very well. Then came the first layer. It seems like the first layer is extruded too high or something, but it is not sticking to the raft! I know that normally, we have problems sticking to the platform, so this issue with the part sticking to the raft was unanticipated. So I figure, 'hey, I have the HBP, I will just print raftless".

So I uncheck the box for raft and I am getting great prints. That is good, except that, as the part gets taller, I'm getting some shrinkage on the layers above the HBP that is changing the profile along the z-axis. This isn't enough to delaminate the part or even to pull up the corner. It is enough to notice, particularly if you are counting on the upper layers to be in-line with the lower layers. The end effect is that the part looks slightly smashed on the bottom. I suspect that the root cause for this is that the upper layers that aren't attached to the HBP are cooling a bit faster than the lower layers. I can trim the unshrunk bottom layers away without any issues, but I would rather it print in a way that this were minimized or unnecessary.

So now the point. I need one of two solutions, both would be nice:
1. How can I get my print to stick to my raft so that the first layer that has the most distortion is the raft itself and, thus, not my part.
2. How can I adjust my settings, probably the HBP settings, in order to make the part shrinkage on the first layers roughly equivalent with the rest of the part.

I'm toying with the idea of enclosing the makerbot and allowing the chamber to heat up a bit. I'm well aware of the effects on the motors and electronics. If anyone has any comments on warming the chamber, the cautions about the effects of a high thermal environment can be skipped. I would be interested in other's experiences on the part itself, however.

Thanks,

J

C'mon, guys, nothing?! The last I saw, there was no shortage of opinions and advice in the world!

Thanks for any help,

J

Thanks, guys. I appreciate the help. I have done a couple of prints with the MkB enclosed. The results are ok. Warping seems to be less, but not by much. I didn't make an effort to seal it very well nor to monitor temperature in any scientific way, but the 'put your hand in there' test tells me it is definitely warmer than the room, but not by much.

I think that ultimately, it is the raft layers that will do the shrinking in the future. I still haven't gotten the raft just the way I like it yet, and I'm still having problems getting the part to stick to the raft, but I will get there. I'm still learning about the various settings and affects in skeinforge.

Thanks for the assist,

J