build table raise after print

[zanderscreations]

Hey everyone

I've recently run into a weird problem after my prints finish with the build table not raising up a couple inches like it did before. It seems to have just decided to do this now and I am not sure why.

Normally the print finishes and the build table raises up whatever the default setting is so you can remove the table and such. My last few prints have not done so and ring is still dipped in the resin. Though it hasn't technically ruined the print, I am concerned about this being a problem and would like to fix it.

Also at the same time this has been happening I've been noticing a little bit of a "jiggle" in the print at a certain height where the xy axis seems to have moved for a few layers, and at the top of most rings there is a line that forms. I will have to take a picture later when I get back to my printer to show what I am speaking of. Not sure if these problems are related or not.

I looked through the settings and did not see a input setting for how much to raise up after finishing a print, is there a way to resolve this issue?

[cl2635]

can't help you with the buildtable raising up but the xy shift may either be because your buildtable wasn't tightened properly, or the 4 screws holding up the projector to the metal wall was loose and caused the projector to shift.

[zanderscreations]

here are some photos of the second problem. I am currently taking the build platform z arm off to clean and re check everything.
This red stuff is hard to photograph but hopefully the pictures help

[Robert Howle]

I have been having the same problem on some builds where the table doesn't raise at the end ot the print. Mike is checking my print log to see it there is anything there. Will keep u advised, or MIke may post something, if he finds anything.

[KNSCi]

Anyone found out anything on this topic? I was initially baffled, as I didn't recall ever seeing the table rise a few inches, more like one or two centimeters in our case was the norm. Today oddly enough the table did raise about 4" after completing the print cycle. Subsequent print with same settings, different layout/job, again only came up about 2cm when done.

[Robert Howle]

Seems like the only times I had the issue of the table not rising after print was when I printed flat objects directly on the table with no supports. Maybe somehow this confuses the software. Not sure, not a puter person.

[KNSCi]

I'm also seeing an intermittent xy shift, usually within the first 3mm. A few days ago I printed some small calibration cubes on 8 attachment layers and they were smooth on all sides. Today I printed the same layout sliced finer and on all the models there is a spot where all the objects shift maybe .1 or .2mm, making a distinct line on the cube-sides. No big deal to the meaning or usability of the print in this case but I would like to eliminate the cause so I don't have to put 5mm supports on everything and avoid the issue in future jewelry prints where the effects would be more significant.

[perpetual_dreamer]

I think you tilting your machine may have something to do with it... I remember the times I inserted paper cardboard under the printer's feet to level the printer in the middle of print.. My print comes out with a slight xy shift around when I tilted it. I think tilting it causes the resin to flow slightly which seems to affect the print

[KNSCi]

Hi perpetual; Could be related, if so another issue to resolve!
Almost every print, we go through a phase of resin not covering the build area, in the first mm's of z rising. If we are using default settings, the vat and everything zips pretty quickly, so we have to quickly tilt and hope it's enough, then gently set the machine back before the settling time/exposure. We also have shims from whatever we found laying around, a pencil, a mould frame component, little things that help level/flow the liquid in the vat. We've used iPhone Compass app to confirm vat surface is level, don't know if that is accurate enough. Looking at the sides of the vat, without shims under the feet, resin appears level.
Should we maybe be using more overlift? Sometimes we leave it at over 6mm, which seems a bit excessive.
Can you offer an opinion or experience with initial/subsequent overlift and initial level height? Thanks!

[brumbaer]

Regarding the build table raise.
When I got my B9Creator, i used it wit my iMac (3.5GHz, i7) and the table only raised once or twice after a print.
Now I put the creator away from my desk and use an "remote controlled" old MacBookPro (2.53 GHz, Core duo) to drive it.
Now the table raises after every print.

As the i7 is much faster and has more cores than the core duo, the problem might be a race condition.

[KNSCi]

@brumbaer, interesting setup! thanks for the info. I think in now about 50 print efforts, the table has done the hi-rise only once or twice. I didn't even know it was supposed to do that! It rises some amount, maybe the overlift amount, and after printing, I just remove the sweeper, manually raise the table and let it drip a bit while I get ready to move it to the wet area for cleaning.

[Robert Howle]

I have sent Mike a job file where table lift did not occur. He was going to look at it, but he is in the middle of a software update so it might be awhile. Could be that he is working on that in his updated software now, just don't know.

[mikej]

Yes, this next update will include a more robust host/printer comm protocol which should help with issues like this.

[zanderscreations]

still having the same issue. I did have one successful raise the other day but couldnt tell you why it worked. it was working fine the first 10-15 prints of the machine i did. It does seem to successfully print for the most part though except still having that xy shift issue at the top of some things i print

[kmchone]

If the controller pc running the B9 software is overrunning the Adunio's input buffer that could explain some things. Just guessing tho. Windows isn't a real time operating system by any means either. If your doing something else on the PC like web browsing while your B9 print is running, there could be communication issues depending on how robustly the B9 communication protocol is implemented. The fact that brumbaer's old dedicated Mac operates consistently may mean something. Or maybe it's because it's Apple. ;)

[akgold]

I have found that when something goes wrong I unplug from the b9 all 3 cables for power and input for a short time and replug it all in and it all goes back to normal. last time was the slider motor was going around 360 deg. and stopped then it would only move back and forth slightly using the manual switch. Unplugged and it works fine now.