M2 Build Plates Slowly Deforming
Posted: Fri Jun 24, 2016 4:03 pm
We have two M2s. One started as a V3b and has been upgraded to a V4, and the newer started life as a V4. The earlier unit had the obsolete bed strain relief and has the larger lead vertical screw. Unit #2 has the finer pitch vertical screw and the bed strain relief with the convolute-sheathed cable.
Both units started out with beautifully flat build plates. Over time unit #2 developed a pronounced saddle shape to the build bed -- a dip about .008" to .012" across the plate's shorter dimension. Flipping and turning the glass doesn't change it any. I could adjust extruder gap at the ends, but I'd always have too much gap in the middle... or I could gap it down a bit too tight at the ends and have acceptable gap in the middle. Finally it got so bad I had to build up a layer of tape across the aluminum plate's shorter centerline. That fixed it completely for a while, but now the gap is coming back, indicating even further deformation of the plate.
The gap matters because we have a lot of fixtures printed on a regular basis that have a lot of features -- mostly holes and pass-throughs -- that start right on the build surface. Motion of the nozzle -- I have a 1mm retraction programmed, but Simplify3D apparently doesn't always apply it between moves -- during the first layer lay-down tends to disturb those features and ruin the print early if the gap isn't close enough to really stick the first plastic onto the tape.
Unit #1, with far more time on it, developed the saddle-shaped plate after unit #2, but it's worse now. I had to start using a tape spacer sooner as the deformation developed and it already needs more layers of tape to get into adjustment at all.
I am well aware that putting the tape under the glass is likely making it worse by placing the plate under additional deformation forces... but short of re-bending the plate or replacing it, there's really been no choice.
I know I've read comments about this before but I can't find them at the moment.
We've run about 40 1kg spools of PLA and ABS through the printers, mostly ABS with a bed temp set to 100. I don't have the hard numbers, but unit #1, which developed the problem later than the newer machine, ran more PLA than ABS and thus has likely had its bed sitting at 70 most of the time, the total time running at 100 probably less than the time unit #2 has had its bed running at 100. Unit #2 got put on the production floor with a flat panel, too, so the cell leads just dial in the tools they need for the next day's setups and let the machine run overnight..... so while unit #2 is much newer, it might actually be catching up to unit #1 in total hours. All this makes me think the deformation is directly related to the amount of time the machines run with their beds set to 100 degrees.
Anyone try re-flattening the bed? I'm thinking of putting them in fixtures in a press and easing the centers back up. Or is it easier just to replace the bed and heating element? For as much as these things have saved us in what we would have spent on Delrin tooling, that would still be a trivial expense.
- ep
Both units started out with beautifully flat build plates. Over time unit #2 developed a pronounced saddle shape to the build bed -- a dip about .008" to .012" across the plate's shorter dimension. Flipping and turning the glass doesn't change it any. I could adjust extruder gap at the ends, but I'd always have too much gap in the middle... or I could gap it down a bit too tight at the ends and have acceptable gap in the middle. Finally it got so bad I had to build up a layer of tape across the aluminum plate's shorter centerline. That fixed it completely for a while, but now the gap is coming back, indicating even further deformation of the plate.
The gap matters because we have a lot of fixtures printed on a regular basis that have a lot of features -- mostly holes and pass-throughs -- that start right on the build surface. Motion of the nozzle -- I have a 1mm retraction programmed, but Simplify3D apparently doesn't always apply it between moves -- during the first layer lay-down tends to disturb those features and ruin the print early if the gap isn't close enough to really stick the first plastic onto the tape.
Unit #1, with far more time on it, developed the saddle-shaped plate after unit #2, but it's worse now. I had to start using a tape spacer sooner as the deformation developed and it already needs more layers of tape to get into adjustment at all.
I am well aware that putting the tape under the glass is likely making it worse by placing the plate under additional deformation forces... but short of re-bending the plate or replacing it, there's really been no choice.
I know I've read comments about this before but I can't find them at the moment.
We've run about 40 1kg spools of PLA and ABS through the printers, mostly ABS with a bed temp set to 100. I don't have the hard numbers, but unit #1, which developed the problem later than the newer machine, ran more PLA than ABS and thus has likely had its bed sitting at 70 most of the time, the total time running at 100 probably less than the time unit #2 has had its bed running at 100. Unit #2 got put on the production floor with a flat panel, too, so the cell leads just dial in the tools they need for the next day's setups and let the machine run overnight..... so while unit #2 is much newer, it might actually be catching up to unit #1 in total hours. All this makes me think the deformation is directly related to the amount of time the machines run with their beds set to 100 degrees.
Anyone try re-flattening the bed? I'm thinking of putting them in fixtures in a press and easing the centers back up. Or is it easier just to replace the bed and heating element? For as much as these things have saved us in what we would have spent on Delrin tooling, that would still be a trivial expense.
- ep