Could my platform be bent?

[roykirk]

Has anyone had weird platform leveling issues with the Flash Forge? I've had my unit for a while now, and only recently I'm starting to have significant difficulty in leveling the platform. At least that's what it seems like. What's happening is that I'll level the platform using the built in utility. This has always worked quite well in the past. But now, even after leveling, if my model extends anywhere closer than about 7 or 8 cm of the left edge of the platform, the print nozzle will be about 2 mm above that section of the platform. Of course nothing sticks at that height so my print gets ruined.


It's almost like the left side of the platform is bent or something, but if that was the case I shouldn't be able to level it perfectly with the utility. I've also printed the leveling grid mentioned earlier in this thread, but the result is the same. I'll level the platform using the grid, but when I go to print a model the nozzle rises up some 2 mm off the bed when it gets near the left edge and the print gets ruined. Weird problem. Any theories?

[ixlr8]

2mm is enough to show up if you put a known straight edge on the platform to inspect gaps, like a perfectly straight tool (even ruler side of a caliper) to see if the platform is warped.

Have I done this? No. What did I do? I attached a dial indicator on my extruders and ran them in the X and Y direction to test a theory. It turns out that the extruders are as much as 0.005" (0.127mm) closer to the build platform at X center. It's not 2mm by any means, but it's enough to make you want to slightly change your leveling process, like making sure the paper you are using as a clearance guide has some friction between the extruder and the build plate at the platform center, but is more free-sliding near the platform edges.

The next question is: What is warped? The build plate or the X guide rods? Is the simple weight of the extruders enough to cause a slight deflection of the X-rods when the extruder is near the center of the platform? (At an atomic level that answer will always be "yes", the question is...how much?) Are both plate and rod warped?

I haven't taken a straight edge to my build platform yet, but I doubt I would see much if any gaps with only 0.005" warpage (a sheet of copy paper is about 0.003"). Your situation may be different.

[Geoff]

2mm is enough to show up if you put a known straight edge on the platform to inspect gaps, like a perfectly straight tool (even ruler side of a caliper) to see if the platform is warped.

Have I done this? No. What did I do? I attached a dial indicator on my extruders and ran them in the X and Y direction to test a theory. It turns out that the extruders are as much as 0.005" (0.127mm) closer to the build platform at X center. It's not 2mm by any means, but it's enough to make you want to slightly change your leveling process, like making sure the paper you are using as a clearance guide has some friction between the extruder and the build plate at the platform center, but is more free-sliding near the platform edges.

The next question is: What is warped? The build plate or the X guide rods? Is the simple weight of the extruders enough to cause a slight deflection of the X-rods when the extruder is near the center of the platform? (At an atomic level that answer will always be "yes", the question is...how much?) Are both plate and rod warped?

I haven't taken a straight edge to my build platform yet, but I doubt I would see much if any gaps with only 0.005" warpage (a sheet of copy paper is about 0.003"). Your situation may be different.

Yep, couldnt have said it better myself.

After some 1000 hours of printing, my hotbed has slightly risen on the edges, to the naked eye it's flat, but yeah it definitely has warped slightly over time. My brother in law is cooking me up a new build plate in his workshop, he used to be a fitter and turner in the navy so he's got some seriously good know how on metals, heat transaference etc..

[jimc]

i hope the op meant .2mm, 2mm is huge. you really do need a perfectly flat surface. a glass build plate is nice but its actually common for those to be out of spec. i have one that .1mm high in the middle. its ok for small items but even being out .1mm is too much for large prints. now i use a mic6 alum plate. its cast, milled and stress relieved so there is no warping after repeated heating and cooling. it gives a much more even heat than glass as well.

[ixlr8]

My brother in law is cooking me up a new build plate in his workshop, he used to be a fitter and turner in the navy so he's got some seriously good know how on metals, heat transaference etc..

Can he make a couple of them?

[Iain]

My heatbed was also warped from new. It was warped a fair bit. If you where printing 6-7 cm in from the edge it would lift after the first couple of layers. I sent a picture with a metal rule across the top and I was sent out a replacement unit. From memory 1-2mm was about the difference.

[Geoff]

Can he make a couple of them?

I'll let you know how this one goes We are seeing if we can maybe make it a bit larger, even 1cm all round would be beneficial, it's just getting the heat to push to the edges from a heating element thats smaller than the plate.

@Iain, this seems to be common with alot of printers, I don't think they use the best aluminium. Mine scratched very very easily, mainly the reason I want a new bed. Apparently my bro has this resin that can handle like 500c, so we are going to coat the new plate with that and see if I can avoid the tape altogether.

[roykirk]

Thanks for the tips everyone. Unfortunately I was definitely talking about a 2 mm difference. This all happened rather suddenly it seems, but I definitely have yanked and pushed on the extruder a few times to free or feed filament, so I suppose I could have bent something. One possible corresponding thing I forgot to mention was that I recently changed out all the bed leveling nuts with wingnuts. I checked, they haven't fallen off or anything, but I wonder if it's possible they're not holding as tight as the originals?

[Geoff]

Thanks for the tips everyone. Unfortunately I was definitely talking about a 2 mm difference. This all happened rather suddenly it seems, but I definitely have yanked and pushed on the extruder a few times to free or feed filament, so I suppose I could have bent something. One possible corresponding thing I forgot to mention was that I recently changed out all the bed leveling nuts with wingnuts. I checked, they haven't fallen off or anything, but I wonder if it's possible they're not holding as tight as the originals?

hmm, if it's the same thread size it really shouldn't matter too much what they are, I can't imagine they would be any different holding the heat bed. If it happened 'suddenly' then it's definitely not warped, as mine happened over a really long period. I have pushed incredibly hard on my extruders and yeah possibly bent my rods a little but never to the extent it couldn't be rectified with heatbed levelling.

2mm is an awful lot tho, I mean mine has warped 0.1mm on the edges, so the prints are not affected that bad, but 2mm.. yeah that's going to need some work sorry mate.

[larrwill]

2mm is enough to show up if you put a known straight edge on the platform to inspect gaps, like a perfectly straight tool (even ruler side of a caliper) to see if the platform is warped.

Have I done this? No. What did I do? I attached a dial indicator on my extruders and ran them in the X and Y direction to test a theory. It turns out that the extruders are as much as 0.005" (0.127mm) closer to the build platform at X center. It's not 2mm by any means, but it's enough to make you want to slightly change your leveling process, like making sure the paper you are using as a clearance guide has some friction between the extruder and the build plate at the platform center, but is more free-sliding near the platform edges.

The next question is: What is warped? The build plate or the X guide rods? Is the simple weight of the extruders enough to cause a slight deflection of the X-rods when the extruder is near the center of the platform? (At an atomic level that answer will always be "yes", the question is...how much?) Are both plate and rod warped?

I haven't taken a straight edge to my build platform yet, but I doubt I would see much if any gaps with only 0.005" warpage (a sheet of copy paper is about 0.003"). Your situation may be different.

I know this is an old post but I am having a similar issue that ixlr8 describes. No matter how carefully I level under the level screws, the center is always high. I thought my build plate was warped so I installed a glass plate and it is still high in the center with new glass. So it seems that the extruder guide rods must be sagging in the center. I have tried slightly rotating the rods in case they were bent (theory being if the rods are bent down then rotating would show high in the center after rotating) but no change after rotating rods.
Has anyone come up with a fix for this?