I am seeing the opposite.. my edges are bent/bowed upward so that as the heads travel towards the center the gap gets larger, up to about 1 mm. it seems the left and right sides are the only ones elevated, and not the front and back.

Currently using a raft allows me to print some things, but the first couple of layers are usually very low quality..  there is a lot of curling too since the raft doesn't get stuck down very good. Sometimes the whole build gets dislodged... Frustrating...

Does anyone know of a way to flatten the plate back out? I'm wondering maybe if I take some small aluminum L channel and bolt it to the bottom it would pull them back down?

I had the same problem:  the edges were about 1/16" (or more) higher than the center (across the width, front to back it seems unwarped):  I really can't get anything to print without the rafting popping off more than 1/3 the way though.  I even re-calibrated the plate to only print on the far side trying to get it flat as possible there, but stil no luck :(

Contacted support, they said this is becoming an issue and are working on new plate tech.  Should probably ping them for a replacement when it comes online.

The wood on my HBP was also a bit warped, but I got the Aluminum build plate & that flattened out the wood.  It is now perfectly flat.

Makerbot is awesome!! Look forward to your solution..

I am seeing the same issue - the platform is bowed with left edge being the worst.  I can compensate to some degree by placement of the parts but larger parts are problematic.

I have the same thing-- my build platform is noticeably lower in the middle, and the lower layers of anything I printed were a total mess (if the model printed at all).  I made a script to compensate for the curved platform though, and I'm now getting pretty decent results-- models stick to the platform, bottom layers look good, and if I use support material it no longer turns into a mass of tangled fibers.

It's a Perl script (sorry) called MainDeflector.pl because as ST:TNG teaches us, there is no problem that can't be solved by reconfiguring the main deflector.  My process now is:

• load a model in ReplicatorG and generate the mymodel.gcode file with whatever options I want (raft, etc)
• on the command line, run "MainDeflector.pl mymodel.gcode > mymodel_fixed.gcode"
• go back to ReplicatorG, load "mymodel_fixed.gcode" and print it

This is only a rough fix but if you're clear about what's going on, you may find it helps you get better prints until there's a more permanent solution.  But make sure you read the comments first!

I thought mine was flat (HBP with aluminum plate).  However, it turns out that it was flat when cool and then when I heated it up it began to bow with the edges lower than the middle.  It is flat in the direction with three bolts and bows up in the middle where there are no bolts to hold it down.  Thinking that this might be caused by differential expansion of the heater board and the aluminum plate, I loosened the screws holding the plate to the heater.  I think that it is less warped now, but it still curves a bit.

I have ben experimenting with print solutions and had two mini breakthroughs.  I had been printing raft-lessly but models started lifting at the edges.  I cleaned surface as recommended.  While persisting, I went back to a raft and paused a print job (when it started lifting) and tried to tape edges with Kapton (picture attached).  This wasn't very effective but sufficiently crapped up the build surface enough that I replaced the Kapton.  Models started printing again, although some lifting toward warped edges.  I decided to start experimenting with the build platform temp and found by edging it up to 108-110 models started adhering again and have been printing raftless all day.  

Not sure if prolonged usage at 110 is problematic.

More data - folks with sticking and warping problems may find these tips helpful - tweak the build platform tight to extrusion heads in as much od build area as possible.  Don't underestimate importance of clean surface, wipe down with acetone often.  Raise platform temp to 108-110.  These have helped me go from no parts to 24 hours of successful builds - pic attached.

I'm suffering a similar problem (the center of my platform is too high). I've lowered platform so the nozzles don't touch in the center, but how do I raise the platform temp?

I am also seeing the problem.  I'm actually kind of relieved to hear other folks are running into this issue!  I had leveled/re-leveled the HBP quite a few times!  I thought I was going crazy.  We were able to run a few test prints the first day or so after receiving our replicator.  After that, edges/outllines would print okay, but middle/fill-in sections would not stick.  We found this to be the case with or without a raft.

Our platform is warped with the edges up and the center down.  example pic attached.  I look forward to a solution!

Hi,

someone has already tested the bent aluminum base? Make base bigger and bent on the all edge down. For flatness, it should be better, but i don´t know if any issue of heat dissipation.

My build platform is significantly warped. Center is lower by a millimeter or more than the left and right edges.

I submitted a support ticket.

Any news one a solution and when we'll get it?  I can't really print anything at all right now.  If I adjust the nozzle height correctly in the center then the nozzles hit and scrape at the edges.

I too am dead in the water until a corrected build plate arrives.  :(

Any news is better than no news.

Thanks!

We received our new/thicker build plate the other day.  The new plate, combined with adding some enclosure panels, (plans for lasercutting a canopy found here http://www.thingiverse.com/thing:20253), and it is working fantastic!

The noticeable difference with the new build plate is that it is thicker, and the surface has been machined flat.

I just got notification that my new build platform has been dispatched so it looks like they should all roll out to you soon...

Coley

I just received my new platform in the mail. I will be installing it either today or tomorrow. Looking forward to printing on it and seeing what happens.

I have an update here as well... I notified MakerBot about my build plate back on April 5th, and my new MUCH flatter build plate arrived today (May 4th) ((to give an idea of lead time)).  First test print is running right now. 

New platform arrived (it is gorgeous).  It took quite a bit of leveling and re-leveling to get it right and have prints properly stick.  The keyword is TIGHT.  Almost touching does the trick.  Will try some large prints tomorrow.

Kudos to Makerbot, I have received my new HBP. I was surprised that it was the whole platform, not just the aluminum plate. This is the way to do customer service, above and beyond what is expected. I have yet to install mine because I already replaced my aluminum platform with a machined one I made. I am sure it will do the trick. Great fix MBI!!! Best service!!!

Just got my replacement.  Whereas the original looked rather crudely made, this one looks magnificently well machined.  Clearly a lot of time was spent on it.  Can't wait to try it out.  Thank you MakerBot!

Got my replacement board, the install instructions where super easy, took all of 5 min to install.  Went through leveling program 3 times just to be sure and every print has been fantastic so far!!!  Great job!

Hey everybody,

We're really glad the new platforms have been an improvement.  Just to clarify a bit for recent customers, all Replicators shipped mid-April 2012 and later should have the new, improved plate.  If you're still experiencing warping or adhesion problems, please create a support ticket.

While replacing my klapton film I noticed that the screws that sandwich the build platform together are loose. They appear to have nylon lock-nuts so I'm guessing that this is intentional?

That's right -- the screws should be slightly loose so that the metal (which expands faster than the PCB) can expand out without bending the assembly too much.  So yes, it's intentional.

I have the new platform and I believe there are still warping issues. If I follow calibration procedure it ALWAYS yields a situation where the nozzles crash the bed in the centre position. I have resorted to getting the centre right first and then trying to make the outsides as best I can but the platform definitely sags on the outer extremes. This is not an issue for the small parts i make but would be for anything bigger

I have the exact same problem where the extruder heads are almost touching the platform in the center, yet have a lot of room on the outer (inner) edges. This difference increases when the platform gets hot. This is a BIG problem for me as most of my custom prints use a good portion of the entire platform. I do have an open ticket with support, but this issue is not being addressed...

Great fix for the warping....

http://www.instructables.com/id/100-Warp-Free-MakerBot-3D-Printing/

That's not a fix for the warping bob .. that's a fix for -sticking- 

The warped bed is a big problem, as it causes the head to be at a different height for the first layer on different parts of the platform.    The fix is to talk to MakerBot support, and get one of the new machined plates (if you have an early April or May makerbot, that doesn't have the nicely machined print beds).

-M

I've only had my Replicator for a few weeks and I really dont know whether mine has the new bed or not (see attached) but as reported above mine sags on the edges ie centre is too high and crashes the nozzles when you follow the suggested calibration method.

Is mine the new bed?

Hi John and Curtis,

All of the Replicators shipped in the last few months have had the new build plates, and so far we haven't seen any warping with the new plates. Sometimes, because of the varying tension on the springs of the z stage, the plate can appear to be slanted with respect to the mounting platform, but this shouldn't affect print quality - as long as the extruder nozzles are calibrated with respect to the suface of the plate.

If it seems that your plate may be warped, try using a straight-edge to check its flatness. If you find that the sides are lower or higher than the center of the plate by more than a few hundredths of a millimeter, please open a support ticket with us so we can have a closer look and supply any necessary replacement parts.

Best,

Ben McCallum
MakerBot Support 

I can not speak to the warping problem, but the popping off problem I solved a while back.

I applied a line of Stanley Dual Temperature Hot Glue to the back of the build surface while the platform was at 50 Deg C.

I used the handle of a hex wrench/ Allen key to drag the bead forward leaving a very thin, smooth film of hot glue on the surface.

My Hex key looks like this one  http://www.metric-tools.com/i//T_handle_allen_wrenches.jpg

I cleaned the excess off the handle, heated the surface a bit more with a heat gun and kept dragging the handle across the surface removing any excess and coating the entire surface.

I find this lets me print with the build surface a bit cooler 70-80 and the parts never pop off during printing.  After a wile the layer starts to look a little rough, though it still feels smooth, I just heat it with the heat gun and it looks like new again.

Hello all:

the plate is one that combined with the Black arms that support the plate also keep moving with heat.

it gets to a point you keep chasing your tail here.

I understand you guys try to make something we can use at a lower cost but with many headaches.

also the plug most likely in time will start to melt is just another ticking time bomb that may not kick in until 

after the warranty.

you guys know of these problems why keep waiting....

sure your seeing how many you don't have to help.

better to just sell us a kit to fix these problems now they to have us keep wasting time & supplies.

I need to make good items now 

not make 10  parts to get maybe 5

enclosing the unit workd great to stop warping the parts but helps to warp the plate & the black arms.

keep this in mind...

by the way if you see the front view of my bed plate and arms its scarry how much 

difference there is ..  

Not smooth and stright enough? Anyone met the problum before?

I just got mine today, and I am seeing this same kind of issue. I do the bed level script, then run a print and the bed is not level anymore, so I did the bed level script right after I canceled the print so the HBP was still hot, and did a relevel... Seemed to work out good.

printer doesen't match patterns

I'm having the same issue with my new (August) Replicator. The HBP is warped so the outer edges are much lower than the center middle. I've filed a trouble ticket and Gavin has told me that this problem is "rare" but after reading on here it seem like it does happen, and is still happening with the new "thicker" HBP. 

I'm hoping Gavin can help correct the issue and I can move forward with making some prints.

I just purchases dual extrusion replicator.  I to have a warped build platform.  It is not as bad as some I have seen on here, but it is too much in my opinion.  As far as sticking, I have used 400 grit sand paper to scuff the Kapton and it has worked great.

I've got my Replicator 3 weeks ago with a warped build platform. The replacement platform is warped, too. It's about 1mm down on the sides. Thus i wasn't able to print a single model yet. I will send the whole printer in to the reseller. That's not a good start.

I've got the replacement from our reseller. He told me they had several complains about the build platform.

I'll try to loosen the bolts next week.

I have to say that I have not found any improvement in sanding the gold colored Kapton.  I only found this to be an improvement on the green powder coating Kapton I was using.  Also, I would not say I was "roughing up" the Kapton as I was using 400 grip paper.  All it did was remove the shine.

Could it be that the built up base is not 100% hardened enough and it continued to support heavier top that getting heavier?

I have received a replacement build platform. It's not 100% even but far better than the last two. It prints now and sticks to the base.

I put a Ticket in 7 days ago still waiting for an answer.

now that my connecter is bad & I just need to get a replacement harness & heater board...

I get no answers from no one anymore.

I cant even call to buy them... go figure...

I was at the makerfaire in NY

and will be there again maybe I will have a few things to say...

I love this machine Just give me an answer.

as I said before I would buy the items...

I just need to get them ASAP

I've gotten a replacement plate from support, once I made it clear that this was a minor issue on day one, and then progressively got worse.  My Rep 1 has the "new" thicker plate, but the center bowed up, and then over time got worse to the point of being unusable.  A flat edge against one side gapped to about 1/8" on the other side due to the bowing.  

Support, while not perfect, have been trying to do the right thing and did the right thing for me, even though the machine is more than a year old.  (I'm not thrilled that the warranty is one year, but I can see my way to forgiveness).  
On the plus side, I upgraded to aluminum stage arms, so when the new plate gets here I'll be doing a major rebuild, which from other user reports may result in a "set it and forget it"stage leveling.  I'm also going to mod it to 3 point leveling, it's just the right thing to do.