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That's odd that it is short, mine was a bit oversize. I drew a 13" circle even though there were 4 straight short edges. That gave me plenty of excess material to work with.

Amazon will exchange if it is big issue. Why would the glass side be unusable? Just because the PEI doesn't go to the very edge is not going to cause any issues.

I'm a pretty unlucky guy... if there were 10 sheets available and only one were cut short, I'd end up with it. It's significantly shorter, I figured it wouldn't be level, as the sides that were short would flex a little where clipped, maybe not enough to make a difference.

Unfortunately, I ordered from Amazon Supply, which means I'll have to wait until Monday to exchange it. Hopefully they won't be out of stock by then.

Edit: Just ordered another one, I didn't want to take the chance of them selling out, and figured I'd get it sooner.

The piece I received was exactly the same width as the borosilicate glass plate. I used metal cutting shears to cut the circle.

About as close as mine gets, with it right up to both edges of the glass.

[img]http://i.imgur.com/zcbZIxs.jpg[/img]

I was / am annoyed. I'll receive the new one on Wednesday.

That's a bummer. What does it measure 11.5"x11.5"?

Yeah, pretty much that. I did notice the length tolerance listed as +0.000/-0.187 inches. Meaning it would be short if anything, but it's a little much. I just hope the new one works out, if not I suppose I'll settle.

Lot's of us have bought from amazon/small parts and the pieces have been basically 12" square. You probably just got an end cut. The other option is mcmaster car. They have 12" .04" sheets. I have one of those on order too.

I actually found 0.04" 12x24 for under $30, but yeah, thought I'd give this another chance from Amazon, since you guys haven't had any problems. Love Amazon for their return policy and of course Prime.

mhackney wrote:Worth every penny. I just ordered a 12x24 sheet for 2 mini kossels. I llllooooovvvveeee PEI.

Now that you will be using PEI on the mini kossels, what are you going to use for a heated bed? I ordered an Orion bed for mine. I wonder if FSR autocalibration would work through all those layers (PEI, glass, Orion bed, melamine insulator)

I ordered an Orion heater too. There is really nothing else on the market near 9"D. The mini kossel default is something like 6.75".

There are 2 parts to the FSR calibration to be aware of. First is the "rigidity" of the plate system itself. A layer of PEI/Glass/Bed/Melamine should be fine. The second is the ability to adjust the FSRs to trigger with the contact force. I struggled tuning mine for a Rostock heated bed setup and finally gave up. It was too variable, even with the compensating circuit I built. The FSRs seem like a great solution but they seem to have a fairly narrow window of usefulness. I think Johann just got lucky with a single piece of 160mm glass. I'm going back to an effector mounted probe that will attach with magnets with an index of some sort - at least for now. This will not be a bad solution given the infrequency of use. I use a removable touch probe on my milling machines and it is used much more frequently than a printer Z problem would be. I am still intrigued with a bed pressure or force activated probe though. However, with a multi head setup it is still a bit problematic.

How much horizontal force can a printing piece take before it pops off mid print? I have issues with some rolls of filament having a nice first layer but only take a pound of pressure to break the PLA off the bed at 60 degrees. On taller pieces if the nozzle catches on anything it rips the print off the bed.

mlapaglia wrote:How much horizontal force can a printing piece take before it pops off mid print? I have issues with some rolls of filament having a nice first layer but only take a pound of pressure to break the PLA off the bed at 60 degrees. On taller pieces if the nozzle catches on anything it rips the print off the bed.

if your having issues with the nozzle knocking prints off, try increasing the zlift in your slicer

Ya it's currently lifting around 2mm, the part just really doesn't have any adhesion with this reel of filament I'm using, others have been fine.

Also, is the .03" thick stuff recommended or is the .09 better somehow?

the thicker the PEI the harder it is for the heat to transfer, so thinner is better imo. there has also been mention of scuffing the surface with some sandpaper a few pages back so you might be interested in that.

Awesome thanks, got a 12" x 24" x .03" sheet ordered from amazon, cut it in half then in circles

So disappointed... just received my second sheet, which is exactly the same size as the one before. Just as short. WTH?

Bummer. I wonder if the sudden spike in demand resulted in a new vendor or the vendor taking short cuts - literally.

I contacted Amazon to return one of the sheets, and figured I'd keep the other and deal with it, but they offered to replace it, so I thought I'd give it another chance. I believe this one was from the same batch that was left over, and recently sold out. They received a new shipment, so hopefully this new batch is cut to length. I'll receive the third on Friday. I don't like having returns marked under my account, especially for sub $100 items, but oh well.

atoff wrote:I contacted Amazon to return one of the sheets, and figured I'd keep the other and deal with it, but they offered to replace it, so I thought I'd give it another chance. I believe this one was from the same batch that was left over, and recently sold out. They received a new shipment, so hopefully this new batch is cut to length. I'll receive the third on Friday. I don't like having returns marked under my account, especially for sub $100 items, but oh well.

Please let us know how the third works out, I have been watching this thread because I need a sheet of the same size.

No luck... just the received the third sheet. Same as the others, but this time it looked very abused. specks and marks all over. I give up.

I just received a sheet of .04" 12x12 from McMaster Carr that is spot on. There is no issue with the slightly thicker material.

May order one from them and do a will call pickup. I'm thinking about picking up a sheet of glass as well, I'm not sure if I want to install it on the expensive borosilicate, unless it's not too difficult to remove.

edit: well, looking at prices, the glass doesn't seem too expensive from SMC, so I guess no need to spend money when it isn't necessary.

You still need to use borosilicate if you plan to heat, especially at ABS temps.

It is pretty easy to remove, I've done it twice!

Good to know! I just placed the order from McMaster-Carr for pickup tomorrow. I'm kind of worried about that +/- 1" tolerance though. My luck it'll be shorter than the one ordered from Amazon.

atoff wrote:Good to know! I just placed the order from McMaster-Carr for pickup tomorrow. I'm kind of worried about that +/- 1" tolerance though. My luck it'll be shorter than the one ordered from Amazon.

Amazon used to be great to buy these from, I wonder what happened?