Solved Anyone ever seen this?

That is correct you must print over the heated portion in order to assure good adhesion with those filaments

 

You can increase the size of your bed in the Y axis and install a larger heater is you are printing lots of large parts. There is a guy on Thingeverse who has the mod for the longer y axis

 

Those filaments refereed to the filaments like ABS which require even heat

 

Similar thing just happened to me. It appears to be a small, smooth chip. We've had our R1+ a couple of weeks, tops, and have so far only printed test prints with bed temps no higher than 65C. Hmm. Guess I'll go ahead and contact Robo, too.

 

One question I have about the PEI. Looking at the this.
Upper Temperature Range 390 Degrees Fahrenheit
Will the nozzle damage the surface while it is auto leveling? I print with PETG mostly between 235c(455f) to 240c(464f).
Just wandering about this. I am thinking about trying it just to protect the bed.

 

If you leave the nozzle touching the bed while hot it will melt the PEI and leave a spot. Bed leveling is not an issue even with high temp 300c.

 

OK Thanks.

 

I'd be careful. On my Delta the FSR leveling routine did indeed melt the PEI sheet some at ABS temps. If you do it and it works I'd like to hear about it because I have some PEI I was considering for the Robo but am concerned about the G29 causing problems with the PEI sheet like delta auto calibration did on my other printer.

Also the recommended 468MP adhesive REALLY sticks so be careful applying it because its a bugger to get back off. Most use the "float" method to align it and then squeegee out the soapy water or window cleaner to get it to adhere.

 

As it happens, I blow borosilicate glass.

Borosilicate glass is the most temperature resistant stuff there is other than fused Quartz. I routinely plunge room temperature glass into the torch, and I don't have any problems with it cracking on heating or shattering when cooling to room temperature before annealing, so trust me, there's NOTHING the hot nozzle can do that would even get it's attention.

I have a couple small divots too. I think it's just small defects in the glass which the print was stuck pretty well to.
There's also no way to polish it out or to fill it with glass, I'm just going to live with it for the foreseeable future.

One thing that might help, is polishing the surface with cerium oxide (ebay). The first step in cutting glass is to make a small, nearly invisible scratch. When stock glass is shipped, it can get numerous tiny scratches. The polishing won't hurt, and it might help.

 

I just lost another divot on my glass.
It's kind of amazing that the forces are that high, and yet it seems like anything less than hairspray results in prints coming detached from the bed.

 

They warrantied my glass. I had the same thing happen; however, it happened within the 1st week of owning the printer. I print everything with a raft and it pops right off. Takes no pressure whatsoever. No idea what caused mine to crack. The customer service is phenomenal. They replied quickly and sent a replacement. That alone was enough to keep me as a life long customer.

 

It finally happened my borosilicate is chipping. It's now to an unusable point. It looks like alot of people are moving to PEI from this and other threads. I'm hesitate to use a thin layer of PEI because of the chips creating low spots. I was wondering if anyone had tried just replacing the glass with PEI using a 1/4 in sheet?